Fig. 5.

Diagram representing the observed fascicle (and deduced muscle fiber) deformation patterns. The gray and red colors indicate the ankle plantar flexed position and most dorsiflexed position, respectively. A: a constant-volume rule dictates that changes in the dimension perpendicular to the plane (−6.0% for passive condition, −3.3% for active eccentric contraction) equate to the reciprocal of the changes in area (6.8% for passive, 3.7% for active eccentric contraction) for both exercise paradigms. B: the asymmetry in fiber cross-section deformation can be confirmed by ∼22% in-plane thickness change and ∼6% through-plane thickness change.