Running style and injuries
Recently I was working with a personal trainer with running related anterior knee soreness. We were talking about running style and the various coaching methods out there. As I've said on the website, I'm not a running coach, so I was given interesting information from a highly experienced and capable trainer on this topic.
What we both agreed on was that research indicates that for a given individual, stride rate stays quite constant over several running velocities. Further, its very common for people to over-stride and lose the benefit of gravity - that effect of falling forward in a controlled manner. Over-striding creates a breaking effect. It's inefficient. For some people this also involves excessive height displacement.
I'm involved in runners with lower-limb stress fractures, patello-femoral pain, hip and ITB pain and back pain. Over-striding and "over-jumping" create excessive, rapid overloading in the lower limb tissues. If video analysis of the injured runner demonstrates this is occurring, the simplest, fastest way for the runner to reduce their loading is to increase the stride rate. You can't overstride or over-jump at a given stride rate.
In injured runners, finding that effective stride rate is worth playing with and implementing over and above other considerations. All those factors such as medial knee collapse, excessive hip-drop, internal tibial rotation can radically improve, immediately, in addition to reducing the lower limb loading. Over-striding creates all these. Naturally, if the stride rate is excessive, the runner fatigues. This is why testing under controlled conditions is useful because it identifies the earliest increase in stride rate giving the best mechanics without performance impairment.
Note that a runner may still avoid controlled falling forward despite the stride rate change. You can see it clearly with very "upright" runners. I don't work with this patterning at this time as I haven't yet seen information suggesting it provokes injuries, but it is a performance issue coaches would work with. I say this to highlight the different role I take compared to a trainer/coach. I don't do running style, I help eliminate injurious running patterns and firmly establish a "new normal" into the nervous system.
Note also there is an ingrained nervous system patterning for the stride rate. There are specific biofeedback principles required to entrain the new stride rate, to make it permanent, alongside of protocols to manage these injuries within a given training need. That's what I manage.
Also note that training strength in the gluteals and trunk musculature will not successfully remove the structural collapses or the strains when there is over-striding present. But where there is weakness/ lack of endurance in these tissues PLUS overstriding, then yes, strengthening is also needed. ie Adequate strength testing is needed in addition to biomechanical analysis.
Further, while you can use metronomes and music to run by to keep your new stride rate, the nervous system will go back to its default setting when that external entrainment is gone. Progressive feedback reduction alongside of retesting on the treadmill establishes that the mechanics have been baked into the system.