Abstract
Movement of the glenohumeral joint while subjects performed shoulder abduction/adduction on the Cybex dynamometer (CYBEX, Ronkonkoma, NY) was analyzed with a procedure similar to that described for the analysis of shoulder flexion/extension. The axis of the glenohumeral joint was aligned with the axis of the Cybex and verified by construction of a special frame that fit directly over the dynamometer spindle and thus revolved with the Cybex lever arm. Five subjects were studied, one of whom performed the movement on three separate occasions. Distinct from the first experiments, the subjects were only tested at one speed of movement: 60 deg/sec. As previously, the glenohumeral joint was found to traverse approximately 8 cm from its position of initial alignment with the axis of the Cybex dynamometer to its position with the arm in full elevation.