Resources

Prosthetics glossary

The words you will hear at the prosthetist, at the doctor and in rehabilitation, explained twice. Once in plain language, once technically. Type a word or browse the categories.

An open book on a stack of books with a prosthetic hand beside it

Basics

Prosthesis

A device that replaces a missing part of a limb. It does not restore the limb, it takes over selected functions: support and walking for a leg, grasp for an arm. How much it takes over depends on the amputation level, the components, and how much practice goes into it.

transferring body load to the ground when walking and standing
restoring grasp in the upper limb
restoring body outline and load symmetry

Technical view

An external limb prosthesis, that is a device worn outside the body, replacing a missing limb segment and restoring part of its biomechanical function. International terminology separates limb prostheses from other external prostheses. A lower limb prosthesis consists of a socket, a suspension system, structural components and a terminal device, with a knee unit added at above-knee level.

Related entries Socket Liner Alignment

CE marking and medical device status

The CE mark is not a quality award, nor proof that something is better than the competition. It means the manufacturer has declared conformity with the applicable requirements and has gone through the assessment procedure laid down for that risk class. A prosthesis and its components are medical devices, so the mark has to be there.

confirms a completed conformity assessment, not product superiority
comes with a duty to report adverse incidents
is a precondition for the device being eligible for reimbursement

Technical view

Medical devices are classified by risk level, and that class determines the conformity assessment route and whether a notified body is involved. The manufacturer issues the declaration of conformity and is responsible for the technical documentation and for post-market surveillance. Individually made limb prostheses fall under the separate requirements set for custom-made devices.

Related entries Prosthesis

Amputation and residual limb

Residual limb

The part of the limb that remains after amputation. In Polish the everyday word for it sounds blunt, but it is the normal term you will hear from every clinician. The socket sits on it, so its shape, skin condition and scar decide whether the prosthesis is bearable all day.

load-bearing surface for the socket
reference for casting and measurement
area checked daily after taking the prosthesis off

Technical view

The limb segment remaining after amputation. Its volume changes over time, most strongly in the first months after surgery and also within the day, which is a leading cause of socket fit loss. It is the load-bearing interface, with areas that tolerate pressure and areas that do not.

Amputation level

The height at which the limb was removed. For the leg, the common levels are below knee and above knee. This distinction drives everything that follows: whether the prosthesis needs a knee, how much energy walking costs, how long learning takes.

determines the set of prosthetic components
affects the energy cost of walking
shapes the course of rehabilitation

Technical view

Limb amputation levels are set out in international terminology, including the full range of partial foot and partial hand amputations. In the lower limb these include below-knee and above-knee levels, knee and hip disarticulation, and amputations within the foot and at ankle height. The level determines how many joints the prosthesis has to replace.

Disarticulation

An amputation in which the limb is removed at the joint and no bone is cut. It is most often done at the hip, a little less often at the knee. After a hip disarticulation no part of the thigh bone remains, so a hip socket carries the body weight instead of an ordinary socket.

limb removed at the joint, without cutting bone
most often at the hip, less often at the knee
at the hip the prosthesis rests on a hip socket

Technical view

In hip disarticulation the whole limb is removed while the pelvis stays intact. There is no residual limb in the usual sense, so the prosthesis has to rest on the pelvis itself. This is the job of the hip socket, made individually from a cast. It stays in place thanks to its upper edge, which reaches over the iliac crests. The weight goes mainly through the ischial tuberosity and the buttock. A prosthetic hip joint, a knee and a foot are attached to the socket. External hemipelvectomy goes further, because part of the pelvis is removed as well.

Related entries Amputation level

Residual limb oedema and bandaging

After surgery the residual limb swells and that is normal. The swelling still has to be brought down, because until it is, the limb will not take the shape a socket can be built on. Compression does that: a bandage applied to a set pattern, or a compression sock. The pattern depends on the level of amputation and differs for the thigh, the shank and the upper limb.

reducing limb circumference before prosthetic fitting
shaping the limb for the future socket
easing pain

In practice
The technique can be learned and done on your own, and good instructional guides are available online. It is still worth going through it once with a physiotherapist, so they can check the tension and pressure distribution on your own limb. If numbness, tingling or pain appear after wrapping, take the bandage off and reapply it more loosely.

Technical view

Post surgical oedema of the residual limb is one of the principal early complications after amputation, alongside pain, contracture and wound healing problems. Management includes compression, limb elevation and active exercise. Compression must be graduated, higher distally and decreasing proximally, because the reverse distribution acts as a tourniquet and impedes drainage. Rehabilitation guidelines address soft dressings, elastic compression and rigid dressings separately.

Related entries Residual limb Shrinker Contracture

Shrinker

A thick, tapered sock pulled onto the residual limb to bring down swelling and shape it before a socket is made. It is worn for long stretches, often at night too, as the team advises. It is not the same sock as the one later added under the socket.

Not to be confused with: with the prosthetic sock added in plies under the socket of a finished prosthesis to compensate volume.

reducing post surgical oedema
giving the limb a socket friendly shape
preparing the skin for contact with materials

Technical view

A compression garment of conical cross section with graduated pressure, intended to reduce oedema and shape the residual limb in the pre prosthetic period. Also used for desensitisation and to counter the adductor tissue roll after amputation at thigh level. Sized to limb circumference and length, it needs replacing as volume decreases.

Surgical scar

The scar on the residual limb has to move over the tissue underneath, because if it adheres to bone, every donning of the socket will pull on it. That is why scar mobilisation starts once the wound has healed: gently moving the skin with your fingers in all directions.

keeping the skin mobile over the limb
reducing the risk of abrasion under the socket
improving pressure tolerance

In practice
A physiotherapist demonstrates the techniques. Before the sutures come out, do not work the incision line itself without the team's approval.

Technical view

Scar condition is one of the criteria for judging a residual limb ready for fitting, alongside wound healing, vascular supply, absence of pain and sufficient load bearing surface. Scar mobilisation means moving tissues relative to deeper layers and is introduced after the incision line has healed. A scar adherent to underlying tissue limits pressure tolerance and may force changes in socket design.

Residual limb hypersensitivity

After surgery even touching the limb can be unbearable. It passes gradually, through desensitisation: touching and massaging with progressively less soft materials, from a cotton ball up to rough fabric. This matters practically, because the socket will touch the whole surface all day long.

preparing the limb for constant socket contact
increasing tolerance of touch and pressure
part of the daily care routine

Technical view

An increased reaction to touch and pressure over the residual limb in the early period after amputation. Management includes desensitisation, that is graded exposure to stimuli of increasing intensity, together with massage and tapping, which can also be done through the dressing. These techniques are described as part of preparation for fitting, also affecting touch tolerance and adjustment to a changed body image.

Abrasions and skin problems in the socket

The skin of the residual limb works inside a closed, warm and humid space, so it reacts fast. Redness that fades within fifteen minutes of taking the prosthesis off is normal. Redness that stays longer, a blister or a broken patch of skin is a sign that something in the fit is off.

a clue to load distribution inside the socket
a criterion for daily limb checks
the basis for deciding on socket correction

In practice
Check the limb every day after taking the prosthesis off, ideally with a mirror for the side you cannot see. Show an open wound to a doctor rather than a prosthetist, and leave the prosthesis off until that is decided.

Technical view

Skin problems on the residual limb arise from a combination of pressure, shear, moisture and friction inside the socket environment. Their distribution has diagnostic value, since it indicates zones of excessive load and can be related to pressure tolerant and pressure intolerant areas. Volume change of the limb and loss of socket fit are among the main causes of increasing friction.

Residual limb desensitisation

Gradually accustoming the residual limb to touch, pressure and different textures. You start with stimuli that are bearable and add harder ones only once the previous ones stop bothering you. This is not an endurance exercise, and pain is not the measure of progress here.

reduces hypersensitivity before the socket is first worn
done in short sessions, several times a day
avoids the scar until it has fully healed

Technical view

Progressive desensitisation means controlled exposure to tactile and pressure stimuli of increasing intensity, using materials of varied texture alongside compression techniques. It runs in parallel with scar mobilisation and compression, and its purpose is to prepare the tissues to carry load inside the socket and to reduce the response to harmless stimuli.

