Fig. 2. The bone segments (right) of Rana pipiens and the local coordinate
frames (LCFs) (left) attached to each bone segment in SIMM software. The bone
segments are positioned in the `reference position', a position in which all
the bones rest in a single, horizontal plane. In the reference position, the
z axis of the LCF points out of the page. The orientation of the
x and y axes for each segment are shown with different
colors (orange, metatarsophalangeals, M; yellow, astragalus—calcaneus,
A; green, tibiofibula, T; red, femur, F; light blue, pelvis, P; purple,
vertebral column, V; dark blue, skull, S). The LCF for the urostyle overlaps
that of V and is not shown. The LCFs for the forelimb bones (humerus, H;
radius, R; hand, Ha) are not shown.
