Running Asymmetries during a 5-Km Time Trial and their Changes

over Time

Rahel Ammann

1,2

and Thomas Wyss

Swiss Federal Institute of Sport Magglingen SFISM, Magglingen, Switzerland

Department of Medicine, Movement and Sport Science, University of Fribourg, Fribourg, Switzerland

Keywords: Inertial Measurement Unit, Injury Risk Factor, Temporal Progress of Fatigue, Elite Runners, Field Condition.

Abstract: Gait Asymmetry during Running Was Proven to Be Inefficient, Uneconomical and a Possible Risk Factor for

injury. Research has either been conducted in laboratory settings or only discontinuous data were collected.

Hence, the present study evaluated gait asymmetries in elite runners by quantifying the differences between

ground contact times (GCT) of the right and left foot and their continuous changes over the course of a 5-km

time trial. Data of 25 female and male runners of the Swiss orienteering national team were obtained during

a 5-km competition on a 400-m outdoor track. By means of the inertial sensor PARTwear, GCT of every step

were assessed, divided into GCT of the left and right foot and averaged over 200-m sections. The results

revealed an overall asymmetry of 2.6%, significant (p < 0.01) longer GCT during left than right foot contacts

and no changes in asymmetry over the course. This is the first study presenting data on asymmetries in elite

athletes during a competitive time trial. In conclusion, low and consistent GCT asymmetries were observed.

The examined athletes had a balanced running style and showed no adverse asymmetry with emerging fatigue,

which in turn could affect acute performance and increase injury risk.

1 INTRODUCTION

There is an impressive number of studies conducted

on mechanics in running. Parameters of interest are

among others step length, step frequency, breaking

time, aerial time and ground contact time (Girard et

al., 2013; Murphy et al., 2003; Nummela et al., 2013).

Knowledge on these parameters is relevant for

athletes, coaches and researchers. The athlete and the

coach need objective information to improve running

technique and performance, whereas researchers need

those running parameters to gain new knowledge

about key performance indicators and injury risk

factors. One possible risk factor identified in the

literature is lower limb asymmetry, which has been

proven to impact the incidence of injuries and

possibly affect athletic performance (Croisier et al.,

2002). It is obvious that a certain asymmetry is

normal, as the running style is optimized over the

years of training. Yet, the threshold at which a deficit

becomes problematic is still to be defined. In terms of

limb asymmetry, a threshold of 15% has been stated

for return to sport after rehabilitation programs (Myer

et al., 2006). However, it is unclear how threshold

values were derived and findings from cross-sectional

studies have been inconclusive. Moreover, there is a

lack of evidence when data were obtained at maximal

speeds during middle- to long- distance runs. This

may be important, as with increasing intensity step

variability was shown to increase (Belli et al., 1995).

Additionally, no previous research investigated the

changes over time concerning running asymmetry.

Such information might provide an insight into the

onset and progression of the athlete’s fatigue and

potential adaptations in running style. Asymmetry

might not be evident during the start phase of a race,

but may arise with the development of muscular

fatigue.

It is difficult to determine most relevant

parameters to assess asymmetry. Running depends on

a variety of parameters but at the end it comes all

down to ground contact time (GCT), as it is the only

moment during running to generate propulsive force,

hence, to move on. The ability to produce and

transmit high amounts of muscular force to the

ground over a short period of time is a major

determinant of performance in running (Weyand et

al., 2000). It was reported that shorter GCT is faster

and more energy efficient than longer GCT

(Nummela et al., 2007). The less economical runners

Ammann, R. and Wyss, T..

Running Asymmetries during a 5-Km Time Trial and their Changes over Time.

In Proceedings of the 3rd International Congress on Sport Sciences Research and Technology Support (icSPORTS 2015), pages 161-164

ISBN: 978-989-758-159-5

161

have lower vertical leg stiffness, which leads to

enhanced braking time, and therefore, longer GCT.

