- My Library
- 2019 Issues
- Issue 23
- Impact of Hip Flexion Angle on…
Impact of Hip Flexion Angle on Unilateral and Bilateral Nordic Hamstring Exercise Torque and High-Density Electromyography Activity
Key Points
- Despite convincing research and the growing popularity of the Nordic Hamstring Exercise (NHE), this movement has its limitations just as all exercises do.
BACKGROUND & OBJECTIVE
Hamstring strains are one of the most common injuries seen in open field sports. Repeated bouts of high velocity sprinting pose a high demand on the hamstrings muscle group as they are rapidly lengthened and exposed to high levels of muscular strain, activity, and torque. The Nordic Hamstring Exercise (NHE) has grown in popularity over recent years as both a means of prophylaxis and rehabilitation (2). The NHE has been shown to be an effective exercise in improving two known modifiable risk factors for hamstring injury: muscle fascicle length and eccentric strength (1).
Despite convincing research, it has been hypothesized that training the hamstrings at relatively short muscle lengths as seen in the NHE may not have sufficient dynamic correspondence to the longer muscle lengths associated with sprinting (3). The authors of this study sought to investigate the impact that changes in hip flexion angle, and thus hamstring length, can have on knee flexion torque and hamstring muscle activity during the NHE.
All hamstring muscle lengths must be trained in order to sufficiently challenge this muscle and its bi-articular action.
METHODS
13 amateur rugby and football players (mean age = 23) who regularly strength train (minimum of 3 days per week) volunteered to be a part of the study. Exclusion criteria included lifetime history of ACL or hamstring injury, or any