Recovery of the dog quadriceps after 10 weeks of immobilization followed by 4 weeks of remobilization.

Abstract

Skeletal muscle fiber areas were measured in three heads of the dog quadriceps after 10 weeks of immobilization followed by 4 weeks of remobilization. Two-way analysis of variance demonstrated a significant decrease in both type 1 (p less than 0.005) and type 2 (p less than 0.001) fiber area. However, there was no significant difference among the three heads of the quadriceps (p less than 0.2). Although muscle fiber areas had not returned to control levels following remobilization, the area fraction of perimysial and epimysial connective tissue was not significantly different from control values (p greater than 0.15). These data suggest that although the degree of muscle atrophy following 10 weeks of immobilization is severe and muscle specific, following 4 weeks of remobilization, muscles uniformly recover to about 70% of control values.