ACL injuries most commonly occur during sports that involve sudden stops or changes in direction, jumping, and landing.
severe pain during exercise, along with a snapping or popping feeling. Pain in the back of the thigh and lower buttock when walking
A hip flexor strain is a stretch or tear of a muscle in your hip. You use the hip flexor muscles when you flex or lift your knee
Tennis elbow is a classic repetitive stress injury caused by overuse. Any activity that strains the muscles around the elbow over and over again can cause it.