Hi.. Your knee pain is due to muscle stiffness and soreness in the back if your knee and calf... Don t worry as it be solved easily and can be prevented to recur.. I suggest you to kindly roll a iced bottle in the back of the knee...knee on top of the bottle and rolling by pressing the bottle gently... Knead gently over the back if knee calf muscle and hamstrings... Gently stretch your calf and hamstrings...glute muscles... I recommend you to kindly start strength training for glutes and lower body... Change your training shoes frequently. . Do good warning up and warming down properly.... Take lot of fluids.. Hope this is helpful for you Kindly revert back in case you need any further clarification....