Human Movement Science 33 (2014) 227–237

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Human Movement Science

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Horse–rider interaction in dressage riding

0167-9457/$ - see front matter � 2013 Elsevier B.V. All rights reserved.http://dx.doi.org/10.1016/j.humov.2013.09.003

⇑ Corresponding author. Tel.: +49 391 67 56972; fax: +49 391 67 56754.E-mail addresses: andreas.muenz@ovgu.de (A. Münz), falko.eckardt@ovgu.de (F. Eckardt), Kerstin.witte@ovgu.de (K

Andreas Münz ⇑, Falko Eckardt, Kerstin WitteDepartment of Sport Science, Otto-von-Guericke-University Magdeburg, Brandenburgerstr. 9, 39104 Magdeburg, Germany

a r t i c l e i n f o

Article history:Available online 26 November 2013

PsycINFO Classification:3720 sports

Keywords:Inertial sensorsPelvisHorse ridingCouplingInteraction

a b s t r a c t

In dressage riding the pelvis of the rider interacts with the horsephysically. However, there is little information about the influenceof riding skill on the interaction of the human pelvis with thehorse. Therefore this paper aims to study the interaction betweenhorse and rider in professional riders (PRO) and beginners (BEG).Twenty riders rode in walk, trot, and canter in an indoor riding hallwith inertial sensors attached to their pelvis and to the horses’trunk. Statistical analysis of waveform parameters, qualitativeinterpretation of angle–angle plots, and cross-correlation of horseand rider were applied to the data. Significant differences betweenPRO and BEG could be found for specific waveform parameters.Over all gaits PRO kept their pelvis closer to the mid-positionand further forward whereas BEG tilted their pelvis further to theright and more backwards. The coupling intensity of horse andrider revealed differences between the gaits. Furthermore phaseshifts were found between PRO and BEG. This paper describes asensor-based approach for the investigation of interactions of thehuman pelvis with the trunk of a horse under in-field conditions.First the results show that the riding level influences the postureof a rider and secondly that differences can be detected with con-temporary available sensor technology and methods.

� 2013 Elsevier B.V. All rights reserved.

1. Introduction

In dressage riding the rider leads the horse by the exchange of tactile information between horseand rider. Connecting the horse and rider physically, besides the rein and legs especially the rider’spelvis plays a key role for the communication with the horse (Blokhuis, Aronsson, Hartmann, van

. Witte).

228 A. Münz et al. / Human Movement Science 33 (2014) 227–237

Reenen, & Keeling, 2008; Schiavone Panni & Tulli, 1994). Different footfall sequences account for gaitdependent kinematics of the horse’s trunk in walk, trot, and canter (Faber, Johnston, van Weeren, &Barneveld, 2002; Faber et al., 2001). In walk and canter the trunk of the horse rotates about the med-ial–lateral axis resulting from the alternating up and down of the cranial and caudal part of the trunk(Hübener, 2004). In contrast, the simultaneously stance phases of the diagonal limb pairs in trot pro-voke concurrent vertical movements of cranial and caudal parts of the trunk. Moreover, tactile com-munication with the horse in terms of efficient and accurate horse commands is based on an optimallyadapted seat. Thus, riders need to adapt temporally and spatially to the movement of the horse’s trunkin order to achieve and to keep a well-adjusted seat. Peham et al. (2010) describe a stable seat as afoundation on which effective communication is based on. In other words, adapting to the horse re-quires a gait specific motion of the rider pelvis (Symes & Ellis, 2009).

Treadmill studies combined with optical motion capturing systems are considered to be the goldstandard for motion analysis in horse riding (Greve & Dyson, 2012). Laboratory conditions help to ob-tain detailed kinematic analysis of a variety of body segments (Byström, Rhodin, von Peinen,Weishaupt, & Roepstorff, 2009, 2010; von Peinen et al., 2009), e.g., pelvis of the rider. However, differ-ences between treadmill studies and field studies have been published before (Barrey, 2004, chap. 12;Barrey, Galloux, Valette, Auvinet, & Wolter, 1993; Buchner, Savelberg, Schamhardt, Merkens, & Barne-veld, 1994; Gomez Alvarez, Rhodin, Byström, Back, & van Weeren, 2009; Savelberg, Buchner, Scham-hardt, Merkens, & Barneveld, 1993). Therefore transferring results from treadmill studies tooverground conditions is apparently questionable. Approaches for collecting kinematics of riders un-der real conditions using optical motion capturing systems could be applied successfully by Kang et al.(2010). They found postural variations between beginners and advanced riders. Both Lovett, Hodson-Tole, and Nankervis (2005) and Symes and Ellis (2009) demonstrated gait depending peculiarities inupper and lower extremities of riders. Regarding joint angles (Schils, 1993) and muscular activity(Terada, 2000; Terada, Mullineaux, Lanovaz, Kato, & Clayton, 2004), comparable results for riding leveland gaits were found. Based on angular displacement, velocity, and acceleration derived from videorecordings (Peham, Licka, Kapaun, & Scheidl, 2001) showed that professional riders move more con-stantly than recreational riders do.