Revision surgery and re-amputation

A second operation to correct a residual limb that is not suitable for fitting, or has stopped being suitable. It does not always mean shortening the limb. Sometimes the problem is protruding bone, excess soft tissue, a scar in a bad place or a painful neuroma.

considered when the problem persists despite socket changes
requires another period of healing and compression
affects the timing and scope of the next provision

Technical view

Indications include poor healing, marginal necrosis, bony spurs, excess subcutaneous tissue preventing stable seating in the socket, chronic ulceration in a load-bearing area, and a symptomatic neuroma. The decision has to be weighed against the alternative of socket correction and an interface change, because surgery means another cycle of oedema, volume fluctuation and gait relearning.

Osteolysis

Loss of bone tissue in which the bone loses minerals, mainly calcium, and gradually wears away at a given site. It often affects bone around an implant, such as an intramedullary nail or a joint replacement, and can lead to implant loosening.

visible on imaging such as plain radiographs or CT
may lead to implant removal or revision surgery of the residual limb

Technical view

A pathological process in which osteoclasts, the cells that resorb bone, remove more bone tissue than the body replaces. Around implants it is most often triggered by an inflammatory reaction to wear particles or by altered load distribution in the bone.

Related entries Revision surgery and re-amputation

Myodesis and myoplasty

Two ways of securing the cut muscles during amputation. In myodesis the surgeon sutures the muscles to the bone, through drill holes or to the periosteum. In myoplasty opposing muscle groups are sutured to each other over the end of the bone. The two are often combined.

anchored muscles help keep muscle balance in the residual limb and the position of the bone in the socket
especially important in transfemoral amputation, where without them the femur tends to drift into abduction
the technique depends on the surgeon and the circumstances of the amputation, and muscles are sometimes attached only during revision surgery

Technical view

Myodesis attaches muscle to bone with sutures through bone tunnels or to the periosteum. Myoplasty sutures opposing muscle groups to each other over the end of the bone. In transfemoral amputation, adductor myodesis is key, because it balances the abductors and helps prevent abduction and flexion contracture. Comparative studies of the two techniques are lacking, and surgical practice varies.

Changes in residual limb volume

The residual limb does not keep one steady volume. It swells and shrinks over the course of a day, changes through the first months after amputation, and reacts to heat, salt, exercise and illness. That is why a socket that fits perfectly in the morning can press or slip by the evening. This is not a fault of the prosthesis but a property of the body, and it is managed rather than cured.

explains why a socket stops fitting
sets the rhythm of adding and removing sock plies
is grounds for socket adjustment or replacement

Technical view

Daily and long-term fluctuations arising from fluid balance, muscle atrophy and tissue remodelling. Assessment means telling reversible change apart from permanent loss of volume.

Lower limb prosthesis

Exoskeletal and endoskeletal (modular) prosthesis

Two ways of building a leg prosthesis. In an exoskeletal prosthesis the hard outer shell is also the structure that carries the weight. A modular prosthesis is made of separate parts, such as the socket, knee, tube and foot, joined by adapters. In a modular prosthesis a single part can be replaced or adjusted without making the whole prosthesis again.

in an exoskeletal prosthesis the shell carries the weight
a modular prosthesis has separate parts joined by adapters
in a modular prosthesis single parts are replaced

Technical view

An exoskeletal prosthesis has an outer frame in which a rigid shell carries the load. The first prostheses after hip disarticulation had this design together with a classic hip socket. In a modular prosthesis the individual modules are joined by structural adapters, such as tube adapters, and functional ones, such as rotation adapters. The list of medical devices issued on prescription lists the definitive exoskeletal and modular prosthesis separately, for both the lower leg and the thigh.

Socket

The part of the prosthesis that encloses the residual limb. Made individually, because every limb is different. This is where the comfort of the whole prosthesis is decided. A good knee in a badly fitting socket will not help.

Not to be confused with: with a silicone liner. In prosthetic clinics the two words are sometimes used interchangeably, and they are two different things.

distributing force between limb and prosthesis
holding the prosthesis on the limb
protecting skin from point pressure

Technical view

The prosthetic component enclosing the residual limb, transferring load to the tissues and connecting the limb to the rest of the structure. Made individually from a plaster cast, a scan or digital measurement. The first socket after surgery is often an interim one, intended for the period of volume change. Designs differ in load distribution, from selective weight bearing to total surface bearing.

Total contact socket

A socket with a soft insert of medical grade silicone that fits against the skin of the residual limb over its whole surface. It is worn without a separate liner, straight onto the skin. A rigid outer part carries the weight, and the soft inner socket holds the prosthesis on the limb. The manufacturer points to this solution for, among other things, an unusual limb shape that cannot be fitted with a standard liner.

silicone fits the skin without a separate liner
made individually from measurements of the limb
a rigid outer frame carries the load

Technical view

A construction with an inner socket of flexible medical grade silicone, fitting the whole surface of the residual limb and replacing a separate liner. One example is the SiOCX system from Ottobock. The HTV silicone inner socket is made individually and screwed to a rigid carbon fibre outer frame. According to the manufacturer, suspension comes from the silicone adhering to the skin, and the socket edges are flexible and follow movement. In the thigh version the inner socket has a valve at its base through which air can escape, and in the Pro version the rigid brim at the front and back is replaced by a fabric strap.

A note on terminology
The name total contact is not standardised, so different clinics may mean different things by it. The safest thing is to ask directly whether it is a socket with a soft silicone insert worn without a separate liner. Do not confuse it with a liner: a liner is worn on the limb under the socket, while here the silicone insert is part of the socket.

Liner

A stretchy silicone or gel cover, closed at the bottom, rolled onto the residual limb. The socket goes on over it. It does two things at once: it protects the skin from friction and it takes part in holding the prosthesis on the limb.

Not to be confused with: with a sealing sleeve, which is open at both ends and pulled over the socket from the outside.

reducing friction and point pressure
part of the suspension system
evening out small volume mismatches

Technical view

An interface between the residual limb and the socket, closed at the distal end, donned by rolling it onto the limb. Made of silicone, gel, thermoplastic elastomer or copolymer. Beyond cushioning it forms part of the suspension system, in versions with a distal pin, with a sealing membrane, or working together with a sealing sleeve. Materials differ in friction, thermal conductivity and behaviour under load, and selection rests largely on clinical experience.

Prosthetic sock and adding plies

A thin sock worn over the residual limb or the liner to fill the gap when limb volume drops and the prosthesis starts to feel loose. Layers can be added or removed during the day. This is routine adjustment, not a sign that something is wrong.

compensating for limb volume change
reducing movement of the limb inside the socket
an additional layer absorbing perspiration

In practice
When you consistently need more plies than before, or the prosthesis still moves despite them, book an appointment for the socket to be assessed. Ask about an adjustable volume socket at the same time, because a rising number of plies is a typical reason to consider one.

Technical view

A knitted item of defined thickness, worn between the limb and the socket or over the liner, compensating for daily and long-term volume change. Volume change is a leading cause of socket fit loss, particularly in the first year. Adding plies is a temporary measure, and a persistent need for several plies indicates the socket should be reviewed.

Related entries Socket Liner Residual limb

Adjustable volume socket

A socket with a mechanism that lets you change its circumference yourself, without a trip to the clinic and without taking the prosthesis off. It answers the plain fact that the residual limb has one volume in the morning and another in the evening. Adjustment works either through a cord tightened by a dial or through chambers filled with air. The idea has been well known in the trade for years, it is simply dearer than a standard socket and for that reason chosen less often.

compensates for daily volume swings without adding sock plies
corrects fit during the day without removing the prosthesis
an option for people for whom sock plies are no longer enough

In practice
Ask about it when the socket is being ordered, not after you collect it. The mechanism is built in while the socket is being made, so adding it later usually means a new socket.

