<P> The all - or - none law is the principle that the strength by which a nerve or muscle fibre responds to a stimulus is independent of the strength of the stimulus . If that stimulus exceeds the threshold potential, the nerve or muscle fibre will give a complete response; otherwise, there is no response . </P> <P> It was first established by the American physiologist Henry Pickering Bowditch in 1871 for the contraction of heart muscle . According to him, describing the relation of response to stimulus, </P> <P> ""An induction shock produces a contraction or fails to do so according to its strength; if it does so at all, it produces the greatest contraction that can be produced by any strength of stimulus in the condition of the muscle at the time ." </P> <P> The individual fibres of both skeletal muscle and nerve respond to stimulation according to the all - or - none principle . </P>

Describe the all or none principle of muscle contraction