(PDF) An investigation into the effectiveness of saddle design and its influence on rider lower leg position when using the light seat. Amanda Purchas 18th March 2013

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CHAPTER ONE

INTRODUCTION

Show jumping is one of the UKs leading equestrian sports, its popularity in

competition and as a spectator sport has led to its recognition at international

events such as the Olympics (FEI, 2013; BSJ, 2013). The discipline requires

the competitor to complete a set of 11-14 jumps, on average, with no

mistakes and thus, relies on the skill, balance and agility of both the horse

and rider (GEF, 2003; BSJ, 2013). The English saddle has become an

imperative piece of equipment that is used and manipulated throughout many

of the top equestrian disciplines (Dressage Today, 1996). This manipulation

of the original English saddle has led to the development of the jump (SJ)

saddle that is designed to suit the discipline specific demands of show

jumping. However, regardless of its imperative role in uniting both the horse

and rider there is a limited range of research available on the subject area.

The main focus of saddlery research as present has investigated the effect of

ill-fitted and fitted saddles. Mechan et al, (2007) and Tiago et al, (2011), both

found that ill-fitted saddles increased the presence of asymmetric pressure

points inflicted on the horse which is suggested to impair communication.

Within these studies there was much speculation on the potential effects of

the saddle on the rider; however, only one paper by Peham et al, (2004) has

actually researched its influence. This study revealed that the ill-fitted saddle

increased the rider movement variability significantly in the forwards plane,

which was suggested to influence the balance of both the horse and rider

(Peham et al, 2004).Yet regardless of Peham et al, (2004) research

indicating the potential negative influence of and ill-fitted saddle on the rider

no further research has expanded the subject area.

Show jumping requires the rider to remove their weight off the horse’s back

to enhance locomotion and jump biomechanics (Randal, Edwards & Button,

2010). This poise known as the light seat, allows for greater dynamic stability

of both the horse and rider (Clayton & Back, 2003). To effectively execute the

light seat the rider must shorten their stirrup length (SL) so that they can

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successfully remove their weight out of the saddle (BHS, 2009). This short

SL and the postural requirement of the jump seat is what lead to the

development of the SJ saddle (GEF, 2003; BHS, 2009).

The general purpose (GP) saddle, much like the original English saddle is

designed for use in dressage and jumping disciplines therefore, its design

sits to accommodate the postural requirements of both sports (GEF, 2003).

The SJ saddle however, is designed specifically for use in jumping disciplines

such as show jumping thus, requiring a more forward cut flap design and a

longer, shallower seat (see plate 1 for comparison of GP and SJ saddle)

(GEF, 2003). From plate 1 it can be seen that between the saddle types

there is a definite difference in saddle design. However, it is not yet proven

that the SJ saddles design aids the rider in competition or that the GP saddle

can act effectively as a multifunctional piece of equipment.

Plate 1: Saddle design a) GP saddle b) SJ saddle. (Millybry Hill, 2013; UK

saddles, 2013)

In principle the GP saddle should struggle to accommodate the SL used in

the SJ saddle, as logic would suggest its deeper seat and straighter cut will

not allow for the higher placement of the knee; nevertheless, this principle

has not yet been investigated. Conversely, there is no research that states

that the SJ saddles design better accommodates the shorter SL and

increases rider stability in the light seat. Therefore, this preliminary study

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investigating the effect of saddle design when using the light seat on rider

lower leg position hopes to answer the following aims, objectives and

research questions.

1.1 Aims and Objectives:

1.1.1 Research Aims:

1) To establish the benefits if any, of using the SJ saddle in show

jumping, with particular reference on its ability to support the rider’s

lower leg when using the lights seat.

And

2) To establish if the GP saddles design can accommodate the discipline

specific demands of show jumping, with particular reference to its

ability to support the rider’s lower leg position when using the light

seat.

1.1.2 Research Objectives:

1) To record videos of rider’s on the mechanical horse in the light seat

at canter in both the SJ and GP saddle.

2) To record SL used in both saddle types.

3) To analyse rider body segment angles and lower leg displacement

in both the SJ and GP saddle with video analysis software.

4) To statistically compare data sets from both saddles to highlight

any significant differences.

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1.1.3 Research Questions:

1) Does the GP saddles design accommodate the rider’s lower leg

position when using the light seat?

2) Does the SJ saddles forward cut design better accommodate the

rider’s lower leg position when using the light seat?

3) Can the SL used in the SJ saddle be used in the GP saddle?

4) Is there any difference between rider lower leg stability in the light seat

when using a SJ saddle compared to a GP saddle?

5) Is there any difference between rider lower body segment angles in

the light seat when using a SJ saddle compared to the GP saddle?

Through the achievement of the previous research questions, it is expected

that the study’s findings can be transferred and applied into the equine

industry. It is hoped that such information can better educate riders on saddle

choice and highlight any areas for improvement in terms of saddle design. As

well as providing the industry with imperative research into the relationship

between the rider and saddle.

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CHAPTER TWO

CRITICAL LITRITURE REVIEW

2.1 Saddle design:

The saddle is widely utilised throughout a range of disciplines to aid

communication, balance, stability and comfort between the horse and rider

(Peham et al, 2010). The coupling of the rider and saddle allows the rider to

distribute their weight evenly over the horses back creating a larger base of

support which in turn enhances balance and stability (Clayton, 2003; Peham

et al, 2010). Saddle design is dependent on the requirements of the discipline

with designs altering to increase stability, effectiveness of aids and

communication (Swift, 1985; BHS, 2007). Despite the obvious importance of

the saddle in uniting the horse and rider dyad minimal research has

addressed its effect on human or equine biomechanics.

Research into the effect of the saddle on the horse and rider is sparse with

most of the current research investigating saddle fit. Peham et al, (2004)

carried out an investigation to distinguish the effect of and ill-fitted and fitted

saddle on rider variability; it was found that the ill-fitted saddle increased the

rider’s variability in the forwards plane. Equitation principles such as those by

the German National Equestrian Federation (GEF), highlight that in order for

the horse remain in balance the rider must remain in sync with the horses

centre of mass (CoM) (Swift, 1985; Clayton, 2003; GEF, 2003). However, if

as found by Peham et al, (2004), the rider is unable to maintain a consistent

balance when in a ill-fitted saddle then the ability of the rider to effectively

control the balance of the horse is lost.

This forwards variability as suggested by Peham et al, (2004) may also

disturb the communication between the horse and rider. Tiago et al, (2011)

theorised a concept similar to that of Peham et al, (2004), when suggesting

that asymmetric pressure points caused by ill-fitted saddles; could confuse

the communication of the rider to the horse, as the horse relies on physical

signs of communication from the rider (BHS, 2007; Print, 2011).

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Mechan et al, (2007) in a study investigating the influence of saddle width on

pressure distribution found that different pressure peaks where present with

each saddle width, with the largest peaks seen in the most ill-fitted saddle of

the selection. The same rider was used throughout the entire study thus, the

mass within the saddles remained consistent. Therefore, it could be assumed

the pressure alterations and asymmetry was caused by the reduced coupling

of the horse and rider. Such information links into that of Peham et al, (2004)

in regards to the effect of an ill fitted saddle and its influence on rider

balance. However, both studies only used gaits up to trot therefore, more

research is needed to establish saddle influence in faster gaits.

Tiago et al, (2011), emphasised the relevance of pressure points on equine

muscular function and how the presence of pressure points can lead to

localised inflammation and impaired nervous activity, which subsequently can

effect equine biomechanics (Peham et al, 2004; Meschan et al, 2007; Tiago

et al, 2011). It was also suggested that show jumping horses have longer

spinal processes and therefore, pressure points occurring on the dorsal

midline in 37.2% saddles could contribute to the development of kissing

spine (Tiago et al, 2011). Thus, the necessity for a fitted saddle is both a

requirement for performance and welfare. However, pressure points found

within Tiago et al, (2011), study cannot be directly linked to saddle fit but

could be caused by rider asymmetry. Therefore, further research is needed

to establish a specific technique for identifying saddle asymmetry whilst

controlling the influence of the rider.