Hence, measuring GCT may be of potential benefit to

investigate the presence of asymmetry and other

alterations as they occur during running. Previous

research showed 3.5% running asymmetries

regarding GCT in Australian Rules football players

while running on treadmill at their individual 80%

VO2max (Brughelli et al., 2010). Similar, Kong and

de Heer (2008) reported an average 3.6% asymmetry

between GCT of both feet in male Kenyan distance

runners. Six gait cycles each, obtained on treadmill at

five submaximal speeds, were analyzed in that study.

So far, the focus in the literature on mechanics in

running lies on constant velocity runs, mainly on

treadmill, or sprint protocols in the laboratory

(Brughelli et al., 2010; Kong and de Heer, 2008; Lee

et al., 2010; Rumpf et al., 2014). However,

technology applied is somewhat limited and restricted

to a specific place, which in turn might affect running

patterns. To seriously work on a specific parameter

and to investigate its variability over different phases

of a distance, the measurement system should be

applicable in field conditions and during entire trials.

By means of portable, light-weighted, and valid

inertial sensors the analysis of stride parameters, such

as GCT, is possible in the field over a whole time trial,

anywhere and anytime. So far, no studies have

evaluated the occurrence and change of asymmetries

in GCT during maximal running performance under

field conditions. Therefore, the aim of the present

study was to examine the asymmetries between GCT

of the right and left foot in elite runners and their

continuous changes over the course of a 5-km time

trial on an outdoor synthetic track.

2 METHODS

2.1 Subjects

A total of 10 female and 15 male (24.5 ±3.4 years,

174.8 ±9.0 cm, 63.0 ±8.1 kg) orienteers, competing at

international level, were recruited to participate in the

study. The local ethics committee approved the study

and all participants provided written informed

consent before testing. A medical questionnaire was

administered to exclude athletes with any known

lower limb injury in the past 6 months.

2.2 Procedure

The measurements took place during a competitive 5-

km running time trial of the Swiss orienteering

national team. The time trial was one part of selection

criterion for the participation in the upcoming world

championships. After an individual warm-up session

the runs were carried out on a 400-m outdoor

synthetic track. The male and female runners started

as a group, respectively, whereby the gender groups

were again split in half to avoid too many runners on

track at the same time. The athletes were free to

choose their own pace in order to realize the shortest

time possible over the 5-km. Additionally to their

own sport watch, split times were provided every

200-m including verbal encouragement. The time

trials were performed in sunny weather with no wind

and air temperature constant at 24 °C.

2.3 Data Collection

Before the start of the testing, each subject received

two PARTwear sensors (HuCE-microLab, University

of Applied Sciences, Biel, Switzerland). The sensors’

validity and reliability in terms of GCT was recently

demonstrated (Ammann et al., under revision). Two

sensors were attached, by means of customized

elastics, to the shoe laces of the left and right foot.

The PARTwear sensor (size: 3.8 x 3.7 x 0.8 cm;

weight: 13 g) consists of a 9-axis MotionTracking

device MPU-9150 (InvenSense, Inc., San Jose, CA,

USA) that combines a 3-axial accelerometer, a 3-axis

gyroscope, and a 3-axis magnetometer.

Accelerometer data was recorded with a full-scale

range of ±16 g and a sampling rate of 1,000 Hz.

Sensor operation and data transmission was

established via Bluetooth and data processing took

place by the proprietary software. In order to assess

split times per 200-m for every athlete, two video

cameras (Handycam HDR-CX700VE, Sony

Corporation, Tokio, Japan) were placed on the track,

one on the 200-m line and one on the finishing line.

2.4 Statistical Analysis

Running velocity and GCT were averaged for each of

the 25 segments of 200-m. Relative asymmetry in

GCT between both feet was computed as in equation



((right GCT– left GCT) / leftGCT ∗ 100)



= % (1)

Statistical analyses were performed by using SPSS

Statistics 22 and the level of significance was set at p

≤ 0.05. Data were expressed as overall means ±SD

and illustrated by means of boxplots. Asymmetry

between GCT of the left and right foot was calculated

by a paired samples t-test. The effect of running

distance on asymmetry was evaluated by a repeated

icSPORTS 2015 - International Congress on Sport Sciences Research and Technology Support

162

measures ANOVA.

