Elite Cross-Country Skiers Who Report Low Back Pain Have More Disk Degeneration Than Their Nonsymptomatic Peers

OBJECTIVE: To investigate the prevalence of low back pain (LBP) and disk degeneration (DD) and the relationship of DD with LBP among elite cross-country skiers. DESIGN: A cross-sectional study of elite cross-country skiers. SETTING: Study participants were recruited during autumn 2022 among elite cross-country skiers and collegiate skiers who were selected to national teams' training groups. PARTICIPANTS: The original study group consisted of 44 skiers (16 national team skiers and 28 sports academy skiers). INTERVENTIONS: The study protocol included a 1.5T lumbar spine MRI, a clinical examination, and an interview with questions about general health and training as well as selected patient-reported outcomes. The morphology of intervertebral disks from T12/L1 to L5/S1 on sagittal T2-weighted midline images was visually assessed using the Pfirrmann classification with a grade 3 or higher considered degenerated in this age group. MAIN OUTCOME MEASURES: Cross-sectional occurrence of DD on MRI and self-reported LBP. RESULTS: Low back pain was reported by 33 (75%) skiers. Half of the skiers had at least 1 disk of ≥grade 3 in the Pfirrmann classification. At least 1 disk grade ≥3 in the Pfirrmann classification was found in 61% (20 of 33) of skiers with LBP and 18% (2 of 11) of skiers without LBP ( P = 0.034). CONCLUSIONS: The most important findings in our study were the high prevalence of self-reported LBP and a statistically significant difference in the occurrence of at least 1 degenerated disk in the Pfirrmann classification between skiers who reported LBP compared with those who did not.