Immobilization and muscle atrophy

After an injury, common signs and symptoms include swelling, redness, pain and decreased functional abilities. Recovering from most injuries requires time to reduce the symptoms, and to regain normal function and level of activity through physical therapy. During this recovery period there could be a time immediately following the injury when the area must be immobilized to protect it from re-injury and reduce the acute signs and symptoms. Depending on the severity of the injury, the period of immobilization could range anywhere from a few days for mild injuries to several weeks for more severe injuries.

Immobilizing muscle results almost immediately in a significant loss in muscle mass and volume. The process of muscle wasting is called muscle atrophy. The muscle enters a catabolic state losing mass and volume, resulting in a decrease in strength and function. Muscle atrophy occurs much quicker than muscle building; the rate is almost 3:1. .

Slowing the rate of atrophy during immobilization is a challenge for every therapist. Exercise is a key tool in developing muscle mass growth and strength. Diet can also play an important role in muscle building and recovery. Exercise stimulates the building of muscles and therefore increases the demand for proteins and carbohydrates. Supplementing protein in the form of Creatine continues to be a controversial subject. However, “the ingestion of creatine, which can be consumed in the form of large quantities of meat and fish or more commonly and effectively as a dietary supplement, has been shown to facilitate the restoration of muscle mass and function during rehabilitation after immobilization-induced muscle wasting.¹

Research shows that when the patient performed prescribed exercises, the muscle underwent a reversal from a period of wasting to a period of growth activation. What this shows is that even a small amount of exercise can slow the rate of muscle loss and change the muscle from a catabolic state to a building or anabolic state, even though, at this stage, the rate of rebuilding is much slower when compared to muscle loss. Further research to identify certain muscle-building protein properties will hopefully lead to new ways to decrease the rate of muscle atrophy and the loss of muscle mass during immobilization.

We have seen that even small amounts of prescribed exercise following a period of immobilization can change muscle protein properties. In a rehabilitation setting, reactivating muscle has always been a primary focus. The goals through Physiotherapy are to regain proper muscle mass and strength, increase muscular control and mobility, and hasten a return to normal activity.

¹ Exerc Sport Sci Rev. 2006; 34(4):159-163. ©2006 American College of Sports Medicine