According to the history provided by you, the leg pain looks like the pain from the lower back that is radiating to the leg which is causing difficulty in moving the leg. It can also be associated with numbness or tingling sensation over the leg. It could also be due to the degenerative changes in the hip joint.
Management of the same would be aimed at reducing the pain as well as strengthening of the muscles of the lower back and adequate rest to the inflammation of the nerve, so that the pain is reduced and the nerve is rested and healed.
Start with hot water bag / heat pad fomentation over the lower back and over the hip joint of the affected side.
Do not allow to bend straight downwards while standing, sitting cross leg or squatting. Avoid her to lift any kind of heavy weight.
Apply a pain relief SPRAY instead of the oil or cream, after 45 mins of heat pad/ hot water bad fomentation.
Do this for 3 times a day. It will definitely start to get better after 2 days and since its a big muscle over the lower back, it will take some time to get back to normal.
For any other queries you can always contact me.
Next Steps
Xray of the lumbo-sacral spine and hip joint