2.2 The Riders position:

The correct riding position is a necessity for clear and consistent

communication between the horse and rider (GEF, 2003). A rider must utilise

muscular endurance, motor skill, flexibility and co-ordination to communicate

with the horse, whilst maintaining balance in both the sagittal and coronal

planes (Deitz, 1999; GEF, 2003; BHS, 2007). The ability to manipulate

biomechanical variables whilst remaining in balance allows the rider to apply

subtle but effective aids that aim to control the speed, direction and

behaviour of the horse (Swift, 1985; Schills, 1993; GEF, 2003).

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The traditional seat dictates in accordance to the British Horse Society riding

manual (BHS) and the GEF; that the riders head should look to the direction

of the movement; the shoulders should be positioned slightly back, open and

supple. The back should be straight but relaxed with no ventral thoratic curve

with the waist strong and central. The thigh should be flat to the saddle with

minimal muscle tone and tension of joints, followed by the lower leg hanging

freely with the ankle in alignment with the hip joint (GEF, 2003; BHS, 2007).

See plate 2 for visual example of the traditional seat.

Plate 2: Traditional seat (Horse Chronicles, 2013)

Asymmetry caused by the in-correct execution of the traditional seat can lead

to a disturbance in force distribution under the saddle which De Coqu et al,

(20101) suggests can impair communication. A later study conducted by De

Coqu et al, (20102) on saddle and leg forces when performing lateral

movements confirmed De Coqu et al, (20101) theory. When finding that it is a

necessity for the rider to asymmetrically distribute their weight when

conducting lateral movements such as Travers. Thus, if a rider is already in a

asymmetric balance then the core aid for the movement is lost as the horse

will struggle to interpret the weight shift. Therefore, an initial poor riding

posture will impact on the clarity of aid communication which can

subsequently result in poor performance (De Coqu et al, 20101; De Coqu et

al, 20102).

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2.2.1 Rider ability and Position:

Schills, (1993) in a study investigating joint angles of rider’s at different levels

of riding ability found that advanced rider’s positioned there trunk closer to

the vertical, whilst placing their thigh and lower legs deeper under their body.

This position subsequently opened up the hip angle allowing greater fluidity

of the hip joint and thus, enhancing the ability of the rider to move in

synchronicity with the horse (Schills, 1993). A beginner rider however,

showed to have a more acute hip angle of 128ͦ, in comparison to that of and

advanced rider whose angles averaged at 140ͦ (Schills, 1993). This more

acute hip angle brings the rider’s CoM over ones toes thus, tipping their

balance forwards whilst limiting the flexibility of the hip joint (Schills, 1993;

Back and Clayton, 2003; GEF, 2003).

A more recent study by Kang et al, (2010) who looked at the development in

rider position in accordance to skill level found results similar to that of

Schills, (1993) study. It was concluded that there is a linear relationship

between hip angle and skill level development. However, Kang et al, (2010)

study used a juju horse whose conformation and movement is unique to the

breed therefore, the study may lack comparability.

For a rider to remain in harmony with the horse they must anticipate the

rhythmic disturbance of locomotion, by doing this they can instinctively

manipulate muscle groups to stabilise their seat (Heleski et al, 2009). This

anticipation is more naturally expressed in advance rider’s as explained by

Janura et al, (2009); who found that advanced rider’s showed less centre of

pressure (CoP) disturbances than novice rider’s. Heleski et al, (2009), also

found correlations similar to that of Janura et al, (2009); when finding that

novice rider’s will undergo cyclic phases of imbalance due to lack of

experience and practice thus, causing the rider to take up greater rein

tension in order to regain balance.

Peham et al, (2001) investigated the limit cycle of a professional and novice

rider to quantify harmony of the horse-rider dyad. It was found that the

professional rider had fewer and smaller deviations to their limit cycle in

comparison to the novice; this implied that the advanced rider’s CoM

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remained in sync with that of the horses. Although Peham et al, (2001), study

lacks validity due to only two test subjects of different genders being used its

findings interlink with that of later studies (Heliski et al, 2009; Janura et al,

2009).

It can therefore, safely be assumed that rider experience resulting in ill

execution of the correct riding posture could result in poor performance of the

dyad. Thus, there is a necessity that the correct rider position is established

at an early stage. It can also be noted that further research into the

interaction of the rider and saddle could provide insight into the manipulation

of saddle variables that could enhance and correct the novice riding position.

2.2.2 Rider somatotype, body composition and gender:

Individuals can be categorised into three basic body types, ectomorph,

mesomorph and endomorph, see plate 3 for visual representation (Print,

2011; Winfield and Lewis, 2012). Unlike other sports there appears to be no

somatotype that predisposes any advantage to riders in competition (Print,

2011), with elite rider somatotypes ranging from the tall ectomorph of William

Fox-Pitt to the shorter mesomorph of John Whitaker.

Plate 3: Body somatotypes. (Peak Performance, 2013)

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An ectomorph is characterised as an individual of tall stature, lean

musculature, low fat stores and a small waist (Print, 2011). This body shape

can be advantageous when riding wider horses and competing in dressage

(Print, 2011). As the longer leg length allows for the rider to more effectively

‘wrap’ their leg round the horse whilst also being able to efficiently execute

leg aids (Print, 2011; Winfield & Lewis, 2012). Ectomorphs tend to have a

long thigh to body ratio meaning that they must use a longer saddle design to

accommodate their thigh (Winfield & Lewis, 2012).

Endomorphs in general are shorter in height, have large bone structure and

greater fat stores (Print, 2011). This somatotype can benefit the rider when

utilising the jumping or light seat as the shorter leg length allows for the rider

to move out of the saddle with greater ease (Print, 2011). Conversely, they

may struggle with balance created by their ‘top’ heavy stature and thus, may

benefit from using saddles with a deeper seat (Print, 2011; Winfield & Lewis,

2012).

Body shape can also provide both benefits and disadvantages when riding,

Dietz, (1999) explained that all body shapes can fit into two categories; that

of a triangle and that of an inverted triangle as shown in plate 4. A rider

whose body complies to the normal triangular shape will have narrow

shoulders and wider hips, a body shape usually seen in the female gender

(Dietz 1999). This body shape is said to be advantageous as the wider base

of support will increase both the balance and stability of the rider (Dietz,

1999; Clayton & Back, 2001).

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Plate 4: Potential body shapes (Wilson, 2013).

The inverted triangle, which refers to a rider with wide shoulders and narrow

hips will struggle with balance more so than the alternative shape (Dietz,

1999). However, the smaller base of support allows the rider to shift their

weight in the saddle with greater speed and thus, provides greater dynamic

balance (Dietz, 1999).

The incorrect alignment of the pelvis can impair the orientation of the spine

and legs hence, it is important that its position remains correct (Dietz, 1999;

Winfield & Lewis, 2012). The structure of the pelvis differs between men and

women. The male pelvis has a backwards tilt and narrower width, which

predisposes men to adopt the ‘chair seat’ as the backwards tilt causes the

flattening of the lumbar vertebrae (Dietz, 1999; Winfield & Lewis, 2012).

Conversely, the female pelvis has a forwards tilt which results in an anterior

curve of the lumber vertebrae causing the back to hollow (Dietz, 1999;

Winfield & Lewis, 2012). The correct spinal alignment is between the two

extremes explained therefore, it is important that rider’s actively alter their

seat to avoid an incorrect riding posture. It could also be possible that saddle

design influences pelvic alignment, i.e the deeper seat of the dressage

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saddle may counteract the backwards tilts of the male pelvis. However, there

is a need for research into this area before such associations can be made.

2.2.3. Rider stirrup length:

Rider SL is a variable manipulated through personal choice however; certain

disciplines such as dressage or show jumping will require significantly

different SL in order for a correct riding style to be established (Swift, 1985;

PCMHS, 2007; BHS, 2007). Plate 5, illustrates the difference in SL and thus,

lower body positioning in the dressage and show jumping disciplines. SL has

a direct effect on the riders lower body kinematics therefore, SL must allow

the correct alignment of body segments in the manor shown in plate 6 (Swift,

1985; Dietz, 1999; GEF, 2003).

