Thanks for using this forum on HCM.
The pain radiating from your spine towards your leg can be due to various reasons. This could include trauma to the spinal vertebrae or spinal column leading to disc herniation causing compression of the nerve
. Other reason can be muscle strain involving the muscles supporting the spinal vertebrae. Firstly you should consider getting an MRI
scan done for your spinal vertebrae after full assessment by your doctor to rule out the above conditions. Avoid too much movements such as excessive flexion or extension. Talk with a physiotherapist after a diagnosis is made for proper exercise regime.
Feel free for further queries.