I injured my knee over the summer playing pick-up basketball. The injury happened when I stepped on a rock and turned my ankle. Why did I hurt my knee instead of my ankle?

Recent research has shown that the ankle’s sense of position (called proprioception) may affect the knee. Muscular fatigue around the ankle changes the ankle’s sense of position. This in turn changes the firing pattern of muscles around the knee. Injury to the ligaments of the knee may be the final result.