Three-Quarter-Type Muenster Socket

W. F. SAUTER, CPO (C)*Toronto, Ontario

Analysis of socket dynamics shows that the proximal posterior quadrant of a typical below-elbow socket issued to the user of a myoelectric prosthesis is of little or no functional value.

The team at The Hugh MacMillan Medical Centre cuts away most of the area covering the elbow. The resulting three-quarter socket shows several distinct advantages:

  1. Because of greatly enhanced ventilation, the amount of heat buildup is reduced. This results in reduction of perspiration and makes for a cooler socket in summer and a warmer limb in winter. The incidence of skin problems will be reduced.
  2. Because the elbow is free to move, an increase in the flexion range has been observed. Many sockets had restricted flexion at the elbow rather than at the biceps tendon.
  3. Sockets modified in this new way produce reduced bulk over the elbow when the joint is fully extended and are, therefore, cosmetically more pleasing.

The procedure has been carried out on more than 30 patients over the past four years with very good results. No negative side effects were noticed. When the limb is very short, caution is to be exercised; the axial length of the cutaway should be less than 50 percent of the actual amputation limb length. Our positive results have been confirmed by Tom Andrews, CP, who has begun to include this procedure in his prosthetic practice.

*Rehabilitation Engineering Department, The Hugh MacMillan Medical Centre (OCCC), 350 Rumsey Road, Toronto, Ontario M4G 1R8, Canada