There is a lack of information about the development of riding skills (Greve & Dyson, 2012). Thereare also few publications considering the human pelvis and its role in the kinematics of beginners andadvanced riders. We state that so far, interaction between horse and rider has been investigated forselected body segments (Witte, Schobesberger, & Peham, 2009) but not for the human pelvis althoughit transmits the rider’s body weight onto the horse (Blokhuis et al., 2008; Schiavone Panni & Tulli,1994). Little is documented about the interactions between horse and rider (Schöllhorn, Peham, Licka,& Scheidl, 2006). This stands in marked contrast to the outstanding role of the human pelvis in themechanical coupling of horse and rider. Here coupling can be understood as the physical connectionof two moving body segments in space, excluding the saddle. Therefore the aim of this paper is toinvestigate the coupling in terms of kinematic interactions between the trunk of the horse and the pel-vis of the rider in professional riders (PRO) and beginners (BEG) in walk, trot, and canter. Three meth-ods were applied to characterize horse–rider interactions: statistical analysis of waveform parameters,qualitative interpretation of angle–angle plots, and cross-correlation analysis of horse and rider.

2. Materials and methods

2.1. Subjects

20 riders participated in this study. According to their riding skill they were split into two groups(BEG and PRO). All ten PRO riders (8 females, 2 males) are either fulltime professional riders or train asa riding instructor at the Fédération Equestre Nationale (FN). The group of BEG consists of ten ridingschool members (9 females, 1 male), who take riding lessons once or twice a week since 6 years onaverage. Table 1 provides a detailed summary of anthropometric features and riding behavior forthe groups. In this study riders classified as BEG were younger due to the fact that usually people startriding earlier than in the age of the PRO group. PRO riders rode their own horses or horses that

Table 1Anthropometry and riding behavior of PRO and BEG (mean ± SD).

Riders Horses

Age[years]

Height[cm]

BodyWeight[kg]

BMI [kg/m2]

Experience[years]

Practice[hours/week]

Right/lefthanded

Height atwithers [cm]

PRO (n = 10) 23.4 ± 5.3 168.4 ± 10.4 61.1 ± 9.6 21.5 ± 2.5 17.3 ± 5.6 33.9 ± 11.9 10/0 170 ± 3.5BEG (n = 10) 16.4 ± 2.9 171.3 ± 5.2 59.3 ± 7.3 20.2 ± 2.3 6.1 ± 1.7 2.6 ± 1.4 9/1 172 ± 5.5

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undergo training at FN. BEG riders rode on horses held by the riding school. For the study warmbloodgeldings or mares were ridden with dressage saddles and bits that are usually used for the observedhorse. The experimental protocol was approved by the Ethical Board of the Otto-von-Guericke-Univer-sität Magdeburg.

2.2. Experimental design

2.2.1. ProtocolA straight-lined trackway of 30 m in the middle of an indoor riding hall was used to capture the

movement data. Starting point and end of this course were indicated for the riders clearly visible withcones. They completed the course four times in walk, sitting trot and right lead canter. All riders wereinstructed to keep a constant working speed throughout the entire trackway. Two 6 degree of freedominertial sensors (Mtx orientation tracker; Xsens Technologies BV, An Enschede, The Netherlands) weresynchronized with a three-dimensional wireless accelerometer (AG, RFTD-A01; Myon AG, Baar, Swit-zerland) and a regular 30 Hz digital camcorder (Exilim ProEX F1 model; Casio, Tokyo, Japan). Both sen-sor systems sampled with 100 Hz. One inertial sensor was placed dorsal at the rider’s pelvis the secondwas fixed centrally on the saddle girth beneath the horse’s sternum (Barrey, 2004, chap. 12). In accor-dance with the method suggested in Starke, Witte, May, and Pfau (2012) and Schamhardt and Mer-kens (1994), the accelerometer was attached laterally on the left cannon bone of the front limb inorder to identify footfall timings. All three sensors were fixed properly with adhesive tape.

