The authors evaluated the isokinetic strength(IS) of a recurrent anterior dislocation and subluxation of the shoulder before a modified Bristow's procedure compared with normal individuals and followed the change of IS before the operation, and of 3 months and 6 months after the modified Bristow's procedure.
Eight cases of recurrent dislocation and 8 cases of subluxation of the shoulder were examined. There were 16 men and 2 women, whose average age was 20.6 years, ranging from 15 to 32 years. All of their involved sides were the dominant sides. As a control,10 baseball players and 10 soccer players were also examined. The average peak torque per body weight at 90deg/sec and total work per body weight at 180 deg/sec were measured with a LIDO active system in flexion(FL), in extension(EX), in external rotation(ER), and in internal rotation(IR).
The average peak torque of the dominant side of the patients was statistically less than the nondominant side by 15% in FL, maybe caused by apprehension. That of the baseball players was statistically greater by 16% in EX and 18% in IR, maybe caused by training. There was no statistical difference between the dominant and nondominant side in the IS of soccer players.
Three months after the operation, the average peak torque of the involved side ranged from 55.5%(IR) to 68.4%(ER) compared with before the operation, but after 6 months, they had recovered to 93.9%(FL) and 110%(EX) of their pre-operative states. Total work ranged from 59.4%(IR) to 90.6%(FL) 3 months after the operation, but they had recovered to 88.3%(IR) and 131%(EX),6 months after a modified Bristow's procedure.
Three months after a modified Bristow's procedure, the recovery of IS was unsatisfactory for athletic sports, but 6 months later, the IS had recovered to almost its pre-operative state. IS of recurrent dislocation of the shoulder tends to decrease in FL compared with normal individuals, and so, more training of the flexor muscles is necessary.
