Is Your Hip Pain Actually Coming From Your Back?

The hip and lumbar spine are anatomically adjacent and neurologically connected. Pain from the lower back can easily be perceived in the groin, buttock, thigh, or even the knee - regions that overlap with pain arising from the hip joint itself. Getting this distinction right is one of the more clinically important diagnostic challenges in musculoskeletal practice.

Hip joint pain: the typical presentation

True hip joint pain (from osteoarthritis, labral tears, femoroacetabular impingement, or avascular necrosis) is typically felt in the groin. The C-sign is a useful clinical observation: patients cup their hand over the front and side of the hip in a C-shape to describe the location. Pain is provoked by hip movement - particularly internal rotation and end-range flexion. There is often a restricted and painful arc of movement on examination.

Referred pain from the lumbar spine

Lumbar facet joints, disc pathology, and nerve root irritation can all refer pain to the hip, buttock, and upper thigh. This pain is typically more diffuse, harder to localise, and associated with lumbar symptoms such as stiffness in the morning or pain provoked by sustained postures. Hip movement itself is often pain-free and full range on examination, even though the patient is convinced the hip is the problem.

How physiotherapists distinguish them

The examination comparison is straightforward:

• Hip joint: pain and restriction on passive hip rotation; hip quadrant (combined movement) test positive
• Lumbar spine: pain on lumbar movement; hip movement does not reproduce the pain; may be positive lumbar provocation tests
• Diagnostic block: a local anaesthetic injection into the hip joint that eliminates pain confirms the hip as the source

Treatment aimed at the wrong structure is ineffective at best and occasionally harmful. A proper assessment that differentiates the two is essential before committing to a treatment direction.