Technical view

A construction allowing the user to change the internal volume of the socket within a range set during fabrication. It is achieved mechanically, through a cord routed in guides and tensioned by a ratchet dial, or pneumatically, through air chambers in the layer next to the residual limb. The range of mechanical adjustment is often quoted as an equivalent number of sock plies. The solution changes only how tight the socket is, not its geometry, so it does not compensate for a change in limb shape.

BOA dial and the RevoFit system

A ratchet mechanism that tensions a cord, originally developed for sports shoe closures and carried over into prosthetics. It is most often met as part of the RevoFit kit from Click Medical. The cord runs through guides in the socket wall, and the dial tightens or releases it, even through clothing. One click is roughly a millimetre of tightening.

stepless adjustment of socket circumference through the day
operated with one hand, without removing the prosthesis or undressing
a range equivalent to about ten sock plies

Technical view

The system consists of a ratchet mechanism, a cord of high tensile strength and guide tubes laminated into the socket wall during fabrication. The manufacturer distinguishes three adjustment layouts: a movable panel in the wall, a slot drawn together by the cord, and a hinge. The placement of the guides decides which part of the socket the adjustment reaches. The cord is a wear part and needs replacing periodically.

A note on terminology
BOA and RevoFit are not the same thing. BOA Technology makes the dial itself, while Click Medical, a company spun out of it, makes the kits that bring it to prosthetic sockets. In the clinic you will hear both names used interchangeably.

Air chambers and inflatable overlays

The second way of changing socket volume, alongside a cord and dial. Instead of drawing the wall in, air fills chambers lying against the residual limb. You pump when the socket goes loose and let air out when it starts to press. The chambers are either built into the soft insert of the socket or held in a separate sleeve pulled over the liner.

stepless compensation for volume swings, without sock plies
even pressure around the circumference instead of a local squeeze
in the sleeve version, possible without altering an existing prosthesis

Technical view

A pneumatic system made up of chambers, tubing and a pump, either hand-held or built in. The thickness of the layer changes within a range quoted as an equivalent number of sock plies. Thin sleeve versions worn between the liner and the socket need no change to the structure of the prosthesis, but they do need a little initial slack, otherwise there is no room to put them in. Compatibility with active vacuum suspension is sometimes limited and should be checked with the manufacturer.

Socket laminated directly on the limb

A way of making a socket in which the composite is formed straight onto the patient’s residual limb, in the working position, with no plaster model in between. The socket cures in a quarter of an hour. In favourable conditions the patient leaves with a finished prosthesis after a single appointment. In Poland the technology is offered by Össur as Direct Socket, in versions for below-knee and above-knee levels.

a shorter path from measurement to a finished socket
shape taken from the limb in the working position, not from a cast
fewer corrections caused by an error at the model stage

Technical view

Resin-impregnated composite is applied over the protected residual limb and compacted with a compression sleeve, which gives an even distribution of material and captures the shape under loading close to working conditions. Curing takes place on the limb. Once the trim lines are cut, the distal fittings and the rest of the structure are assembled. The method requires trained staff and a dedicated tool kit.

A note on terminology
How a socket is made is a separate matter from how its volume is adjusted. A directly laminated socket may or may not have an adjustment mechanism, exactly as with a socket made from a plaster model or by 3D printing.

3D printed socket

A socket produced from a digital model, printed layer by layer instead of laminated over plaster. The shape comes from a scan of the residual limb, so the casting stage disappears entirely. It is used for both test and definitive sockets.

repeatability, since a digital model can be saved and printed again
a faster route to a test socket while limb volume is still changing
easier small corrections between successive versions

Technical view

Additive manufacture from a three-dimensional scan of the residual limb, after the model has been corrected in prosthetic software. Material, wall thickness and infill density are matched to body mass and activity level. A saved model allows the socket to be reproduced without repeating the measurement, which matters during the period of greatest volume change. Additive manufacture says nothing in itself about whether an adjustment mechanism is present.

Pin-lock suspension

A pin at the end of the liner locks into a mechanism at the bottom of the socket. You step in, hear the clicks, and it holds. A release button lets it go.

Not to be confused with: with vacuum suspension, where there is no pin and no lock.

simple and predictable attachment
donning without assistance

Technical view

Mechanical suspension based on a distal pin on the liner engaging a ratchet lock in the socket. It gives a definite, repeatable connection with audible confirmation, can be donned seated, and tolerates volume fluctuation well. Its drawback is point loading at the distal end of the limb during swing phase.

Suction and elevated vacuum suspension

The prosthesis is held by suction: air is drawn out of the socket. No pin, no lock. It can be passive, with air pushed out as you walk, or active, with a pump maintaining the vacuum.

even load distribution without a pulling point
less movement of the limb inside the socket
more stable limb volume through the day

Technical view

Suspension based on a pressure difference between the socket interior and the surroundings. The passive version uses a one-way valve and air expelled under load, the active version a mechanical or electronic pump. Sealing is provided by a sleeve rolled over the socket and thigh, or by a liner with a sealing ring or membrane. The valve needs regular cleaning.

Related entries Liner Pin-lock suspension Socket

Non-microprocessor knee

A prosthetic knee with no sensors and no electronics, in which movement is limited by friction, a lock or a brake. It does not read what you are doing, so safety rests on your gait technique and on settings your prosthetist adjusts from time to time. Knees in which air or fluid provides the resistance are described separately, as pneumatic and hydraulic.

flexion and extension when walking, sitting and standing up
stabilising the limb under load

Technical view

A knee unit whose behaviour is set by its mechanical construction, without sensors or real-time adjustment. In the classification used by the Polish Integrated Educational Platform, knees are divided by number of axes into single-axis and multi-axis, including polycentric, and by type of movement control into mechanical, pneumatic, hydraulic and electronic. Mechanical knees include friction knees, knees with a manual lock and knees with a brake engaged by loading. Multi-axis designs gain stance stability through joint geometry rather than friction. Pneumatic and hydraulic units control flexion and extension speed through a cylinder with adjustable valves, while stance flexion resistance, which matters on stairs and when sitting down, is in practice provided by hydraulic designs.

A note on terminology
The term mechanical knee is used more broadly in clinics, for anything without electronic control, including pneumatic and hydraulic knees. Descriptions of studies comparing microprocessor knees with knees without a processor sometimes do the same. Here we follow the division used in educational materials. It is worth asking which division is meant.

Microprocessor knee

A knee with sensors and a processor that checks what is happening dozens of times a second and adjusts resistance in real time. Stairs, ramps, uneven ground, a stumble. It does not walk for you and does not remove the need to learn, but it forgives more mistakes than a mechanical knee.

greater stability on uneven ground and stairs
reduced risk of falling after a stumble
less effort when walking at varying speed

Technical view

A knee unit with sensors, typically inertial plus force and angle, controlling hydraulic or magnetorheological resistance in stance and swing. It recognises gait cycle phases and situations that deviate from the pattern, including loss of balance, by increasing flexion resistance. It requires charging and periodic servicing, and its available functions depend on the configuration set by the prosthetist.

Energy storage and return foot

A prosthetic foot built from curved carbon blades. It flexes under load and returns part of that energy at push-off. A review of studies found only a small difference in the effort of walking, but users generally prefer it to a simple foot. Stiffness is matched to body weight and activity.

Not to be confused with: with a blade style running foot, which has no heel and is not suitable for everyday walking.

stronger push-off and a more symmetrical step
adaptation to uneven ground
standard provision for active users

Technical view

An energy storing and returning foot built from carbon laminate, selected by body mass and expected activity level. Energy return occurs at push-off. In a review of ten studies the cost of walking with such a foot was about 97 percent of the cost with a solid ankle cushioned heel foot, and the authors judged that difference too small to matter clinically. In a study of fifteen people with a transtibial amputation, this type of foot gave higher push-off work and better step length symmetry. Designs differ in blade length, keel position and range of motion in the frontal plane. Teaching classifications call feet that return energy dynamic feet, as opposed to the rigid SACH foot with a cushioned heel, which stores no energy.

