Todd Hargrove had a great post on his better movement blog; I definitely recommend checking out his site, where he talks about the relationship between flexibility, sports performance and injury prevention. In it he makes some great points on the lack of correlation between flexibility and injury rates. It got me thinking about the issue of improving the range of movement of any joint and how this relates to stretching, of any form, soft tissue work, in the form of hands on and foam roller type work, and strength.
Todd makes the point that great flexibility shows us that there is a ability to move a joint from point A to point B but tells us nothing of the quality of the movement, that is our ability to control the limb involved through the range of movement available. I totally agree that having a large ROM without the ability to control it is counterproductive and potentially dangerous from the point of increasing the injury risk. In one of the studies Todd mentions, football study, they mention a significant risk of injury in those with previous groin injuries was high. This is something that has been documented in a number of studies, 12 month sports injury study, ankle sprains , and previous injury is probably the most reliable indicator of future injury risk.
When we talk about the need for improved flexibility in injury prevention we are not talking about the need to develop the range of movement demonstrated by a gymnast merely that we have the normal range of movement for our joints. That is to say that we have these types of range of movement of about 120⁰ of flexion at the knee, 130⁰ of flexion at the hip, 70⁰ of hip flexion when we are looking at the hamstrings specifically, but these are ranges of movement lacking in many people though not in the elite athletes who will generally demonstrate normal range of movement in their joints, previous injury dependent. Range of movement beyond this is unlikely to be beneficial to us and isn’t really something we need to strive for.
Far more important is to have control over the movement, something Todd mentions, that we do have and from there look to improve our ROM, assuming it is lacking, to where we have what is normal for the joint involved in that movement. To this end improving your flexibility is desirable though may involve more than just stretching but you are definitely going to have to work on it. It’s ok to say that improving flexibility, or at least normal joint range of motion, doesn’t prevent injury in elite athletes as it is true as pointed out in a number of studies but again these athletes have good ROM in the first place where as many recreational athletes often do not and nor do they have good control over their movement either. This combination of poor control and poor range of movement is a recipe that will lead to injury. Often what is considered a large range of motion is simply what you should be able to achieve barring injury but is rarer than it should be and as such seems more extreme.
One of the things we may want to consider when looking at our range of motion is the relative flexibility of one area to another within a multi joint movement, as most of our daily activities are, and look at where we are achieving our movement from. If we look at walking or running and look at the hip extension component of the movement as an example it may be that the lumbar spine is more flexible than the hips due to relatively stiff hip flexors, the hip flexors providing more resistance to the movement. In this scenario the lumbar spine extends to compensate for the lack of extension at the hips and creates a potential problem at the lumbar spine since we don’t really want to be moving here as we propel ourselves, ideally this area will be stiff to help with efficient locomotion. It is also possible, in fact very likely, that there will not just be adjustments to the lack of extension ability in the hips in the lumbar spine but also downstream in the lower leg as well, creating over pronation issues and torsion of the tibia.
To address this we need to look at both the stiffness in the hip flexors and the likely weakness the abdominals. The abdominals should be strong enough to prevent the movement in the lumbar spine whilst we move and the hip flexors, let’s assume it is rectus femoris that is the problem, “soft” enough or have sufficient extensibility to allow for a full range of hip extension in the push off phase of walking or running. It may be that the stiffness in rectus femoris is due to the weakness in the abdominals and is the body’s way of attempting to prevent any uncontrolled movement and if so then their apparent stiffness can be corrected by strengthening the abdominal musculature. It may be that it is not the case and they do require work to regain the normal range of movement for the joint. In this case then some form of soft tissue work and stretching may be more appropriate. If we are to stretch the area how are we going to do it? I prefer to use MET/PNF style stretching along with a more “tissue flossing” approach over static stretching but I am not averse to it as part of the mix I just feel we need to think about what we are trying to achieve and what is appropriate at the time.
If we are to tackle flexibility issues fully with we need to think beyond simply stretching, in any form, as to why we lack ROM within a joint but that whilst stretching will not prevent injury, there is no evidence that it does, there is no reason not to utilise various stretching type techniques to help regain our normal range of motion. We also need to develop the strength to control the movement we have or desire to have. Simply being more flexible for no reason or beyond what we can control is counterproductive and is likely to result in the injury you may be trying to prevent as such we need to develop the strength to control the movement not just simply increase the ability to move the joint though a pre-prescribed range.
To sum it up, maintaining normal joint range of motion and ensuring we are able to control that movement are what is required if we want healthy injury free movement.