One problem often seen with runners is the development of claw toes. While this can have a few reasons as to why, a very important cause to rule out is the health of the flexor digitorum longus muscle. This muscle as the name implies, flexes the last four toes.
Often times the toes will appear flat and normal, but if you do a calf raise or dynamic lunge, you will see the toes claw the ground to gain stability. I was reading a post by Charlie Weingroff the other day and he believes that not only does the clawing inhibit the deep intrinsic muscles of the foot, but because the clawing allows less of an arch, it neurally inhibits the hip muscles. Your body doesn't feel the strong arch, so it doesn't think you need the hip strength, because you are not in a propulsive position. How interesting is that!
I have seen this in my own practice, but didn't really correlate it with inhibition of the deep intrinsic muscles and neurally inhibiting the hip. I always assumed by bringing back the length of the FDL muscle, the whole fascial chain got stronger.
A quick evaluation you can do on yourself is to just get up on your toes and do several calf raises. Do your toes start to claw? If you do, do some myofascial work on the flexors and then proceed to concentrate on keeping the toes flat into the floor as you do another set of calf raises. I find it helps to feel the big toe push into the floor as well. Keep this up for several weeks. In the long term it will help keep gait smooth and relaxed.