Related entries Hydraulic foot Alignment Pyramid adapter

Hydraulic foot

A foot with a hydraulic ankle that adjusts its angle to the ground. On slopes and stairs it sits flat instead of forcing you to compensate with the hip and back.

adaptation to slopes and uneven ground
less compensation at the pelvis and spine
steadier ground contact at slow walking speed

Technical view

A foot with a hydraulic ankle joint allowing controlled dorsiflexion and plantarflexion, with damping adjusted independently in each direction. It improves ground conformity and load distribution in stance. It also exists combined with energy storage and in microprocessor-controlled versions.

Pyramid adapter

An unassuming truncated-pyramid connector joining parts of the prosthesis. Four screws around it let the prosthetist tilt one part against another by fractions of a degree. It is what makes alignment possible at all.

joining components of a modular prosthesis
adjusting angle and offset during alignment
replacing single parts without rebuilding the whole

Technical view

A standardised modular connector with a four-sided cone and a receiver with four set screws, allowing angular adjustment and linear shift between components. It underpins the modular system, in which socket, structural parts, joint and foot come from independent ranges. Adjustment through these screws is the basic tool for correcting alignment.

Alignment

How the socket, the shafts and the foot are set against each other and against your body. Millimetres and fractions of a degree decide whether you walk straight or your limb starts hurting after an hour. Alignment is not set once and is revisited whenever something changes.

gait symmetry and efficiency
pressure distribution inside the socket
knee stability in stance

In practice
Come back to it after a change of socket, component, body weight or shoes with a different heel height, or when a new abrasion appears in the same place.

Technical view

The spatial relationship of prosthetic components in the sagittal, frontal and transverse planes, shaping the path of the ground reaction force relative to joint axes. Bench, static and dynamic alignment are distinguished, the last corrected from gait observation. Faulty alignment shows as characteristic gait deviations and local overload of residual limb tissue.

Interim and definitive prosthesis

The first prosthesis is an interim one, because limb volume changes over the early months and no socket will fit for long. The definitive prosthesis comes once volume settles. This is a stage, not a lower grade of equipment.

earlier standing and walking
shaping the limb under load
avoiding an expensive socket for a limb that is still changing

Technical view

The interim, also called preparatory, prosthesis supports early mobilisation and limb shaping during the period of greatest volume change. The definitive prosthesis is made once volume has stabilised. In the Polish reimbursement schedule both appear as separate items, with their own funding limits and replacement intervals.

Stance phase and swing phase

The two parts of every step. Stance is when the leg is on the ground carrying body weight. Swing is when the leg is in the air moving forward. Your prosthetist will use these two words constantly, because a prosthesis behaves completely differently in each and each is adjusted separately.

the framework used to set up a prosthesis
shared language with the prosthetist and physiotherapist
a reference point when describing gait problems

In practice
When you report a problem, say at which point of the step it appears. Giving way under load is stance, catching your toes on the floor is swing. That halves the time it takes to diagnose.

Technical view

The basic division of the gait cycle. Stance runs from foot contact to toe off, swing from toe off to the next contact. In a lower limb prosthesis the two phases have separate control systems: flexion resistance in stance governs safety of the loaded limb, resistance in swing governs the pace and smoothness of shank advance. Adjusting one phase does not change behaviour in the other.

Stance stability of the knee

The mechanism that stops the prosthetic knee from folding under you while you stand on that leg. Simpler knees rely on friction or on joint geometry, knees with a cylinder rely on fluid resistance. Newer designs do more than block flexion, they let the knee bend slowly and under control, which is what makes step over step stair descent possible.

Not to be confused with: with swing phase control, which governs the limb in the air, not the loaded limb.

holding extension while the limb is loaded
controlled yielding on slopes and stairs
reduced fall risk after a stumble

Technical view

Stance phase control, that is the system generating flexion resistance at the knee joint while the limb is loaded. Achieved by a load activated friction brake, by a polycentric design placing the instantaneous centre of rotation posterior to the load line, or by hydraulic damping. Hydraulic solutions permit controlled yielding flexion under load, which polycentric knees without stance damping generally do not offer.

Swing phase control

The system that decides how fast the prosthetic shank swings forward while the leg is in the air. Without it a prosthesis has one speed, so when you pick up the pace the knee either lags behind or slams into extension. With it you can change walking speed and the leg follows.

Not to be confused with: with stance stability, which acts when the limb is loaded.

matching the prosthesis to variable walking speed
damping terminal impact before heel contact
symmetry of step length

Technical view

The system generating flexion and extension resistance at the knee joint during swing. Implemented mechanically with a spring and friction, pneumatically or hydraulically. A pneumatic unit compresses air during flexion and returns energy during extension, a hydraulic unit provides resistance dependent on fluid flow rate through orifices. Its role is to limit heel rise at the start of swing and damp terminal impact at its end.

Microprocessor-controlled ankle-foot

A foot with sensors and a microprocessor that changes the ankle setting by itself depending on what you are walking on. Uphill it lifts the forefoot, downhill it drops it, and when you sit down it can set the foot flat. It needs charging and servicing, like any electronic part of a prosthesis.

adapting ankle angle to the slope of the ground
easier roll over when walking uphill
greater ground clearance during swing

Technical view

A foot with microprocessor control of ankle position and resistance. Sensors detect direction and velocity of movement and the unit regulates dorsiflexion and plantarflexion in real time. Biomechanical studies have shown a greater ankle range of motion and a dorsiflexed position during swing compared with feet on a rigid attachment, and on slope ascent also a reduced knee extension moment. Evidence favouring powered push off feet over energy storing feet remains limited.

A note on terminology
The term is used both for feet that only adjust ankle position and for feet with powered push off. These are two different designs with different bodies of evidence, so it is worth asking which one is meant.

Pylon

The tube connecting the socket to the knee, or the knee to the foot, that is the shank of the prosthesis. It looks like nothing much, yet it carries your entire weight. It is shortened and lengthened when the height of the prosthesis is set.

transmitting loads between modules
setting the height of the prosthesis
mounting point for rotation and shock adapters

Technical view

The load bearing element of a modular assembly, joining the remaining modules and transmitting axial loads. Usually a tube of aluminium alloy, steel or carbon fibre, of standardised diameter, clamped to adapters. Pylon length determines prosthesis height and is one of the parameters set during alignment.

Related entries Pyramid adapter Alignment Prosthesis

Sealing sleeve

An elastic sleeve open at both ends, rolled from the socket up onto the thigh to close off the inside of the socket and hold the vacuum. It wears out faster than the rest of the prosthesis, because it works with every bend of the knee.

Not to be confused with: with a liner, which is closed at the distal end and rolled directly onto the residual limb.

sealing the socket space
maintaining vacuum suspension
limiting movement of the residual limb inside the socket

Technical view

A suspension component in the form of an elastomer sleeve covering the proximal socket brim and the limb segment above it, creating the seal of a vacuum system. It works together with an expulsion valve or a pump. Material and thickness affect sealing, resistance to flexion and durability, and damage to the sleeve shows up as loss of suspension.

Heel height

A prosthesis is set up for one specific heel height. With a foot that has no adjustment, changing to markedly higher or lower shoes tilts the whole structure and changes how the leg behaves. There are, however, feet with heel height adjustment, and microprocessor feet set the ankle angle by themselves. If you want to wear shoes of varying height, tell your prosthetist, because it is a criterion for choosing the foot rather than an obstacle you have to live with.

maintaining the designed load line
knee stability in stance
a criterion for foot selection with varied footwear

In practice
State the range of heel heights you need for everyday and for special occasions when components are being chosen, not after you collect the prosthesis. That is a question to ask before the foot is selected.

