Spondylolisthesis Identified Using Ultrasound Imaging.

57-year-old woman was recruited for a research study of muscle activation in persons with low back pain. She described a progressive worsening of left lower lumbar pain, which began 5 years prior without any precipitating incident, and intermittent pain at the left gluteal fold (diagnosed as a proximal hamstring tear 2 years prior). Ultrasound revealed marked anterior displacement of the L3-4 and L4-5 facet joints.