Plate 5: Demonstration of the rider in the ‘traditional’ dressage seat and ‘light’

show jumping seat respectively (Life and Horses, 2012; Equine Links, 2012).

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Plate 6: Correct rider body segment alignment (Swift, 1985).

In the dressage discipline the rider is required to communicate with the horse

through a series of complex aids whilst remaining in perfect harmony

therefore, a longer SL is required as shown in plate 5 (Swift, 1985; GEF,

2003; BHS, 2007). Through utilising the longer SL the rider’s body weight is

taken through their seat bones allowing the legs to remain supple (GEF,

2003). This allows for the rider sit deep into the saddle and encourages the

correct dressage posture (GEF, 2003). However, if SL is too long the rider

will reach with their toes resulting in imbalance. Conversely, if the stirrups are

too short then the rider will create tension through their inner thighs and thus,

lose the required depth of seat (GEF, 2003).

The show jumping discipline largely relies on the rider remaining in balance

through quick changes in direction and pace thus, a shorter SL is used as

shown in plate 5 (Swift, 1985; GEF, 2003; BHS, 2007). This shorter SL

allows for the rider to poise their centre of mass (CoM) directly over that of

the horses rather than through the saddle, bringing the rider’s centre of

gravity (CoG) closer to their base of support (GEF, 2003; BHS, 2007). This

combined increases balance and stability of both the horse and rider (Swift

1985; Back & Clayton, 2003; Print, 2011). For a rider to correctly ride in the

light seat the weight of the rider must be taken through their heals (GEF,

2003). However, if the stirrups are too long the rider will distribute their weight

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through their toes thus, tipping the balance forwards and impairing the

synchronicity of the dyad (GEF, 2003; BHS, 2007).

As explained above the manipulation of SL is imperative for optimal

performance in any discipline. However, for the rider to remain in a correct

riding posture specific saddle designs are needed; such as the deeper

straighter cut of the dressage saddle and more forward cut SJ saddle (GEF,

2003). Nevertheless, the degree in which these saddle designs

accommodate the discipline specific SL is unknown. Thus, further research is

needed to establish their effectiveness so that beneficial advancements in

saddlery and rider performance can be made.

2.2.4 The light seat:

The light seat is utilised in disciplines such as show jumping and racing

(GEF, 2003) which require the rider to take their weight off the horses back

(Dietz, 1999; GEF, 2003; BHS, 2007). The light seat is used in training as

well as competition as the posture required closely mimics that of the jumping

position (GEF, 2003; BHS, 2007). A firm knee and stable lower body position

is a necessity for creating the basis of the light seat (Swift, 1985; BHS, 2007).

Hence, it is important that the rider shortens their SL appropriately in order

for their weight to be taken through their heals (Swift, 1985; GEF, 2003; BHS,

2007). The degree of bend at the hips is discipline specific; see plate 7 for

comparison (GEF, 2003). Racing will require a more drastic bend as jockey’s

adopt a shorter SL hence, developing a greater distance between

themselves and the horses CoM (Back & Clayton, 2001).Therefore, by

closing the angle at the hip their CoM will come closer to their base of

support thus, increasing their balance and stability (Back & Clayton, 2001). In

the aforementioned disciplines, the importance in SL is again highlighted and

thus, supports the previous ending point of section 2.2.3 on the importance of

understanding the interaction of saddle design in supporting SL.

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Plate 7: The variation in light seat adoption throughout disciplines. A) Racing

b) Cross-country c) Showjumping. (Discover Ireland, 2013; Iron Gatewell,

2013; Breene Equestrianism, 2013)

Preliminary studies conducted by Randal et al, (2010) on the effect of rider

position on step and stride length of canter; found that by adopting the light

seat canter stride length was significantly increased conversely, when the

deep seat was used hind limb step length increased. This increase in canter

stride length was theorised to be a result of the rider moving off the horses

back and thus, enhancing the horse’s ability to lengthen the extensor muscle

chain (Randal et al, 2010). The increase in hind limb step length was

suggested to be due to the rider supporting the forehand and thus,

encouraging positive hind limb placement (Randal et al, 2010). This shows

that the correct manipulation of rider position can be utilised throughout the

disciplines to enhance equine performance, in addition to highlighting the

impact of the rider position on equine biomechanics.

2.2.5 Physiological demands of riding:

Research into the physiological requirements of riding is conflicting

particularly in reference to cardiovascular (CV) demands. The ability for

researchers to effectively manipulate the exertion of equine competition has

become a struggle. Westerling, (1983), used a cycle ergometer to measure

VO2max with the concept that cycling mimicked the posture and muscular

demands of riding. However, Meyers and Stirling (2000), theorised that the

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use of the ‘light seat’ by riders initiated higher levels of exertion on the upper

body and thus, the use of a treadmill was more appropriate.

Both studies produced relatively low VO2max values of 43.8±4.0ml.kg.min and

33.8±9ml.kg.min for Westerling (1983) and Meyer and Stirling (2000),

respectively. These values would indicate that riders do not rely on CV

endurance to perform, as other athletes who require CV endurance produce

VO2max values of 58.ml.kg.min and 70.ml.kg.min for female and male athletes

respectively (Wilmore, Costill and Kenneny, 2008; Douglas, 2012).

Yet, such results contradict heart rate (HR) readings produced by Trowbridge

et al, (1995), who found that national hunt jockey’s spend the entire race

duration at 80% of their maximal HR. Roberts et al, (2010), also established

that event rider’s HR started at an average of 172bpm in dressage, 180bpm

in show jumping and finished on 184bpm in the cross country phase. These

HR readings would suggest that aerobic pathways are being utilised in

competition however, the VO2max values suggest otherwise. Thus, there is a

need for the further development in method design to investigate the aerobic

requirements of the rider.

In terms of muscular endurance Terada et al, (2004), suggests that rider’s

utilise tonic contraction in muscles such as the rectus abdominus and

trapezius for postural control when riding. In order to sustain this type of

contraction for long period’s rider’s will require some degree of muscular

endurance (Terada et al, 2004; Wilmore, Costill and Kenney, 2008). Terada

et al, (2004), study was conducted in trot only thus, further research is

needed to investigate muscle activity in faster gaits as the riding posture

used in trot differs from that used in the canter and gallop (GEF, 2003).

As like the CV demands methods for accurately measuring a rider’s strength

are unrefined. Alfredson et al, (1998) used a isokinetic dynamometer to

measure rider strength and found that rider’s had a significantly greater

strength than their controls. Yet, later research by Meyers, (2006) using

exercises such as bicep curls; found that participants undergoing a 14 week

equitation program showed no improvement in strength apart from that in the

rectus abdominus. Similar results were found previously in study by Meyers

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and Stirling, (2000). Hence, as like CV demands rider strength remains

inconclusive thus, further development in the methodologies for establishing

the riders physiological demands are needed for both the advancement in

rider research and training.

It may also be beneficial to look at the physical exertion of novice and elite

rider’s, as it could be found that more stable rider’s exert less physical

energy. Such information could interlink with the development of a new

saddle designs that could better enhance stability; which would reduce the

need for novice rider’s to consciously stabilise themselves. This in turn could

focus rider concentration; conversely, it could also limit rider development.

2.3 Equine Biomechanics:

The CoM is a key part of any biomechanical analysis as its movement

determines load distribution and balance (Butchner, Obermuller & Schield

2000; Clayton & Back, 2001) Benke (1934), was the first researcher to

accurately establish the positioning of the horses CoM. A Borelli moment

table was used to determine the positioning of the CoM with the results

revealing its location on the cranio caudial axis. Benke (1934), results

dictated it to be on the 13

th

thoracic rib, below the line connecting the

shoulder to the buttock, see plate 8 for visual representation (Benke, 1934).

Plate 8: X) Horses CoM on the cranio caudial axis. (IRGAF, 2013) (check)

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Dynamic balances is defined as the ability to remain in a state of equilibrium

in which all parts of the body are moving with the same constant velocity; the

ability for a horse to effectively achieve this strongly relies on the equilibrium

of the CoM (Clayton & Back, 2001). Buchner, Obermuller & Schield (2000)

found that a horses CoM moved accordingly to the propulsion and

deceleration of the stride. The largest displacement of the CoM was 54mm

on the ventral axis which occurred in the trot gait. However, it was strongly

emphasised that visual displacement of the trunk was significantly greater

than that of the CoM (Butchner, Obermuller & Schield, 2000). Thus, the

greater displacements of the trunk act to maintain the CoM in a state of

equilibrium by counteracting opposing forces (Clayton, 2003).

