For large cursorial birds such as the ostrich, during low-speed gaits (walk) the femur stays practically in the same position during the locomotor cycle, due to the position of the center of mass of the body (Hutchinson et al., 2005), which can also be inferred for extinct birds of larger size.
Our results demonstrate that cursorial birds cannot always be useful in attempting to reconstruct the locomotor kinematics of primitive theropods, both because of their differences in the proportions of the bone segments of the hindlimbs and also because of the position of the center of mass with respect to the joints, which modifies the movements of the limb during the locomotor cycle. On the other hand, the limbs of ungulates and felines have greater similarity of design with respect to the non-avian theropods, with femurs of greater length with respect to the complete limb and with a greater excursion during the locomotor cycle.
The locomotor behavior of Chrysemys picta marginata (Testudines, Emydidae) studied by Walker (1971) showed the locomotor cycle
during terrestrial movement in a straight line.
The degree of coordination was expressed as a percentage of breaths starting during the same phase of the locomotor cycle. For a same and a constant metabolic rate, acute hypoxia did not influence significantly the degree of coordination (mean [+ or -] SEM, normoxia: 20.0 [+ or -] 6.2 %, hypoxia: 21.3 [+ or -] 11.1 %, p > 0.05) while ventilation and breathing frequency were significantly greater in hypoxia.
Further, it is now well established that locomotion entrains breathing rhythm, that is that the locomotor cycle contributes to the respiratory flow (Bernasconi et al., 1995; Bramble and Carrier, 1983; Hill et al., 1988; Rassler and Kohl, 1996) by mechanical linkage mechanisms.
They used a hexapod--like alternating tripod gait, which provides a stable base of support throughout the locomotor cycle
Regarding the forelimb motion during the locomotor cycle, on L.
As during each locomotor cycle the center of gravity changes, some compensatory adjustments must be continuously made.