The force–length relationship is usually obtained for isometric contractions with maximal activation, but less is known about how sarcomere length affects force during submaximal activation. During submaximal activation, length-dependent alterations in calcium sensitivity, owing to changes in cross-bridge kinetics (rate of attachment and/or detachment), result in an activation-dependent shift in optimal length to longer sarcomere lengths. It is known that sarcomere length, as well as temperature and phosphorylation of the regulatory light chains of myosin, can modify Ca²⁺ sensitivity by altering the probability of cross-bridge interaction. This altered calcium sensitivity is particularly important for submaximal force levels, as it can change the shape of the length dependence of force, with peak force occurring at sarcomere lengths longer than those associated with maximal filament overlap. In athletic contexts, contractions typically do not reach maximal intensity. Therefore, understanding that the ability to produce force under both maximal and submaximal conditions can differ, and that peak force can be generated at different lengths, could influence the development of targeted training regimens optimal for each sport.

力 - 长度关系通常是在最大激活期间获得，但关于肌节长度如何影响次最大激活期间的力知之甚少。在次极大期激活期间，由于跨桥动力学（依附和/或分离速率）的变化，钙敏感性的长度依赖性改变导致最佳长度向更长的肌节长度的激活依赖性转变。众所周知，肌节长度以及肌球蛋白调节轻链的温度和磷酸化可以通过改变跨桥相互作用的可能性来改变 Ca²⁺ 敏感性。这种改变的钙敏感性对于次最大力水平尤其重要，因为它可以改变力的长度依赖性的形状，峰值力发生在肌节长度比与最大细丝重叠相关的肌节长度长时。在运动环境中，收缩通常不会达到最大强度。因此，了解在最大和次最大条件下产生力量的能力可能不同，并且峰值力量可以在不同的长度下产生，可能会影响针对每项运动的最佳目标训练方案的开发。