Fatigue effects on the coordinative pattern during cycling: Kinetics and kinematics evaluation

https://doi.org/10.1016/j.jelekin.2008.10.003Get rights and content

Abstract

The aim of the present study was to analyze the net joint moment distribution, joint forces and kinematics during cycling to exhaustion. Right pedal forces and lower limb kinematics of ten cyclists were measured throughout a fatigue cycling test at 100% of POMAX. The absolute net joint moments, resultant force and kinematics were calculated for the hip, knee and ankle joint through inverse dynamics. The contribution of each joint to the total net joint moments was computed. Decreased pedaling cadence was observed followed by a decreased ankle moment contribution to the total joint moments in the end of the test. The total absolute joint moment, and the hip and knee moments has also increased with fatigue. Resultant force was increased, while kinematics has changed in the end of the test for hip, knee and ankle joints. Reduced ankle contribution to the total absolute joint moment combined with higher ankle force and changes in kinematics has indicated a different mechanical function for this joint. Kinetics and kinematics changes observed at hip and knee joint was expected due to their function as power sources. Kinematics changes would be explained as an attempt to overcome decreased contractile properties of muscles during fatigue.

Introduction

Fatigue has received attention in sports sciences mainly because of its effects on athletes’ performance (Faria et al, 2005). Abiss and Laursen (2005) have presented several models to explain the fatigue process, including biomechanical and neuromuscular model. In the biomechanical model, they have explained the fatigue process by means of economy/efficiency of movement, while in the neuromuscular model, fatigue occurs due to a failure on central control of movement or neuromuscular propagation. Both impairments reduce the force production and could affect movement control (Lepers et al., 2000). However, these models are insufficient to completely explain the occurrence of muscle fatigue or to indicate its effects on cycling performance and movement control.

Coordinative pattern, by means of muscle activity, has been analyzed during cycling to fatigue (Hautier et al., 2000, Lepers et al., 2000, Lepers et al., 2002, Duc et al., 2005, Dingwell and Diefenthaeler, In press), competition simulation (Bini et al., 2008), pedaling cadence (Suzuki et al., 1982, Baum and Li, 2003), and workload management (Baum and Li, 2003, Laplaud et al., 2006). Another possible analysis of the coordinative pattern relies on the measurement of net joint moments, which have been computed as an indicative of muscle stress (Kautz and Hull, 1996, Marsh et al., 2000), and have been described to be affected by fatigue process (Sanderson and Black, 2003). It was observed a change at the ankle, knee and hip moments in the final minute of cycling to exhaustion (Sanderson and Black, 2003).

Several studies have analyzed the effects of different mechanical set-ups on the net joint moments, as pedaling cadence (Neptune and Hull, 1999, Marsh et al., 2000), saddle height (Ericson et al., 1986b, Horscroft et al., 2003), workload (Ericson et al., 1986b, Caldwell et al., 1999). Ericson et al., 1986a, Ericson et al., 1988 have analyzed the relative joint contribution to the global lower limb activity during cycling task, as an indicative of coordinative pattern. However, only Sanderson and Black (2003) have described the influence of fatigue process on joint moments. Mornieux et al. (2007) have re-analyzed data from Sanderson and Black (2003) and indicated that the contribution of each joint to the total joint moments (i.e. coordinative pattern) have not changed during fatigue process.

Amoroso et al. (1993) observed kinetics and kinematics adaptations as mechanical responses to fatigue process, however they have not analyzed joint moments distribution neither joint forces nor kinematics. Amoroso et al. (1993) have proposed that the analysis of joint moments would be an important approach to understand the reasons for the external forces and kinematics changes throughout fatigue process. Additionally, Mornieux et al. (2007) indicated that ankle joint is tuned to transfer the force produced by the hip and knee joints to the crank. However, it is not well understood how does joint forces and kinematics are tuned for the control of the joint moment’s distribution during fatigue process.

Herewith, the main purpose of the present study was to analyze the net joint moment distribution in attempt to understand the coordinative pattern during cycling to exhaustion. As indicated by Mornieux et al. (2007)), the fatigue process is not supposed to change joint moment distribution, which is defined as the hypothesis of the present study. Herewith, our secondary purpose was to analyze joint forces and kinematics which would change in the attempt to maximize joint stiffness and optimize force transmission to the crank.

