gms | German Medical Science

Objective: To compare the sagittal thoracic and lumbar spinal curvatures and pelvic inclination in highly trained cyclists when relaxed, standing on the floor, and when sitting on a bicycle.

Material/Methods: A total of 30 highly trained cyclists (mean age: 22.23±3.15 years) were evaluated. The Spinal Mouse system (Idiag, Switzerland), a hand-held, computer-assisted electromechanical-based device, was used to measure sagittal spinal curvatures and pelvic inclination in relaxed standing on the floor and seated on the bicycle in high, medium and low handlebar-hands positions. The measurements were made in a randomized order. For each position, the thoracic (T1-2 to T11-12) and lumbar (T12-L1 to the sacrum) spine and the pelvic inclination (difference between the sacral angle and the vertical) were recorded. In the lumbar curve, negative values corresponded to lumbar lordosis (posterior concavity). With respect to the pelvic inclination, a positive value reflected an anterior pelvic tilt. The classifications proposed by Mejia et al. [1] and Tüzün et al. [2] were used to classify the posture in categories for thoracic kyphosis and lumbar lordosis in standing.

Results: The mean thoracic and lumbar curvatures and pelvic tilt in the evaluated postures are shown in Figure 1 [Fig. 1]. The ANOVA analysis revealed significant differences for the main effects of thoracic and lumbar curvatures and pelvic tilt (p<0.001). Post hoc analysis with Bonferroni correction showed significant differences between standing posture and the three handlebar-hand positions for all dependent variables (p<0.0125). A high percentage of thoracic hyperkyphotic postures in the standing position was observed (60%) whereas predominately neutral values were found in the lumbar spine (93.3%).

Conclusion: The thoracic hyperkyphotic posture in standing in cyclists may be related to factors other than the posture adopted on the bicycle. Cyclists adopted a more neutral thoracic posture when sitting on the bicycle in all handlebar-hand positions. The lumbar flexed posture and high anterior pelvic tilt when sitting on the bicycle do not influence the sagittal configuration of the lumbar spine in standing.