When i do anything that requires me to stride my legs like sprint all out or

[Michael P]

walk up stairs my legs get tight? This is on and off but for the most part this always happends. Whenever i do an activity and then i stop my legs get tight. Im not able to legthen my gait of stride. My legs feel weak/ tight. I think it has to do something with my hips or back. Please Help ive had this for the longest time