Section snippets

Subjects

Ten well trained male cyclists (USCF Category 3 or higher level of competition) volunteered to participate in this study. All subjects had competitive experience. All participants signed an Informed Consent Term in agreement with the Committee of Ethics in Research with Humans of the University of Texas at Austin in accordance with the Declaration of Helsinki. The cyclists were asked to avoid high-intensity or exhaustive exercise at least 24 h before the laboratory trials. The mean and standard

Results

Cyclists’ performance at fatigue test was measured by the total time of fatigue cycling test (TT), which was 405 ± 90 s. Pedaling cadence was compared in attempt to verify if it was influenced by fatigue process, and it is depicted in Fig. 2.

It was observed a significant reduction in pedaling cadence at 90% of TT in relation to 10 (p = 0.01), 40 (p < 0.01), and 70% of TT (p < 0.01) for F1.118, 10.062 = 19.315, p < 0.01.

Representative data of the net joint moments from a subject are presented in Fig. 3.

The

Discussion

The main purpose of the present study was to analyze the net joint moment distribution in attempt to understand the coordinative pattern during cycling to exhaustion. The main result of the present study was that only ankle joint have a reduced contributed to the total joint moments during fatigue test. It was different from our hypothesis, which suggested the maintenance on joint moment distribution during fatigue, as previously reported by Mornieux et al. (2007). At this regard, our secondary

Acknowledgements

Special thanks to Dr. Ton van den Bogert for extensively discussion surrounding inverse dynamics of cycling. The data collection was conducted in the Nonlinear Biomechanics of the University of Texas at Austin. Herewith, the authors would like to thank Dr. Richard Neptune for lending pedal dynamometers and Dr. Jonathan Dingwell for technical support concerning kinematics evaluations. During the time of this study Rodrigo Bini was supported by CNPQ – Brazil Master’s scholarship, and Fernando

Rodrigo Rico Bini is a member of the Biomechanics and Kinesiology Research Group of the UFRGS – Brazil. He received his master degree in Human Movement Sciences at the UFRGS – Brazil in 2008. His research focuses on cycling biomechanics and internal force during human movement.

References (39)

  • W. Smak et al.

    The influence of pedaling rate on bilateral asymmetry in cycling

    J Biomech

    (1999)
  • S. Suzuki et al.

    EMG activity and kinematics of human cycling movements at different constant velocities

    Brain Res.

    (1982)
  • F.E. Zajac

    Understanding muscle coordination of the human leg with dynamical simulations

    J Biomech

    (2002)
  • C.R. Abiss et al.

    Models to explain fatigue during prolonged endurance cycling

    Sport Med

    (2005)
  • C.R. Abiss et al.

    Dynamic pacing strategies during the cycle phase of an Ironman triathlon

    Med Sci Sport Exerc

    (2006)
  • Amoroso A, Sanderson DJ, Hennig EM. Kinematic and kinetic changes in cycling resulting from fatigue. In: Proceedings of...
  • Black AH, Sanderson DJ, Hennig EM. Kinematic and kinetic changes during an incremental exercise test on a bicycle...
  • G.E. Caldwell et al.

    Lower extremity joint moment during uphill cycling

    J Appl Biomech

    (1999)
  • Dingwell JB, Joubert JE, Diefenthaeler F, Trinity JD. Changes in muscle activity and kinematics of highly trained...
  • Cited by (0)

    Rodrigo Rico Bini is a member of the Biomechanics and Kinesiology Research Group of the UFRGS – Brazil. He received his master degree in Human Movement Sciences at the UFRGS – Brazil in 2008. His research focuses on cycling biomechanics and internal force during human movement.

    Fernando Diefenthaeler is a Ph.D student in Human Movement Sciences at UFRGS – Brazil. He received his master degree in Human Movement Sciences at UFRGS-Brazil in 2004. His research focuses on cycling biomechanics and fatigue during human movement.

    Carlos Bolli Mota is a professor of Biomechanics in the UFSM – Brazil. He is also the dean of Biomechanics Laboratory of UFSM – Brazil. He received his Ph.D in Human Movement Sciences at UFSM – Brazil in 1999. He earned his master and bachelor degree in Mechanical Engineering in 1991 and 1981, respectively. His research interests concerns on kinematics of human movement and sport biomechanics.

    View full text