You may be having what's called referred pain. This means you are having pain in an area some distance away from the actual problem. The reason this happens has to do with the nerves and how they work.
pinal nerves leave the spinal cord and travel down the back to the buttocks, legs, and feet. Anything that can put pressure on the nerve can send pain messages down the nerve to areas further down.
The doctor can usually tell which nerve is aggravated based on the location of your symptoms. Pressure on the nerve can cause back, buttock, or leg pain. Usually the patient has back pain that goes down the leg. This is called radicular pain. But it's possible to have just the leg pain without back pain from the same problem in ths spine.
Pressure on the nerve can also cause numbness, tingling, or an electric shock sensation. Let your doctor know if you develop these or any other symptoms. Early treatment is the key to a good result.