Lumbar Lordosis and Transversus Abdominis Performance Among Sports, Cruiser, and Commuter Motorcycle Riders: A Cross-Sectional Study

Methods

This cross-sectional observational study included 75 male riders aged 20–28 years, with 25 participants in each motorcycle group. Lumbar lordosis was measured using the Flexicurve method, and transversus abdominis performance was assessed indirectly using a Pressure Biofeedback Unit (PBU). Between-group differences were examined using one-way analysis of variance and Bonferroni post hoc tests.

Regression analysis evaluated the combined contribution of motorcycle type and average riding time. Results: Lumbar lordosis differed significantly among groups (F = 29.881, p < 0.001, η² = 0.454), with the highest mean in sports riders (44.44 ± 8.61°), followed by commuter (38.56 ± 11.11°) and cruiser riders (25.75 ± 5.62°). Significant pairwise differences occurred between cruiser and sports riders and between cruiser and commuter riders.

PBU values also differed overall (F = 5.237, p = 0.008), with a significant pairwise difference only between cruiser and commuter riders. Motorcycle type and riding time explained 52.4% of the variance in lumbar lordosis, compared with 13.9% in PBU values; the latter model was not statistically significant. Conclusion: Motorcycle type and riding time were associated with lumbar alignment, while associations with PBU-measured muscle performance were less consistent.

These findings highlight the relevance of motorcycle ergonomics to rider spinal posture.