ALTERATIONS IN SKELETAL-MUSCLE RELATED TO SHORT-TERM IMPAIRED PHYSICAL MOBILITY

The purpose of this investigation was to describe and compare two meth ods of recovery of atrophied skeletal muscle following short-term impa ired physical mobility. An animal model was used to study morphologic adaptations of atrophied soleus and plantaris muscles to the effects o f 7 days of hind-limb suspension (HS) followed by either sedentary rec overy or run training during a 28-day recovery period. Significant atr ophy, demonstrated by decreased mean fiber area (MFA, in square microm eters), occurred during the 7-day period of HS. During recovery, MFA r eturned to control values 14 days earlier in the sedentary compared wi th the trained groups. Run training following short-term atrophy induc ed by HS did not result in the high levels of frank muscle damage and type IIC fibers previously reported following long-term (28-day) atrop hy. (C) 1996 John Wiley & Sons, Inc.