Later research by Nauwelaerts et al, (2009), implies possible counter-

indications for Buchner, Obermuller & Schield (2000). Their research

suggested that the methodology for assuming that the trunk is a rigid

structure when investigating CoM displacement could cause an inaccuracy in

results by 25% in the longitudinal plane. However, Nauwelaerts et al, (2009),

research only implies and inaccuracy in previous CoM values and does not

disprove the concepts of previous research as similar conclusions were

drawn from their investigation.

2.3.1 The application of CoM displacement when jumping:

Movement of the CoM occurs as a result of locomotion, the displacement of

the limbs causes an asymmetric balance and thus, to counteract such

imbalance a shift in the CoM occurs (Clayton, 2003; Nauwelaerts et al,

2009). When a horse jumps its ability to successful clear the jump is largely

attributed to the horse’s capability to remain in balance (Clayton & Back

2001; Clayton 2003). In each stage of the jump process CoM alignment is

altered; at take-off there is a progressive upwards orientation of the trunk

(Clayton & Back, 2001), causing the CoM to displace vertically by 1cm as

found by Bobbert & Santanmaria (2004). The eccentric muscle activity of the

hind limbs as the take-off progresses into suspension will then cause the

CoM to elevate cranially (Thoulan 1991; Clayton et al, 1996). In suspension

the horses body is moving at the same constant velocity and therefore, its

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CoM will return to neutral (Clayton & Back, 2001; Clayton, 2003; Bobbert &

Santanmaria, 2004). In the progression to landing a cranial shift in the CoM

will occur in par with the gradual decrease in orientation of the trunk; its state

will then return to neutral on the sagittal plane on hind limb ground contact

(Clayton & Back, 2001; Clayton, 2003; Bobbert & Santanmaria, 2004).

2.4 Influence of the Rider on Equine Biomechanics:

Clayton et al, (1996) and Galloux & Barry (1997), established there is

negative correlation between the altitude and velocity at take-off and the

height of the horses flight arc. This correlation can therefore, be manipulated

by the rider to maximise performance (Clayton & Back, 2001). This can be

achieved by riders in par to research by Clayton et al, (1996) and Galloux &

Barry, (1997), by manipulating the speed and orientation of the head, neck,

trunk and hindlimbs on jump approach. Through manipulating the previous

variables the rider is able to control the angle of take-off; for example

approaching a jump in a uphill steady canter will produce a steep angle and

thus, produce a higher and shorter flight arc (Clayton et al, 1996; Galloux &

Barry, 1997). Alternatively approaching a jump in a fast canter will impair the

ability of the horse to get close into the jump and thus, its take off will occur

earlier at a more acute angle, subsequently producing a longer and flatter

flight arc (Clayton et al, 1996; Galloux & Barry, 1997; Clayton & Back, 2001).

Therefore, rider’s can dramatically influence the success of a jump effort by

controlling the horses speed and engagement on approach.

Reaserch by Lewczuk, Sloniewski and Reklewski (2006) found that rider’s

have a stabilising effect on the horse when jumping; as their presence allows

for the manipulation of stride length and jump preparation which increases

the ability to repeat jump parameters. On the other hand, rider influence is

not always beneficial. Symes & Ellis (2009), found in an investigation of rider

asymmetry that rider’s with a left anterior rotation of the shoulders blocked

the ability of the horse to flex right in canter and thus, impaired the fluidity

and engagement of the gait. However, Symes & Ellis (2009), findings could

lack reliability as the 17 riders used had varying levels of ability therefore, the

impact on equine performance cannot be directly isolated to the rider

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asymmetry, as rider ability has been seen to impact equine performance

(Peham et al, 2001; Heleski et al, 2009). Nevertheless, Symes & Ellis (2009),

research does interlink and correlate with the findings of Meschan et al,

(2001), Moore, (2010) and Tiago et al, (2011).

Two key studies have investigated the effect of the forces imposed by the

rider in trot. Peham et al, (2010) and De Cocq et al, (20101) found that peak

loading forces where greatest when the rider used sitting trot and that rising

trot initiated significantly lower loading forces. Peham et al, (2010)

additionally found that the light seat dramatically reduced the loading on the

horses back whilst better maintaining the riders CoM over that of the horses.

From such data it was concluded that using the light seat or rising trot was

more suited for use on young or in-advanced horses. As the reduced loading

better allows for the activation of the back extensor chain which could be

easily impaired in weak backed horses if the alternative method was used

(De Cocq et al, 2010; Peham et al, 2010).Conversely, advanced horses

should have a greater ability to cope with the increased loading as their back

muscle tone and strength will be more established (De Cocq et al, 2010;

Peham et al, 2010).

Moore, (2010), highlights several riding implications that jeopardise the

equine gait with the most emphasised point being the ‘posting’ of the rider.

Moore, (2010), explains ‘posting’ be a rider who sits with locked joints angles

which create a rigid structure. This is said to cause the ‘sagging’ of the

horse’s back which is initiated by concentrated loading forces that result in

the dis-engagement of the back extensor chain (Peham et al, 2010; Moore,

2010). Such effect impairs hind quarter engagement and thus, the clarity of

the gait (Clayton & Back 2001; Clayton, 2003; Moore 2010).

Through the analysis of peer reviewed literature it can be found that a rider

who can correctly manipulate equine gait variables such as speed,

engagement and balance, can significantly optimise equine performance.

Alternatively, riders can more easily impair performance through

asymmetrical balance and incorrect manipulation of gait variables.

21

CHAPTER THREE

MATERIALS AND METHODS

3.1 Research Design:

The study design utilised quantitative methods to produce numerical data to

establish if the aims and objective of the study have been met. Numerical

data in the form of angles and measurements allowed for accurate data

readings whilst producing both reliable and valid results (Cox et al, 2006).

3.2 Sampling Technique:

The study was advertised through social media channels to Hartpury Collage

(UWE) and The University of Gloucester students using a voluntary

population sampling technique. Participant information sheets and the terms

and conditions of the study where made available on request to those

interested.

Potential participants where required to have an inside leg length of between

30-36” so that a standard 17.5” saddle could be used throughout. An

additional pre-requisite was for the potential participants to be a ‘capable’

rider; it was standardised that rider’s must ride at a minimum of BHS stage 2

or equivalent (BHS 2007). This could be established through verbal/written

affirmation from a BHS qualified riding instructor or BHS equitation

certificates. BHS Stage 2 riding specifications are available in the appendix

1.0.

The population sample was limited to Gloucestershire out of convenience

and due to its thriving equine industry. However, by limiting the sample

population to such a small loci a natural bias may occur thus, it must be

highlighted that the findings of the study cannot be reliably applied to the

entire equine industry.

22

3.2.1 Study Population:

8 ‘capable’ female collegiate riders aged 18-23, height 178.9cm ± 14 and

inside leg length of 83.06cm ± 2.59 (See Appendix 2.0).

3.2.2 Equipment:

The Racewood simulator (mechanical horse) fitted with a 17.5” Wintect

Synthetic GP saddle (E406250) and a 17.5” John Paul show jumping saddle

was used within the study. A list of additional equipment is listed in the

appendix 3.0.

3.2.3 Ethical Considerations:

Participants were required to provide a signed permission slip and where

requested to read the participant information booklet before entering the

study (See appendix 4.0). In both documents and throughout the study it was

clearly stated that participants were free to leave the study at any time.

3.3 Data Collection:

Data collection was undertaken at the Hartpury Collage (UWE), Therapy

yard, Gloucester, over the duration of 2 days.

