CHAPTER 30
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The Child with a Limb Deficiency
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TABLE 30.4
Comparison of Myoelectric with Body-powered Prostheses
Myoelectric
Body-powered
Weight
Heavier; passive prostheses are weighted to prepare the
patient for the myoelectric system
Weight spread across the shoulders
Grip Strength
Stronger than a body-powered prosthesis; strength
built into the system; less work for the child
Strength is provided by rubber bands that increase or decrease
the tension and force needed to open the hand; more work
needed through scapular control
Cosmesis
More accepted; resembles the hand; more self-esteem
for the child; greater parental acceptance
Hooklike or clawlike in appearance; usually rejected by the
child or parent; object of ridicule by other children
Maintenance
Requires gloves; requires maintenance and electronics;
electrodes lose contact and require occasional adjustment;
adjustments required for growth
Requires gloves if mechanical hand is used; frequently
requires repair for broken cables caused by friction; requires
adjustments for growth on a regular basis
Harness
No harness or straps on body; suspension through socket
Harness is bulky on a toddler, difficult to keep on without
pinning to undergarment; children dislike harness especially
in summer months
Muscle Control
Uses muscles in limb to control terminal device; with
prosthetic hand, the child can experience direct “cause and effect”
Uses muscles distant from the terminal device, biscapular
abduction to control hand or hook; very confusing for toddler
whose control and balance is developing; easier for older
children
Grip Control
Maintains grip more easily through muscle contraction
at the end of the residual limb; is the most successful type of
control
Toddlers lose grip very easily, overall gross movements allow
the object being grasped to release and fall involuntarily;
tension on the cable to the harness does not remain
constant; becomes very frustrating for the child
FIGURE 30-40.
A
: Preoperative clinical photograph of a
patient with a transverse forearm deficiency.
B
: Intraoperative
photograph during the Krukenberg procedure. The muscle in
the Alis clamp is the pronator teres, which will function during
pincher grasp.
C
: Intraoperative photograph at the end of surgery.
Split-thickness skin grafts are necessary to complete skin closure.
