Fig. 4. Increasing acceleration correlated with a decrease in hindlimb protraction angle (A) and an increase in retraction angle (B). The net pitch of the body (the angle at toe-off minus the angle at toe-down) did not change significantly (y=0.84x+1.15, r²=0.06, P=0.10) with increasing acceleration (C). Linear regressions (N=49) are shown for protraction angle (y=2.64x+34.36, r²=0.55, P<0.01) and retraction angle (y=2.92x+18.74, r²=0.49, P<0.01).