Before mounting the horse, the orientation of the riders’ pelvis in their natural standing posturewas measured for four seconds to account for inter-individual postures. Orientation of the rider pelvisand the horse’s sternum are represented by rotations about two axes, afterwards called anterior–posterior (AP) and lateral (LT). For both, pelvis and sternum AP corresponds to a rotation about themediolateral axis. LT of pelvis describes the rotation about the sagittal axis of the rider pelvis, LT ofthe horse the rotation about the craniocaudal axis of the horse trunk. The term LT is supposed toimprove readability without claiming to be the anatomically correct term. Fig. 1 shows the locationsof the sensors and the definition of the rotation axes’ sense of direction according to the right-handrule.

Fig. 1. Locations of the sensors at the pelvis (left) and the horse (right). Dashed arrows represent anterior–posterior rotations(AP), dotted arrows lateral rotations (LT).

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2.2.2. Data processingThe signal of the cannon bone accelerometer was zero-phase-shift low-pass filtered (digital third-

order Butterworth filter). Following the procedure proposed by Challis (1999) to find the optimal cut-off frequency, a cutoff frequency of 10 Hz was applied to remove artifacts. One stride was defined asthe time between two successive ground contacts of the left front limb. This event was clearly iden-tifiable in the acceleration signal of the cannon bone. The pelvis orientation of the rider was expressedwith respect to the natural upright standing posture, trunk orientation of the horse with respect to thehalt (Johnston et al., 2002) using the procedure described by Faber, Kingma, Bruijn, and van Dieën(2009). In order to analyze the data stride by stride, time series data were separated into stridesand time-normalized (cubic spline interpolation, 101 samples per stride) using MATLAB 2012b (Math-Works, Inc., Natick, MA). Additional information about the methods section can be found elsewhere(Münz, Eckardt, Heipertz-Hengst, Peham, & Witte, 2013).

2.3. Analysis

To determine group differences, each of the time series of angles was averaged across 30 strides foreach subject in each gait. Statistical analysis was carried out on three waveform parameters gatheredfrom the average cycles: Range of motion (ROM), Maximum (MAX), and Minimum (MIN). To investi-gate the structure of the movement qualitatively angle–angle plots of rider pelvis and horse trunkwere drawn for group averages. Details on how to read angle–angle plots can be found in Winsteinand Garfinkel (1989). The time lag between the maximum cross-correlation (pelvis vs. trunk) wasused to quantify the phase shift between group averages. Groups were tested for significant differ-ences (p 6 .05) using t-tests for normally distributed data and Mann–Whitney-U-test if data werenot normally distributed. Due to measurement errors group averages in walk for both groups andin canter for the BEG group are based on nine subjects.

3. Results

3.1. Walk

Both groups showed comparable ROM in AP rotation (Table 2). However, the pelvis of PRO riderswas tilted significantly further forward while their horses showed higher MAX values. A look at theshape of the AP trajectories reveals a similar pattern of both graphs (Fig. 2). Considering AP rotations,both PRO and BEG rotate opposite in phase which becomes obvious through the shape of the trajec-tories. They run from bottom right to top left and are elongated. It is remarkable that PRO riders seemto produce a more congruent trajectory than BEG. At the time of maximal AP rotation of the horse(about 30% and 80% of the stride), the pelvis of PRO is tilted stronger dorsally compared to BEG whatmakes the top of the trajectory look more spherically. In both groups the tight radius at the turningpoints and the elongated shape indicate strongly coupled movements of horse and rider in AP rotation.The phase shift between the two groups in AP was found to be 5% of the total stride duration.

In LT there are no significant differences between the two groups. ROM of riders and horses arebroadly similar. In LT the pelvis of PRO tends to be tilted slightly less to the right, whereas therewas no difference in the MAX, MIN, or ROM of the trunk. In contrast to AP, the LT rhythm in walkcan be described as a right slanted eight what can be interpreted as in phase movement of rider pelvisand horse trunk. However, due to the bellied shape of the LT trajectory a weaker coupling than in APcan be assumed. No phase shift between PRO and BEG could be detected for LT rotation in walk.

