Fig. 7.

Joint contributions to stride length. The tracings represent displacement of the fingertip during a single stride from Alligator1 after subtracting motion of each subsequent joint. The percentages represent the average contribution (20 strides; three animals) of each element to the fore-aft translation of the manus. (a) Treadmill reference frame. (b) Vertebral reference frame. (c) Hand and wrist motion account for 9.2% of stride length on average. (d) The elbow accounts for 19%. (e) The glenohumeral joint contributes 24.2%. (f) Coracosternal motion accounts for 30.5%. (g) The remaining stride length (16.7%) results from yaw of the body in the region of the shoulder girdle. Scale bar: 1 cm.