Untitled

Abstract

The ostrich is a highly cursorial bipedal land animal with a permanently elevated metatarsophalangeal joint supported by only two toes. Although locomotor kinematics in walking and running ostriches have been examined, these studies have been largely limited to above the metatarsophalangeal joint. In this study, kinematic data of all major toe joints were collected from walking to running during stance period in a semi-natural setup with selected cooperative ostriches. Statistical analyses were conducted to investigate the effect of locomotor gait on toe joint kinematics. The MTP3 and MTP4 joints exhibit the largest range of motion whereas the first phalangeal joint of the 4th toe shows the largest motion variability. The interphalangeal joints of the 3rd and 4th toes present very similar motion patterns over stance phases of walking and running. However, the motion patterns of the MTP3 and MTP4 joints and the vertical displacement of the metatarsophalangeal joint are significantly different during running from walking. This is probably because of the biomechanical requirements for the inverted pendulum gait at low speeds and also the bouncing gait at high speeds. Interestingly, the motions of the MTP3 and MTP4 joints are highly synchronised from slow to fast locomotion. This strongly suggests that the 3rd and 4th toes really work as an integrated system with the 3rd toe as the main load bearing element whilst the 4th toe as the complementary load sharing element with a primary role to ensure the lateral stability of the permanently elevated metatarsophalangeal joint. The ostrich is highly cursorial bipedal land animal with a permanently elevated