Fig.2. Two-dimensional angular excursions of the hip and knee joints during walking (A,E), trotting (B,F) and galloping (leading limb, C,G; trailing limb, D,H). These plots reveal the general kinematic patterns observed at the hip and knee during rat locomotion and some of the variation related to changes in gait. Data are from four individuals, three strides per individual. Dark background shading represents the stance phase, and light background shading represents the swing phase. Values are means ± S.D. In all gaits, the hip mainly extends during stance and flexes during swing. The knee typically exhibits flexion followed by extension during both the stance and swing phases. The timing and extent of these angular excursions differ among gaits.