Internal Risk Factors for Low Back Pain in Pole Vaulters and Decathletes: A Prospective Study

BACKGROUND: Pole vaulters and decathletes frequently experience several types of injuries to their lower back, often resulting in mechanical low back pain (LBP). However, the risk factors for the occurrence of LBP in these athletes have not been defined. PURPOSE: To determine the physical factors that relate to LBP occurrence for collegiate pole vaulters and decathletes. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: We observed 31 pole vaulters and decathletes for 1 year. At the start of the observation period, isokinetic flexion and extension muscle strength of the knee and hip joints were recorded along with active and passive range of motion (ROM) and muscle tightness. Participants were then divided into 2 groups using the median value of each measurement: those below the median (low group) and those above the median (high group). The log-rank test was used to compare LBP occurrence between the low group and high group for all measurements. Multivariate regression analyses were thereafter applied using the Cox proportional hazards regression. RESULTS: Log-rank tests revealed a statistically significant change in the survival curve for the occurrence of LBP in the participants with chronic LBP (P = .037), the low group for hip flexion peak torque per body weight on the non-takeoff leg (P = .047), and the low group for passive hip flexion angle on both legs (takeoff leg: P = .034; non-takeoff leg: P = .023). In addition, log-rank tests revealed a statistically significant change in the survival curve for the occurrence of LBP in the low group for passive hip extension angle on the takeoff leg only for the participants without chronic LBP (P = .014). CONCLUSION: It may be necessary to acquire sufficient ROM and hip flexion to prevent LBP occurrence in pole vaulters and decathletes.