Impacts, like volleyball and basketball,karate, handball, might cause some cartilege damage eventually where the dozens of metatarsal bones are held apart. I ran in shock causing combat boots for years at the insistance of the US Army, and I certainly am missing a lot of cartilege right behind my knee where I really need it. It's called arthritis by me or "a white spot on the MRI image" by the orthopedic surgeon. I'm 59. General aerobic exercise like track, maybe tennis, raquetball, build up general muscle and ligament tone due to the hormones generated. I worked as a factory mechanic 2000-2008, and using my hands turning drivers and wrenches certainly maintained my strength to get back into piano now that I am not employed. Factory safety people tell mechanics all the time not to use their hands as hammers, use the actual tool to hit things with. The shock causes joint pain. Volleyball, Basketball, karate involve hitting heavy things as part of the sport. Factory safety people also have a whole list of stretching exercises for hand and forearm tendons; I recommend piano teachers review the ergonomics texts.