Bicycle Set-Up Dimensions and Cycling Kinematics: A Consensus Statement Using Delphi Methodology.

Bicycle set-up dimensions and cycling kinematic data are important components of bicycle fitting and cyclist testing protocols. However, there are no guidelines on how bicycles should be measured and how kinematic data should be collected to increase the reliability of outcomes. This article proposes a consensus regarding bicycle set-up dimensions and recommendations for collecting cycling-related kinematic data. Four core members recruited panellists, prepared the document to review in each round for panellists, analysed the scores and comments of the expert panellists, reported the decisions and communicated with panellists. Fourteen experts with experience in research involving cycling kinematics and/or bicycle fitting agreed to participate as panellists. An initial list of 17 statements was proposed, rated using a five-point Likert scale and commented on by panellists in three rounds of anonymous surveys following a Delphi procedure. The consensus was agreed upon when more than 80% of the panellists scored the statement with values of 4 and 5 (moderately and strongly agree) with an interquartile range of less than or equal to 1. A consensus was achieved for eight statements addressing bicycle set-up dimensions (e.g. saddle height, saddle setback, etc.) and nine statements for cycling kinematic assessment (e.g. kinematic method, two-dimensional methodology, etc.). This consensus statement provides a list of recommendations about how bicycle set-up dimensions should be measured and the best practices for collecting cycling kinematic data. These recommendations should improve the transparency, reproducibility, standardisation and interpretation of bicycle measurements and cycling kinematic data for researchers, bicycle fitters and cycling related practitioners.

Cycling: joint kinematics and muscle activity during differing intensities.

Full body kinematics and electromyographic (EMG) patterns may alter based on the workloads that are encountered during cycling. Understanding the effect of differing intensities on the cyclist can guide clinicians and bike fitters in improving specific muscle strength and cycling posture to optimise training and racing. We aimed to assess changes in lower limb EMG magnitudes and full body 3D kinematics of 17 well-trained cyclists at three different exercise intensities: 60%, 80% and 90% of maximum heart rate. Significant results were demonstrated for all the joints except the hip and shoulder. Cyclists' ankle dorsiflexion and knee extension increased between 6% and 9% with higher intensities. The elbow adopted a significantly more flexed position, increasing flexion by 39% from 60% to 90% intensity, whilst the lumbar and thoracic flexion increased by 7% at the higher intensity. There were significant increases in EMG signal amplitude at higher intensities for all muscle groups measured. These results will guide clinicians in strengthening specific muscles at specific ranges of the cycling pedal revolution. Guidelines for optimal bicycle configuration should take into account the full body position of the cyclist as well as the training and racing intensity when assessing kinematics.

Muscle recruitment patterns and saddle pressure indexes with alterations in effective seat tube angle.

Alteration of the effective seat tube angle (ESTA) may affect muscle activation patterns of the lower limbs in cycling. There is conflicting evidence due to inadequate kinematic controls in previous studies. The primary aim of this study was to determine the muscle activity of seven lower limb muscles during alterations of the ESTA by altering the position of both the handlebars and saddle forwards or backwards by 3 â€‹cm while ensuring controlled kinematics. Secondly, to determine the effect on the saddle pressure indexes. Ten participants performed two 5 â€‹min electromyography (EMG) trials at 70% of peak power output (PPO) for three consecutive visits. There was a significant increase in muscle activity in the biceps femoris, gluteus maximus, and medial gastrocnemius with reductions in ESTA while a significant increase in tibialis anterior with increases in ESTA was observed. Saddle pressure indices demonstrated a significant change in frontal versus back pressure as well as mean pubic pressure with changes in ESTA. Alteration in the ESTA affects muscle activity in some, but not all of the lower limb muscles. Further research needs to be conducted to adequately understand the mechanism behind the differences in muscle activation.

A Dynamic Approach to Cycling Biomechanics.

Cycling biomechanics is a complex analysis of the cyclist and the bicycle. It is important to assess the cyclist dynamically because kinematics and muscle patterns are influenced by their type of riding and fatigue and intensity. Intrinsic factors such as anthropometrics and flexibility should guide the initial bicycle configuration. Static kinematics are a valid and reliable tool in the process of bike fitting, providing an initial fast and cost-effective method of assessing the cyclist. Dynamic assessment methods should then be used to fine tune the bicycle configuration according to the specific needs and workloads of the cyclist.

Anthropometrics, flexibility and training history as determinants for bicycle configuration.