Technical view

An alignment parameter defining the height difference between the heel support point and the forefoot, for which the angles and load line of the prosthesis were set. Deviation from the design value shifts the ground reaction force resultant relative to the knee joint axis, changing stance stability. Designs differ fundamentally here: feet on a rigid attachment require realignment at the clinic, feet with an adjustment mechanism allow the ankle angle to be changed by the user within a set range, and feet with microprocessor ankle control adapt the position automatically.

Cosmetic cover

A cover giving the prosthesis the shape of a leg, usually foam or silicone, sometimes a light shell. It is not compulsory. Some people want the prosthesis to look like a leg, others leave the structure exposed. It is entirely your decision and it can be changed at any time.

giving the prosthesis a limb contour
protecting modules from dirt and impact
matching circumferences to the other leg

Technical view

An outer layer giving the prosthesis a contour close to that of a limb, made of shaped foam, silicone elements or composite shells. It carries no load. It may restrict access to adjustments and add mass, and with some designs affect resistance to joint movement.

Related entries Pylon Prosthesis Pyramid adapter

Shower prosthesis

A simple prosthesis meant for wet conditions, used in the shower, at the pool and around water. It exists because an everyday prosthesis with electronics or steel parts does not tolerate water and soap. It has a simplified build and is not meant for long walks.

safe movement in the bathroom and at the pool
protecting the everyday prosthesis from moisture
keeping independence while washing

In practice
Ask about it when the prescription for the definitive prosthesis is written, not a year later. Publicly funded provision has separate criteria and intervals worth knowing in advance.

Technical view

A prosthesis of water resistant construction intended for use in wet conditions, usually without electronic components, built from non corroding parts and with a sole surface limiting slip. In the Polish list of medical devices issued on prescription it is covered separately from the primary prosthesis, with its own award criteria.

Suspension

The way a prosthesis stays on the residual limb and does not come off while you walk. Without reliable suspension even the best socket and the most expensive knee will disappoint, because the prosthesis will shift with every step. There are several solutions and they are matched to the shape of the limb, the condition of the skin and how much you move.

determines how secure the prosthesis feels in swing phase
affects the load on the skin of the residual limb
drives the choice between pin, vacuum and strap-based solutions

Technical view

An umbrella term covering pin suspension, passive and active vacuum, sealing sleeves and anatomical or strap suspension.

Osseointegration

A way to attach a prosthesis without a socket. A titanium implant is placed in the bone of the residual limb and passes through the skin, and the prosthesis connects to it directly. It is most common at thigh level but is also done below the knee. For some people it is an answer when a socket cannot be made to fit.

a prosthesis without a socket
a permanent opening in the skin that needs care
assessment at a specialist centre

In practice
The opening in the skin needs daily care. Infections around it are the most common complication, and deep bone infections and mechanical problems also occur. In Poland the surgery is done at Avimed Hospital in Piekary Śląskie (avimed.pl) together with Rzeszowskie Zakłady Ortopedyczne (osseointegracja.pl), who make the prostheses. OPSA in Warsaw (opsa.pl) also offers osseointegration. This is information, not a recommendation. Current as of September 2026.

Technical view

Percutaneous skeletal attachment of a prosthesis. The implant is inserted into the medullary canal of the residual bone, and a connector exits through a permanent skin opening called a stoma. Surgery is done in one or two stages, depending on bone quality and the implant system. Outcomes are best documented after transfemoral amputation. In studies with five year follow up, superficial infections around the stoma were common, while deep infections and mechanical complications were less frequent but significant.

Upper limb prosthesis

A prosthesis replacing a hand, a forearm or the whole upper limb. No design restores every function at once, so the choice starts with what matters most in your day. For one person that is a dependable grip at work, for another the ability to hold something steady while the sound hand does the fine work, for another the way it looks. Two people with the same level of amputation often end up with completely different devices and both are right.

sets the range of activities you get back
drives the choice between a body-powered and an electronically controlled design
shapes how you learn to use the device

Technical view

The main groups are cosmetic, body-powered and myoelectric prostheses. The level of amputation determines how many degrees of freedom must be replaced and how much room is left for components.

Passive and active prosthesis

The two basic types of upper limb prosthesis. A passive prosthesis does not move its grip on its own. The cosmetic version is meant above all to look like a hand, while the working version gets a terminal device for supporting and holding. An active prosthesis opens and closes the terminal device with the power of your body or with a drive. Passive does not mean worse, because the choice depends on what you need the prosthesis for in daily life.

a passive prosthesis does not move its grip and can be cosmetic or working
an active prosthesis moves the terminal device by body power or a drive
the list of medical devices funds the two types separately

Technical view

The list of medical devices issued on prescription divides upper limb prostheses into passive cosmetic, passive working with a terminal device, and active. Each of these types is listed separately for the forearm, the upper arm and the whole limb after shoulder disarticulation. Among active prostheses the list separates the mechanical active prosthesis from other active prostheses and assigns them different funding limits.

Body-powered upper limb prosthesis

A prosthesis in which the grip opens and closes through body movement, usually the shoulder, transmitted by a cable in a harness. No battery, no electronics, no trouble with water or dust. In exchange it needs force and offers fewer types of grip. Many people doing physical work choose it deliberately, not because they cannot afford anything else.

works without power and in demanding conditions
gives a sense of grip force through cable tension
is simpler to repair

Technical view

Cable-driven control, with the grip opened or closed by movement of the shoulder girdle. A terminal device can open by body power and close by spring, or the other way round, but one device cannot have both. The version closed by body power can reach a higher grip force, while the version opened by body power is more practical, because tension does not have to be held while carrying something. The advantages of cable-driven systems include durability, low weight, low cost, speed of action and the feedback carried by cable tension. The literature does not settle whether body-powered prostheses are functionally better or worse than myoelectric ones.

Harness and control cable

Straps worn over the shoulders and a cable running from them to the prosthesis. Together they turn movement of the arms and shoulder blades into a command for the terminal device or the elbow. The harness does two things at once: it carries force to the cable and helps keep the prosthesis on the body. It is also worth asking how the cable is routed, because that decides how many functions you can operate with one movement.

carries shoulder movement to the cable
helps keep the prosthesis on the body
the cable layout decides how many functions you can operate

Technical view

The system consists of a harness, a control cable in a housing and a mechanism on the prosthesis side. The most common design is the figure-of-eight harness, whose loop passes round the axilla on the sound side, anchors the suspension and provides the counterforce for the cable. A figure-of-nine harness is used only to control the terminal device. For people for whom axillary pressure is uncomfortable, a chest strap is an alternative, and for heavier work a shoulder saddle with a chest strap. A cable activating a single function, for example the terminal device, is called a single-control or Bowden cable system. In a dual-control system one cable, routed through two housings, operates two functions: elbow flexion and, once the elbow is locked, the terminal device. With an elbow, the lock is switched by a separate movement, for example with the other hand, the chin or the shoulder on the prosthetic side, because without it the force from the harness does not reach the terminal device.

A note on terminology
Figure-of-eight and figure-of-nine are everyday names taken from the shape of the straps on the back. You will hear them in the clinic more often than technical names. Ask whether the harness is only meant to control the terminal device or also to hold the prosthesis on, because those are two different jobs.

Myoelectric prosthesis

A prosthesis controlled by the muscles left in the residual limb. You tense a muscle, an electrode picks up the signal, the hand closes. Learning to do this deliberately and repeatably takes time and is tiring at first. It is not for everyone, because it needs working muscles, a well fitted socket and charging every day.

allows grip control without the other hand
requires training of the muscle signal
depends on power and servicing

Technical view

Control uses electromyographic signals collected from the skin surface by electrodes seated in the socket. The number and type of grips depend on how many reliable signals are available and on the control scheme.

Related entries Upper limb prosthesis Socket Mobility level

Terminal device

The part of an arm prosthesis that replaces the hand. It can be a cosmetic glove, a passive cosmetic hand or a gripping device for work. In the list of medical devices each of them has its own item and its own funding limit, separate from the limit for the prosthesis itself.

replaces the hand in an arm prosthesis
a glove, a passive hand or a gripping device
its own item and limit in the list of devices

Technical view

The list of medical devices issued on prescription names the cosmetic glove, the passive cosmetic hand and the passive working gripping device as separate devices. The glove is available with an active or passive prosthesis of the forearm, upper arm or whole upper limb. The passive hand and the gripping device are available with a passive prosthesis at the same levels.