3.3.1 Marker Placement:

High visibility markers where placed on the right side of the participants

clothing at relevant anatomical points as shown in plate 9; allowing for

accurate analysis of joint angles and measurements. Makers where placed

on the following points: front of toe, posterior point of boot heal, lateral

malleolus (ankle), lateral portion of the condyles of the femur (knee), greater

trochanter of the femur (hip) glenohumeral joint center (shoulder) and lateral

side of hat directly above and parallel to ear. Tight dark clothing was required

to be worn by participants to increase visibility and decrease the

displacement of makers. Appropriate riding gear was also requested for both

health and safety and ease of data collection.

23

Plate 9: High visibility marker placement on lateral side of rider. (Not to scale)

3.3.2 Video Equipment:

A Zodia Zi8 High definition video camera with 720 fps was positioned on a

tripod 3.95m from the mechanical horse at a height of 128.5 cm. This allowed

for the camera to catch the entire view of the study. Figure 1, shows the

setup with relative distances.

Figure 1: Study set-up including camera range of view and key. (Not to scale)

Key:

Mechanical Horse

Camera

Distance

Field of View

24

3.3.3 Data Collection Process:

Each participant underwent strict marker placement, height, inside leg and

thigh measurements before mounting the mechanical horse. Each rider

underwent a 10 minuet warm-up/acclimatisation period before data collection

commenced. Three, one minuet videos and one photo was recorded three

times for each rider in the light seat at canter. A detailed data collection

procedure is shown below in table 1.

Participants where first put into the SJ saddle and asked to shorten their

stirrups to jumping length; as SL was determined through personal choice,

the rider’s position and seat within the saddle was analysed in accordance to

a pre-determined specifications (see appendix 5.0). The test specifications

where designed to ensure the rider was sat correctly in the saddle and that

their riding position was not impaired by the choice of SL. If any problems did

occur the rider’s SL was altered until it met the specifications. This process

was then repeated when the rider sat in the GP saddle.

Table 1: Stage and progression of data collection process. * see appendix

5.0 for test specifications.

Stage:

Description:

Duration:

1

Warm up (walk, trot and canter in both classical and light seat)

10 minuits

2

Mount SJ saddle & shorten stirrup lengh to jumping length. (record length)

2 minuits

3

Check seat position and posture in accordance to the test specifications* . (Alter

stirrup length if neccesary) Photograph rider.

5 -10minuits

4

Video-Light seat- Canter (SJ saddle)

1 minuit

5

Mount GP saddle with previouse stirrup length

1 minuit

6

Check seat position and posture in accordance to the riding specifications.

Photograph rider

5-10minuits

7

Video -Light seat- Canter (GP saddle)

1minuit

If alteration in stirrup length was needed at stage 6; Alter stirrup length to meet the test

specifications and repeat step 7. (record stirrup length & photograph)

Complete stage 7 even if in same stirrup lengh used in SJ saddle even if stirrup lengh needs to be

changed to meet the test specifications.

Breif.

De-Brief

* The test specifications Avaliable in the appendix 3.0

25

3.4 Analysis of Data:

The videos where analysed using Dartfish Software v6 allowing for

quantitative values to be produced (Cox et al, 2006). Rider joint angles where

measured at the same point in the canter stride allowing for accurate cross-

comparison of the study’s findings too previous and future research (Shills et

al, 1993; Kang et al, 2010). Angle measurements were taken 3 times for

each video to discount anomalies and provide an average joint angle. Joint

angles measured by video analysis are displayed in plate 9. The data was

analysed at only the suspension phase of the stride in order to standardise

the point of analysis.

The use of the canter gait increased the relevance and comparability of the

data; as the use of the light seat is encouraged in this gait particularly in the

show jumping discipline (GEF 2003; BHS, 2007). Lower leg stability was

determined by monitoring the movement of the lower leg (lower leg

displacement). This was achieved by finding the point in the stride where the

rider weight distribution was neutral, the heal marker was then tracked for its

displacement along the sagittal plane (GEF 2003; BHS, 2007). See plate 10

for visual explanation. All data gained through analysis was presented in

Microsoft Excel 2010 (See attached CD).

Plate 10: A) Represents the angles being measured in the study. a = hip, b=

knee and c= ankle. B) Represents the heal marker displacement on the

sagittal plane.

a

b

c

26

3.5 Statistical Analysis:

Statistical analysis was performed using the program SPSS 21.0. This

allowed for comparison of data averages and calculation of standard

deviation values from the raw data.

Each rider acted as their own control thus, providing related data sets. The

Kolmogrov-smirnov test was used to establish if the data was parametric; on

confirmation a paired T-test was used determine if there was a significant

difference. A level of 0.05 significance was used for all in all test outputs.

27

CHAPTER FOUR

RESULTS

4.1 Descriptive statistics.

Out of the 12 data collection samples used only 8 of the participants data

could be used for data analysis. Within the methodology there was no pre –

requisite for what discipline the rider competed in. However, it became

apparent in the data collection that the 4 dressage rider’s where less

competent riding at a short jumping length. Because of this the light seat

could not be maintained correctly and therefore, their data was not used for

analysis.

Out of the 3 videos (see table 1) collected for each individual the statistical

analysis focused on only 2 videos; the SJ saddle and the GP saddle with the

necessary lengthened SL. Thus, from this point onwards any reference to the

GP saddles data refers to that of when the SL was altered.

Table 2 shows the descriptive statistics for the SL used in the GP and SJ

saddle. The protocol of the study required the SL used to meet the test

specifications before data collection could begin.

Table 2: Descriptive statistics of SL used in the GP saddle and SJ saddle.

Table 3 shows the descriptive statistics for the rider lower leg displacement

(LLD); with negative referring to the posterior movement of the lower leg and

positive referring to the anterior movement.

Stirrup length (cm)

SJ

GP

MEAN

51.3

54.4

SD

2.8

2.6

28

Table 3: Descriptive statistics for LLD when in the SJ and the GP saddle.

Table 4 shows the descriptive statistics for the population rider body segment

angles when riding in the SJ saddle and GP saddle.

Table 4: Descriptive statistics for rider body segment angles when in the SJ

and the GP saddle.

4.2 Statistical Analysis.

4.2.1 Stirrup length used in the SJ and GP saddle.

One aim of the study was to establish if the SL used in the SJ saddle could

be used in the GP saddle. The test specification found in the appendix 5.0

determined if a SL was suitable for the rider and saddle.

The mean SL used in the SJ saddle was 51.44cm with a standard deviation

(SD) of 2.6; the mean SL increased to 54.78cm with a SD of 2.67 when riding

in the GP saddle. Figure 2 shows the comparison of SL used between the

two saddle types.

SJ SADDLE- LLD (CM)

GP SADDLE-LLD (CM)

NEGATIVE

POSITIVE

OVERALL

NEGATIVE

POSITIVE

OVERALL

MEAN

7.11

4.25

11.36

10.1

2.57

12.66

SD

2.59

2.16

1.87

2.53

1.74

2.09

SJ SADDLE.(DEGREES)

GP SADDLE.(DEGREES)

A

B

C

A

B

C

MEAN

124.37

119.81

66.30

126.04

119.69

69.87

SD:

9.97

10.17

10.04

7.24

9.14

4.90

29

Figure 2: A comparison of SL used in the SJ saddle compared to the GP

saddle for individual participants.

4.2.1.1 Statistical comparison of SL used between the two saddle types.

After a normal distribution was established a Paired T-test was used to

compare the two SL; it was found that the SL used in the GP saddle was

significantly greater than the SL used in the SJ saddle. The statistical output

provided a P-value of 0.000 which was significant at a level ≥0.001. See

appendix 6.0 for statistical output.

4.2.2 Lower leg displacement between saddle types.

The study aimed to establish if there was any significant difference between

rider lower leg stability when in the SJ saddle compared to the GP saddle.

The mean overall LLD when in the SJ saddle was 11.36cm with a SD of 1.87;

when in the GP saddle the overall LLD increased to 12.66cm with a slightly

larger SD value of 2.093, Figure 3 shows that comparison of overall LLD.

0

10

20

30

40

50

60

70

1 2 3 4 5 6 7 8

Length (cm)

Participant

SJ

GP

30

Figure 3: A comparison of overall LLD when in the SJ and GP saddle.

4.2.2.1 Comparison of overall LLD.

After a normal distribution was confirmed a Paired T-test showed there was

no significant difference in overall LLD in the GP saddle in comparison to the

SJ saddle. See appendix 6.0 for statistical output.

