Figure 4: Hysteresis before and after gelsolin treatment. (a) Protocol. Skinned muscles were stretched to a given length followed by a release back to slack and hysteresis was calculated from the area of the resultant force-sarcomere length curve. Measurements were made before and after gelsolin treatment. (b) Comparison of hysteresis at SL 2.25  𝜇 m with % hysteresis reduction. All tissues showed an increase in hysteresis with SL and a reduction in hysteresis following actin extraction with gelsolin. Error bars are SE. 𝑃 < . 0 1 .