3 RESULTS

Mean 5-km performance time for both gender was 17

min 06 s ±1 min 39 s (ranging from 14 min 43 s to 20

min 21 s), resulting in an average speed of 4.92 ±0.48

m·s

-1

(Table 1). Men were running significantly (p <

0.01) faster than women and had shorter GCT.

Overall, the GCT of the left foot was significantly (p

< 0.01) longer compared to the GCT of the right foot

(194.4 vs 193.0 ms). The observed asymmetries

between GCT of the left and right foot were 2.57

±2.14% without gender differences. The applied

repeated measures ANOVA with a Greenhouse-

Geisser correction revealed no significant changes

over the 25 segments of 200-m (F

4.2, 100.7

= 1.645, p =

.166). Figure 1 illustrates the changes in asymmetries

over time.

4 DISCUSSION

The present study sought to examine gait

asymmetries during running and their changes over a

5-km time trial. Asymmetry was quantified by the

difference between the GCT of the left and right foot.

Overall, asymmetry in all elite orienteers was 2.6%.

This was noticeable lesser when compared to

Brughelli et al. (2010) and Kong and de Heer (2008)

who reported 3.5% and 3.6% asymmetry in GCT,

respectively. However, it is difficult to make direct

comparisons between studies as the applied

methodologies differed. The cited studies obtained

data of male subjects on treadmill at submaximal

speeds. Moreover, subjects were Australian Rules

football players demonstrating a different running

style compared to athletic running specialists

(Brughelli et al., 2010). Or else, data were measured

during six step cycles only, which was reported to be

very little, and therefore, less conclusive (Belli et al.,

1995; Kong and de Heer, 2008). The current 5-km

time trial was executed under field conditions that

automatically lead to greater variability in pacing.

This in turn could impact asymmetry even more.

However, it appeared that the present female and

male elite athletes had smaller asymmetries although

running at maximal velocity over approximately 17

min.

Interestingly, the athletes in the present study kept

gait asymmetries constant over the entire course of 5-

km because no 200-m segment could be detected as

Table 1: Subjects’ performance presented as means ±SD.

Overall Women Men

5-km time

[min:ss]

17:06

±01:39

18:54

±00:56

15:55

±00:35

Speed

[m·s

-1

]

4.92

±0.48

4.42

±0.26

5.24

±0.26

GCT

[ms]

193.7

±14.3

199.3

±13.9

190.0

±13.3

Asymmetry

[%]

2.57

±2.14

2.47

±1.79

2.65

±2.34

< 0.01 between gender.

being particularly different to the others (Figure 1).

Related literature is lacking, and therefore, in

previous research on sprint running it was

recommended to obtain data of longer distances than

30-m because asymmetries might differ during

different phases or at steady state running (Rumpf et

al., 2014). However, in the current study this

assumption could not be confirmed as no progression

in asymmetries over time was observed. Hence, our

elite athletes were able to consistently deal with the

emerging fatigue and they did not show potential

physical limitations in an uneconomical imbalanced

behavior, which in turn could have increased injury

risk.

Throughout the run, the GCT were significantly

longer during the left than the right foot contacts. One

could assume that the left leg is on the inside lane of

the 400-m synthetic track and that running the curve

would have an impact on GCT asymmetry. This

observation was in line with the study of Kong and de

Heer (2008) who also reported longer GCT with the

left foot. However, as their study was conducted on

treadmill the impact of the curve and inside line of the

track is questionable.

