Author: Udit Bhatt, DO
Co Author #1: Marcia Faustin, MD, CAQ-SM, FAAFP UC Davis Department of Family and Community Medicine UC Davis Department of Physical Medicine and Rehabilitation
Senior Editor: Kristine Karlson, MD, FAMSSM
Editor: Timothy Huang, MD

Patient Presentation:
A 19-year-old female with a history of mild scoliosis presented to the training room with atraumatic lumbar back pain for 5 months.

History:
The pain was daily, sharp, rated 5 out of 10, located across her lumbar spine and radiated to her posterior thigh. The pain was typically above the knee, but also went to her feet. It was exacerbated by walking, running, and flexion (greater than extension). During practice, she reported no pain on the bars, but experienced pain on the floor and beam. She denied numbness, tingling, night pain, saddle anesthesia, or urinary/bowel changes. She reported morning stiffness and mild weakness, particularly when walking on her right leg. She admitted to a family history but no personal history of psoriasis. She trained a few days per week at her home gym.

Physical Exam:
On physical exam, inspection of the lower back, hips, and ankles was grossly unremarkable with a normal gait as well. Palpation was notable for tenderness in the right paraspinal muscle and right SI joint with no midline tenderness. Active range of motion was intact throughout the hips and lumbar spine, though there was notable pain with end-range flexion and extension of the lumbar spine. She had 5/5 strength in hip flexion, knee flexion and extension, ankle dorsiflexion and plantar flexion, and toe extension. Her sensation to light touch was intact, her deep tendon reflexes of the patellar tendon and Achilles were symmetric, and she had a negative Babinski exam, along with no clonus. The Pelvic distraction, FABER, and Fortin finger tests were positive, localizing to right sacroiliac joint pain. Her exam was also notable for a negative straight leg raise, slump test, stork test, Gaenslen test, Yeoman's test, pelvic compression test, and thigh thrust test with intact heel and toe walking.

Click here to continue. Challenge yourself by writing down a broad differential diagnosis before moving to the next slide.