FIG. 1.

Kinematic hindlimb data from runway crossings and obstacle negotiations pre-injury. Stick figures of one representative swing phase during basic locomotion (A) and obstacle negotiation (B) illustrate qualitative differences in hindlimb movement patterns between the two tasks. Arrow indicates direction of movement (A, B). Waveform graphs are of a single step or obstacle negotiation from a representative animal. Each is shown from paw down to paw down. The hip (C), knee (D), and ankle (E) joints are compared between tasks. The position of the obstacle is represented by the vertical thick gray line. Angular changes were seen at all joints, with the greatest occurring at the knee during clearance of the obstacle. Maximal vertical displacement of the limb was significantly greater (‡) during obstacle negotiation compared to basic locomotion (F). Error bars denote standard deviation (SD).