Pain in the leg, most commonly down the back of the leg, can result from the lumbar spine, even in the absence of low back pain. The source of low back-related leg pain can involve either musculoskeletal or neurological structures, and in many cases, it can be hard to differentiate based on symptoms alone.
Lumbar related leg pain is most commonly referred from the outer wall of the disc when it becomes inflamed. These injuries can result from prolonged sitting, repetitive bending or heavy lifting. Most disc-related referred pain does not require any imaging and can be well treated conservatively by a physiotherapist with manual therapy and exercises.
Leg pain can also result from an inflamed nerve root. Inflammation of a nerve root is not sinister and does not require any imaging. It is usually managed well conservatively with anti-inflammatory medication, offloading positions and gentle exercises. However, closely related, nerve root compression in the low back can refer pain into the leg. This condition can result in loss of strength and function of particular muscles in the leg and if not assessed and treated may result in permanent neurological damage. The treatment can vary depending on severity; physiotherapy has been demonstrated to be effective in resolving the condition; however, in some cases, surgery is required for a successful outcome.
Physiotherapists play a key role in diﬀerentiating between diﬀerent sources of radiating leg pain, which is important to make an appropriate diagnosis and identify the underlying pathology.