3.2. Trot

The comparison of AP rotations of PRO with BEG shows significant lower values for MAX and MINbut not for ROM (Table 3). In other words, the pelvis of the group of PRO is tilted more forward. Nosignificant differences could be found for AP rotation of the horse trunk, neither in MAX or MIN norin ROM. Despite the fact, that differences could not be assessed statistically in AP rotation of the trunk,

Table 2Group means ± SD [�] for anterior–posterior (AP) and lateral (LT) rotation of rider pelvis and horse trunk in walk. Significantdifferences (p 6 .05) between PRO and BEG are shaded in grey.

Fig. 2. Coupling behavior and time series of rider pelvis and horse trunk in walk (group averages). Positive rotations about theanterior–posterior (AP) axis (panels a and c) represent the dorsal tilt of the pelvis and a lowering of the caudal part of the trunkrelative to the cranial part. Positive rotations about the lateral (LT) axis (panels b and d) stand for a right tilt of the pelvis (dorsalview) and a rotation to the right of the trunk (caudal view). In panels (c) and (d) solid lines indicate the rotation of the riders’pelvis, dashed lines the rotation of the horses’ trunk.

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a tendency towards higher AP values can be seen. The shape of AP trajectories suggests a weaker cou-pling than in walk with the exception of the turning points which in contrast show short periods ofhighly coupled body segments (Fig. 3). Compared to the trunk of the horse the ROM of the pelvis ishigher, what cannot only be seen in the ROM values but also in the horizontally stretched shape ofthe trajectory. First and second half of a stride show very similarly shaped trajectories in AP rotationswhich mirrors the two beat rhythm of the trot. A phase shift of 2% stride duration underpins the sim-ilarity of the trajectories of the two groups in AP.

There were no statistically significant differences verifiable between the two groups in MIN andMAX of pelvis and trunk rotation about the LT axis. However, the ROM of both pelvis and trunk aresignificantly higher in BEG than in group of PRO.

Regardless of the group of riders, the movement of pelvis and trunk is out-of-phase in LT. Two lin-early vertical parts in LT trajectories indicate periods in which only the orientation of the horse’s trunkchanges whereas the pelvis of the rider remains unaffected tilted sideways. This shows a weak cou-pling behavior. Apparently the shapes of the trajectories of the two groups differ from each other.

Table 3Group means ± SD [�] for anterior–posterior (AP) and lateral (LT) rotation of rider pelvis and horse trunk in trot. Significantdifferences (p 6 .05) between PRO and BEG are shaded in grey.

Fig. 3. Coupling behavior and time series of rider pelvis and horse trunk in trot (group averages). Positive rotations about theanterior–posterior (AP) axis (panels a and c) represent the dorsal tilt of the pelvis and a lowering of the caudal part of the trunkrelative to the cranial part. Positive rotations about the lateral (LT) axis (panels b and d) stand for a right tilt of the pelvis (dorsalview) and a rotation to the right of the trunk (caudal view). In panels (c) and (d) solid lines indicate the rotation of the riders’pelvis, dashed lines the rotation of the horses’ trunk.

232 A. Münz et al. / Human Movement Science 33 (2014) 227–237

While for the group of PRO the shape can be described with a constricted zero, the trajectory of BEGlooks like a recumbent eight. This difference is caused by a calculated phase shift of 23% between bothgroups in LT.

3.3. Canter

There was a significantly lower MAX value in the group of PRO in AP rotation (Table 4). Eventhough MIN and ROM of the PRO group seem to be lower, these differences were not significant. InMAX, MIN, and ROM of the horses’ trunk only tendencies could be observed however no statistical sig-nificance was found.

The trajectory of AP shows a left tilted shape indicating out-of-phase characteristics of the move-ment (Fig. 4). The most prominent difference can be seen in the run of the trajectory itself which is anelongated oval for the group of PRO but a skewed eight for the group of BEG. This is due to a phase shiftof 13% stride duration in AP (PRO reach their maximal dorsal tilt later than BEG).

Table 4Group means ± SD [�] for anterior–posterior (AP) and lateral (LT) rotation of rider pelvis and horse trunk in canter. Significantdifferences (p 6 .05) between PRO and BEG are shaded in grey.

