| Abstract: | The cineradiographic technique, whereby, at 64 frames/second, the successive positions of every bone segment of animals in motion can be accurately analyzed, was used to study the vertical leap of a Galago alleni from the ground position. This jump, 13 to 14 times the body length of the animal excluding the tail, is a record among primates challenged only by the tarsier. Such vertical leaps from the ground are a common mode of locomotion for the galago. Two different patterns were observed, a symmetrical and an asymmetrical jump. In the former, the two hind limbs move in the same manner and simultaneously; and the propulsive force is equally distributed in both limbs. In the latter (more frequent in our records), the animal shifts its weight onto one foot during the preparatory phase and lifts the other; thus, only one of the hind limbs is responsible for the launching. The angular variations of every knee and ankle articulation and the successive positions of the hind limb bones were measured and diagrammatically analyzed frame by frame. A short film was made to illustrate the cineradiographic technique; it cinematographically and cineradiographically records in successive sequence the galago's leap from the ground. The symmetrical and asymmetrical jumps are also schematically presented. |
