Muscle fibre and tendon lengths in the distal limb segments of primates.

The dimensions of the distal leg muscles in ten different primate species were examined in order to determine whether locomotor specialization is reflected in the fibre and tendon lengths of these muscles. For comparative purposes a non-primate was also included in the study. The locomotor specializations displayed by the investigated species were leaping, quadrupedal walking or running on the ground, quadrupedal climbing, and brachiation. After removal of the muscles and measurement of their free tendon lengths, fibres were isolated from several locations in the muscle and their lengths measured. Statistical tests revealed some differences between the species in fibre and tendon lengths. These did not show a consistent correlation with the locomotor specialization. It was concluded that every primate species has the potential to perform a variety of movements and to specialize in any locomotor mode.