Unlabelled: Cyclists frequently use a nonseated posture when accelerating, climbing steep hills, and sprinting; yet, the biomechanical difference between seated and nonseated cycling remains unclear.
Purpose: This study aimed to test the effects of posture (seated and nonseated) and cadence (70 and 120 rpm) on joint power contributions, effective mechanical advantage, and muscle activations within the leg during very-high-power output cycling.
Methods: Fifteen male participants rode on an instrumented ergometer at 50% of their individualized instantaneous maximal power (10.74 ± 1.99 W·kg; above the reported threshold for seated to nonseated transition) in different postures (seated and nonseated) and at different cadences (70 and 120 rpm) while leg muscle activity, full-body motion capture, and crank radial and tangential forces were recorded. A scaled, full-body model was used to solve inverse kinematics and inverse dynamics to determine joint displacements and net joint moments. Statistical comparisons were made using a two-way repeated-measures ANOVA (posture-cadence).
Results: There were significant main effects of posture and cadence on joint power contributions. A key finding was that the nonseated posture increased negative power at the knee, with an associated significant decrease of net power at the knee. The contribution of knee power decreased by 15% at both 70 and 120 rpm (~0.8 W·kg) when nonseated compared with seated. Subsequently, hip power and ankle power contributions were significantly higher when nonseated compared with seated at both cadences. In both postures, knee power was 9% lower at 120 rpm compared with 70 rpm (~0.4 W·kg).
Conclusion: These results evidenced that the contribution of knee joint power to leg power was reduced by switching from a seated to nonseated posture during very-high-power output cycling; however, the size of the reduction is cadence dependent.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1249/MSS.0000000000002285 | DOI Listing |
J Am Heart Assoc
September 2023
Sports Biomech
April 2023
Department of Health and Sport Sciences, University of Louisville, Louisville, KY, USA.
The aim of the study was to compare the Force-Velocity profiles of track sprint cyclists obtained in seated and non-seated positions. Athletes were tested on a stationary cycle ergometer for the seated position and on a racing bike at the velodrome for the non-seated position. We modelled torque and power vs.
View Article and Find Full Text PDFJ Biomech
September 2021
Centre for Sensorimotor Performance School of Human Movement and Nutrition Sciences, The University of Queensland, St Lucia, Queensland, Australia.
Unlabelled: Instantaneous crank power does not equal total joint power if a rider's centre of mass (CoM) gains and loses mechanical energy. Thus, estimating CoM motion and the associated energy changes can provide valuable information about the mechanics of cycling. To date, an accurate and precise method for tracking CoM motion during outdoor cycling has not been validated.
View Article and Find Full Text PDFJ Biomech
August 2021
Locomotion Laboratory, Department of Integrative Physiology, University of Colorado, Boulder, CO, USA.
Competitive cyclists typically sprint out of the saddle and alternately lean their bikes from side to side, away from the downstroke pedal. Yet, there is no direct evidence as to whether leaning the bicycle or conversely, attempting to minimize lean, affects maximal power output during sprint cycling. Here, we modified a cycling ergometer so that it can lean from side to side but can also be locked to prevent lean.
View Article and Find Full Text PDFMed Sci Sports Exerc
July 2020
School of Human Movement and Nutrition Sciences, Centre for Sensorimotor Performance, The University of Queensland, St Lucia, Queensland, AUSTRALIA.
Unlabelled: Cyclists frequently use a nonseated posture when accelerating, climbing steep hills, and sprinting; yet, the biomechanical difference between seated and nonseated cycling remains unclear.
Purpose: This study aimed to test the effects of posture (seated and nonseated) and cadence (70 and 120 rpm) on joint power contributions, effective mechanical advantage, and muscle activations within the leg during very-high-power output cycling.
Methods: Fifteen male participants rode on an instrumented ergometer at 50% of their individualized instantaneous maximal power (10.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!