EMG activity in various hamstring exercises
This study found that the straight-knee bridge, upright hip extension, and leg curls produced the highest hamstring activity in both the concentric and eccentric phases.
Hip extension was the only exercise that produced a higher activity of the biceps femoris. Lower distal semitendinosus activity was found during the leg curl and bent-knee bridging exercises in comparison with the proximal and middle portions.
Hamstring strains are the most common injury in high-speed running sports and have a high recurrence rate.
Given the varied factors that increase injury risk and the non-uniform adaptation to exercise interventions, it is important to determine how each exercise challenges different portions of the hamstrings to allow for more effective injury prevention protocols.
Nineteen amateur athletes performed 9 hamstring exercises. Concentric and eccentric biceps femoris long head and semitendinosus electromyographic activity was recorded and normalized to % maximum voluntary isometric contraction.
Activity levels were compared between muscles and between the proximal, middle, and distal regions of each muscle.
The findings demonstrate that there are not only inter-muscular but also proximal-distal activity pattern differences across different exercises.
This information highlights the importance of proper exercise selection to achieve specific goals across the different rehabilitation phases.
Expert opinion by José Pedro Correia
Although there have been many studies about hamstring EMG activity during different exercise, this study adds information about within-muscle proximal-distal differences in activity.
This information may be useful to promote exercise specificity both in early stages of rehabilitation to allow exercise without excessive muscle activity and during later phases to promote activity in the affected region
> From: Hegyi et al., Scand J Sci Med Sports 29 (2019) 34-43 (Epub ahead of print). All rights reserved to John Wiley & Sons, Inc.. Click here for the online summary.