Shoulder cap

The part of a prosthesis that encloses the shoulder. It is needed when the upper arm residual limb is very short or absent, that is after shoulder disarticulation and after removal of the whole shoulder girdle. The list of medical devices provides separately for replacing the cap alone, without making a new prosthesis.

encloses the shoulder in a whole upper limb prosthesis
used with a very short upper arm residual limb or none
the list provides for replacing the cap separately

Technical view

A component of a whole upper limb prosthesis used after amputation with a very short upper arm residual limb, after shoulder disarticulation and after removal of the whole shoulder girdle. The list of medical devices issued on prescription contains a separate item covering replacement of the shoulder cap in a whole upper limb prosthesis.

Pain

Phantom limb pain

Pain felt in a part of the limb that is no longer there. It is real, it can be severe, and it is not a psychiatric symptom. Treatments exist and it is worth telling a doctor rather than waiting for it to pass.

Not to be confused with: with phantom sensation, which is not painful.

it does not rule out prosthesis use, and for some people eases once fitting begins
it worsens with fatigue, stress and weather change
it warrants medical assessment, as some causes are reversible

Technical view

Pain localised to the missing limb segment, with peripheral and central mechanisms linked to sensorimotor cortical reorganisation and altered neuronal excitability. Distinct from residual limb pain, which arises in tissue that is present. Management includes pharmacotherapy, neuromodulation techniques and approaches based on visual-motor feedback.

Related entries Phantom limb sensation Residual limb

Phantom limb sensation

The sense that the missing part of the limb is still there. You may feel its position, tingling, warmth or itching. It is not the same as phantom pain and is not in itself a cause for concern.

Not to be confused with: with phantom limb pain.

Technical view

A non-painful perception of the missing limb segment, covering its position, movement and sensory qualities. It is common and distinct from phantom limb pain, although both may occur together. It needs no treatment but matters in therapies using visual feedback.

Related entries Phantom limb pain

Residual limb pain

Pain felt in the part of the leg that remains, not in the missing part. That is what separates it from phantom limb pain, though the two can occur together and are often confused. It has concrete causes, from an overtight socket through bone spurs to a neuroma, so it is worth describing precisely rather than filing under one heading.

Not to be confused with: with phantom limb pain, which concerns the part of the limb that is no longer there.

distinguishing it from phantom pain when talking to a doctor
a clue to a mechanical or neural cause
grounds for reviewing prosthetic fit

Technical view

Pain felt in the remaining part of an amputated limb. A meta-analysis covering 6716 patients after lower extremity amputation found a pooled prevalence of 59 percent. Causes divide into somatic, covering wound and prosthesis related problems, bone changes, vascular dysfunction and infection, and neuropathic, including neuromas. The literature notes that residual limb pain is often not properly recognised, which accounts for the varying prevalence reported.

Neuroma

A thickening at the end of a cut nerve, formed during healing. It does not have to hurt and is sometimes found by chance. When it does hurt, the pain is usually pinpoint and sharp, described as an electric shock, and appears on pressing that one spot or on donning the socket.

an identifiable cause of pinpoint pain
part of the differential diagnosis of residual limb pain
a reference point when planning treatment

In practice
If you can point a finger at one spot where pressure reproduces the pain, say so plainly. That is the piece of information diagnosis starts from.

Technical view

Overgrowth of nerve tissue at the site of nerve transection, resulting from disordered fibre regeneration. A meta-analysis after lower extremity amputation found symptomatic neuromas in 15 percent of patients, against 59 percent for residual limb pain overall. Asymptomatic neuromas are a common incidental finding on imaging. Diagnosis uses ultrasound together with reproduction of symptoms on compression.

Mirror therapy

A method used for phantom limb pain. A mirror is placed so that the reflection of the remaining leg takes the place of the missing one, and movements are performed while watching the reflection. It is cheap, non invasive and can be done at home. Research findings are mixed, so treat it as one option rather than a sure solution.

a non invasive method that can be done at home
part of a wider pain therapy programme
no interaction with drug treatment

Technical view

A method based on visual feedback, in which the mirror image of the intact limb replaces the image of the amputated one. The evidence is divided. A meta-analysis of randomised trials found a significant reduction in pain intensity, with high heterogeneity of results. Other systematic reviews point to low quality of the included studies, no advantage over sham intervention and uncertainty about long term effect. The method is also used as the third stage of graded motor imagery.

A note on terminology
Reported results differ depending on what mirror therapy was compared against. That is the main reason for the divergence in the literature and the reason no firm recommendation can be made today.

Radiofrequency ablation

A procedure in which a doctor, guided by imaging, places an electrode in a nerve or neuroma and heats it with high frequency current. There are two kinds. Continuous mode, at about 80°C, destroys the nerve. Pulsed mode, at about 42°C, leaves the nerve intact and changes how it fires. In Poland it is called termolezja.

done through a needle, without an incision
two modes that work differently
one of the treatments for a painful neuroma

In practice
Ask which mode you are having. It decides what to expect and how long the effect may last. In the Polish public system look for the service called zabiegi w zakresie termolezji i blokady.

Technical view

A procedure using radiofrequency current. In continuous mode the electrode tip reaches about 80°C and causes thermal damage to the fibres. In pulsed mode the current is delivered in bursts, the temperature stays at about 42°C or below, and the effect is attributed to altered conduction without destroying the nerve. For neuromas after amputation the evidence comes mainly from case series.

Related entries Neuroma Cryoablation Residual limb pain

More in the article Neuroma, radiofrequency ablation, cryoablation and nerve surgery

Cryoablation

A procedure in which a thin probe is placed at the nerve and freezes it. The nerve stops carrying pain signals for several months, then recovers. The procedure can be repeated. Also called cryoneurolysis. In Poland it is called kriolezja.

done through a probe, without an incision
temporary effect, the nerve regrows
can be repeated

In practice
This is not a one time cure. If the pain comes back after a few months, it does not mean the procedure failed.

Technical view

Also called cryoneurolysis or cryoanalgesia. A probe cooled by expanding gas lowers tissue temperature to several tens of degrees below zero. Axons are damaged temporarily while the connective tissue sheaths remain intact, which allows the nerve to regenerate. Pain relief usually lasts from several months to over a year. For pain after amputation the evidence is limited.

More in the article Neuroma, radiofrequency ablation, cryoablation and nerve surgery

Targeted muscle reinnervation (TMR)

Targeted muscle reinnervation. Surgery in which a cut nerve is joined to a motor branch of a nearby muscle. The nerve gets a new target and does not form a neuroma. It was developed for controlling myoelectric prostheses and is now also used to treat and prevent pain.

surgery on the nerve, not the bone
the best studied method in this group
also helps with myoelectric prosthesis control

In practice
It makes most sense before an amputation or a revision. Done then, it lowers the risk that pain appears at all. If you are facing such surgery, ask your surgeon whether they would consider it.

Technical view

The stump of a mixed nerve is coapted to the motor nerve of a denervated muscle. A randomised trial published in 2019 compared it with neuroma excision and burying the nerve in muscle. The TMR group did better on phantom limb pain, with a trend in its favour for residual limb pain. It is also performed primarily, at the time of amputation.

More in the article Neuroma, radiofrequency ablation, cryoablation and nerve surgery

Regenerative peripheral nerve interface (RPNI)

Regenerative peripheral nerve interface. Surgery in which the end of a cut nerve is wrapped in a small piece of muscle taken from elsewhere. The nerve fibres grow into that muscle instead of forming a neuroma. The evidence is still weaker than for TMR.

surgery on the end of the nerve
newer and less studied
considered mainly at the time of amputation

In practice
Treat it as promising, not proven. If a surgeon suggests it, ask about their experience with it and why they prefer it to TMR.

