MUSCLE FATIGUE - CLINICAL IMPLICATIONS FOR FATIGUE ASSESSMENT AND NEUROMUSCULAR ELECTRICAL-STIMULATION

Muscle fatigue can be defined as a decrease in the force-generating ab ility of a muscle that resulted from recent activity. Recent studies o f muscle fatigue are reviewed that are relevant to two areas of intere st to physical therapists: clinical assessment of muscle fatigue and n euromuscular electrical stimulation. Volitional and electrical tests h ave been used to quantify muscle fatigue. Several variations on each t ype of test are discussed, as are the possible sites in which fatigue might occur. The rate of fatigue during the therapeutic application of electrical stimulation of skeletal muscle is much greater than that s een during volitional contractions Factors contributing to this phenom enon are examined The unique requirements affecting bow stimulus varia bles can be manipulated to minimize muscle fatigue in three specific t herapeutic uses of neuromuscular electrical stimulation are addressed.