Paining in muscle upside and downside of kness in my legs?

Could be anything: it really could be anything from muscle pain to a joint pain the muscle pain could be fatigue or over use or cramping or inflammation list is long and all the possibilities had to be ruled out go and see a doctor

Stretch/water: Muscle pains can be caused by medical illness so if you are not feeling well in general or if the pain is severe, see a doctor. In general muscle pain may be due to dehydration, overuse or deconditioning. Walking regularly for about 30 minutes a day, doing regular stretches, drinking 60-80 oz of water daily and taking a multivitamin may help.