Acute effects of Nordic hamstring exercise on ultrasound shear wave elastography.

Aim: The Nordic hamstring curl appears effective in reducing the incidence of injury in physically active young adults, likely through its capacity as an eccentric exercise to increase muscle stiffness. Although eccentric exercises have been shown to increase muscle stiffness, medium- and long-term Nordic hamstring curl training programs have not demonstrated an effect on muscle stiffness. This study examined the acute effects of a single session of Nordic hamstring curls on the stiffness of the biceps femoris, semitendinosus, and semimembranosus muscles using ultrasound shear wave elastography, an accepted method for measuring passive muscle stiffness. Material and methods: Twenty physically active adults (ages 19-27 years) were randomly assigned to either the Nordic hamstring curl group ( Results: Repeated measures ANOVA revealed no significant main effects or interactions for the biceps femoris or semitendinosus ( Conclusions: These results are in agreement with findings indicating that long- and short-term Nordic hamstring curl training has no impact on hamstring stiffness, although the effects of Nordic hamstring curl on reducing the probability of hamstring injury are still valid.