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Upper limb amputation and prosthetics — body-powered versus myoelectric
In the upper limb the main choice is between a body-powered prosthesis (harness and cable), which is light, durable and gives proprioceptive feedback, and a myoelectric prosthesis controlled by residual limb muscles, which is stronger and looks more natural — but is heavy, expensive, sensitive to water and gives no feedback.
Why it matters in the exam
The exam asks about the advantages and disadvantages of each type, the timing of fitting and the meaning of the amputation level. In a body-powered prosthesis shoulder and scapular movement tightens a cable that opens or closes the terminal device; the common device is a voluntary-opening hook closed by rubber bands. Advantages: low weight, durability, low cost, tolerance of water and heavy work, and feedback through the harness. Disadvantages: an uncomfortable harness, a less natural appearance and limited grip force.
A myoelectric prosthesis picks up electrical signals from residual limb muscles through electrodes and drives a motor. Advantages: no harness, high grip force, natural appearance and good overhead function. Disadvantages: weight, cost, battery dependence, sensitivity to water and sweat, maintenance and no proprioceptive feedback. Early fitting — within about a month of amputation — is linked with better acceptance rates, and abandonment rates of upper limb prostheses are higher than in the lower limb, especially at high levels.
Levels: transradial is the common level in the upper limb; the longer the forearm residual limb, the more pronation and supination is kept, and wrist disarticulation keeps most of it. At transhumeral level and above, function with a prosthesis is much harder. The thumb accounts for about 40% of hand function, so its reconstruction matters; amputation of the little finger alone affects function little (mainly grip strength). In children, the common congenital deficiency is a transverse deficiency below the elbow, and a passive prosthesis is started around the age when the child sits.
Key points
- Body-powered: light, durable, cheap, with feedback.
- Myoelectric: strong and natural-looking, heavy and expensive, no feedback.
- Early fitting — within about a month.
- Transradial — the common level; a long residual limb keeps rotation.
- The thumb — about 40% of hand function.
Summary table
| Feature | Body-powered | Myoelectric |
|---|---|---|
| Control | Harness and cable, shoulder and scapular movement | Muscle signals from the residual limb |
| Weight and durability | Light and durable | Heavier and more delicate |
| Feedback | Feedback through the harness | No proprioceptive feedback |
| Water and harsh settings | Tolerant | Sensitive to water and sweat |
| Appearance and force | Less natural appearance, limited grip | Natural appearance, strong grip, no harness |
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Sources
- VA/DoD Clinical Practice Guideline for the Management of Upper Extremity Amputation Rehabilitation, 2022 — Prosthetic options and timing of fitting
- Atlas of Amputations and Limb Deficiencies (AAOS), 4th edition (2016) — Upper limb prosthetic components
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.