Fig. 4. Coupling behavior and time series of rider pelvis and horse trunk in canter (group averages). Positive rotations about theanterior–posterior (AP) axis (panels a and c) represent the dorsal tilt of the pelvis and a lowering of the caudal part of the trunkrelative to the cranial part. Positive rotations about the lateral (LT) axis (panels b and d) stand for a right tilt of the pelvis (dorsalview) and a rotation to the right of the trunk (caudal view). In panels (c) and (d) solid lines indicate the rotation of the riders’pelvis, dashed lines the rotation of the horses’ trunk.

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Compared to walk and trot, the trajectory in AP reflects a strong rotation of the pelvis and of thetrunk. The left tilted shape shows a constant tilt of the pelvis with concurrent rotation of the trunk,which can be interpreted as a relatively strong coupling.

Neither for pelvis nor for trunk significant differences in LT rotations between the two groups inMAX, MIN, and ROM could be found. Both trajectories show a slightly out-of-phase structure as theyrun along an imaginary axis from bottom right to top left. Small radii at the turning points indicate astrong coupling of pelvis and trunk. The phase shift between PRO and BEG in LT was found to be 8%stride duration.

4. Discussion

Significantly differences and tendencies could be found in AP rotations in all gaits. However thiscould not be found in rotations about the LT axis. In accordance with the findings of (Terada, Clayton,& Kato, 2006), especially MAX and MIN values but also the ROM of the rider pelvis varied greatly

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between subjects in both groups. Furthermore, the strongest movement of the pelvis could be found incanter for AP rotation, followed by trot and walk. The trunks of the horses however rotated most incanter, followed by walk and trot. In LT rotation no such order occurred. In contrast all gaits showeda comparable amount of rotation about the LT axis. Further, higher AP angles in the trunk of the PROhorses were observed in all gaits. This finding might result from a higher level of schooling(Holmström & Drevemo, 1997; Holmström, Fredricson, & Drevemo, 1995; Johnston et al., 2002;Matsuura, Ohta, Ueda, Nakatsuji, & Kondo, 2008) which is strongly connected with a lowering ofthe croup.

LT rotations did not show any statistical stressable differences between the groups. But in all gaitsthe group of PRO kept their pelvis closer to mid-position while the group of BEG tended to tilt theirpelvis more to the right. Asymmetry of horses and riders is a topic lively discussed in equine sports.Our findings support the attitude that asymmetry in the rider exists and cannot only be found in theshoulder (Symes & Ellis, 2009) or in the rein (Warren-Smith, Curtis, Greetham, & McGreevy, 2007) butalso in the pelvis. The majority of right-handed people flex their right hip stronger when riding ahorse. Clayton (2013) explains this with leg length asymmetry. They further describe an elevationof the right ischium and posterior ilium what is caused by the rotation of the right ilium anteroven-trally. In our opinion however, one could also interpret the described elevation as not necessarily pro-voking a lift of the right side of the pelvis. Instead the right hip flexors might cause a slight downwardpulling of the right side of the pelvis. Whereas the mid tendency of PRO can be explained with higherbalancing skills, a conclusive explanation for the fact that the BEG tilt their pelvis to the right and notto the left cannot be given.

The comparison between two groups of riders showed that the rider’s seat in the group of PRO isfeatured by a more forward tilted pelvis. Several studies (Kang et al., 2010; Lovett et al., 2005; Schils,1993) demonstrated how beginners lean their trunk forward and take up a posture that is further fromthe vertical than the posture of advanced riders. According to the biomechanical back model (Hess,Kaspareit, Miesner, Plewa, & Putz, 2012) a forward tilted pelvis leads to a straightened back and abackward shift of the shoulders. When using body markers, the dorsal leaning of the rider’s trunkcould therefore be overestimated due to the definition of the body segment (hip and shoulder). More-over as a result of the forward tilted pelvis the center of mass (COM) of the rider’s (upper) body isshifted cranially towards the horse’s head (Betz, Bodem, & Eckardt, 2005). Following (Sprigings &Leach, 1986) the location of COM in a standing horse does not change, regardless of whether it carriesa rider or not. This finding can be explained by the fact that the COM of a rider would lie right abovethe COM of a horse. Contrarily (de Cocq, Clayton, Terada, Muller, & van Leeuwen, 2009) demonstratedthat different upper body postures cause craniocaudally shifts of weight distribution when sitting on astanding horse. Consequently also the COM ought to shift.

