2006/08/01 by R Benjamin Keeton, R. Benjamin Keeton, Stuart A Binder-Macleod +1
Engineering · Biochemistry, Genetics and Molecular Biology · Neuroscience · #Muscle activation and electromyography studies #Muscle Physiology and Disorders #Neuroscience and Neural Engineering
paper · pdf · doi:10.1093/ptj/86.8.1146
uscle fatigue has been defined as a temporary loss in force or torque-generating ability due to recent muscle contraction. he mechanisms underlying muscle fatigue are numerous and may have their origins anywhere from the central nervous system (CNS) to cellular-level cross-bridge cycling. The major proposed mechanisms of fatigue production are: (1) inadequate excitation of motoneurons, (2) poor action potential transmission along axonal branch points, (3) failure of the action potential to invade the synaptic bouton or failure to trigger transmitter release at the myoneural junction, (4) failure of the post-junctional membrane to be depolarized adequately, ( til recently, muscle fatigue was thought to be caused by lactic acid accumulation or a lowered pH within the muscle due to a rising hydrogen ion concentration ([H]) during anaerobic metabolism. 4 -6 Recent literature, however, has shown that at the cross-bridge level, [H] may not be a major causative factor of muscle fatigue. [7][ ][9][10][11][12][13][14] During the study of muscle fatigue, a phenomenon known as low-frequency fatigue (LFF) was observed. It was first described by Edwards and colleagues This form of fatigue is longlasting, taking hours or even days to subside, and may play a significant role in the decline in the force-generating capabilities of skeletal muscle. This update will focus on reviewing the characteristics, possible mechanisms, and clinical implications of LFF.