Information
The body’s network of muscles, tendons, and ligaments provides strength and flexibility. Most of our physical strength comes from groups of large muscles, especially those in the buttocks, thighs, back, shoulders, and upper arms. Weakness is usually seen as loss of strength in any of these muscles.
Some of the springy fibers of the large muscles are replaced with connective tissue as we age. This results in a slow but steady loss of muscle mass and brings increasing weakness. Inactivity results in muscle loss and weakness. Part of the weakness can be reversed by muscle-building exercises such as lifting weights.
Weakness, especially if it is accompanied by other symptoms such as fever or diarrhea, is also a sign of many diseases. Depending upon the cause, the weakness may be widespread or confined to a specific part of the body. Muscle weakness will be temporary in the case of an infection. Other diseases can cause the weakness to be progressive and permanent.
Inactivity due to the pain and joint deformity of rheumatoid arthritis can result in muscle wasting and weakness in the affected areas. A plan that combines medication, exercise, rest and physical therapy usually minimizes muscle loss and weakness.
Guillain-Barre’ syndrome is a nerve disorder that develops following a viral illness such as the flu. It comes on suddenly and is characterized by numbness in the lower limbs and hands, and rapidly progressive weakness that may become paralysis. The weakness results from the destruction of the nerves’ protective myelin sheath. The nerves impulses cannot reach the muscles, which cause the weakness and paralysis. Intensive physical therapy is usually needed to regain muscle strength and function.
The disorder known as amyotropic lateral sclerosis or ALS is characterized by gradual destruction of motor neurons, the nerve cells that control muscles. Symptoms include progressive clumsiness and muscle weakness that eventually lead to paralysis, breathing problems and death.
Multiple sclerosis is a nerve disease characterized by the gradual destruction of the myelin coating of the nerve cells that control voluntary muscles. Symptoms may include tremors, gait changes, speech problems, hearing loss, loss of bladder control, and possible paralysis of affected limbs.
Most forms of muscular dystrophy are genetic diseases that affect boys and are characterized by progressive muscle weakness and wasting. Muscular dystrophy usually starts in childhood and causes progressive disability.
Myasthenia gravis is an autoimmune disorder—an illness in which the immune system attacks body tissue. In myasthenia gravis, the receptors between nerves and muscles are destroyed, resulting in progressive weakness of the affected area. Early signs usually include a droopy eyelid, difficulty eating or chewing, and weakness.
Muscles that are not exercised regularly shrink and weaken. A fitness program that includes both strength- building and aerobic exercise can prevent or reverse many cases of muscle weakness. Physical therapy is a vital component of treatment for neuromuscular disorders to preserve as much muscle strength and function as possible.