As we age, we lose a certain amount of hip extension range during walking. By hip extension range, I mean the amount that our hip extends backward during walking. That may not sound too surprising. Don’t we lose, as we get older, a certain amount of range in ALL of our joints during walking?
Well, actually, no.
Through a series of gait laboratory studies (see below) we found, surprisingly, that only hip extension range during walking decreases with aging. When elderly subjects are asked to walk at a faster than normal speed, their joint range of motion matches or exceeds that of a young adult subject for every lower extremity joint in every direction. Except for the hip joint, in extension. We found peak hip extension to be on average 10 degrees less in an elderly subject (age 65-85) compared to a young adult subject (age 20-40).
Simultaneous with this age related reduction in hip extension, we find not only a shortened stride, but an increase in pelvic or low back motion. Presumably, the concurrent age-related increase in pelvic / low back motion is a compensation for the reduced hip extension range.
Walking and running are the only regular activities we do in a day that can stretch the hip into full extension. Standing or lying down, for example, require that the hip only gets to a neutral position. Only during walking or running, can the hip be stretched into full extension. Being bedridden or sedentary results in a loss in hip extension flexibility.
Gait form and footwear can affect hip extension range during walking. A gait that allows the trailing limb to fully extend before weight is borne on the lead foot provides maximum hip extension.
Outside of walking and running, there aren’t a lot of ways you can actively stretch your hip into extension. This led us to researching and studying specific exercise stretches that DO stretch the hip into extension. We found that most Western exercise regimens do not include stretching the hip into extension. On the other hand, we found that every form of Yoga we investigated, included at least one stretch that stretched the hip into full extension.
The next question was, could a two-minute stretch to the hip flexors reverse our age-related changes in gait? To answer this, we studied the isolated effect of stretching the hip into extension and in fact did find a modest improvement in age-related changes in gait.
Ways to stretch the hip into extension (besides regularly walking) include the Sun Salutation and Warrior Pose. Different yogis might call the pose I am doing above different things but you can see how my trailing hip is fully extended beyond neutral.
What I do is take a step forward and extend my trailing leg back as shown, with the knee extended and my weight slightly forward, and I slowly lift my arms up overhead. Then I hold it there for 20 seconds. I do the same thing on the other side and then repeat. You should only do it after you’re warmed up, after a hot shower or a workout (and of course there’s no need to do it if your workout IS Yoga). I usually do the stretch / pose after I run. All in all, it takes less than 2 minutes.
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