Effect of Unweighting the Hindlimbs on Joint Contractures when Performing Joint Fixation for 2 Hours a Day or 4 Hours a Day in Rats

Abstract

The purpose of this study was to clarify the effects of unweighting the hindlimbs on joint contractures when performing joint fixation for 2 hours a day or 4 hours a day. The subjects of this study were fourteen female Wistar rats. All of the ratsʼhindlimbs were suspended by hindlimb suspension. The rats were divided into two experimental groups. In the first experimental group, the right ankle joints were fixed in full plantarflexion for 2 hours a day (2 h). In the second experimental group, the right ankle joints were fixed in full plantar-flexion for 4 hours a day (4 h). The period of this study was one week. On the first and last days of this study, all of the ratsʼangles for ankle dorsiflexion were measured. On the last day, the angles of dorsiflexion in both the 2 h and 4 h groups were not significantly decreased from those on the first day. Our results indicate that unweighting the hindlimbs does not cause joint contractures in rats when performing joint fixation for 2 hours a day or 4 hours a day.