Noteworthy, individual asymmetry is masked

when data is averaged for a whole sample, like in the

present study. Therefore, in high performance

settings data should remain individualized when

assessing athlete’s strengths and weaknesses for

diagnostic and prognostic purposes. Furthermore,

obtaining long-term measurements could be useful, as

classifying one’s deficits after an injury is difficult

when individual baseline data are lacking. Having

long-term data at hand would be useful for athletes,

coaches, and medical staff to e.g., monitor return to

sport after a rehabilitation program. Also, the present

results might be important to bear in mind for young

talents that they should aim for symmetric running

patterns throughout time trials. Recently, due to

maturation substantial greater asymmetries in youths

regarding horizontal and vertical forces were reported

(Rumpf et al., 2014). Hence, it may be meaningful to

youth coaches to compare young talents to elite

Running Asymmetries during a 5-Km Time Trial and their Changes over Time

163

Figure 1: Relative differences in ground contact times between both feet at each 200-m segment during the 5-km time trial.

No significant asymmetry changes over time.

athletes in same settings.

The PARTwear sensor seems to be a device with

high practical application to regularly monitor and

evaluate gait asymmetries in running during entire

training sessions and competitions. The sensor is

light-weighted and does not hamper the athlete when

running. Additionally, data can be evaluated in real

time even for a group of athletes.

5 CONCLUSIONS

The present study showed very low and consistent

GCT asymmetries in elite orienteers over a 5-km

running time trail. The athletess appeared to have the

ability to compensate emerging fatigue in an efficient,

at least not adverse, manner, as no alteration in

asymmetry occurred over time. By means of the used

technology subsequent data will be obtained to

further investigate gait asymmetries in e.g., young

talents, different distances and speeds or inside versus

outside lane of the track.

REFERENCES

Ammann, R., Taube, W., & Wyss, T. (under revision)

Accuracy of PARTwear inertial sensor and Optojump

optical measurement system for measuring ground

contact time during running. J Strength Cond Res.

Belli, A., Lacour, J.R., Komi, P.V., Candau, R., & Denis,

C. (1995) Mechanical step variability during treadmill

running. Eur J Appl Physiol 70: 510-517.

Brughelli, M., Cronin, J., Mendiguchia, J., Kinsella, D., &

Nosaka, K. (2010) Contralateral leg deficits in kinetic

and kinematic variables during running in Australian

Rules football players with previous hamstring injuries.

J Strength Cond Res 24: 2539-2544.

Croisier, J.L., Forthomme, B., Namurois, M.H.,

Vanderthommen, M., & Crielaard, J.M. (2002)

Hamstring muscle strain recurrence and strength

performance disorders. Am J Sports Med 30: 199-203.

Girard, O., Millet, G.P., Slawinski, J., Racinais, S., &

Micallef, J.P. (2013) Changes in running mechanics

and spring-mass behaviour during a 5-km time trial. Int

J Sports Med 34: 832-840.

Kong, P.W., & de Heer, H. (2008) Antropometric, gait and

strength characteristics of Kenyan distance runners. J

Sports Sci Med 7: 499-504.

Lee, J.B., Sutter, K.J., Askew, C.D., & Burkett, B.J. (2010)

Identifying symmetry in running gait using a single

inertial sensor. J Sci Med Sport 13: 559-563.

Myer, G.D., Paterno, M.V., Ford, K.R., Quatman, C.E., &

Hewett, T.E. (2006) Rehabilitation after anterior

cruciate ligament reconstruction: Criteria-based

progression through the return-to-sport phase. J Orthop

Sports Phys Ther 36: 385-402.

Murphy, J.A., Robert, G.L., & Coutts, A.J. (2003)

Kinematic determinants of early acceleration in field

sport athletes. J Sports Sci Med 2: 144-150.

Nummela, A., Keranen, T., & Mikkelsson, L.O. (2007)

Factors related to top running speed and economy. Int J

Sports Med 28: 655-661.

Rumpf, M.C., Cronin, J.B., Mohamad, I.N., Mohamad, S.,

Oliver, J.O., & Hughes, M.G. (2014) Kinetic

asymmetries during running in male youth. Phys Ther

Sport 15: 53-57.

Weyand, P.G., Sternlight, D.B., Bellizzi, M.J., & Wright, S.

(2000) Faster top running speeds are achieved with

greater ground forces not more rapid leg movements. J

Appl Physiol 89: 1991-1999.

icSPORTS 2015 - International Congress on Sport Sciences Research and Technology Support

164