Technical view

The nerve end is placed in a free muscle graft with no nerve supply of its own. The nerve fibres reinnervate the graft, which limits neuroma formation. Current data come mainly from observational studies without a control group, rated in reviews as low quality. Most data concern preventive use at the time of amputation.

More in the article Neuroma, radiofrequency ablation, cryoablation and nerve surgery

Rehabilitation

Contracture

A lasting restriction of joint movement that develops when a joint stays in one position for too long. It builds up quietly over weeks and can undo an otherwise well-built prosthesis.

In practice
Prevention: avoid resting the residual limb permanently on a pillow, spend time in extended positions during the day as advised by your physiotherapist, and move from the first days after healing.

Technical view

Reduced range of motion resulting from adaptive change in muscle, joint capsule and periarticular tissue. At above-knee level a hip flexion and abduction contracture predominates, favoured by prolonged sitting and by resting the limb on a pillow. It changes alignment geometry and can prevent proper fitting.

Related entries Residual limb Alignment Amputation level

Gait compensations

The ways the body works around what the prosthesis does not do, or does badly. Swinging the leg out to the side, hitching the hip, leaning the trunk, uneven step length. Early on they appear by themselves and that is normal. Once entrenched they can overload the other leg and the spine.

a clue to the cause of a prosthetic problem
a target of work during gait training
a factor loading the other limb and the spine

In practice
If someone close to you notices a change in your walking, treat it as technical information. A short video from the side and from behind is often more useful to a prosthetist than a description.

Technical view

Deviations from the gait pattern caused by limitations of the prosthesis, its alignment or the state of the residual limb. Typical mechanisms after amputation at thigh level include abduction and circumduction of the prosthetic limb, pelvic hiking and asymmetry of stance time. Causes divide into those related to alignment and component choice, to socket fit, and to muscle strength and range of motion, so correction requires establishing which of them dominates.

Mobility level

A number from one to four describing how and where you move about. It is entered by the person issuing the prescription, and it determines which listing you fall under and what funding limit applies. Level one means moving on the level indoors, with crutches, a cane or a walking frame. Level two means walking and clearing small obstacles, with limited movement outdoors. Level three means independent walking without restriction, indoors and outdoors. Level four is the same freedom of movement, with additional demands on the prosthesis arising from high physical activity and the loads that come with it.

determines the listing code and funding limit
guides the choice of knee and foot
defined in a footnote to the list, grade by grade

Technical view

A provision parameter for lower limb prostheses, taking values from one to four and stated when the prescription is issued. Item names in the Polish list of medical devices issued on prescription contain it directly, as a note on mobility at a level given by two adjacent values, and a separate footnote to the list sets out the mobility level classification with a definition and description of each grade. The level governs assignment to a list item, and thereby the funding limit and permissible choice of components.

A note on terminology
Prosthetic clinics and international literature also use the notation K1 to K4. That is a separate functional classification, developed in the United States for reimbursement there, which additionally includes a zero level and refers not only to current ability but also to rehabilitation potential. The Polish classification speaks solely of the patient's ability. The number of grades is similar, but they are not the same systems, and only the mobility level appears in the list. When discussing reimbursement, refer to the level on the prescription.

Anti-contracture positioning

How the residual limb is positioned during the day and at night so that the joint does not set in a comfortable but harmful position. The greatest damage is done by whatever feels best: a pillow under the knee, the limb hanging off the bed, hours in an armchair. Prevention is cheaper here than treatment.

prevents a contracture becoming fixed in the first weeks
includes regular time spent lying face down
needs no equipment, only consistency

Technical view

Positioning counteracts the flexed and abducted setting favoured by the imbalance of muscle groups after their attachments are divided, and by the reflex antalgic posture. Standard advice is to avoid support placed under the joint, to control sitting posture, and to spend periods lying prone, at a frequency set individually by the physiotherapist.

Related entries Contracture

Walking with a prosthesis and gait asymmetry

Walking with a prosthesis is never as symmetrical as walking was before the amputation, because one side of the body works differently from the other. The prosthetic side is usually loaded for a shorter time and step length tends to be uneven. Part of that difference can be reduced by training and by setting up the device, part of it stays. The goal is not to walk perfectly but to walk safely and without pain for many years.

serves as a measure of progress in gait training
points to alignment errors
once established, loads the sound limb and the spine

Technical view

Differences in stance time, step length and loading between the prosthetic and the sound side. They are assessed by observation, functional tests and, in specialist centres, instrumented gait analysis.

Falls and safety

A fall is the most common reason people stop trusting a prosthesis and start leaving the house less often. The risk rises on wet floors, going down stairs, carrying something in both hands, and whenever you are tired. Changing the order in which you do things at home helps more than it sounds. If you are falling more often than before, that is a reason to book a visit, not something to wait out.

a change in how often you fall can be the first sign of a fault
leads to activity being limited out of fear
is a frequent cause of secondary injury

Technical view

Risk depends on the level of amputation, the type of knee, the state of the sound limb, vision and medication. Stance stability of the knee is one of the main technical factors.

Returning to driving

An amputation does not by itself take away a driving licence. What it does require is confirmation that you drive safely, and in many cases changes to how the car is operated, such as relocated pedals or hand controls. This goes through a medical assessment and sometimes a practical check of your skills. An annotation on the licence states what vehicle and what equipment you are cleared for.

sets the conditions for driving again
determines whether the vehicle needs adapting
affects independence in getting to work and to rehabilitation

Technical view

Clearance rests on a medical opinion, and restrictions are recorded as codes on the licence. The extent of adaptation depends on the level of amputation and which side of the body is affected.

Paperwork and funding

Prescription for a medical device

The document, issued by an authorised clinician, that starts the route to a reimbursed prosthesis. Without it the national health fund contributes nothing.

the prescription can only be filled at a provider contracted with the fund
in defined situations an early replacement can be requested
some repairs are covered by the schedule as well

Technical view

The document entitling the holder to a publicly funded medical device, issued by an authorised clinician within the scope set out in the schedule of devices supplied on prescription. The schedule sets device categories, eligibility criteria, funding limits, patient contribution and replacement intervals. Legal basis: the Minister of Health regulation of 29 May 2017 on the schedule of medical devices supplied on prescription, as amended.

Funding limit and disability fund grant

The national health fund covers a prosthesis only up to a set amount. Anything above it you pay yourself or fund from another source, most often a grant from the state disability fund applied for at the local authority.

the disability fund grant is not automatic and has its own criteria
ask about the price difference before deciding on components

Technical view

The funding limit is the maximum amount covered from public funds for a given device, alongside a defined patient contribution. Anything above the limit is paid by the patient. The schedule is published in a Minister of Health regulation, and since 1 January 2024 devices are identified by alphanumeric codes rather than sequential numbers. Disability fund money is a separate, application-based source handled by county-level bodies.

A note on terminology
Limits and codes have changed in recent years, so descriptions published before 2024 are often out of date. Current amounts and codes are in the Navigator, with a date of last verification.

Service life and repair

Publicly funded provision gives you a prosthesis once per set interval, not when it breaks. That interval runs from confirmed collection, not from the date of the prescription. During it you can apply for a funded repair and, in justified situations, for the interval itself to be shortened and provision brought forward.

sets the point of the next provision
determines access to funded repair
provides a route to earlier provision when condition changes

Technical view

Service life is one of the parameters of the Polish list of medical devices issued on prescription, alongside the funding limit, patient contribution, award criteria and repair price limits. It runs from the date of confirmed collection. Shortening it requires a prescription issued by an authorised person with detailed medical justification consistent with the award criteria. Funded repair applies to devices covered by repair price limits and is possible during the service life, and carrying it out extends that period proportionally. Manufacturer warranty operates separately and should last at least half the service life.

A note on terminology
Specific intervals, codes and repair price limits change with amendments to the list, so numerical values belong in the Navigator, with a date of last verification, not here.

