Sir, Visit a good physio in your area. The muscle in the buttocks area sometimes get tightened which might compress the nerve tissues passing from there.

Physiotherapy treatment and stretching exercises must

Short Arcs: Lie flat on your back or sit upright with your leg placed horizontally on a flat surface like a chair or bed. Place a rolled up towel under the knee. Pull your toes towards you and clench you thigh muscles. Slowly lift your foot up off the bed until your knee is straight (keep your knee resting on the towel). Hold for 3 secs and slowly lower them on the chair. Repeat 10 times twice a day. Straight Leg Raise: Lie flat on your back. One leg and knee will be straight and other leg should be bent. Pull your toes towards you and tighten/clench the muscle on the front of the thigh, locking your knee straight. Lift your foot up in the air, about 6 inches off the bed. Hold for 3 secs and slowly lower the leg. The knee must remain straight the whole time you are doing this exercise.

- He is suffering from pivd which causes compression of sciatic nerve called sciatica. - check for vit d , b12, uric acid level - precautions: 1 avoid heavy weight lifting 2 avoud forward bending of spine 3 use of firm matress 4 always take side turn while coming out of bed from lying position to siiting position or vice versa. - do hot water fermentation 2 - 3 tines daily for 5 days to releive back muscles. - kindly fix appointment with physio to strength back and hip muscles  exercises .

Leg pain , at his age is often associated with a nerve getting pinched in the spine. Do not get worried , this is very easily manageable. Unfortunately an X-ray does not help detect this , as an X-ray is done to look at the spinal alignment and bones but this is a issue with soft tissue (nerves). If his pain has been persisting for two years and is getting worse , I would suggest you to do an MRI of the lumbar spine to confirm the suspicion. Once we know the exact cause, it is much simpler to start a physiotherapy protocol in accordance with the pathology. This is a very common issue faced in old age and has simple solutions ! 80 percent of those suffering from this condition get better with a well structured physiotherapy protocol and a gel / gabapentin / hot compress and exercises. Please read my blog for the exercises that will benefit him. All the best !

This is a condition known as sciatica.

Agree with Dr Dutta. Please follow advice.