What should you know about unilateral spondylolysis?

The pars interarticularis is a small bridge of bone at the back of a vertebra. Repeated loading, especially with repeated back extension or rotation, can stress this area. Some people have no symptoms, while others notice focused low back pain during sport, standing, or particular movements. A clinician may assess posture, movement, strength, and nerve function, then use imaging when needed. A defect on one side does not automatically mean that the vertebra has slipped, but stability should be checked when symptoms persist.

Temporarily reduce the movements that reproduce pain, while keeping gentle activity that does not aggravate symptoms. A physiotherapist can guide trunk and hip strengthening, movement control, and a gradual return to loading. Exercise therapy should be individualised rather than copied from a general routine. Keep a record of pain during activity and recovery afterward. If symptoms continue despite a structured non-surgical plan, a spine specialist can discuss further imaging or options such as spinal fusion in selected situations.

Seek urgent assessment for new leg weakness, loss of bladder or bowel control, numbness around the inner thighs or genitals, fever with severe back pain, or pain after major trauma. Arrange a routine review when pain repeatedly limits sport, sleep, school, work, or walking, or when symptoms spread into a leg with tingling or numbness.

Where is the defect, and is the spine stable? Which activities should I pause? What should my physiotherapy programme include? How will progress be assessed, and what would make another treatment appropriate?