Abstract
The purpose of this study was to investigate whether there is a difference in the influence of peripheral nerve injury and spinal cord injury on muscle elasticity in contractures of the soleus muscle of rats. Twenty-four female 8-week-old Wistar rats were divided into four groups. One group was used as a control and animals in the three experimental groups were immobilized to cause contractures. Animals in one of the experimental groups also received a spinal cord lesion and in another a peripheral nerve lesion. After four weeks, sacrificed soleus muscles were stretched to the tearing point to measure contractures. Muscle tension necessary to reach the tearing point of the lengthened soleus muscles was 5.1 ± 0.4 N in the control, 3.5 ± 0.6 N for the immobilized, 2.5 ± 0.5 N for the spinal cord lesion, and 1.6 ± 0.8 N for peripheral nerve lesion groups. These results were significantly different at the 0.05 level for all groups. Peripheral nerve injury with immobilization in a shortened position caused the severest contracture, indicating that spinal cord injury and peripheral nerve injury may have different effects on muscle contractures.
