<P> In severe cases of muscular atrophy, the use of an anabolic steroid such as methandrostenolone may be administered to patients as a potential treatment . A novel class of drugs, called SARM (selective androgen receptor modulators) are being investigated with promising results . They would have fewer side - effects, while still promoting muscle and bone tissue growth and regeneration . These claims are, however, yet to be confirmed in larger clinical trials . </P> <P> One important rehabilitation tool for muscle atrophy includes the use of functional electrical stimulation to stimulate the muscles . This has seen a large amount of success in the rehabilitation of paraplegic patients . </P> <P> Inactivity and starvation in mammals lead to atrophy of skeletal muscle, accompanied by a smaller number and size of the muscle cells as well as lower protein content . In humans, prolonged periods of immobilization, as in the cases of bed rest or astronauts flying in space, are known to result in muscle weakening and atrophy . Such consequences are also noted in small hibernating mammals like the golden - mantled ground squirrels and brown bats . </P> <P> Bears are an exception to this rule; species in the family Ursidae are famous for their ability to survive unfavorable environmental conditions of low temperatures and limited nutrition availability during winter by means of hibernation . During that time, bears go through a series of physiological, morphological and behavioral changes . Their ability to maintain skeletal muscle number and size at time of disuse is of significant importance . </P>

Unused muscles deteriorate at a rate of about