Muscle atrophy is a loss of muscle tissue due to disuse, disease or injury. A decrease in physical activity can lead to muscle loss in as little as 72 hours. Atrophy can occur more suddenly with illness or injury to the muscles or their nerves, and the muscles in the legs are among the first to weaken. Even after muscle loss, the atrophy in your legs can be reversed through physical activity.
What Causes Atrophy of the Leg Muscles?
The most common reason for atrophy to occur in the legs is disuse. Lack of activity for any reason -- illness, injury, seated desk job, sedentary lifestyle -- can lead to loss of leg muscle. Alcoholism and malnutrition can also inhibit muscle growth and cause the body to use muscle proteins for energy. Muscle loss also occurs as part of the natural aging process. A less common cause of atrophy of the leg muscles is injury or illness affecting the nerves that connect to the muscles. Amyotrophic lateral sclerosis, Guillain-Barre syndrome, neuropathy and polio are examples of nerve disease.
Impact of Leg Muscle Atrophy
As the muscles in your legs waste away, you will find it increasingly difficult to walk or hold the body in a standing position for extended periods. The knee, hip and ankle are at increased risk of injury or pain as the muscular support needed to hold them in place weakens. Aesthetically, you may notice skin starting to sag in the legs as it stretches to support hanging muscle.
Increasing Physical Activity to Prevent/Treat Muscle Loss
Increasing physical activity is the key to both preventing and treating muscle atrophy. The American College of Sports Medicine recommends 150 minutes of aerobic activity each week, plus at least two strength-training workouts per week. Focus on aerobic activities that use the legs, such as walking, running, bicycling, elliptical training or stair climbing. Strength exercises that focus on the quadriceps, hamstrings and calf muscles will build muscle mass in the legs.
Medical Treatment for Atrophy
If atrophy was caused by illness or injury, consult your doctor for treatment. Physical therapy designed to work around your specific condition will help rebuild lost muscle without aggravating your condition. In the case of nerve damage or illness, the connection between the nerve and muscle will need to be reestablished to return muscle function. In some cases surgery may be required before you can start the rebuilding process.