4.2.2.2 Positive lower leg displacement between saddle types.

The mean positive LLD (anterior displacement) was 4.25cm with a SD of

2.16 in the SJ saddle; a lower mean positive LLD was seen in the GP saddle

with a value of 2.57cm with a smaller SD of 1.73. Figure 4 shows the

comparison of positive LLD.

0

2

4

6

8

10

12

14

16

SJ GP

DISPLACEMENT (CM)

SADDLE

31

Figure 4: A comparison of positive LLD when in the GP saddle compared to

the SJ saddle.

4.2.2.2.1 Comparison of positive lower leg displacement.

The two data sets showed normal distribution, however a Paired T-test

identified that there was no significant difference between positive LLD in the

SJ compared to the GP saddle. See appendix 6.0 for statistical output.

4.2.2.3 Negative lower leg displacement between saddle types.

The mean negative LLD (posterior displacement) in the SJ saddle was

7.11cm with a SD of 2.59; in the GP saddle the greater mean of 10.1cm with

a marginally smaller SD of 2.54 was recorded for negative LLD. Figure 5

shows the comparison of negative LLD.

0.0

1.0

2.0

3.0

4.0

5.0

6.0

SJ GP

POSITIVE DISPLACEMENT (CM)

SADDLE

32

Figure 5: A comparison of negative LLD when in the GP saddle compared to

the SJ saddle.

4.2.2.3.1 Comparison of negative lower leg displacement.

A normal distribution was established in the two data sets. A Paired T-test

identified that there was a significantly greater negative LLD when in the GP

saddle compared to the SJ saddle. A P-value of 0.041 was significant at

≥0.05. See appendix 6.0 for statistical output.

4.2.3 Body Segment angles between saddle types.

As the degree in which a rider folds into the light seat is dependent on

personal preference then a mean population value will not accurately

represent the individuals within it. This was confirmed with the SD values

which ranged from 7.23- 10.18 thus, highlighting that the mean values

presented in table 4 are not a true reflection. Individual means and SD for

angles A, B and C are shown below in table 5.

0.0

2.0

4.0

6.0

8.0

10.0

12.0

SJ GP

NEGATIVE DISPLACEMENT (CM)

SADDLE

33

Table 5: Individual means angles and SD values when riding in the SJ saddle

and the GP saddle.

A Kolmogorov-Smirnov test for normality established that all angle data

obtained through data analysis was normally distributed. As a population a

Paired T-test showed that there was no significant difference between angles

A, B, and C when riding in the GP saddle compared to the SJ saddle.

4.2.3.1 Comparison of angles between the saddle types.

Individual Paired t-tests identified that 6 of the 8 riders showed to have a

significant difference in one or more angles when riding in the GP saddle

compared to the SJ saddle. All of the riders had P-values significance at a

level ≥0.05.

4.2.3.1.1 Comparison of angle A.

A Paired T-test established that there was a significant difference between

angle- A in 5 of the 8 participants when riding in the GP saddle compared to

the SJ saddle. Of the 5 participants 4 of the individuals angles-A where

significantly greater when riding in the GP saddle and 1 individual angle-A

was smaller. All differences where significant at a level ≥0.05. Figure 6 shows

individual comparisons of angle A. See appendix 6.0 for statistical output.

A SD B SD C SD A SD B SD C SD

1 118.30 3.82 114.17 6.16 70.87 0.40 115.03 4.87 110.50 1.95 73.77 0.95

2 128.30 2.07 128.33 4.17 63.13 3.89 135.30 2.62 123.97 2.35 63.57 1.84

3 109.90 3.21 105.03 1.02 67.50 0.50 118.87 4.05 109.87 4.46 66.33 2.36

5 115.53 4.98 111.27 2.37 68.77 3.58 118.17 2.94 111.63 2.80 74.23 1.91

7 116.13 3.19 134.77 0.86 44.13 0.86 122.90 3.21 128.40 1.97 65.13 1.10

8 120.67 12.33 120.23 1.63 70.83 1.66 130.73 4.30 125.63 1.50 71.90 2.26

9 117.97 4.31 108.30 2.17 77.17 0.95 126.73 1.86 107.47 1.50 77.37 1.31

10 142.20 2.81 120.93 3.41 72.63 0.23 131.07 1.53 128.47 1.80 70.27 0.35

SJ SADDLE ANGLES MEANS & SD

GP SADDLE ANGLES MEANS & SD

34

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

1 2 3 4 5 6 7 8

ANGLE (DEGREES)

PARTICIPANT

SJ-A

GP-A

Figure 6: Comparison of participants angle –A in the GP and SJ saddle.

4.2.3.1.2 Comparison of angle B.

A Paired T-test showed that there was no significant difference in angle –B

when riding in the GP saddle compared to the SJ saddle. 1. Figure 7 shows

individual comparisons for angle- B. See appendix 6.0 for statistical output.

Figure 7: Comparison of participants angle B in the GP and SJ saddle.

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

1 2 3 4 5 6 7 8

ANGLE (DEGREES)

PARTICIPANT

SJ-B

GP-B

35

4.2.3.1.3 Comparison of angle C.

The Paired T-test showed that angle-C was significantly greater in 3 of the 8

participants when riding in the GP saddle compared to the SJ saddle, the P-

values of the statistical output where significant at a level ≥0.05. Figure 8

shows individual comparisons for angle – C. See Appendix 6.0 for statistical

output.

Figure 8: Comparison of participant’s angle – C in the GP and SJ saddle.

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

1 2 3 4 5 6 7 8

ANGLE (DEGREES)

PARTICIPANT

SJ-C

GP-C

36

CHAPTER FIVE

DISCUSSION

5.1 Rationalisation of Methodology:

A key part of the study was to investigate the comparative difference in rider

lower leg stability when in the SJ and GP saddle. This was achieved by

analysing the negative and positive displacement of the lower leg along the

sagittal plane. There is no previous research available regarding rider lower

leg stability and as a result the studies research design was experimental

however, a preliminary study was undertaken in order to develop a more

effective methodology. As the research design was experimental it is not

without fault nevertheless, its development will provide a basis for further

research.

The pre-requisite for participation within the study was for rider’s to be of

capable ability. This was standardised as rider’s having a skill level of BHS

stage 2 or equivalent. The use of BHS stage 2 was chosen due to its syllabus

requiring the rider to have competent ability in the light seat and jumping. As

the use of the light seat was imperative for data collection it was deemed that

this level of skill must be the minimum requirement for participation.

Marker placement and angle calculation was carried out in par to previous

methodologies conducted in papers by Schills, (1993) and Kang et al, (2010).

Similar to other biomechanical research several angle measurements were

taken throughout the data analysis (Schills, 1993; Kang et al, 2010). This

minimised the presence of anomalies and increased the data’s repeatability

and reliability (Schills, 1993; Kang et al, 2010). This process also allows for

the comparison of data sets to new or previous research and subsequently

permits for greater application.

Randal et al, (2010) highlighted the canter gaits wide application throughout

the equine disciplines and the need for further research into horse and rider

interaction within this gait. Therefore, due to the predominance of the canter

37

gait in show jumping and to be in par with future research suggestions only

the canter was used throughout the study.

The study collected data on the mechanical horse as it allowed for the control

and repetition of speed and movement patterns for each participant, whilst

closely mimicking the equine gaits (Lovett et al, 2004; Daniels, 2012).

Therefore, data fluctuations could be accurately applied to the variables

under study.

Research by Lovett et al, (2004) and a dissertation study by Daniels, (2012),

found that there is no significant difference in rider body segment angles at

the different limb impacts of the canter gait. Thus, angle calculations were

taken at only one point in the canter stride and remained consistent for each

participant.

5.2 Comparison of Results to Related Research:

This study into the effect of saddle type on rider stability has produced

repeatable valid data. However, due to individual variance in the execution of

the light seat and the lack of previous research a comparison of numerical

data cannot be made.

