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"It Ain't the Hamstrings"

By Bruce Kelly

As many people know low back pain is an epidemic in this country and one of the most frequently cited causes of low back pain are tight hamstrings.

But in many, if not most, cases tight hamstrings aren't really the root cause. In fact, it is the opposite: tight hip flexors that cause the problem.

A little functional anatomy lesson here will help illustrate what is commonly the problem. Because we sit so much the muscles on the front of our body like the hip flexors and abdominal muscles get shortened and tightened. Conversely, the muscles on the back side, like the hamstrings, get lengthened and weakened. Posturally, the short tight muscles in the front of the body pull the pelvis into a position called anterior pelvic tilt where the front side of the pelvis is tilted forward and the back side of the pelvis is pulled/tilted up. Because the hamstrings attach on the back of the pelvis they are actually pulled into a lengthened position and are weakened because they aren't at their optimal length to express force properly. Also, the gluteal muscles are frequently inhibited/turned off by the constant forward flexion and sitting and can't exert force well or activate properly. Some people have even coined a term called "gluteal amnesia" to refer to the lack of gluteal function or function that so many people have because of the constant sitting and forward flexion we do in our daily lives. This has bad implications for the hamstrings as then they are frequently asked to be the primary hip extensors which is the task of the glutes. The hamstrings are intended to be synergistic/helper muscles to the glutes in hip extension and if they are asked to carry the bulk of the work in hip extension the repercussions aren't pretty. Many experts think that lack of proper glute function/activation is the root cause of hamstring pull/tears.

So what does this mean to those who suffer with low back pain? The frequent suggestion is to stretch the hamstrings which just exacerbates already poor posture and function. What really needs to be addressed is lengthening of the hip flexors/quads so that the pelvis can get back to a neutral position. At that point the hamstrings will perform better in their primary functions of knee flexion and hip extension.

Practically what this means is that a person has to do a combination of dynamic mobility work, static stretching, and soft tissue work to get the hip flexors/quads lengthened. In addition, activation work of the glutes has to be done to get them to function properly so that the hamstrings can return to their synergistic role and not be overtaxed.

If you have low back pain talk to your fitness professional/trainer and have them do a functional movement screen or postural assessment. Many times you will find that you do have anterior pelvic tilt; it is very common. From that point your fitness professional can design a program to address the issues presented by this postural alignment problem and many have found relief from their low back pain as a result of such programming.

About the Author:

Bruce Kelly, MS, CSCS, NSCA-CPT, NASM-PES has written articles for sportspecific.com, completetrackandfield.com as well as local publications. He has been a fitness professional/performance enhancement coach for nearly 20 years. He owns a Fitness Together training studio franchise in Media, Pa. His website is www.ftswarthmore.com.