Lower limb injuries : vicious circles

[Gerrard Farrell]

Footwear makes our feet weak even if we are active, so there is a foot strength/ rest of body strength imbalance, even before an exercise program is begun.

Now we start an athletic training program but still with splinted feet. The bodies muscles get stronger but not the vital foot muscles , and this may lead to injury such as plantar fasciitis or PFP affecting the knee. A period of rest allows the injury to recover but also allows the trained leg muscles to get a bit weaker again. Once the subject resumes athletic activities they have less powerful legs so the feet are initially under less strain than before so things are ok for a while .

But; the other muscles get stronger again and once more the foot can't cope with the demands being placed on it because shoes stop the foot from getting stronger.

And round and round we go. The solution seems pretty straight forward ,correct foot weakness with specific exercises.

[Edmund Cramp]

I found reading Daniel Lieberman's book, "The Story of the Human Body: Evolution, Health, and Disease" very helpful, it pretty much documents the issues you describe and how they have become factors in our lives, making me think about what has influenced the way I have always walked and run. It's a field that I have not been studying, only working with people in clinical gait labs for years which has resulted in a lot of education for me about how patients and athletes have issues that are studied to help everyone.

[Gerrard Farrell]

Hi Edmund ,
I certainly agree with one of Lieberman's more recent papers, that toe springs in shoes make a big difference to toe flexor strength and function, but I feel that medial arch supports and cushioning are much more benign modern shoe features.

Note ; Although it can be argued that increased quad/glut strength can help reduce peak forces in leg structures during some parts of the running cycle by absorbing some of the forces generated, it should be noted that peak stain in the plantar fascia occurs during push off as the heel clears the ground . Extra power at this point will presumably lead to increased load in the PF.