5.2.1 Rider stirrup length:

By design the SJ saddle has a more forward cut knee roll which

accommodates for a shorter SL (GEF, 2003). As explained by equitation

manuals it is necessary for a rider to substantially shorten their SL; as a rider

needs to distribute their weight through their heal in order to counteract the

forwards posture of the light and jumping seat (Swift, 1985; Dietz, 1999;

BHS, 2007). This study found that the SL used in the SJ saddle was unable

to be replicated in the GP saddle without jeopardising the rider’s position and

subsequent balance. On average SL had to be lengthened by 3.13cm when

in the GP saddle.

An acceptable SL was deemed appropriate if it met the predetermined test

specifications (see appendix 5.0). All rider’s had to lower their SL when the

same SL used in the SJ saddle was replicated in the GP saddle. The most

38

common violation of the test specifications that resulted in the increase in SL,

was that the rider could no longer sit with their seat bones in the deepest part

of the saddle and that their thigh could no longer run parallel with the saddles

cut (GEF, 2003; BHS, 2007). This impairment of the rider’s seat is thought to

be caused by the GP saddles deeper and shorter seat dimensions that do

not allow for the higher placement of the knee caused by the short SL. As a

consequence, the rider’s seat bones could no longer be placed in the

deepest part of the saddle without their knee being inappropriately placed

over the saddles perimeter. Additionally, the straighter cut of the GP saddle

impaired the rider’s ability to place their knee correctly below the knee roll.

Equitation manuals state that the longer the SL the less ability the rider has

of getting off the horses back without taking their weight through the ball of

the their foot and toes (GEF, 2003; BHS, 2007). When this occurs it is

commonly seen that the lower leg swings back and places the rider in a

forwards balance (GEF, 2003; BHS, 2007). It was found that there was a

significant increase in the negative LLD of riders with the longer SL; a finding

that interlinks with the previous equitation concept. However, this finding

cannot be directly linked the SL as its occurrence was in a different saddle

type to its control counterpart. Therefore, it will be of benefit to investigate the

effects of SL on lower leg stability in the same saddle.

5.2.2 Lower leg stability:

It is explained in equitation manuals that a firm knee and stable lower leg

creates the basis for balance in the light seat (GEF, 2003; BHS 2007). It was

found within this study that rider’s had a significant increase in negative LLD

when riding in the GP saddle compared to the SJ saddle. Posterior

displacement of the lower leg results in an anterior shift in the rider’s CoM

(Back & Clayton, 2001). This shift consequently places the rider’s balance on

the horse’s forehand, as the positioning of the lower leg can no longer

counteract the forwards posture of the light seat (GEF, 2003; BHS 2007).

Rider imbalance particularly when placed anteriorly can influence the

success of a jump effort by impairing the ability of the horse to shift its weight

onto its hindquarters and open up the angle of trajectory at take-off (Clayton

39

& Back, 2001). Therefore, the GP saddles inability to effectively stabilise the

lower leg could potentially impair performance in terms of jump success.

However, the degree of its influence on the approach and landing of a fence

would need investigation.

Previous research into rider stability can loosely be applied to the study’s

findings. Peham et al, (2001), found that complete synchronicity of the horse

and riders CoM minimised and stabilised a riders limit cycle. This concept

would imply that the imbalance caused by instability of the lower leg will

reduce the coupling of the horse and rider, in terms of their harmony in

movement (Peham et al, 2001; Janura et al, 2009). It could also affect the

rider’s ability to predict disturbance in the gait as the impaired synchronicity

will reduce the rider’s ability to percept subtle changes in movement (Janura

et al, 2009). Hence, instability of the rider can not only be of detriment to

jump success but can negatively affect the events between jump efforts.

5.2.3 Rider joint angles:

As a population there was no significant difference between rider joint angles

when comparing the influence of the two saddle types. Nevertheless, as

individuals significant differences where seen in 6 of the 8 participants in one

or more of the recorded angles. However, due to the gap in knowledge

surrounding the subject area, only speculation can be made regarding the

reasons for the change in angle size.

Angle-A (hip) showed to be significantly larger in 4 of the 8 participants when

riding in the GP saddle. Previous studies investigating rider segment angles

in the traditional seat have concluded that advanced riders have a larger

angle of the hip than novice riders (Schills, 1993; Kang et al, 2009). This

occurrence however, is not limited to the traditional seat as a dissertation

study conducted by Daniels, (2012), found similar findings when comparing

rider competence in the light seat. Therefore, if the study’s findings are

compared against previous data then the increase in angle-A when in the GP

saddle would imply a more stable riding posture. However, the increase in

negative LLD when in the GP saddle contradicts the previous stipulation.

40

As discussed in section 5.2.2 the significant increase in negative LLD in the

GP saddle will cause the riders CoM to shift onto the horse’s forehand.

Hence, the increase in angle-A could be the result of the rider actively

opening the hip joint in order to counteract the forwards balance induced by

the swing back of the lower leg (Clayton & Back, 2001). Nevertheless, a

more in-depth study would be required to confirm this concept as the study’s

data can only presume the movement of the CoM.

The knee joint (angle-B) showed to have no significant changes in angle size

between the two saddle types. On visual analysis of the video data it became

apparent that the knee acted as a pivot in which the upper and lower body

rotated around (Clayton & Back, 2003; Jahiel, 2013). This finding interlinked

with the fact that there was no significant change in angle-B. As the increase

in negative LLD displacement should have suggested that the angle of the

knee became more acute. Thus, the concept of the knee acting as a postural

pivot explains why no significant change was recorded.

Angle- C (ankle) was significantly increased in 3 of the 8 participants when

riding in the GP saddle. The GEF, (2003), suggests in par to other equitation

manuals that a too long a SL when executing the light seat results in the rider

taking their weight through their toes (BHS 2009). This concept could relate

to the increase in angle-C in 3 of the participants as the distribution of weight

through the toe increases the angle of the ankle. However, this increase only

occurred in 3 of the 8 participants and therefore, is not a significant change

when viewed as a population.

5.3 Study Limitations:

5.3.1 Population sample:

The studies time scale and complexity dictated the small population sample

of the study (n=8) nevertheless, its number is not dissimilar to previous

studies such as that by Kang et al, (2009) where a total of 9 participants

where used. However, the small population sample does impair the studies

validity and application to the wider equestrian public.

41

The smaller population sample also reduced the statistical power of the

Paired-test as it produced some p-values that where only marginally greater

than the 0.05 significance level. If the population size was greater it would

have been probable that the data output would have been significant.

Therefore, it would be beneficial to complete a similar study with a larger

population size in order to strengthen the validity of the study’s findings.

BHS stage 2 was the minimum requirement for participation within the study

however, no upper boundary was set to standardise the experience of the

rider. This lapse in standardisation could influence the results of the data, as

studies into rider competence suggest that a more experienced rider can

better stabilise and predict the onset of unbalance (Peham et al, 2001 Janura

et al, 2009). However, as each rider acted as their own control and statistical

analysis was carried out both as a population and individually the influence of

this limitation is minimised.

5.3.2 Mechanical Horse:

Use of the mechanical horse within the study allows for the control of external

influences, whilst closely mimicking the motion pattern of a live horse (Lovett

et al, 2004; Daniels 2012unpublished). However, due to the angled

placement of the girth on the mechanical horse the saddle sat in an “uphill”

posture. This meant that the rider could not effectively use the knee support

of the saddle whilst in motion. This factor could influence the validity of the

results however, as the girth placement brought about the same effect in both

saddles its influence became standardised. Nonetheless, its occurrence does

impair the studies comparability to a live horse as the positioning of the

saddle would differ and may bring about a different effect.

5.3.3 Marker displacement:

As like previous biomechanical research, markers where placed the surface

of tight clothing (Schills, 1993; Lovett et al, 2004; Kang et al, 2009; Janural et

al, 2009). This method results in the common limitation of displacement error

(Maslen & Ackland, 1994). Maslen & Ackland (1994) found that the largest

discrepancy between skeletal and surface markers was seen on the rotation

42

of a joint. Thus, as riding relays on subtle changes in motion through flexion

and extension, there is a reduced potential for large displacement errors. The

method of surface marking is also non-invasive and requires no ethical

approval, because of this and the experimental nature of the study surface

markers where deemed more appropriate.

