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This occurs when a muscle's motor unit is stimulated by multiple impulses at a sufficiently high frequency. Each stimulus causes a twitch. If stimuli are delivered slowly enough, the tension in the muscle will relax between successive twitches. If stimuli are delivered at high frequency, the twitches will overlap, resulting in tetanic contraction.
Within the branch of materials science known as material failure theory, the Goodman relation (also called a Goodman diagram, a Goodman-Haigh diagram, a Haigh diagram or a Haigh-Soderberg diagram) is an equation used to quantify the interaction of mean and alternating stresses on the fatigue life of a material. [1]
Muscle fatigue is when muscles that were initially generating a normal amount of force, then experience a declining ability to generate force. It can be a result of vigorous exercise , but abnormal fatigue may be caused by barriers to or interference with the different stages of muscle contraction .
Depiction of smooth muscle contraction. Muscle contraction is the activation of tension-generating sites within muscle cells. [1] [2] In physiology, muscle contraction does not necessarily mean muscle shortening because muscle tension can be produced without changes in muscle length, such as when holding something heavy in the same position. [1]
When the back stress is the same magnitude as the applied stress, the material no longer creeps. When the original stress is taken away, the accumulated back stresses will cause the polymer to return to its original form. The material creeps, which gives the prefix visco-, and the material fully recovers, which gives the suffix -elasticity. [2]
In chemistry, a molecule experiences strain when its chemical structure undergoes some stress which raises its internal energy in comparison to a strain-free reference compound. The internal energy of a molecule consists of all the energy stored within it. A strained molecule has an additional amount of internal energy which an unstrained ...
The Golgi tendon reflex operates as a protective feedback mechanism to control the tension of an active muscle by causing relaxation before the tendon tension becomes high enough to cause damage. [7] First, as a load is placed on the muscle, the afferent neuron from the Golgi tendon organ fires into the central nervous system .
Generally, muscle relaxants or quinine can help with cramps and is warranted when they become troublesome. But these medication cause their relaxing effect in both groups by moderating their tone. The cause of disproportionate intermittent contractions of either flexors or extensors or the cause of cramps is unknown.