Muscle atrophy in the legs 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.
Muscle atrophy, or muscle loss, can occur with disuse of your legs during extended illness or because of underlying medical conditions.
Muscle Deterioration in Legs
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-Barré syndrome, neuropathy and polio are nerve diseases that can cause muscle loss in the legs.
Impact of Leg Muscle Atrophy
As muscle deterioration occurs and your legs get smaller, 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.
Increase Physical Activity
Increasing physical activity is the key to both preventing and treating muscle atrophy in your legs. The Office of Disease Prevention and Health Promotion recommends at least 150 to 200 minutes of moderate to vigorous 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.
Disc Herniation and Muscle Atrophy
Some conditions that lead to muscle loss in the legs require medical intervention. For example, leg muscle atrophy can be caused by a herniated disc, causing pressure on a nerve that feeds your leg muscle as it exits your spinal cord. While you can attempt to strengthen the affected muscle, your efforts will be less than effective until pressure is relieved from the nerve. In rare cases, surgery is required.
Physical therapy interventions are designed to treat muscle atrophy in your legs and help rebuild lost muscle without aggravating your underlying 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. While this is occurring, a physical therapist might use electrical stimulation to contract the weak muscles until they are functioning on their own.
- MedlinePlus: Muscle Atrophy
- MDHealth.com: Muscle Atrophy
- Nursing Times: Effects of Bedrest 3: Musculoskeletal and Immune Systems, Skin and Self-Perception
- Office of Disease Prevention and Health Promotion: Top 10 Things to Know About the Second Edition of the Physical Activity Guidelines for Americans