Affiliations: Faculty of Education Sciences, Nursing and Physiotherapy. Laboratory of Kinesiology, Biomechanics and Ergonomics (KIBIOMER Lab.), University of Almería, Spain
Correspondence:
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Corresponding author: José M. Muyor, University of Almería; Edificio Humanidades A. Despacho, 2.54; Ctra. Sacramento s/n. 04120; La Cañada de San Urbano, Almería, Spain. Tel.: +34 950 015 239; E-mail: josemuyor@ual.es
Abstract: BACKGROUND AND OBJECTIVE:Systematic repetition or prolonged posture in specific postures adopted during training could generate modifications on the sagittal spinal curvatures. Spinal alteration in its physiologic curvatures in the sagittal plane has been associated with predisposition to spinal disorders. The objective was to evaluate and compare the changes produced on the sagittal thoracic and lumbar spinal curvatures, and pelvic tilt from standing posture on the floor to upper, middle, lower and aerodynamic handlebars postures adopted on their own road bicycles. MATERIAL AND METHOD:A total of twenty-eight male professional cyclists (179.92 ± 5.78 cm; 67.18 ± 5.74 kg) participated in the study. Cyclists had an experience of 17.22 ± 6.16 years in cycling, and spent 6.52 ± 0.51 days per week and 3.78 ± 0.61 hours per day training on their bicycles. Sagittal spinal curvatures (thoracic and lumbar) and pelvic tilt were measured in the standing position on the floor and while sitting on a bicycle with different handlebar-hand positions (high, middle, low and aerodynamic) using a Spinal Mouse system. RESULTS:The thoracic spine showed significantly greater angular values while in a standing posture than on the bicycle in all handlebar-hands postures evaluated. The lumbar curvature changed from lordosis (negative values – anterior convexity) in standing posture to kyphosis (positive values – posterior convexity) in all handlebar-hands positions on the bicycle. The aerodynamic handlebar positions showed the greatest lumbar flexion (lumbar kyphosis) and anterior pelvic tilt. CONCLUSIONS:Professional cyclists passively maintain their thoracic spine straighter on the bicycle due to handlebar-hands support than in standing posture. However, the lumbar spine is flexed on the bicycle in all handlebar-hands evaluated. The pelvis is modified to greater anterior pelvic tilt when the handlebar-hands position is farther and lower regarding the saddle of the bicycle.
