Fig. 2

Distribution of humeral head position (the left scatter plot graphs) and mean value of humeral head position (the right line graphs). X-axis represents shoulder rotation (Full IR: Full internal rotation; Full ER: Full external rotation). Y-axis represents the humeral head position from the center of the glenoid fossa (mean ± SD mm). Square markers (top row) are for low velocity. Round markers (middle row) are for medium velocity. Triangular markers (bottom row) are for high velocity. The darker markers and lines represent IR and the lighter markers and lines represent ER