Muscle oxygenation regulation in physical therapy and rehabilitation

Skeletal muscle oxygenation reflects the balance between oxygen delivery from the microcirculation and oxygen consumption of the muscle cells. Oxygenation in the muscle tissue is an essential factor in muscle contractions for performing activities of daily living and exercise as well as muscle tissue viability. It is until the development of near-infrared spectroscopy for providing a noninvasive, continuous monitoring of muscle oxygenation. The principle of near-infrared spectroscopy is to use light property to assess oxygenation based on the appearance of oxygenated blood in red and deoxygenated blood in darker red to black. To date, there is no comprehensive review focusing on muscle oxygenation regulation and its applications in physical therapy and rehabilitation. The objectives of this comprehensive review are to: 1) highlight the recent technical advances in near-infrared spectroscopytechnology for rehabilitation researchers, 2) present the advances in pathophysiological research in muscle oxygenation, and 3) evaluate findings and evidence of recent physical therapy and rehabilitation studies on improving muscle oxygenation. The review also evaluates findings and evidence of aerobic exercise, resistance exercise, contrast bath therapy, wound healing, cupping therapy, stretching, and electrical stimulation on muscle oxygen in healthy adults and patients with cardiovascular diseases. The use of near-infrared spectroscopy allows the assessment of muscle oxidative metabolism for personalized rehabilitation and exercise training.