Wasting of Muscles
Wasting of muscles, also referred to as muscle atrophy, is cited as a definite decrease in the muscle mass. This decrease could be partial or even a complete wasting of muscle. When a muscle is wasted or in words, atrophied, it definitely is weaker, because its ability to sustain a force decreases significantly. Since the capability of a muscle to exert force is related to mass of the muscle, the muscle being weak, can now even exert a force. Wasting of muscles or muscle atrophy is also referred to as a co-morbidity of various diseases, which are common in nature, such as AIDS, cognitive heart diseases, cancerous growth, severe burns, renal failure, and chronic obstructive pulmonary disease (COPD). Patients, who suffer from ‘cachexia’ in these disease settings, generally have a poor prognosis.
Two types of muscle atrophy are commonly known – disuse atrophy and neurogenic atrophy.
Disuse Atrophy
Complete negligence of physical exercise results in disuse atrophy. Generally speaking, this type of wasting of muscles results because of a lack of physical exercise by the human body. In today’s sedentary lifestyle, people do less physical work and spend most of their time sitting in front of computer monitors or TV screens. Thus, the medical condition of their bodies limits their physical movement and decreased activity levels leads to losing of muscle tone, thereby developing atrophy. As obvious, disuse atrophy can be counteracted by doing some physical work on a regular basis, accompanied with balanced nutrition.
Some categories of people who are prone to disuse atrophy include bedridden people and astronauts, who being away from Earth’s gravity, develop a decrease in the muscle tone and shape and also lose calcium from the bines after few days of weightlessness.
Neurogenic Atrophy
The other and more severe type of muscle wasting or muscle atrophy is neurogenic atrophy. This type of atrophy takes place when there is a nerve disease or the person is suffering from an injury. Neurogenic atrophy is cited to occur more suddenly, as compared to disuse atrophy.
Quality of life
Muscular atrophy decreases quality of life as the sufferer becomes unable to perform certain tasks or worsen the risks of accidents while performing those (like walking). Muscular atrophy affects a major number of elderly.
Pathophysiology
Muscle atrophy or wasting of muscles occurs by a deviation in the otherwise normal balance between degradation of proteins and synthesis of proteins. During wasting of muscles or atrophy, the pathways of protein synthesis are down-regulated, while the pathways of protein breakdown are activated. The particular pathways for protein degradation that are the reasons behind the wasting of muscles are the ‘ATP-dependent, ubiquitin / proteasome’ pathway. In this type of protein system, some particular proteins are actually aimed to be destroyed. Ligation of at least four copies of ubiquitin, a pretty small peptide, is responsible for this act on to a substrate protein. The, proteasome then targets the destruction of the ‘poly-ubiquitinated’ substrate. Some of the typical enzymes in the pathways of ubiquitin/proteasome permit the ubiquitination to be aimed to some of the proteins but not all. Other proteins gain the specificity by the coupling of targeted proteins to an ‘E3 ubiquitin ligase’. After this, each E3 ubi
quitin ligase then binds to the substrates of a particular set, thereby leading to their ubiquitination.
Causes of Wasting of Muscles
Some of the muscle wasting or muscle atrophy occurs with aging. A list of other causes of atrophy includes Guillain-Barre syndrome, burns, injuries, long-term immobilization, polio, osteoarthritis, muscular dystrophy, long-term corticosteroid therapy, motor neuropathy, starvation, stroke, and spinal cord injury.
Diagnostic Tests for Wasting of Muscles
The medical tests for diagnosis of muscle atrophy, includes studies of nerve conditions, x-ray of affected muscles, ultrasound therapy, biopsy of muscles, electromyography, and CT scans of affected muscles/areas.
Treatment of Wasting of Muscles
Muscle atrophy or wasting of muscles can be treated by signaling pathways, which actually induce an increase in the size of muscles, also referred to as muscle hypertrophy. Thus, one of the ways in which physical exercise results in an increase in mass of the muscles is to down-regulate the protein pathways, which induces the opposite effect on muscles.
Home Care 
A physical exercise program, under the active guidance of a medical practitioner, is suggested to be followed at home. This can also include some exercises in water, so as to decrease workload of muscles, and other categories of muscle rehabilitation.
People, who are not advised to move actively, can perform some physical exercise with the aid of splints or braces.
