Final answer:
Impaired muscle performance may be due to muscle fatigue, muscle atrophy, and neuromuscular disease. Muscle fatigue can result from reduced ATP reserves, lactic acid buildup, and imbalances in ion levels. Muscle atrophy can be caused by diseases, conditions, or age-related muscle loss. Neuromuscular diseases can lead to weakness and other symptoms.
Step-by-step explanation:
Impaired muscle performance can be due to three main factors: muscle fatigue, muscle atrophy, and neuromuscular disease.
Muscle fatigue occurs when a muscle can no longer contract in response to signals from the nervous system.
This can be caused by factors such as reduced ATP reserves, lactic acid buildup lowering intracellular pH, imbalances in Na+ and K+ levels, and damage to the SR and sarcolemma.
Muscle atrophy, the decrease in muscle mass, can be caused by diseases like cancer and AIDS, as well as conditions like congestive heart disease and liver diseases.
Age-related muscle loss, known as sarcopenia, is also irreversible and results in a decline in muscle mass and strength.
Neuromuscular diseases can lead to impaired muscle performance, with symptoms such as weakness, spasticity, myoclonus, and myalgia.
Diagnostic procedures like measuring creatine kinase levels and electromyography can help identify muscular disorders.