What is the term for the peak force production of a motor unit when frequency of stimulation reaches full summation?

Tetanus refers to the phenomenon where a motor unit generates its maximum force output due to a high frequency of stimulation, leading to a sustained contraction without any relaxation phase. When stimulation reaches this point of full summation, the individual twitches that would normally make up the contraction blend together, resulting in a smooth and strong force. This is particularly important in activities that require sustained strength, where muscle fibers need to maintain contraction for an effective performance.

The concept of recruitment, while relevant in a broader context of muscle activation, refers to the process of activating additional motor units to increase force production, rather than specifically to the maximum force produced by already activated motor units at high frequency.

The all-or-none principle states that when a motor unit fires, it generates a full muscle contraction; however, it does not encompass the aspect of force production due to frequency of stimulation.

The size principle involves activating smaller motor units first and larger ones as more force is required, but it does not directly address the maximum force from frequency or summation.

Thus, the term that best describes the peak force production due to full summation of stimulation in a motor unit is tetanus.