Lack of physical activity (like walking, yoga gymnastics, jumping on a trampoline, swimming, jogging, wheeling, among other sports) could be the main cause of muscle wasting.
Dr Eric Mutabazi, a senior physiotherapist at Oshen-King Faisal Hospital, Kigali, says skeletal muscle is a plastic organ that is maintained by multiple pathways regulating cell and protein turnover.
He says that during muscle atrophy, proteolytic systems are activated, contractile proteins and organelles are removed, thus resulting in shrinkage of muscle fibres.
Excessive loss of muscle mass is associated with poor prognosis in several diseases, including myopathies and muscular dystrophies, as well as in systemic disorders such as cancer, diabetes, sepsis and heart failure.
Dr Anita Nkusi, a physiotherapist at Oshen-King Faisal Hospital, says that muscle atrophy is wasting or decreased muscle bulk occurring from injury or disease or paralysis.
CAUSES
Skeletal muscle atrophy can occur due to degenerative processes originating within the skeletal muscle fibres, secondary to denervation (denervation atrophy), or spontaneously in ageing rodents. It is a common reaction to any injury that results in the degradation or loss of myofiber organelles, Mutabazi states.
He adds that examples include disuse, cachexia, nutritional or metabolic derangements, vascular insufficiency, disturbances of hormonal growth control mechanisms, and administration of myotoxic xenobiotics. Compensatory hypertrophy of surviving or unaffected myofibers is often present concurrently, regardless of the cause.
Mutabazi adds that spontaneous atrophy of ageing rodents (often referred to as hind leg myopathy) is histologically characterised by decreased myofiber size and number; increased myofiber size variation; increased accumulation of degenerative inclusion bodies, lipofuscin, and lipid droplets; and increased connective tissue.
He further says that muscle atrophy can also happen if you are bedridden or unable to move certain body parts due to a medical condition. Astronauts, for example, can also experience some muscle atrophy after a few days of weightlessness.
Ageing, alcohol-associated myopathy, a pain and weakness in muscles due to excessive drinking over long periods of time, could also be a cause of muscle wasting, Mutabazi notes.
He explains that burns, injuries, such as a torn rotator cuff or broken bones, malnutrition, spinal cord or peripheral nerve injuries, stroke, and long-term corticosteroid therapy can lead to muscle wasting.
"Diseases can also cause muscles to waste away or can make movement difficult, leading to muscle atrophy. These include; amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, that affects nerve cells that control voluntary muscle movement,” Mutabazi says.
Dermatomyositis causes muscle weakness and skin rash. Guillain-Barré syndrome is an autoimmune disease that leads to nerve inflammation and muscle weakness. Multiple sclerosis is an autoimmune disease in which the body destroys the protective coverings of nerves, he explains.
Mutabazi says that some of the diseases that cause muscle wasting include muscular dystrophy; this is an inherited disease that causes muscle weakness. Osteoarthritis causes reduced motion in the joints. Polio is also a viral disease affecting muscle tissue that can lead to paralysis.
He adds that rheumatoid arthritis is a chronic inflammatory disease that affects the joints, yet spinal muscular atrophy is a hereditary disease causing arm and leg muscles to waste away.
SYMPTOMS
"If one of your arms or legs is noticeably smaller than the other, when you are experiencing marked weakness in one limb or if you have been physically inactive for a very long time, then you are suffering from muscle wasting,” Mutabazi says.
DIAGNOSIS
He explains that you can do blood tests, X-rays, magnetic resonance imaging (MRI), computed tomography (CT) scan, nerve conduction studies, muscle or nerve biopsy and electromyography (EMG).
TREATMENT
Nkusi says that sometimes muscle atrophy may be treated by exercise, appropriate dietary changes and supplements.
Mutabazi further says that treatment will depend on the diagnosis and the severity of muscle loss. Any underlying medical conditions must be addressed. Common treatments for muscle atrophy include; physical therapy, ultrasound therapy, surgery and dietary changes.
According to Nkusi, other cases of treatment involve addressing the cause, for example, the disease causing atrophy. In certain cases it cannot be treated if there’s severe or complete paralysis of nerves supplying that particular muscle group.
Mutabazi states that, recommended exercises might include water exercises to help make movement easier. Physical therapists can also teach you the correct ways to exercise. A physical therapist can move your arms and legs for you if you have trouble moving.
To him, ultrasound therapy is a non-invasive procedure that uses sound waves to aid in healing. Also, surgery may be necessary if your tendons, ligaments, skin, or muscles are too tight and prevent you from moving. This condition is called contracture deformity.
He says that surgery may be able to correct contracture deformity if your muscle atrophy is due to malnutrition and a torn tendon may cause muscle atrophy. However, surgery may also be able to correct it.
General muscle wasting from lack of exercise or in the ageing individual may be addressed by strengthening exercises, Nkusi notes.