Toenails can fall off due to many of the reasons you stated. If the shoes are too short or the toes hit the end of the shoe during activity, then the nails might do this. Hammer toes can cause the nails to deform as well.
There are other possible reasons but without seeing the feet, I can't guess. I suggest you see a podiatrist for further evaluation.
Posted By Vivian Abrams DPM on September 06, 2004 at 18:13:01:
In Reply to: toe nails
posted by Grace on September 06, 2004 at 15:34:01:
This soft padded night splint with contoured posterior shell provides passive dorsi flexion to address plantar fasciitis and achilles tendonitis. Shipped with toe wedge for additional stretch on plantar facia.