Low Back Pain Caused by Traction Peripheral Neuropathy Due to Chronic Ankle Instability: Three Clinical Cases

Non-specific low back pain without identifiable causes on imaging is a common and frustrating problem for both patients and physicians. While proximal symptoms such as shoulder pain from distal upper extremity neuropathies such as carpal tunnel syndrome are well-known, peripheral neuropathy of the foot or ankle is rarely considered in the differential diagnosis for low back pain. This study aims to highlight the potential link between chronic ankle instability (CAI) and low back pain. We present three cases: a 32-year-old woman with chronic low back pain for over 10 years, a 59-year-old woman with transient low back pain after long drives, and a 42-year-old woman with acute low back pain while gardening. All patients had normal imaging studies but exhibited CAI on examination. Diagnostic modalities included the ankle anterior drawer test, application of ankle brace, superficial peroneal nerve (SPN) blocks, and assessment of the active straight leg raise (aSLR) angle. In the first case, low back pain disappeared after SPN neurolysis and ankle ligament reconstruction. The second case showed significant improvement in aSLR and pain reduction with SPN block and ankle brace. The third case experienced substantial pain relief with the use of an ankle brace. These findings suggest that addressing ankle instability and associated traction neuropathy can significantly alleviate low back pain symptoms. CAI may be an underrecognized cause of non-specific low back pain. Interventions such as ankle brace, SPN blocks, SPN decompression, and ankle ligament reconstruction can be effective for diagnosis and treatment, potentially offering relief for patients with chronic low back pain.