for support during the last phase of pinch was observed 19 percent of the subjects for both hands. 4. Another type of two-s pinch using digits 1 and I11 first and digit I1 last was recorded f percent of the major and 4 percent of the minor hands. 5. Pinch betw digits I and I11 was the fifth type of grasp preferred and was found 1 percent of the major hands and 3 percent of the minor ones. Table 3 shows the average strength of the chuck pinch for the vari groups examined. A small difference in strength of pinch was obs between the sedentary and manual workers. The minimal to maxi strength of chuck pinch recorded for the major hand was 6.0 to 14.5 in the male group and 4.0 to 10.0 kg. in the female group. The int FIGURE 2.-a. Preferred pinch with digits I, 11, and I11 (chuck pinch), b. the IP joi of the thumb becomes hyperextended when maximal chuck pinch strength is applie 148
Swanson et al.: Strength of the Hand TABLE 3.-Average Strength of Chuck Pinch by Occupation (100 Subjects) phalangeal joint of the thumb was hyperextended in most cases when the maximal force of chuck pinch was applied (Fig. 2b). Occupation Skilled Sedentary Manual Average PINCH WITH SEPARATE DIGITS The end device of the electronic pinch meter was squeezed with each separate digit from index to little finger using alternate hands (Fig. 3). The interphalangeal joint of the thumb became hyperextended in 88 percent of the females and 50 percent of the males (Fig. 3b). This tendency was decreased for pulp pinch with digits IV and V. Table 4 shows the average strength of pinch for each separate finger recorded in kilograms of force. The middle finger (digit 111) pinch was the strongest for both hands in males and females (Fig. 3, c and d). Pinch with digit V was half as strong as pinch with digits I1 or 111. The weakest separate pinch observed in the male group was 2.0 kg. for digit V and the strongest was 11.8 kg. for digit 111. Amongst the females the weakest value was 1.3 kg. with digit V and the strongest 7 kg. with digit 111. A tendency to hyperextend either the proximal interphalangeal (PIP) or the distal interphalangeal (DIP) joints was evident when maximal pinch force was applied (Fig. 3, e and f). For the PIP joint this tendency increased from the radial to the ulnar sides of the hand. Chuck pinch, kg. LATERAL PINCH For this test the pinch meter was held between the pulp of the thumb and the lateral aspect of the index finger (Fig. 4). The manual group recorded the highest figures (Table 5). The maximal to minimal values of lateral pinch strength with the major hand of males were 14.5 and 6.0 kg. respectively. The female group showed a maximal strength of Male hand Female hand Major 7.3 8.4 8.5 7.9 Major 5.4 4.2 6 . 1 5.2 Minor 7 . 2 7.3 7.6 7.5 Minor 4.6 4.0 5.6 4.9
Bulletin of Prosthetics Research-Fall 1970 FIGURE 3.-a. Pulp pinch between digits I and 11, b. hyperextension of the I of the thumb occurs when maximal pulp pinch strength is applied, c, d. pull with digit 111, e, f. pulp pinch with digit V showing hyperextension of the PI of digit V when maximal strength is applied.
- Fall '12
- Hand strength, pinch, Chuck Pinch