Although in some ways it seems counterintuitive, weight lifting injuries, lower back pain, and even the inability to perform certain movements or sports related activities can be caused by limited flexibility of the hamstrings.

The hamstrings are comprised of three separate heads, the semitendinosus, semimembrinosus, and biceps femoris (long and short).  The function of the hamstring is to flex the knee, extend the hip, and even rotate the lower leg when the knee is bent.  The hamstring is the antagonist to the quadriceps and is even called upon for deceleration of knee extension during walking.

The reason tight or short hamstrings can cause pain or injury is related to the origin of the muscle.  Part of the biceps femoris and both semitendinosus and semimembrinosus originate at the pelvis.  Tightness can cause the pelvis to be pulled out of neutral alignment which in turn results in lower back pain, postural problems, or other back pain such as sacroiliac joint pain.

Limited flexibility can also cause improper muscle firing by the lifter or athlete.  For example, when performing a dead lift, an individual with tight hamstrings and/or glutes often has the tendency to initiate movement from the lumbar spine instead of the glutes and hamstrings.  Initiating the movement in the lumbar spine limits the amount of weight the lifter can handle and often leads to lower back injury.  A healthy, flexible hamstring allows maximum range of motion through the hip and knee and will allow the lifter or athlete to fire the muscles in the proper sequence.

Hamstring flexibility can be measured by testing your range of hip flexion.  To do this, lie down face up and, while keeping your leg straight, raise one leg off the floor as high as you can.  The ideal range is between 80-90 degrees.  This means the leg should be nearly perpendicular to the floor to be considered ‘flexible’.  Irrespective of the test result, a great regimen for keeping your hamstrings (and therefore your lower back) healthy is to try one or all of the following suggestions:


1) Foam roller
The foam roller is used to release tension in myofascial tissues, often called myofascial release.  Place the roll on the floor and teach your client how to lay the legs on top of the roll, knees straight and then gently and slowly glide over the roll.

2) Static stretching
Use of equipment such as the MB Stretch bands will enable you to stretch your hamstrings more effectively and intensely than simply reaching over to touch your toes. The MB Stretchband is a simple tool designed by physiotherapists that assists people to use correct body positioning during stretching.

You may be surprised at the level of improvement you can achieve if you test your hamstring flexibility and utilize the stretching techniques I mentioned.  You could potentially notice improved running speed, increased strength during certain lifts, reduced back pain, and improved agility.  At the very least you will just be more comfortable during daily activities and you’ll experience a general improvement in mobility.  It may seem like a burden that offers limited return, but flexibility actually is worth the time and effort.


References:

1. http://www.sportsinjuryclinic.net/cybertherapist/back/hamstrings/tighthamstrings.htm

2. http://www.performbetter.com/catalog/matriarch/OnePiecePage.asp_Q_PageID_E_303_A_PageName_E_Tighthamstringscorrectiveex