Elite sprint coach David Sadkin takes us into the science of the role the adductor magnus plays in sprint mechanics. The Brake's companion piece serves to further translate this article's expert insight. Food for thought. Performance nerds read on...
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Glute Max Function
The glute max doesn’t function only as a hip extensor but also externally rotates the thigh outward when the hip joint is in an extended position. These combined movements cause backwards rotation of the pelvis on the side of the free leg during support phase, which may potentially hinder the forward swing of the free leg.
Glute max also has an abducting effect on the leg especially in the case of an angled hip joint, which could have a negative effect on the straight movement of the support leg from anterior to posterior.
Besides hip extension, additional glute max function of abduction and external rotation could be of no consequence during sprinting if there was another muscle that could work in synergy with glute max for support during hip extension, counteracting this abducting effect.
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Step Forward Adductor Magnus
Adductor magnus is an important contributor to hip extension and forward propulsion in sprinting movements and can be considered a preferable synergist to glute max.
The direction and mass of the adductor magnus, particularly when the hip joint is in a flexed position, is a strong hip extensor and not so much an adductor (the adducting effect is minimal when considering the sagittal plane and the thigh is vertically below hip joint).
While the hip of the support leg is being extended, adductor magnus works to balance out the abducting effect of glute max through dampening the contraction (eccentrically) of abductors after the propulsion phase.
In addition, working in synergy with glute med for increased stability by preventing lowering of the pelvis on the contralateral side during the stance phase.
Following on, during the late swing phase, adductor magnus works to avoid overloading the bicep femoris during terminal swing which is responsible for ~80% of all hamstring related injuries (‘adductor magnus may be considered a fourth hamstring; origin at ischial bone, medially beside origin of hamstrings & inserts into medial epicondyle’).
Decrease Your Injury Risk
Research has shown a decreased injury risk at the hip joint exists when adductor strength is equal to, or greater than 80% of the abductors. Similar findings were apparent within elite track athletes where adduction:abduction strength ratios were ~120% in favour of adductors.
Takeaway?
Research has backed the necessity to train adductors with the mindset they should be as strong as the hip abductors. Reduce injury risk and improve performance.
Don't just prioritise the band around the knee glute activators, look to balance yourself out with adduction exercises too.
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Follow David on Instagram: @davidsadkin
David is available for contact for further coaching and international contract work. If you're interested in exposing your athletes to speed and acceleration, he is your man. Get in touch with us barbara@thebrakeman.org or DM him through his Instagram
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References And Further Reading
Wiemann, K., & Tidow, G. (1995). Relative activity of hip and knee extensors in sprinting – implications for training.
IAAF, 10, (1), 29-49. Lee, S. S. M., & Piazza, S. J. (2009). Built for speed: musculoskeletal structure and sprinting ability.
The Journal of Experimental Biology, 212, 3700-3707. Wingerden, J. P., Vleeming, A., Buyruk, H. M., & Raissadat, K. (2004). Stabilization of the sacroiliac joint in vivo: verification of muscular contribution to force closure of the pelvis.
Euro Spine Journal, 13, (3), 199–205. Morin, J. B., Gimenez, P., Edourd, P., Arnal, P., Reyes, P. J., Samozino, P., Brughelli, M., & Mendiguchia, J. (2015). Sprint acceleration mechanics: The major role of hamstrings in horizontal force production. Frontiers in Physiology, 6, 404.