Contracted provider

A place holding a contract with the National Health Fund that can dispense a device under reimbursement. Not every prosthetic clinic is a contracted provider, and the reverse also holds: not every provider makes prostheses. Your choice is not restricted by where you live, nor by which regional branch issued the prescription.

confirms the prescription for fulfilment in the system
settles the publicly funded part with the Fund
agrees with the patient the amount payable above the limit

Technical view

A provider holding a contract for fulfilling prescriptions for medical devices. The register of providers, together with the scope of each contract, is publicly available in the search tool run by the Fund. The contracted scope is often narrower than the entity’s actual activity, so it is worth checking before a visit whether that particular site settles this specific device group.

Patient contribution

The part of the price you pay yourself. It comes from two things at once: the percentage share assigned to that device, and how far the price exceeds the funding limit. With a prosthesis the second part is often many times larger than the first.

the excess above the limit is not reimbursed in any part
may be covered by funding applied for separately
worth establishing the amount before choosing components

Technical view

The amount paid by the patient has two independent elements: the percentage contribution set in the list for that device code, and the difference between the price agreed with the provider and the funding limit. Funding from the State Fund for the Rehabilitation of Disabled Persons (PFRON) relates to the amount actually incurred, not to the limit.

Active Local Government programme (Aktywny samorząd)

A targeted programme of the State Fund for the Rehabilitation of Disabled Persons (PFRON), run by district authorities but financed centrally and settled under its own rules. It is a separate route from ordinary funding towards device provision, with different application windows and a different scope. For lower limb prostheses this is usually the route that offers a chance of support towards more expensive components.

applications open only in set periods; outside them they are not considered
requires an expert opinion on whether the chosen solution is justified
some modules are tied to employment or education

Technical view

The programme is divided into modules and areas with separate participation conditions, covering among other things provision of a high-technology prosthesis, electronic equipment, vehicle adaptation and support for education. The conditions, the maximum funding and the required own contribution are set in the governing document for a given year, so the version in force in the current application round should always be checked. Applications are submitted electronically through the Support Handling System.

Support Handling System (SOW)

The platform used to apply for funding from the Fund without going to an office. You log in with the trusted profile, the Polish state electronic identity. It is commonly called SOW, and district support centres use that name in their announcements.

lets you file an application and attach scans without a visit
shows the status of the case and any requests for further documents

Technical view

An electronic application channel serving both targeted programmes and funding from money transferred to local government units. The range of matters available electronically depends on the configuration adopted by the particular district unit, which is why a paper route still runs in parallel in some districts.

Related entries Active Local Government programme

Electronic prescription for medical devices (eZWM)

A prescription issued straight into the system and confirmed at the same moment at the doctor’s office. There is no longer any need to travel to a regional branch of the Fund for a stamp. You are given a number and an access code, and it is those, not a sheet of paper, that are the actual document.

the number and code are enough for a provider to take the prescription on
the printout is only a confirmation; losing it does not invalidate the prescription
the details are visible in the Patient Internet Account

Technical view

Prescriptions for medical devices are issued and verified in the national IT system, which allows entitlement to be confirmed at the moment of issue. Fulfilment is based on the prescription identifier and the access code. Where there is no connection to the system, a fallback procedure with later confirmation is provided for.

Disability cause code

A code in the certificate stating what the disability results from. After an amputation it is usually the code relating to the locomotor system that appears. One certificate can carry several codes where there is more than one cause, and that can matter for certain forms of support.

is sometimes a condition of access to particular programmes
does not in itself determine the degree of disability
a missing appropriate code is grounds for appeal

Technical view

Disability cause codes are letter-and-digit designations set out in the implementing regulations on disability assessment. More than one code may be entered in a certificate where conditions coexist and each of them independently justifies the ruling. The code is information separate from the degree of disability and from the indications recorded in the numbered points of the certificate.

Related entries Disabled parking card

Disabled parking card

A document entitling the holder to use designated parking bays. The certificate alone is not enough. It must contain the specific indication on this point, and the card itself is applied for separately and for a fee, once the certificate has been issued.

requires an indication written expressly in the certificate
is issued for a fixed period, not indefinitely
belongs to the person, not to the vehicle

Technical view

The card is issued on the basis of a certificate containing the indication that the criteria for concessions in road traffic are met, together with the relevant cause code. It is issued by the chair of the district disability assessment board, on application, for a period no longer than the validity of the certificate. The entitlement belongs to the person, including when they travel as a passenger.

Related entries Disability cause code

Care allowance and supporting benefit

Two different payments, confused constantly. The care allowance is a fixed, modest amount granted on the basis of a certificate. The supporting benefit is newer, higher, and depends on a separate assessment of how much help you actually need in everyday functioning.

the supporting benefit requires a separate decision establishing the level of support needed
a certificate of the degree of disability does not by itself settle that decision
drawing one benefit affects entitlement to the other

Technical view

The care allowance is a family benefit of fixed amount, granted on the basis of a certificate. The supporting benefit is due to a person for whom the regional assessment board has established a level of support need, in a decision issued after a separate examination, and its amount is linked to the number of points awarded. The rules on drawing both benefits, and the effect on the carer’s allowance, are set by the Act on the supporting benefit.

Related entries Disability cause code

Returning to work

Work after an amputation is possible more often than it seems at the start, though it rarely looks exactly as it did before. Sometimes the role changes, sometimes only the shape of the day and having somewhere to take the prosthesis off during a break. A disability certificate is not an obstacle to employment and you do not have to show it to every employer. There are also programmes that fund travel, equipment and training.

influences the activity level chosen when specifying a prosthesis
opens access to support for travel and workplace adaptation
carries employment entitlements following from the certificate

Technical view

Available routes include funding for travel and equipment under targeted programmes, and the employer duties regarding workplace adaptation.

Appealing against a disability certificate

A disability certificate can be appealed and often is, because the first decision may understate the situation or leave part of it out. The appeal goes to the higher-tier authority, but is filed through the same board that issued the decision. What counts is the deadline and whether you have added documentation that was not in the file before. Writing that the decision feels unfair will change nothing on its own.

allows an understated grade or missing indications to be corrected
depends on meeting the deadline
rests on medical documentation rather than on how strongly the case is argued

Technical view

A two-tier administrative procedure, after which an appeal to the labour and social insurance court remains available. Success depends on how well the documentation matches the criteria tied to the cause-of-disability code.

Repair and servicing

A prosthesis is used every day and simply wears out. Some repairs are publicly funded during the service life and some are not, and many faults begin as a small thing you can hear or feel weeks in advance. A click, a new bit of play, a fresh sore on the residual limb are all reasons to go in. It pays to write down what was done and when, because that history becomes useful later when applications are made.

keeps the prosthesis serviceable through its service life
a documented repair history supports an application for early replacement
reporting early reduces the risk of a fall

Technical view

Repairs are carried out against a prescription, and the schedule sets separate repair price limits for some devices. Scope and frequency depend on the components and on how intensively the device is used.

Early replacement of a prosthesis

If a prosthesis has stopped doing its job before the expected time is up, you can apply for a replacement sooner. The application is not written by the patient but by the person authorised to issue the prescription, and it is they who prepare the medical justification. Your part is to supply the material that such a justification can be built from. The two usual grounds are a change in physical condition and adjustment and repair having been exhausted.

opens a route to a new device ahead of schedule
needs a medical justification from an authorised prescriber
rests on a documented history of visits and repairs

Technical view

Early replacement requires a prescription with a detailed justification referring to the eligibility criteria in the schedule. The second ground is in practice evidenced only by clinic records.

Sources

Entries are based on primary sources. ISO standards are cited by number, without reproducing their text.

Disclaimer

This glossary is educational and does not replace consultation with a doctor, physiotherapist or prosthetist. Reimbursement amounts and codes change, so check current values in the Navigator or in the official schedule.

Where this comes from

We run it at the Świat Bioniki Foundation so that a conversation about a prosthesis does not have to start with explaining words. It will keep growing, entry by entry.