Inputs to motor neurons may lead to various degrees of tension, which depends on muscle length, load on the muscles, and degree of muscle fatigue. Feedback informs the motor control systems of the tension achieved, which is provided by vision, as well as skin, muscle, and
joint receptors. Golgi tendon organs are afferent nerve fibers that supply the motor control systems with information about muscle length and tension, allowing for modification of ongoing motor programs. Muscle spindles monitor muscle length and rate of change in muscle length.2
Learning of a movement involves refinement of a motor program characterized by faster execution and smoother movement, made possible by plasticity of synapses. This …show more content…
Fatigue leads to an overall decrease in performance, characterized by an increased perceived effort to output an intended force and eventual failure to output it. Also observed is a decrease in motor neuron discharge frequency resulting from optimization of 1, 5 3, 4 force. Proprioceptive input is altered, and force output becomes more variable. Muscle spindles are also affected by fatigue. Fatigue causes a decrease in muscle spindle discharge. In local muscle fatigue, basic metabolic products such as arachidonic acid, prostaglandin E , and 2 lactic acid directly impact the muscle spindle discharge