Angle–angle plots allow for qualitative and quantitative comparisons of movement patterns (Bart-lett, 2007). The characteristics of the intersegmental phase and the coupling intensity can be deducedfrom trajectories of angle–angle plots, what is difficult to see in other representations (Winstein &Garfinkel, 1989). In this study the shapes of the trajectories suggest a stronger coupling in AP rotationthan in LT rotation, regardless of the observed gait. Notably higher ROM in AP rotation is supposed tobe the main reason for this finding. Looking from a rider’s view it becomes obvious, that a strongerrotation of the horse’s trunk about the AP axis requires a closer coupling than about the LT axis. Inap-propriate coordinated movements along the AP axis would provoke more serious consequences for thebalance of the rider’s seat and thus for the communication with the horse.

Phase shifts based on vertical displacement data of a trotting horse and body parts of two riders ofdifferent skill levels (Lagarde, Peham, Licka, & Kelso, 2005) and higher adaptations of PRO riders to themovement pattern of a horse (Schöllhorn et al., 2006) have previously been published. In this studyphase shifts could be found between the group of PRO and the group of BEG in all gaits expect forLT rotation in trot (Fig. 5).

However, for this finding it is believed that the phase shift is possibly overestimated due to effectsthat the particular run of the LT waveforms have on the maximum of the cross-correlation. In contrastto the conclusive argumentation of Lagarde et al. (2005) our findings suggest that the pelvis of the BEGmoves ‘‘ahead’’ of the horses’ movement. The findings of Lagarde et al. (2005) however are based on anoptical tracking and mainly refer to the coordination of riders’ upper limbs and the caudal part of the

Fig. 5. Cross-correlation between rider pelvis and horse trunk about anterior–posterior (AP) and Lateral (LT) axes for PRO andBEG. Time lags with maximal correlation coefficients are indicated black. Maxima occurring on positive time lag indicate thetrunk being ahead of the pelvis, and vice versa.

A. Münz et al. / Human Movement Science 33 (2014) 227–237 235

horse’s trunk what could explain the discrepancy. Especially in equine sports where remarkableindividual variations are known (Terada et al., 2006) general conclusions based upon one single sub-ject should be handled with care.

5. Conclusion

A swinging pelvis and a well-adjusted seat enable the rider to control the horse more effectivelyand accurately. In horse riding however, few studies focus on the kinematics of the rider and especiallyon the rider’s pelvis. More attention is drawn to the performance of the horse although both, rider andhorse contribute to the overall performance. Trying to enhance performance, riding instructors andriders should be aware of the difference in posture that is presented in this paper. To the authors bestknowledge this paper first describes the kinematics of the human pelvis and its interaction with thetrunk of the horse in different gaits under in-field conditions. It should be emphasized that the data forthis study was collected under realistic conditions. Riders and horses were able to ride in their every-day surrounding in order to harm their natural behavior as little as possible. However, this benefit isconfronted with the disadvantage of restricted possibilities of standardization (e.g., riding a straightline with constant speed). One should be aware that a variety of influencing variables which deter-mine the motion of horse and rider can only be controlled to a certain degree and individuality shouldnot be underestimated.

In this study it was found that PRO riders tilt their pelvis further forward than BEG do. Their struc-ture of interaction is similar but characterized by a phase shift. However, observing the pelvis of the

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rider describes the physically measurable communication between horse and rider only incompletely.In order to gather all aids completely rein aids and leg aids should also be considered. The single im-pulses of all three aids only become a powerful and sensitive mean to control the horse when theyinteract correctly. Peham et al. (2001) conclude that the camera-based systems could be replacedby a sensor on the rider’s head in order to quantify harmony objectively what corresponds with theresults. It could be shown that skill dependent differences can be measured to a certain extent withcontemporary available technology and methods. Additionally it should be emphasized, that resultsdepend on the choice of the specific body segments under investigation. Based on these findings itseems possible to contribute a lot to the sport of horse riding with further and more sophisticated ap-proaches (e.g., synchronization of whole-body kinematics of horse and rider, muscle activity, pressuresensors on the saddle, and force sensors in the rein). However, drawing a more precise picture ofhorse–rider interactions still remains a challenging task that should be faced with intense researchand more sophisticated approaches.

Conflict of interest

All authors deny having any financial and personal relationships with other people or organizationsthat could inappropriately influence our work.

Acknowledgments

We would like to offer our special thanks to all riders who participated in the study, to the Fédé-ration Equestre Nationale (FN), and the Reitsportverein am Maifeld e.V. who made this study possible.

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