Impact of exercise selection on hamstring muscle activation

Abstract

We highlight the heterogeneity of hamstring activation patterns in different tasks. Hip-extension exercise selectively activates the long hamstrings, and the Nordic exercise preferentially recruits the semitendinosus. These findings have implications for strategies to prevent hamstring injury as well as potentially for clinicians targeting specific hamstring components for treatment (mechanotherapy).

ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION & THE HAMSTRINGS Implications for injury prevention & rehabilitation

“…However, it can be argued that such metabolic changes are secondary to reduced muscle activation. Finally, while there was no control group (without a history of ACLR) in this study, the activation patterns of the uninjured control limbs are very similar to those that have been observed in healthy uninjured limbs (Bourne et al, 2016;Bourne, Williams, et al, 2017;Messer, Bourne, Williams, & Shield, 2017). …”

“…The present findings of relatively low levels of post-surgical ST activation in the demanding NHE also suggest that this muscle receives a limited stimulus for adaptation, even during a supramaximal exercise which is known to preferentially target this muscle (Bourne, Duhig, et al, 2017;Bourne, Williams, et al, 2017).…”

“…The Nordic hamstring exercise has been shown to selectively activate the ST in male athletes (Bourne, Opar, Williams, Al Najjar, & Shield, 2016;Bourne, Williams, et al, 2017; and is commonly employed in ACL injury prevention programs (Sugimoto, Myer, Foss, & Hewett, 2015).…”

Infographic. Impact of the Nordic hamstring and hip extension exercises on hamstring architecture and morphology: implications for injury prevention

“…We recently showed that the long hamstrings, including the BFLH, are relatively more evenly activated during a hip extension exercise than in the NHE1 and this suggests the possibility that the latter may be more effective at increasing BFLH muscle size. This may be important in rehabilitation given the observation of persistent BFLH atrophy after strain injury 8…”

“…However, it has been argued that the NHEs may be suboptimal for injury prevention because it involves preferential activation of the semitendinosus and biceps femoris short head muscles 1. It has also been proposed that exercise at longer muscle lengths than those observed in the NHE may be more effective at increasing BFLH fascicle length,6 an apparent risk factor for hamstring injury 7…”