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

Abstract

31The architectural and morphological adaptations of the hamstrings in response to training  Hip extension training promotes more hypertrophy in the biceps femoris long head and semimembranosus than the Nordic hamstring exercise, which preferentially develops the semitendinosus and the short head of biceps femoris.4

The effect of Nordic hamstring strength training on muscle architecture, stiffness, and strength

“…We expected eccentric NH strength training to increase hamstring muscle fascicle length, as shown previously with eccentric strength training (Alegre et al 2006;Blazevich et al 2007;Potier et al 2009;Baroni et al 2013;Bourne et al 2016). However, fascicle length did not increase in the NH training group, possibly due to the joint positions assumed during training.…”

“…Previous studies showing increased muscle fascicle lengths after eccentric training have used dynamometry-based training interventions, with the hip at 90° and resistance through full knee range of motion (Blazevich et al 2007;Potier et al 2009). Bourne et al (2016) were able to show hamstring fascicle length increases after NH training. However, from the exercise in Fig.…”

“…However, from the exercise in Fig. 1 (Bourne et al 2016), it appears that participants were provided with resistance through a large knee range of motion (more than 90°), enabled by the elevated training surface and additional torso weight. Comparatively, participants in this NH intervention were required to keep the hip at 0° and only provided resistance through a smaller knee range of motion (because of the non-elevated surface) resulting in training at shorter muscle lengths.…”

“…In contrast to these two reports, the knee angle of peak eccentric hamstring torque was unchanged following 4 and 6 week NH interventions (Iga et al 2012, Delahunt et al 2016. Only one study to date has directly evaluated hamstring length adaptations following a NH strength intervention, showing a 20.8% fascicle length increase after 10-weeks (Bourne et al 2016). Although increases in hamstring muscle fascicle length would be a likely mechanism by which the NH exercise can be injury-protective, shifting of the torque curve is an indirect measure of sarcomerogenesis and evidence of the shift in optimum torque production towards longer lengths is controversial.…”

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

“…However, the discrepant findings may be explained by the contraction mode of the knee flexor strength tests, the time since injury and surgical procedure and the nature of the rehabilitation programs employed. Bourne and colleagues (2016;2017) have previously shown that the Nordic hamstring exercise preferentially recruits the ST muscle, which suggests the possibility that this exercise may be more sensitive than other tests (i.e., isokinetic dynamometry) for assessing the function of this muscle.…”