Recovery in Skeletal Muscle Contractile Function after Prolonged Hindlimb Immobilization

Document Type




Format of Original

8 p.

Publication Date



American Physiological Society

Source Publication

Journal of Applied Physiology

Source ISSN


Original Item ID

DOI: 10.1152/jappl.1985.59.3.916


Contractile properties of slow-twitch soleus (SOL), fast-twitch extensor digitorum longus (EDL), and fast-twitch superficial region of the vastus lateralis were determined in vitro (22ºC) in rats remobilized after prolonged (3 mo) hindlimb immobilization (IM). For all muscles the muscle-to-body weight ratio was significantly depressed by IM, and the ratios failed to completely recover even after 90 days. The contractile properties of the fast-twitch muscles were less affected by IM than the slow-twitch SOL. The IM shortened the SOL isometric twitch duration due to a reduced contraction and half-relaxation time. These parameters returned to control levels by the 14th day of recovery. Peak tetanic tension (P0, g/cm2) declined with IM by 46% in the SOL but showed no significant change in the fast-twitch muscles. After IM the SOL P0 (g/cm2) recovered to control values by 28 days. The recovery of P0 in absolute units (g) was considerably slower and did not return to control levels until 60 (SOL) to 90 (EDL) days. The maximum shortening velocity was not altered by IM in any of the muscles studied. These results demonstrate that both fast- and slow-twitch skeletal muscles possess the ability to completely recover normal contractile function following prolonged periods of hindlimb IM.


Journal of Applied Physiology, Vol. 59, No. 3 (September 1985): 916-923. DOI.