Neuromechanics of Cycling: Opportunities for Optimizing Performance (original) (raw)
Related papers
Sport Science Review, 2010
The aim of this review paper is to outline the effects of several biomechanical factors on cycling efficiency and safety. The paper begins with a short introduction and listing of basic concepts important for understanding the biomechanics of cycling, followed by an explanation of mechanical forces and torques that are created during pedalling. Workloads and joint movement are detailed in chapter three, which is augmented by chapter four on muscle activation patterns. Throughout the text we have paid careful attention in interpreting the results of research studies into changes in bicycle geometry, feet position, terrain incline and other cyclingrelated factors. The paper closes with an overview of all issues and solutions as well as presenting proposals for additional research.
Effects of ‘posture length’ on joint power in cycling
Procedia Engineering, 2012
Problems of posture in cycling are closely related to a badly adjusted saddle. Many of these problems can be prevented if the bicycle is correctly adjusted. In the search for an optimum posture of the cyclist, a balance should be found to both prevent injuries and enhance performance. If the influence of bicycle 'posture height' on generation of muscular power is largely investigated, little attention is carried out about the effects of 'posture length' on the cyclist neuromuscular strategy. The purpose of the present study is to compare joint powers for different configurations of the cyclist 'posture length'. Fourteen competitive cyclists and triathletes (28.2 ± 7.5 years) perform 3-min trials on a stationary cycloergometer at four different 'posture lengths' (preferred, backward, intermediate, forward) each separated by one minute of rest. The cyclists exercise an external power of 3.8 ± 0.1 W.kg -1 and pedaling cadence is controlled at 90 ± 5 rpm for all trials. Three-dimensional external forces and moments were measured at each pedal using six components force sensors. Using pedal forces and lower limb three-dimensional kinematics, joint powers are calculated at the ankle, knee and hip joints using an inverse dynamics procedure and normalized to the subject body mass. The results of pedal and joint powers output show that preferred and forward posture lead to develop larger knee power than backward posture. The latter requires to develop supplementary joint power at the hips that compensate joint power deficiency at the knees.
British Journal of Sports Medicine, 2007
Objective: To assess which of the equations used to estimate mechanical power output for a wide aerobic range of exercise intensities gives the closest value to that measured with the SRM training system. Methods: Thirty four triathletes and endurance cyclists of both sexes (mean (SD) age 24 (5) years, height 176.3 (6.6) cm, weight 69.4 (7.6) kg and VO 2 MAX 61.5 (5.9) ml/kg/min) performed three incremental tests, one in the laboratory and two in the velodrome. The mean mechanical power output measured with the SRM training system in the velodrome tests corresponding to each stage of the tests was compared with the values theoretically estimated using the nine most referenced equations in literature (Whitt (Ergonomics 1971;14:419-24); Di Prampero et al (J Appl Physiol 1979;47:201-6); Whitt and Wilson (Bicycling science.
Comparison of nine theoretical models for estimating the mechanical power output in cycling
British Journal of Sports Medicine, 2007
Objective: To assess which of the equations used to estimate mechanical power output for a wide aerobic range of exercise intensities gives the closest value to that measured with the SRM training system. Methods: Thirty four triathletes and endurance cyclists of both sexes (mean (SD) age 24 (5) years, height 176.3 (6.6) cm, weight 69.4 (7.6) kg and VO 2 MAX 61.5 (5.9) ml/kg/min) performed three incremental tests, one in the laboratory and two in the velodrome. The mean mechanical power output measured with the SRM training system in the velodrome tests corresponding to each stage of the tests was compared with the values theoretically estimated using the nine most referenced equations in literature (Whitt (Ergonomics 1971;14:419-24); Di Prampero et al (J Appl Physiol 1979;47:201-6); Whitt and Wilson (Bicycling science.
Relationship between physiological and biomechanical variables with aerobic power output in Cycling
Performance in cycling may be determined by physiological and biomechanical parameters. The aim of this study was to assess the relationship between biomechanical and physiological variables with aerobic power output in cycling. Twelve cyclists and twelve non-athletes performed an incremental cycling test to exhaustion during their first evaluation session and a constant load cycling test in a second evaluation session. Aerobic power output and oxygen uptake were measured during the first evaluation session, while muscle volume (determined using ultrasound measures in static conditions) and pedal forces were measured at the second session. Pedal forces were used to compute total force applied to the pedal and force effectiveness. Two multivariate stepwise regression analyses were conducted to measure the relationship between power output and oxygen uptake obtained at the second ventilatory threshold (VT2), muscle volume, total force applied to the pedal, force effectiveness and lower limb muscle activation for cyclists and non-athletes. Only oxygen uptake at the VT2 was significantly related to power output for non-athletes ( ) (r = 0.64, p = 0.03), whereas the resultant force was included in the regression model for cyclists (r = 0.66, p = 0.02). Muscle volume, pedal force effectiveness and muscle activation seem to have a minor effect in aerobic power output during cycling.
Pedal force effectiveness in Cycling: a review of constraints and training effects
Pedal force effectiveness in cycling is usually measured by the ratio of force perpendicular to the crank (effective force) and total force applied to the pedal (resultant force). Most studies measuring pedal forces have been restricted to one leg but a few studies have reported bilateral asymmetry in pedal forces. Pedal force effectiveness is increased at higher power output and reduced at higher pedaling cadences. Changes in saddle position resulted in unclear effects in pedal force effectiveness, while lowering the upper body reduced pedal force effectiveness. Cycling experience and fatigue had unclear effects on pedal force effectiveness. Augmented feedback of pedal forces can improve pedal force effectiveness within a training session and after multiple sessions for cyclists and non-cyclists. No differences in pedal force effectiveness were evident between summarized and instantaneous feedback. Conversely, economy/efficiency seems to be reduced when cyclists are instructed to improve pedal force effectiveness during acute intervention studies involving one session. Decoupled crank systems effectively improved pedal force effectiveness with conflicting effects on economy/efficiency and performance.
A study on the biomechanical efficiency of different cycling positions
2009
This study was designed to determine how modifications in cycle geometry and lower-limb kinematics determine changes in oxygen uptake and lactate accumulation during submaximal cycle ergometry. First a series of tests with ten athletes was carried out with different seat-tube angles (STA test) determining different frame geometries. The tests performed with a rigid protocol show an interesting relationship between the trend of the coefficient of variation of O2 consumption (respiratory dynamics) and the forces measured on saddle and handlebar. The stabilization of the respiratory dynamics registered for a particular position could be considered as a first step of O2 consumption physiologic adaptation. For this reason a long term adaptation test (LTA test), in which the subject trained for 8 weeks with a determined STA, was executed to find out how long time spent using a specific frame geometry results in a minimization of the energetic cost of pedalling at a constant power output. ...