Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Groin pain can be caused by a wide variety of medical conditions, and sometimes the source of pain may be from different anatomic areas. Possible causes are like problems in the lower abdomen, problems in or around the hip joint, and problems in the scrotum, can all lead to symptoms of groin pain. Commonly related to hip bursitis or a pinched nerve in the back. Pain behind the hip is more commonly coming from the lumbar spine. It is pain that is deep within the groin that is often a sign of a problem within the hip joint. You already mentioned that not able to lift your hip on lying down position may be due to hip osteoarthritis or bursitis or hip labrum tear, etc. You may consult your Orthopedician and get X-ray of lumbar spine and hip joint. Also get ultrasound abdomen to confirm groin area then get treated accordingly. Hope I have answered your question. Let me know if I can assist you further. Regards.