Journal of Science and Medicine in Sport (2009) 12, 31—34

SHORT REPORT

Do differences in muscle recruitment betweennovice and elite cyclists reflect differentmovement patterns or less skilled musclerecruitment?

Andrew Chapmana,b,c,d,∗, Bill Vicenzinoa, Peter Blanchb, Paul Hodgesa

a Division of Physiotherapy, The University of Queensland, Brisbane, Australiab Department of Physical Therapies, Australian Institute of Sport, Canberra, Australiac School of Kinesiology, Simon Fraser University, Vancouver, Canadad Applied Research Centre, Australian Institute of Sport, Canberra, Australia

Received 27 April 2007; received in revised form 14 August 2007; accepted 18 August 2007

KEYWORDSCycling;Motor control;Motor learning;Adaptation;Electromyography;Three-dimensionalmovement analysis

Summary It has been shown that novice and elite cyclists use different patternsof leg muscle recruitment when cycling. These differences may reflect less skilledmuscle recruitment by novice cyclists or different, but not necessarily less skilled,movement patterns. We compared kinematics of the pelvis and lower limbs and legmuscle activity during cycling between novice and elite cyclists, to determine ifdifferences in leg muscle activity are associated with differences in movement pat-terns. Three-dimensional pelvic and lower limb kinematics and electromyographic(EMG) activity of leg muscles were measured during cycling at 55—60, 75—80,90—95 rpm and preferred cadence. Differences were found between novice and elitecyclists in the recruitment of leg muscles, which were consistent with previous find-ings. Joint-angle and velocity were not different between groups. Absolute range ofsagittal plane motion of the ankle was less in novice cyclists than in elite cyclists.Cadence did not influence kinematics. Coordination of sagittal plane motion of thehip and ankle, and knee and ankle, was stronger in elite cyclists. Furthermore,coordination of these movements was more consistent between pedal strokes inelite cyclists. Individual variance of kinematics was not different between groups.We conclude that differences in leg muscle recruitment between novice and elite

cyclists may be explained in part by small kinematic variations at the ankle, i.e. lessabsolute range of motion, but contend that differences in muscle recruitment areprimarily a reflection of more skilled muscle recruitment by elite cyclists.© 2007 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

∗ Corresponding author.E-mail address: andrew.chapman@ausport.gov.au (A. Chapman).

1440-2440/$ — see front matter © 2007 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.doi:10.1016/j.jsams.2007.08.012

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Introduction

Studies spanning nearly a century have focused onmotor learning and adaptations to movement con-trol that occur with practice [see 1]. However,these studies have examined changes in movementcontrol that occur over a small number of repeti-tions, e.g. 96—120 repetitions,2 and provide littleinsight into adaptations that may occur in ath-letes in response to years of continued training.We have shown that novice and elite cyclists usedifferent patterns of leg muscle recruitment whencycling.1 These differences may reflect continuedadaptation of the movement control system in elitecyclists—–continued adaptation of this nature hasnot previously been demonstrated. More specifi-cally, novice cyclists were characterized by greaterindividual variance of muscle recruitment (i.e.greater variability between pedal strokes for indi-vidual cyclists), greater population variance (i.e.greater variability between cyclists), more exten-sive and more variable muscle coactivation, greateramplitude of muscle activity in periods betweenprimary bursts, and greater duration and amplitudeof muscle activity at higher cadences. While thesedifferences may reflect less skilled muscle recruit-ment by novice cyclists, they may also reflectdifferent, but not necessarily less skilled, move-ment patterns. Here we compared pelvic and lowerlimb kinematics and leg muscle activity betweennovice and elite cyclists, to determine if differ-ences in cycling muscle activity are associated withdifferent movement patterns.

Method

Participants were 10 elite and 10 novice cyclists.Inclusion criteria have been described previously.1

Participants provided written informed consent.Procedures were approved by Institutional HumanResearch Ethics.

We replicated the experimental procedures ofour previous studies:1,3 three-dimensional pelvicand lower limb kinematics and intramuscular elec-tromyographic (EMG) activity of leg muscles weremeasured during four experimental conditions ofcycling at preferred cadence, 55—60, 75—80 and90—95 rpm.

We replicated data management and analysis1,3

procedures described in our previous studies. In

addition, correlations, and variability of correla-tions, between motion of the hip, knee and anklewere calculated for individual pedal strokes of eachcyclist.4

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A. Chapman et al.

As differences found between novice and eliteyclists in muscle recruitment were consistent withur previous findings, we have chosen to focusesults and illustrations on the comparison of kine-atics. We refer the reader to Ref. 1 for a detailedescription of EMG data.

esults

he comparison of leg muscle recruitment patternsf novice and elite cyclists revealed differencesn all parameters of muscle recruitment excepthose of the timing of peak EMG amplitude. Thereas variation in EMG-waveforms for each muscle

p < 0.05). These differences were primarily greatermplitudes and durations of activity, and more vari-bility in novice cyclists [see 1].

