THE EFFECT OF POSITIONING ON SHOULDER ISOKINETIC MEASURES IN FEMALES

Weakness of the shoulder rotator musculature is a frequently encounter ed clinical concern in shoulder injuries. However, glenohumeral intern al and external rotation in the frontal plane (FP) in an abducted posi tion often causes impingement of the supraspinatus tendon, whereas sim ilar activity in the scapular plane (SP) does not cause impingement. T herefore, the purpose of this study was to determine if assessment in two planes affected bilateral internal and external peak torque (PT), total work (TW), and average power (AP). Twenty recreationally active females (age = 24.9 yr; ht = 163.3 cm; wt = 60.7 kg) were randomly ass essed in FP and SP for dominant and nondominant side shoulder internal rotation (IR) and external rotation (ER) isokinetic strength (Cybex 6 000, Lumex Inc., Ronkonkoma, NY). Subjects were assessed at 1.047 and 2.094 rad . s(-1) in the supine position with the shoulder abducted to 90 degrees. Four-way MANOVA revealed significant differences for PT, TW, and AP in all measured conditions (P < 0.05). These findings indic ate that muscular strength is affected by positioning in different pla nes. Due to differences in PT, TW, and AP, it is advisable to maintain consistent positioning during assessment to assure consistency in the reporting of muscular performance variables.