Intrinsic factors such as leg length, arm length, flexibility and training history are factors that may be relevant to the optimisation of the individual bicycle configuration process. Bike fitting methods do not always take all these variables into account, and as yet there have been limited studies examining how these variables can affect the cyclist's position on the bicycle. The main aims of this study were to establish how individual anthropometrics, training history and flexibility may influence cyclists' freely chosen bicycle configuration, and to determine the full-body static flexion angles chosen by cyclists on the bicycle. Fifty well-trained male cyclists were recruited for the study. A multivariate linear regression analysis was performed to predict the four main configurations of a bicycle (saddle height, saddle setback, handlebar reach and handlebar drop) based on individual anthropometrics, flexibility and training history. Average joint kinematic ranges for the knee (36°±7°) and elbow (19°±8°) joint supported previous recommendations. Hip (77°±5°) and shoulder (112°±7°) joint angles should be determined as true clinical joints. Trochanteric leg length (p < 0.01), Knee Extension Angle test (p < 0.01) and mSchober test (p = 0.04) were significant predictors for determining saddle height. Hamstring flexibility can be used to predict handlebar drop (p = 0.01). A cyclist who wishes to adopt a more aerodynamic position with an increased handlebar drop should aim to improve their hamstring flexibility.

Performance variables associated with bicycle configuration and flexibility.

OBJECTIVES: Cycling races are often won by the smallest of margins. Research has focused on optimal saddle height for performance, however the relationship between freely chosen bicycle configuration and individual factors such as anthropometrics and flexibility have not yet been investigated adequately. The aim of this study was to determine if an association between power production, bicycle configuration and flexibility exists. DESIGN: Experimental, quantitative study. METHODS: Fifty male cyclists were recruited for the study. Individual anthropometrics, flexibility and individual bicycle configuration were recorded before the participants performed a peak power output and peak oxygen consumption test to determine their VO2max. RESULTS: There was a significant correlation between performance and hamstring flexibility, handlebar drop, saddle setback and ankle plantarflexion. An increased lumbar flexibility demonstrated an inverse relationship with relative VO2max. A more anteriorly rotated pelvis correlated with improved hamstring flexibility, hip flexion angle and an increased handlebar drop. SIGNIFICANCE: The results from this study have clinical implications for bike fitters and cyclists. Greater saddle setback and lower handlebar height may increase peak power output. Improving a cyclist's flexibility and ability to adopt an anteriorly rotated pelvis and lower handlebar height may increase the force generated in the push phase of the pedal stroke and thus improve cycling performance.

Cycling Biomechanics Optimization-the (R) Evolution of Bicycle Fitting.

Optimal bicycle configuration has been the topic of numerous studies. A majority of these have investigated the optimal saddle height and have used either static kinematics or two-dimensional kinematic measurements. Other joints, such as the hip, shoulder, and elbow joint, have not been investigated to any meaningful extent. There is, therefore, a paucity of data describing the optimal position of the upper body and pelvis in cycling. More recently, it has been recommended that bike fitting be conducted in a dynamic functional manner, as kinematics can be influenced by cycling workload. Full-body three-dimensional kinematics and saddle pressure are newer modalities available to the clinician. This review of the literature investigates the current research pertaining to the configuration of all components of the bicycle, from static methods to dynamic methods, and related to optimal performance and injury prevention. Setting the saddle height using the Holmes static method is optimal for injury prevention and performance. Guidelines for optimal bicycle configuration should take into account the training intensity when assessing kinematics as compensatory lower-limb kinematics occur during higher-power outputs. Optimal KFA using dynamic measurements should range from 33° to 43° at low intensity to 30° to 40° at high intensity when measured at the bottom dead center crank position. Saddle pressure mapping should ideally be performed at an intensity similar to what cyclists will encounter during the majority of their training and racing. Reference values and recommendations for dynamic assessments are still required for all other joints. Furthermore, intrinsic factors, such as training load and flexibility, which may affect bicycle configuration and performance, should be investigated to assess how these may influence the optimal bicycle configuration.

The effects of relative cycling intensity on saddle pressure indexes.

OBJECTIVES: To compare pressure load and distribution in various saddle zones through a range of workloads in order to provide clinicians and bike fitters with a better understanding of how to optimise saddle positioning. DESIGN: Experimental, quantitative study. METHODS: Saddle pressure of seventeen male well-trained cyclists was recorded at 60, 80 and 90% of maximal heart rate, based on data collected during a peak power output test. RESULTS: Loaded area increased significantly and progressively with increased workload while mean pressure did not change significantly. Point of load indexes in longitudinal and transverse planes both increased significantly and progressively with increases in workload. Distribution of load did not change with intensity. CONCLUSIONS: Saddle pressure mapping should ideally be performed at an intensity similar to that which the cyclist will encounter during the majority of their training and racing. Comparative measurements of saddle pressures should also standardise workload intensity to ensure reliability of these measurements.