Characteristics of the patient and his limb remnant determine the appropriate power unit and sensor selection. As described in earlier issues of the Bulletin of Prosthetics Research, EXPAC units have been arranged in 2 different equipment configurations: an above elbow (A) configuration and a below elbow (B) configuration. To satisfy individual needs, 3 different proportional control signal sensors, certain power assisted variations of conventional elbow locks, and a unit to provide externally powered flexion extension at the shoulder have been designed and used. Experience with this series of amputees and paralytics indicates: the EXPAC combination of choice for a wrist disarticulation or below elbow amputee is a Type B unit with myoelectric sensor placed over the active remnant of finger and wrist extensor muscles on the posterolateral aspect of the proximal forearm. For the elbow disarticulation amputee, the Type B unit with myoelectric sensor placed over the biceps muscle is indicated. External locking hinges are used to avoid lowering the elbow center. For an above elbow amputee with stump length short enough that the elbow center will not be unduly lowered by using an internal elbow unit, the Type A unit is indicated. For a shoulder disarticulation amputee, the Type A unit is indicated, preferably in association with the externally powered shoulder flexion extension unit. For flail elbows with functional hands the Type B EXPAC can be used to provide useful, active elbow flexion extension with the harness described provided the scapulohumeral joint can be controlled by remaining muscles or surgical arthrodesis.
|Number of pages
|Bulletin of Prosthetics Research
|Published - Jan 1 1975
ASJC Scopus subject areas
- General Engineering