Pain in the thighs and legs after workouts like squats or jumping is often due to muscle strain or delayed onset muscle soreness, especially if intensity or technique is not optimal. Give your body adequate rest, do proper warm-up and stretching before and after exercise, and gradually increase workout intensity instead of suddenly overloading. Stay well hydrated and include enough protein in your diet to support muscle recovery. A knee cap may give temporary support, but it won't fix the root cause. If the pain is sharp, persistent, or keeps recurring, it is important to get your exercise technique and muscles evaluated by a trainer or doctor to prevent injury.