Knee injuries have always plagued athletes. Unfortunately, they are particularly difficult to diagnose, in part because the source of your knee pain could be elsewhere in your body.

In particular, stiff hips and ankles can cause knee injuries to develop, says physical therapist Gray Cook. If your ankles cannot move throughout their full range of motion, your knees have to compensate for the lack of mobility. This forces the tendons and ligaments in the knee to go beyond their range of motion, causing a strain or a tear. Ankles that can comfortably dorsiflex [point foot toward shin], plantarflex [point foot toward ground], invert [point foot toward center of body], evert [point foot away from body], pronate [shift toward the arch of your foot] and supinate [shift toward the outside of your foot] will take the burden off the knee.
Athletes can integrate those movements into their training with a couple of exercises.
National Academy of Sports Medicine fitness coach Nick Ng instructs, “Stand with your legs about hip width apart and your feet pointing forward. Place your hands on your hips, and shift your weight toward the balls of your feet.” Continue shifting your weight until your heels are lifted off the ground and you are in a complete plantarflexed position. In a controlled manner, begin to shift the weight back to your heels and pull your toes off the ground and as close to your shins as possible. Slowly move back to the starting position. “Perform 10 rotations in each direction for two sets,” suggests Ng.
After working on your ankle mobility, move on to strength exercises, such as Squats and Lunges, to strengthen joints and muscles. “This balances the strength, stability and mobility of your joints to prevent injuries,” says Ng.
NBA All-Star Devin Harris and MLB slugger Mark Reynolds show how to perform lower body strength exercises to increase ankle strength, stability and mobility.
Three-Way Med Ball Lunge With Devin Harris

• Perform this in a circuit fashion with other exercises
• Perform forward, lateral and reverse lunges
• Hold the med ball at chest level
• Keep chest up and core tight

Sets/Reps: 3×3 in each direction, each leg
Mark Reynolds BOSU Dumbbell Squat
This exercise provides an extra challenge to the stabilizing muscles in the ankles, thanks to the BOSU ball.

• Set up BOSU balls just wider than shoulder width
• Keep weight back on heels
• Use core to maintain balance
• Keep knees behind toes

Sets/Reps: 3×8
Source:  Livestrong.com
Photo:  fit-pro.com