Meeting Abstract

69.1  Tuesday, Jan. 6  Development of interlimb coordination in young horses NAUWELAERTS, S*; MALONE, S; CLAYTON, HM; Michigan State University, East Lansing nauwelae@msu.edu

Motor control development is the sequential, continuous age-related process whereby neurological control of skilled and coordinated movements changes. The process involves changes in coordination of locomotion, development of strength, posture control, balance, and perceptual skills. Young horses are able to stand and walk around within hours after birth despite their relatively small muscle mass and immature motor control. This study analyzes the development of interlimb coordination in young horses using timing between the footfalls of all four limbs. It was hypothesized that early locomotion would be geared towards maintaining dynamic stability while efficiency of locomotion would become important in more mature locomotion. Horses were videotaped at 60 Hz while moving freely out in the pasture, starting from the first time they went outside (usually the second day after birth). They were observed daily during the first week, and weekly until the foals reached one month of age. Footfall diagrams were obtained from the videos. Duty factor for each hoof, diagonality and ipsilaterality for both sides, and front and hind limb lag were calculated for a random selection of 50 strides. Based on similar data for adult horses, specific regions in the gait plots were appointed to known gaits. Results show that young horses have higher duty factors, indicating the importance of stability during locomotion. In addition, their interlimb repertoire was larger and less restricted to specific gaits. There was considerable inter-individual variation between foals. This study is part of a larger project that will test whether the development of dynamic and static stability is linked in horses.