Normalised joint-angle and velocity of the pelvis,ip, knee and ankle were not different betweenovice and elite cyclists (Fig. 1a). The absoluteange of sagittal plane ankle motion was lessn novice cyclists (13.2 ± 7.7◦) than elite cyclists21.5 ± 9.0◦) (p < 0.03). Absolute ranges of motionf the pelvis, hip and knee were not differentetween groups. Cadence did not influence joint-ngle and velocity or absolute ranges of motion forither group.

Sagittal plane motion of the hip and anklei.e. hip flexion—extension and ankle dorsiflexion—lantarflexion, p < 0.02) and knee and ankle (i.e.nee flexion—extension and ankle dorsiflexion—lantarflexion, p < 0.01) was less coordinated inovice cyclists (r = 0.65 ± 0.09 and 0.53 ± 0.08,espectively; elite cyclists r = 0.85 ± 0.06 and.76 ± 0.08, respectively; Fig. 1b). The consistencyf coordination between these movements waslso less in novice cyclists (RMSE 9.2 ± 3.1% and1.6 ± 2.9%, respectively; elite cyclists 4.0 ± 2.4%nd 5.3 ± 2.7%, respectively; p < 0.03). Coordina-ion and variability of coordination of sagittal planeip and knee motion, and of frontal and transverselane motions, were not different between groups.

Individual variance was not different betweenroups at alpha-0.05 but there was a tendencyor greater individual variance in novice cyclistsFig. 1c). Population variance (illustrated by vari-tion about the mean in Fig. 1a) was not differentetween groups.

iscussion

revious studies provide evidence that practice ofmovement results in formation of an internal

Kinematics: novice versus elite cyclists 33

Figure 1 (a) Joint-angle waveforms (mean ± 95% CI) for sagittal plane motion of the pelvis, hip, knee and ankle inn otionfl are sp an ±

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ovice and elite cyclists. Absolute values for range of mexion—extension and ankle dorsiflexion—plantarflexionanel shows 10 pedal strokes. (c) Individual variance (me

epresentation for that movement, which drivesredictive movement control.2 As practice con-inues, accuracy of this internal representationncreases and stiffness decreases.2 This decrease intiffness is achieved with decreased amplitude anduration of muscle activity, greater modulation ofuscle activity and decreased muscle coactivation.he resulting movement is also less variable.5 Thesedaptations are consistent with differences in mus-le recruitment we have found between novice andlite cyclists.1

Differences in EMG-waveforms of leg muscle

ecruitment between novice and elite cyclistsay be explained in part by small differences in

nkle movement. However, less absolute range ofnkle motion in novice cyclists does not appear

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are shown in the y-axis. (b) Angle—angle plots for hiphown as an example of data of joint coordination. Each95% CI) of pelvic and lower limb movement.

n adequate explanation for the full extent ofifferences we found in leg muscle recruitment.e conclude that these differences in muscle

ecruitment are likely a reflection, at least inart, of less skilled muscle recruitment by noviceyclists. Furthermore, kinematic variations may benterpreted as further evidence of more skilledontrol of movement in elite cyclists. Greater inter-oint coordination, as well as greater consistencyf inter-joint coordination in elite cyclists whenompared to novice cyclists, may reflect greaterdaptation of the neuromuscular system and pro-

ression toward a more skilled movement pattern.his is consistent with consideration of movementariability as a manifestation of inherent noisen the neuromuscular system, which is greater in

34

novel movement tasks.5 One suggestion is thatvariability may reflect exploration of the move-ment task, which occurs to optimize future per-formance.6

There are a number of methodological consid-erations relating to the standardization of cyclingintensity, kinematic modelling and bicycle geome-try, which we have discussed previously.1,3

References

1. Chapman AR, Vicenzino B, Blanch P, Hodges PW. Patternsof leg muscle recruitment vary between trained and novicecyclists. J Electromyogr Kinesiol 2008;18:359—71.

Available online at www.

A. Chapman et al.

2. Osu R, Franklin DW, Kato H, Gomi H, Domen K, Yoshioka T, etal. Short- and long-term changes in joint co-contraction asso-ciated with motor learning as revealed from surface EMG. JNeurophysiol 2002;88:991—1004.

3. Chapman AR, Vicenzino B, Knox JJ, Dowlan S, Blanch P,Hodges PW. The influence of body position on leg kinemat-ics and muscle recruitment during cycling. J Sci Med Sport2008;11:519—26.

4. Schache AG, Blanch P, Rath D, Wrigley T, Bennell K. Three-dimensional angular kinematics of the lumbar spine andpelvis during running. Hum Move Sci 2002;21:273—93.

5. Broderick MP, Newell KM. Coordination patterns in ball

bouncing as a function of skill. J Mot Behav 1999;31:165—88.

6. Takahashi CD, Nemet D, Rose-Gottron CM, Larson JK, CooperDM, Reinkensmeyer DJ. Neuromotor noise limits motorperformance, but not motor adaptation, in children. J Neu-rophysiol 2003;90:703—11.

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