The effect of fear of reinjury on joint power distribution during a drop countermovement jump two years after an Achilles tendon rupture

The incidence of Achilles tendon rupture (ATR) is increasing and at least 20% do not return to preinjury activity. The aim of the study was to evaluate biomechanical differences between those assigned to a Fear group and No‐Fear group based on fear of reinjury during activity after ATR, by evaluating a drop countermovement jump. Twenty‐five participants were evaluated 23.5 months after ATR. Peak values for eccentric and concentric joint power were identified for ankles, knees, and hips. Participants were assigned to Fear group or No‐Fear group depending on their answers to a question regarding fear of reinjury during activities. Interlimb peak power was compared between groups for landing and push‐off with a mixed model ANOVA. Compared to the No‐fear group, the Fear group presented significant decreased power in the ankle (P < .001) but increased power in the knee (P < .001) in involved limb during both phases. A 3‐way interaction was found between group, side, and phase for frontal plane hip power (P < .001). Our findings indicate that those who are afraid of reinjury demonstrate higher interlimb differences compared to those who are not. They also compensate for ankle deficits with greater knee and hip power.