upper extremity prosthesis-uci

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UPPER EXTREMITY PROSTHESISKINESIOLOGY, COMPONENTS, MATERIALS & CHECK OUT

Facilitator : dr I Nyoman Murdana SpKFR-K

Yuli Suciati

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KINESIOLOGY

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FUNCTIONAL ANATOMY

Shoulder girdle joints : costovertebral, costosternal, sternoclavicular, scapulocostal, acromioclavicular, suprahumeral & glenohumeral

Great mobility – less stability

Krussens’s Handbook of PM&R, 4th Ed, 1990

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FUNCTIONAL ANATOMYELBOW, FOREARM & WRIST

Combine motions produce shortening & lengthening of the support system of the hand & rotation of the hand through 180° from full pronation to extreme supination.

Forearm anchors most muscle that flex, extend & rotate wrist, provide also power grip & MCP extension fine functions of the fingers

Krussens’s Handbook of PM&R, 4th Ed, 1990

PREHENSION

Tip –to-tip Prehension

Lateral Prehension

Palmar (three-jaw chuck)Prehension

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GRASP

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Cylindrical Grasp

Spherical Grasp

Hook grasp

Intrinsic plus

grasp

http://www.bsu.edu/web/jkshim/handfinger/overview/overview.htm

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CONGENITAL SKELETAL DEFICIENCY

Most common : absence of the distal two thirds of the forearm, the wrist, the hand

Transverse deficiency: absence of all skeletal elements distal to deficiency along a designated transverse axis plus the level in that area

Longitudinal deficiency : absence extending parallel to the long axis of the limb.

Krussens’s Handbook of PM&R, 4th Ed, 1990

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LEVELS OF AMPUTATION

emedicine.medscape.com

Percentage of Normal

Classification

Above Elbow00-3030-5050-9090-100

Below Elbow0-3535-5555-9090-100

SDHumeral NeckShort AELong AEED

Very Short BEShort BELong BEWrist disarticulation

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Above elbow caseStump length (acromion to stump end)Arm length (acromion to lateral epicondyle) X 100

Below elbow caseStump length (Lateral epicondyle to stump end)Fore arm length (Lateral epicondyle to ulnar styloid) X 100

CALCULATION OF AMPUTEE

STUMP GIRTH Measurements

2 inch intervals, starting from the lateral epicondyle on BEA & from acromion on AEA

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COMPONENTS OF PROSTHESIS

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FUNCTIONAL CONSIDERATIONS

Each components = subtitute for (replace) one/more function

Gadget tolerance predicated partly on the patient’s age, sex, intelligence, education & coordination.

Man machine combination

AAOS, Artificial Limbs Vol 2, 1960

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PROSTHESIS COMPONENTS

Hand subtitutes

Terminal devices

Wrist- flexion units

Wrist units Forearm shells Elbow units

Shoulder units

Transmission cables &

fittings

Miscellaneous fittings

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TERMINAL DEVICES

Energy for operation provided from the shoulder harness or cinetized muscle in the form of tension & excursion.

Use spring/elastic force to oppose the motion induced by tension applied to control cable eliminating 2nd source of body energy for control of the return motion.

AAOS, Artificial Limbs Vol 2, 1960

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TERMINAL DEVICES, HANDSAVAILABLE IN USA

Becker Lock Grip Hands Miracle Mechanical Hands Robin-Aids Functional

Hands Pecorella Voluntary-Closing

Hand Becker Plylite Hand Cosmetic hands

AAOS, Artificial Limbs Vol 2, 1960

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TERMINAL DEVICES, HOOKS

Northrop-Sierra Two load hook APRL-Sierra Voluntary –

Closing Hook Dorrance Utility Voluntary

Opening Hooks Miracle Lever Holder Trautman Locktite Hook

AAOS, Artificial Limbs Vol 2, 1960

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WRIST UNITS

attachment of terminal device & manually positioned at degree of pronation-supination

Friction-Type Wrist Units Positive –Lock wrist units

AAOS, Artificial Limbs Vol 2, 1960

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ELBOW UNITS

HINGES FOR BELOW-ELBOW & ELBOW-DISARTRICULATION CASES

ELBOW UNITS FOR ABOVE-ELBOW & SHOULDER DISARTRICULATION CASES

Flexible below-elbow hinges

Rigid below elbow hinges

Above elbow set up

AAOS, Artificial Limbs Vol 2, 1960

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TRANSMISSION CABLES & FITTING

Cable Cable housing Base plates & retainers Hanger Ball terminal Triple swivel Floating anchor/ housing cross bar Cable extensors

AAOS, Artificial Limbs Vol 2, 1960

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PROSTHESIS PARTS

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PROSTHESIS PARTS

http://www.aalonline.com/about.htm

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SUSPENSION

This is the means by which any prosthesis is held on. There are 5 main types of suspension: 

1) Straps: This includes anything that is attached at specific points on the prostheses and then attached to a higher point on the body. These can be made of anything from leather to cotton and rely on their tightness in order to keep the prostheses from slipping off. (e.g. PTB Strap) 

2) Sleeves: These rely on constriction on the prostheses and the limb above the prostheses and depending on the material of the sleeve, it can even seal the prosthesis to the limb and create suspension with suction. 

