Quality of a muscle contraction

Quality of a muscle contraction - Quality of a muscle...

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Quality of a muscle contraction The following factors contribute to the strength and maximum duration of a muscle contraction: Frequency of stimuli. If stimuli are repeatedly applied to a muscle fiber, Ca 2+ may not be completely transported back into the sarcoplasmic reticulum before the next stimulus occurs. Depending upon the frequency of stimuli, Ca 2+ may accumulate. In turn, the extra Ca 2+ results in more power strokes and a stronger muscle contraction. Depending upon the frequency of stimuli, several effects are observed: A staircase effect (treppe) is produced if each successive stimulus occurs after the relaxation period of the previous stimulus (refer to Figure 1b). Each successive muscle contraction is greater than the previous one, up to some maximum value. In addition to the accumulation of Ca 2+ , other factors, such as increases in temperature and changes in pH, may contribute to this “warming up” effect commonly employed by athletes. Wave (temporal) summation occurs if consecutive stimuli are applied during the relaxation
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Quality of a muscle contraction - Quality of a muscle...

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