Fig. 5. Representative traces showing relative instantaneous fast muscle power output during a single sinusoidal strain cycle (strain ±5%). Solid lines represent instantaneous power output during simulated swimming, and dashed lines represent instantaneous power output during simulated crawling. Black traces show stress in preparations from 0.45BL and red traces show stress in preparations from 0.75BL. The dotted line represents muscle length. BL, total body length. Power outputs are scaled relative to peak instantaneous power at 0.75BL under simulated swimming conditions.