How much is too much?
Recently, I had a conversation with a patient who was worried that she couldn’t bend over and touch her toes. She asked if she should be concerned and how could she improve her hamstring flexibility so that she would be able to reach her toes like she could when she was younger. She was worried that having tight hamstrings was contributing to some of her neck, back, and knee issues, and causing her to have pain after most of her workouts.
This is a question I get asked at least on a weekly basis. And it’s an important question, because going about stretching your hamstrings the wrong way can be a great source of instability through your pelvis and hips. There is, in my opinion, much misconception and misinformation about hamstring flexibility and flexibility in general. Every joint has an optimal amount of flexibility based on functional and postural demands; we need our soft tissues to be mobile and responsive enough to allow us to move. However, we also need them to be structurally sound in order to provide stability, which goes hand in hand with having the proper amount of strength and responsiveness to keep our bones in the right place at precisely the right time.
It is clearly a problem if you’re too tight and one or more joints can’t move enough to allow you to perform the simple movements needed for activities of daily living as well as the more complex set of movements required for athletic endeavors or movement art. As a physical therapist, this is usually fairly easy for me to treat using whatever form of mobilization, exercise, or self-mobilization that I have in my toolbox. Although it may take some time to restore normal range of motion, short and stiff tissues usually respond well to treatment applied with enough force and finesse.
More difficult is the situation in which tissues are too long. Yes, it is possible to overstretch muscles and other soft tissues. With overly aggressive stretching, the contractile elements of muscle fibers, along with the other connective tissues that envelop and surround the muscles, can be damaged. This can render the muscle long, weak, and chronically irritated (signaling to the chronic stretcher’s brain to “stretch more!” because that’s what one is “supposed” to do when something feels tight and irritated). If that over-stretching is addressed early in life, muscle tissue can repair itself. But the later in life that one maintains a rigorous stretching program and long, excessively stretched soft tissues, the less likely he or she will be to ever rebound to normal range of motion.
Now, back to my patient’s question: Should she worry about her inability to touch her toes? The answer is “maybe," since it depends on how she bends over and whether or not there is a proper amount of movement through the hamstrings, hips, and spine combined. Besides the hamstring’s function of bending the knee and extending the hip, the hamstrings act on posture to check or slow down the forward tilting of the pelvis. If the hamstrings are too long and not strong enough, it is likely that we will see the pelvis tilting too far forward, resulting in a deep lumbar curve. Habitually being stuck in this lumbopelvic position leads to a cascade of postural alterations.
A forward-tilted pelvis is associated with lengthened abdominals and tight hip flexors. This situation is one in which your abdominals are at a mechanical disadvantage for acting as the important “core” stabilizers that they should be. With loss of abdominal tone, the belly protrudes and the front lower ribs flare, deepening the lumbar curve even more. Most people who have this deep lumbar curve develop, over time, hyperactive and short low back muscles (paraspinals, latissimus dorsi, quadratus lumborum) so that, when they bend over, their lower back cannot completely come out of a deep curve and they can’t fully round (or flex ). This perpetuates the hamstring situation. Every time they bend, they utilize their excessive hamstring length and do not appropriately round their back. This simply becomes how they move. Sitting and standing forward bends in yoga are easy to do by pivoting through the hips and not rounding the back at all; dead lifts are performed with too arched of a back; runners may over-stride and overextend their back.
Whether an individual has tight hamstrings can only definitively be determined through a series of objective tests. But a quick screen can give one a pretty good idea of his or her situation. Lie on your back and see how far one leg at a time can be brought up and toward your head while keeping your knee straight. I’ve found that, on average, men can get to around 80 degrees and women can get closer to 90 degrees. However, if your pelvis is already tilted too far forward, you may get a false impression that your hamstrings are short because they’ve been placed on stretch before you even start the test. A good way to decide whether your pelvis is in the proper position is to look for a decent amount of rounding through your lower back when you reach to touch your toes. My golden rule is that you can touch your toes with normal lumbar flexion. If you can lay your palms on the floor (like many ex-dancers, gymnasts, and cheerleaders can), it is very likely you’re pivoting too much at the hips through excessively flexible hamstrings.
The main point is that, when you feel your hamstrings are tight, they may actually be too long and are just irritated. In this case, if you continue stretching, you will actually be worsening the health of these tissues. You really may need to be strengthening them so that they can act as efficient pelvic stabilizers. Find a physical therapist to do a more in-depth assessment of your situation so you don’t risk making matters worse.