There is a common trend these days of boot camp classes emphasizing hip and core strength. Proximal strength prevents common injuries especially for young female athletes. An aura of invincibility accompanies our pre-pubescent years. We get dinged up as we play only to seemingly recover instantly. The tide shifts as girls hit puberty. Injuries become more frequent as young women go through musculoskeletal and hormonal changes.
A study found pre-pubescent males and females had no difference in their flexibility; however, during puberty 33.3% of females were considered hyperflexibile compared to 2.3% of males (1). So what’s the problem? Being flexible is a good thing right? Not necessarily. In sport and life our muscles need to control for our motion. A surge of flexibility during puberty leaves the muscles untrained for their new length. In high demand sports this can translate to injury.
An example of this muscle failure is the mechanism behind non-contact ACL tears. The ACL is ligament attaching your thigh and shin bone. At the most basic level, the ACL prevents the tibia (lower leg bone) from sliding forward when landing from a jump or changing directions. A sudden increase in flexibility paired with lax ligaments can cause the knee to buckle, tearing the ACL and resulting in surgery.
We see this with less traumatic injuries quite often. One study analyzed 100 female runners and discovered a link to knee injuries (Iliotibial Band (ITB)) in those who had greater knee adduction (knee falling inward) and rotation forces at ground contact. (4) In other words, their glutes (hip muscles) failed to control the collision forces with the ground.
Strong muscles truly are the checkrein to the surge of flexibility found in women. Aside from running, a strong core serves a great purpose for throwing and racket sports, too. One research study discovered the core contributes 50% of the force necessary to throw. (5) Another study found tennis players with poor glute (core) activation placed 23-27% more force through their shoulders and elbows. (5)
So that means an athlete’s elbow pain is due to weak hips? You bet. Think about it. Would you rather swing a racket/bat using your teeny shoulder and elbow muscles or bring in the big powerful glutes and abdominals to help out. I think the answer is pretty obvious.
With a clear understanding that hip and core strength is important, the focus shifts to proper strengthening techniques. One glance around a gym in search of glute exercises would reveal a host of non-functional strengthening: leg press, leg extensions and curls, and seated hip movements. While those exercises target the glutes, it does so in a manner that fails to translate to life.
A proper core and hip strength program should incorporate motions performed similar to the sport. For example, a runner’s strength program should focus on training the glutes to control ground collision forces. Other sports require more dynamic movement in multiple planes (sideways and rotational movements. Multi directional single leg squats and lunges are far superior than sitting and pushing weight around. Throwing athletes should emphasize the relationship between the hips, trunk and shoulder during the throwing motion, not simply isolating their biceps or triceps in curls or extensions.
If your goal is reducing injury rates and improvement in speed/power your best bet is a focus on glute and core strength. Be aware not every glute and core exercise will translate to your sport. Make sure your exercise looks similar to your sport.
References:
1. 1. Quatman et al. The Effects of Gender and Maturational Status on Generalized Joint Laxity in Young Athletes. J. Sci Med Sport. Volume 11 Issue 3. 2008. P 257-263.
2. Hewett, T, Zazulak, B, Myer, G. Effects of the Menstrual Cycle on Anterior Cruciate Ligament Injury Risk. A Systematic Review. The American Journal of Sports Medicine. Volume 35. Issue 4. 2007. P. 659-668.
3. Enoka, Roger M.Neuromechanics of Human Movement 3rd edition. United States. Library of Congress Cataloging-in-Publication. 2002.
4. Powers, C. M. The Influence of Abnormal Hip Mechanics on Knee Injury: A Biomechanic Perspective. JOSPT. Volume 40 Issue 2. 2010. P. 42-51.
5. Kibler, B. W, Press, J, Sciascia, A. The Role of Core Stability in Athletic Function. Sports Medicine. Volume 36. Issue 3. 2006. P. 189-198.