3) Suction: By creating an air lock between the residual limb and the socket a very strong suspension is created. This can be done by sealing the socket with a sleeve or having a very intimate fitting socket with a valve in the end. 

4) Supracondular: This is when a portion of the socket is 'pinched' in above the bony protrusions that are present at most joints.

5) Liner Suspension: By incorporating a nut into the bottom of a form fitting gel liner, a mechanical locking mechanism can the be incorporated into the leg so when the amputee steps into the socket the locking mechanism engages with the liner and suspends the limb. A release mechanism is then incorporated so that the patient can remove the socket.

AAOS, Artificial Limbs Vol 2, 1960 

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HARNESS PATTERNSMORE DETAILS SEE ATTACHMENTS

BELOW ELBOW SHOULDER DISARTICULATION

Figure of 8 Chest strap Double axilla loop Below elbow dual control

system Below elbow biceps-

cineplasty system Above elbow figure of 8 AE chest strap AE triple control

For men- dual control with shoulder-elevation elbow lock- dual control with shoulder extension elbow lock- triple control

For women

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INTERFACE

An interface is anything placed between the skin of the residual limb and the hard inner surface of the laminated socket. It is used in order to absorb some of the forces that would otherwise be transferred to the skin from the socket or to take up volume that the residual limb has lost.

1) Socks: These can be made of cotton, wool, spandex or any combination of these or other materials. The primary use for socks is to counter fluctuations in residual limb volumes. The thickness of prosthetic socks is measured in 'ply' therefore as the residual limb shrinks, the # of ply of sock the patient wears increases. 

2) Foam liners: There are a number of different types of foam that are used in prosthetics, but the main ones are plastizote and pelite. The foam performs three functions: 1) it absorbs a greater amount of forces than just socks alone 2) it can be used to accommodate shapes of residual limb that would be difficult to pass into the rigid socket of the prosthesis and 3) it can be easily modified to accommodate large fluctuations in shape of the stump. 

3) Gel liners: This is the newest form of interface and comes in three specific materials, urethane, thermoplastic polymer, and silicone. Each have different characteristics but the goal is that the intimate fitting liner absorbs not only some of the direct pressure forces but also the shear forces that occur between the socket and the skin. In some cases by using a method of attaching the liner to the prostheses we take advantage of the suction between the liner and the leg and use it to suspend the socket.

AAOS, Artificial Limbs Vol 2, 1960

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SOCKET

the custom made 'cup' that fits over the residual limb. It is the link between the residual limb and the prosthesis and must disperse the sometimes-extreme forces from the prosthesis into the residual limb. In order to make the socket strong and light a composite material is usually used. 

A composite is a material made up of two parts: 

Reinforcement materials - This is a strong inert material which supplies the majority of the strength and stiffness of the composite. These are usually materials with long fibers such as glass, carbon, nylon, etc that are in woven form. To be effective this reinforcing material must form a strong adhesive bond with the resin. 

Matrix material - This is the 'glue' which binds the reinforcing materials together so that they can transfer forces between each other and work as one unit. The matrix itself supplies minimal strength but is the source of the majority of the laminations weight. This is why the amount of resin in the lamination should only be enough to fully saturate the reinforcing materials.

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MATERIALS

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MATERIALS MOST COMMONLY USED IN THE CONSTRUCTION & FITTING OF UPPER-EXTREMITY PROSTHESIS

Casting of stump

Making of check socket

Plastic laminating

Harnessing

1. Cotton stockinet

2. Plaster-of-paris bandage

3. Casting plaster

4. Modelling clay5. Stearic acid

powder in kerosene

6. Dental-impresson materials

7. Dental stone8. Celluloid

1. Shellac2. Petrolatum

jelly3. Polyvinyl

alcohol film4. Cotton

stockinet5. Beeswax6. Linen thread7. Talcum

powder

1. Parting lacquer

2. Silicone oil3. Nylon

stockinet4. Linen thread

5. Wood spatula6. Polyester

resin7. Pressure

sensitive tape8. Polyurethane

foam

1. Strap leather2. Rubber

cement3. Nylon solution4. Vinyon tape5. Dacron type6. Elastic

webbing7. Tubular rivets8. Rigid

thermoplastic

AAOS, Artificial Limbs Vol 2, 1960

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CHECK OUT PROSTHESIS

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RECOMMENDED PROCEDURES FOR TESTING THE QUALITY OF THE CONSTRUCTION

See attachments

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THANK YOU