What Causes Severe Pain Spasms In The Hip Upon Standing Up?

I m having severe right hip pain, had x-ray which was negative for pathology. When rising from sitting or lying I have very sharp pain and spasms which usually subside after a few steps. Generally, restricted with hip/low back extension due to pain. Hip ROM when non-weightbearing is generally good. There is mild pain when non-weightbearing as well. This has been happening for about 2 months. Insidious onset. I m 50, male, active in sports (softball, hockey, volleyball). Wondering if there is a ligamentous issue as palpation is not significant for pain. Pain is also not constant, relieve with rest and ibuprofen does help.