Update on Running Mechanics
128
Much of the theory behind the common approaches to evaluating, and addressing, what we believe are the biomechanical causes of running injuries started out as just that – theory.
That is to say, the development of this line of thinking began when some very smart individuals hypothesized that certain abnormal patterns of movement and posture could be related to the occurrence of specific injuries. While the scientific reasoning behind this was sound, there was initially little clinical and laboratory research to support these theories.
Over the past two decades, however, more and more evidence has accumulated to confirm much of what these experts claimed. There is, in fact, a clear connection between faulty movement and increased incidence of running injuries. But one question that has always remained is – which patterns cause which injuries.
Those of you who follow this series know that I have on several occasions pointed to the hips as a key segment of the lower limb in relation to injury risk. Specifically, weakness of the hip abductors and external rotators seems to be a common finding in injured runners. Now, a recent study published in the American Journal of Sports Medicine [The American Journal of Sports Medicine
2018;46(12):3023–3031] appears to confirm this theoretical model.
Researchers compared the running mechanics (kinematics) of 72 injured runners with 36 healthy controls. The injured runners were sub-categorized into 4 groups, based on their injury: patellofemoral pain (Runner’s Knee); iliotibial band syndrome; medial tibial stress syndrome (shin splints); and Achilles tendinopathy.
The study found that the injured runners, compared to the non-injured, exhibited 4 key abnormal movement patterns. First and foremost was an increase in the drop of the opposite side of the pelvis from the stance leg, which is the result of weak hip abductors. Additionally, the injured group showed an increased forward trunk lean, extended knee and flexed ankle at heel strike (initial contact). These faulty patterns were consistent across all injury sub-groups, so there is no clear connection between a particular movement and one particular injury.
What is clear, however, is what many of us have suspected for years: strong and functional hip abductor muscles are a key player not only in treating injured runners, but more importantly, in preventing the development of a number of injuries. According to this study, for every 1o increase in pelvic drop, there is an 80% increase in the risk for incurring one of these injuries. (What isn’t clear is if there is a causative relationship between weak hip abductors and the other faulty patterns.)
So once again I find myself preaching on the importance of working this particular muscle group for preventive reasons. As I’ve said in the past, don’t worry about stretching before you run – it’s more important to warm up with easy jogging and to work these muscles by doing a couple of exercises that I have described in previous installments [TC 89 and TC 95]. Check those out online and make them part of your regular routine.