Magnetic resonance imaging findings of the lumbar spine in elite horseback riders: correlations with back pain, body mass index, trunk/leg-length coefficient, and riding discipline.

BACKGROUND: Most orthopaedic problems experienced by competitive horseback riders are related to pain in the lower back, hip joint, and hamstring muscles. Riders-especially, show jumpers-are frequently hampered in their performance because of lumbar pain. To date, there has been no research into lumbar disk degeneration in elite competitive riders.

HYPOTHESIS: Competitive horseback riding accelerates lumbar disk degeneration.

STUDY DESIGN: Cross-sectional study; Level of evidence, 3.

METHODS: Fifty-eight elite riders (18 men, 40 women; mean age, 32.4 years) and a control group of 30 nonriding volunteers (17 men, 13 women; mean age, 28.7 years) were evaluated for lumbar disk degeneration, cross-sectional area of paraspinal muscles, spondylolysis, and spondylolisthesis, using magnetic resonance imaging (MRI). The prevalence of disk degeneration between the 2 groups was compared, and the relationship was investigated between low back pain (LBP), riding discipline, body mass index (BMI), trunk/leg-length coefficient, and MRI results.

RESULTS: Eighty-eight percent of elite riders (n = 51) had a history of LBP, versus 33% of the controls (P < .05). There was no statistical difference for the prevalence of LBP among the different riding disciplines. However, there was a high rate of pathologic T2 signal intensity of the lumbar intervertebral disk among riders-specifically, dressage riders-yet no significant increase when compared with controls. History of LBP symptoms, riding discipline, BMI, and trunk/leg-length ratio had no significant effect on the development of lumbar disk degeneration. Occult fractures of the pars interarticularis and manifest spondylolysis were not seen for any rider. Two controls had spondylolisthesis Meyerding grade 1 not associated with back pain.

CONCLUSION: Although riders have a high prevalence of LBP, there is no conclusive MRI evidence to suggest that the cause lies in undue disk degeneration, spondylolysis, spondylolisthesis, or pathologic changes of the paraspinal muscles of the lumbar spine.