Low back pain is the fifth most common reason for all physician visits and the second most commonly reported symptom. In most cases, low back pain signals a muscular disorder that can be managed conservatively. However, physicians should have heightened vigilance for low back pain combined with bowel and/or bladder incontinence, motor and/or sensory loss in the lower extremities, and saddle anesthesia, as this may represent a neurosurgical emergency termed cauda equina syndrome.

The cauda equina (from the Latin for “horse’s tail”) is the descriptive name for the lumbar nerve roots emanating from the distal tip of the spinal cord. The spinal cord terminates as the conus medullaris typically at the L1–L2 level. The lower lumbar and sacral nerve roots continue caudally in the cauda equina, exit their respective neural foramina, and ultimately provide motor and sensory innervation to the muscles and skin below the waist.