As a trainer, I have found that clients seeking to improve their flexibility complain about tight hamstrings more than any other muscle group. Time and time again, clients are consistently surprised to find that hamstring flexibility can be improved without stretching at all.
Before I can talk about flexibility, we need to define what a “tight muscle” really is. A very big flexibility misconception is that muscles need to be physically lengthened and the best way to lengthen muscles is through stretching. This is simply not true! Muscles already have all the length they need and attempting to change that length via intense stretching is liable to cause ligament damage rather than actually increase the range of motion.
Riddle me this: If muscles need to be lengthened, then why are people incredibly flexible when unconscious or under anesthesia? If a normally stiff man who can not touch his toes is put under anesthesia, he will become as flexible as a professional ballerina. The key concept here is that the flexibility of a muscle is determined by the central nervous system. The human body is wired for survival, and the brain only doles out as much flexibility as it thinks is safe to use.
With that said, over the years as a trainer I have encountered three common presentations of tight hamstrings:
In the first situation, you have someone who once was very mobile but simply experienced a loss of range of motion (ROM) due to inactivity over the years. For this group of people, traditional static stretching is often enough to quickly return ROM to normal levels. However, if you were in this group, you probably would not be reading this article. This group is also one of the reasons why static stretching remains popular; for this particular subset of the population, it works quite well and acts fairly quickly.
In the second situation, there is the person who has a marked difference between active ROM and passive ROM. Active ROM is the range of motion a person can actively control their hamstring through (think trying to touch your toes). Passive ROM is the range of motion a hamstring can be moved by an outside force (like when a partner stretches you out). To test your active ROM, lie on your back and lift one leg up as high as you can without bending the knee. To test your passive ROM, perform the same test but have a partner move your leg up and back as far as she can. Differences of more than an inch or two between active ROM and passive ROM are a very undesirable trait and come along with a high risk of injury. This essentially means that your brain is allotting more range of motion than it can actively control. A lack of motor control is an injury risk; if you were forced into a position in which you had no muscular control (falling for example) an injury is likely to occur. In my experience, this is most common in females.
If you are in this group, an easy fix is proprioceptive neuromuscular facilitation (PNF) stretching. It is a mouthful, but it is not as difficult as it sounds. This basically is stretching interspersed with muscular contractions. Here is how to do it:
– Lie on your back, and have a partner lift your leg (with a slight knee bend) in a traditional partner hamstring stretch.
– Once you reach the end of your range of motion, push down into your partner’s hand to contract the hamstring. Start the contraction slow and build up to a strong contraction over the next 10 seconds.
– Release the contraction, and have your partner push your leg back a little further.
– Repeat this process for a few more repetitions.
This is effective in fixing discrepancies between active and passive ROM because the muscular contraction in combination with stretching builds strength in the stretched position, thereby increasing involvement of motor neurons. This practice will lead to improved motor control over time and as a result, more active flexibility.
The third group consists of people who have had “tight hamstrings” since birth. This group has never been able to touch their toes. This group can stretch, get professional massage, therapy – the whole nine yards without seeing the hamstrings budge more than an inch or two.
As mentioned before, this is completely neural in nature. Not everyone was born as a gymnast. In this situation, for whatever reason, the brain is not comfortable with allowing too much range of motion from the hamstrings. There is a myriad of reasons why this could occur, the discussion of which is far beyond the scope of this article. In this situation, PNF stretching is sometimes effective, but usually only results in a few inches of ROM increase. The most effective way to improve flexibility in this situation is through various motor control drills. As motor control improves, the brain will loosen the reins and allow for more flexibility on a whole body level.
If you wish you could get a little more range of motion out of your hamstrings, rather than just stretch, try to figure out which group you belong to and act accordingly. You will not be disappointed!