An assessment of posture in bipedal rats.

Alteration in posture was examined following foreleg amputation in rats. After the surgical induction of bipedal stance, a detailed, quantified, and longitudinal assessment of rat posture and the amount of time spent in the upright stance was undertaken. An experimental group of rats had both forelimbs amputated. A group of unaltered quadrupedal rats served as controls. A standardized series of photographs of altered and control rats was taken. Postural differences between the two groups of rats were analyzed through photographic analysis of their profiles in upright and in crouched positions. Analysis of the photographs showed that the percentage of rats assuming upright posture did not differ between the experimental and control groups. Foreleg amputation forced the rats to adopt an altered posture, but did not result in habitual assumption of upright stance to a greater degree than that of controls. Adaptation to bipedalism was marked by a tucking of the hindlimbs under the body, and a flexure of the vertebral column and the head.