5.3.4 Saddles:

The basic design of the SJ saddle and GP saddle is consistent throughout

the equine industry. However, the dimensions of the saddle flap and seat

vary with each manufacturer. Therefore, the conclusions of the study cannot

be accurately applied to saddle makes different to those used in the study.

5.4 Suggested areas of further research:

The current study investigated the SJ saddle suitability in the canter gait

however; the design of the SJ saddle is to optimise a rider position over the

jump. Therefore, it would be beneficial to investigate the stabilising effect of

the SJ saddle over the jump with particular reference to rider position on

approach, take-off and landing.

With the lack of research into the area of saddlery it would be advantageous

to investigate the effects of other discipline specific saddle designs, such as

the dressage saddle on rider biomechanics. Achievement of such data will

allow for a better understanding of the relationship between rider and saddle,

and how certain designs and fits can either negatively or positively influence

rider performance. A better understanding of the saddle and rider relationship

will also allow for the advancement of saddle designs in favour of both the

horse and rider and educate the equine public on saddle choice.

Rider body segment angle research in the light seat is limited. Therefore,

there is a need for further investigation on rider angles when executing the

light seat on a live horse. Provision of such information will provide a basis

for comparison in other rider biomechanical studies and will provide valuable

knowledge to the couching industry in optimising rider position.

43

CHAPTER SIX

CONCLUSION

The main aim of this exploratory study was to investigate the suitability of the

SJ saddle and GP saddle for use in show jumping, with particular reference

to rider SL and lower leg stability in the light seat.

Research into rider position has repeatedly highlighted the negative influence

of an incorrect riding position on equine gait kinematics. In terms of saddlery

there is growing portfolio of research investigating the effects of an ill-fitted

saddle on the horse. However, there is still a gap in knowledge regarding

saddle variables such as saddle fit and design and its influence on rider

biomechanics.

The results of the study found that the jumping SL used in the SJ saddle

could not be replicated to an acceptable standard in the GP saddle; as the

straighter cut and deeper seat did not allow for the correct placement of the

knee and seat bones. Therefore, the SL had to be lengthened. This

lengthening of the SL increased the posterior displacement of the lower leg

when in the light seat and thus, created an incorrect forwards balance. Such

scenario was not replicated in the SJ saddle, as the more forward cut and

shallower seat allowed for the higher placement of the knee. As a result the

SJ saddle could sufficiently contain and better stabilise the rider’s lower leg.

From this preliminary study it can be assumed that the SJ saddle can

optimally maintain and stabilise the rider’s position in the light seat and thus,

it is suitable for use in show jumping. Conversely, the GP saddle cannot

structurally support the shorter SL needed in the light seat without impairing

the riders position hence, it cannot meet the specific rider demands for use in

show jumping. This conclusion will allow for the recognition of the effect of

saddle type on rider position in future biomechanical research and will

provide knowledge to both coaches and riders into the benefits of training

with either saddle type.

44

LIST OF REFERNCES

Adam Elis (2013) Close Contact jump saddle. [photograph]. Adam Ellis of UK

saddles. Available through: http://www.uksaddlesltd.com/products/close-

contact-jump-saddle.html [12.03.13]

Alfredson, H., Hedburg, G., Bergstrom, E., NordstrÖm, P. & Lorentzon, R.

(1998) High thigh strength but not bone mass in young horseback riding

females. Calcified Tissue International. 62, pp. 497-501.

Back, W., Clayton, H. (2001) Equine locomotion. First edition. London:

Harcourt Publishers Limited.

BEF (2013) British Equestrian Federation. Available from: www.bef.co.uk

[10.03.13]

Benke, G. (1934). Generic in the various studies and utilized for determining

the center of gravity of horses and changes. Contribution to the determination

of Focus change in horses Thesis .Budapest.

Bobbert, M., Santanmaria, S. (2004) Contribution of the forelimbs and

hindlimbs of the horse to mechanical energy changes in jumping. The

Journal of Experimental Biology. [online] 208, pp.249-260. Available through:

Science Direct [11.11.12]

Breen Equestrianism (2013) Showjumping two point seat. [photograph].

Breen Equestrianism. Available through: http://www.breenequestrian.com/

[12.03.13]

BSJ (2013) British Show Jumping. Available from:

www.britishshowjumping.co.uk [13.02.13]

Buchner, H., Obermuller, S., Schield, M. (2000) Body center of mass

movement in the sound horse. The Veterinary Journal. [online] 160, pp. 225-

234. Available through: Wiley online Library [8.11.12]

Clayton, H. (2003) The Dynamic horse. First edition. Mason: Sports Horse

Publications.

Clayton, H., Colborne, G., Lanovaz, J., Bums, T. (1996) Linear Kinematics of

water jumping in Olympic show jumpers. Pferdeheikunde. [online] 12(4), pp.

657-660. Available through: Google Scholar [11.11.12]

45

Cox, D., Commenges, D., Davison, A., Solomon, P. & Wilson, S. (2006) The

Oxford Dictionary of Statistical Terms. Sixth Edition. Oxford: Oxford

University Press.

Daniels, E. (2012) Effect of Rider Competence on stability in the ‘light- Seat’

Position during canter. Dissertation. BSc (Hons). University of the West of

England.

[1] De Cocq, P., Duncker, A., Clayton, H., Bobbert, M., Muller, M. (2010)

Vertical forces on the horses back in sitting and rising trot. Journal of

Biomechanics.[online] 43, pp627-631 Available through: Science Direct

[15.11.12]

[2] De Cocq, R., Mooren, M., Dortmans, A., Weeren, P., Timmerman, M.,

Muller. M. & Leeuwen. (2010) Saddle leg forces during lateral movements in

dressage. Equine Veterinary Journal. [online] 42(38),pp. 644-649. Available

through: Science Direct [2.12.12]

Dietze, S. (1999) Balance in Movement, The seat of the Rider. First edition.

London: J.A. Allen & Co Ltd.

Discover Ireland (2013) Race horse and jockey. [photograph]. Discover

Ireland. Available through: http://www.discoverireland.com/gb/about-

ireland/experience-ireland/festivals-and-events/horses-and-horse-racing/

[12.03.13]

Douglas, J., Price, M. & Peters, D. (2012) A systematic review of physical

fitness, physiological demands and biomechanical performance in equestrian

athletes. Comparative Exercise Physiology. 8(1),pp.53-62.

Dressage Today (1996) Dressage Today Magazine. Available from:

http://www.equisearch.com/magazines/dressage-today/ [10.2.13]

FEI (2013) Ferderation of Equestre Internationale. Available from:

www.fei.org [13.02.13]

Galloux, P., Barry, E. (1997) Components of the total kinetic moment in

jumping horses. Equine Veterinary Journal. [online] 29(23), pp41-44.

Available through: Science Direct [11.11.12]

German National Equestrian Federation. (2003) The principles of Riding.

Second Edition. Addington: Keniworth Press.

46

Heleski, C., McGreevy, P., Kaiser, L., Lavagnino, M., Tans, E., Bello, N. &

Clayton, H. (2009) Effects of behaviour and rein tension on horses ridden

with or without martingales and rein inserts. The Veterinary Journal. 181(1),

pp. 56-62

Iron Gatewell (2012) Cross country Seat. [photograph]. Iron Gatewell.

Available through: http://www.irongatewell.com/horses/competition/eventing/

[04.12.12]

Jahiels, J. (2012) Jessica Jahiel’s Horse-Sence- The Newsletter of Holistic

Horsemanship. Available from: http://www.horse-

sense.org/archives/dealhuma.php [31.12.13]

Janura, M., Peham, C., Dvorakove, T. & Elfmark, M. (2009) An assessment

on pressure distribution exerted by a rider on the the back of a horse during

hippo therapy. Human Movement Science. [online] 28, pp. 387-393.

Available Through: Google Scholar [11.1.13]

Kang, O., Ryu, Y., Ryew, C., Oh, W., Lee, C. & Kang, M. (2010) Comparative

analysis of rider position according to skill levels during walk and trot in jeju

horse. Human Movement Science. [online] 29, pp.956-963 Available through:

Science Direct [18.11.12]

Lewczuk, D., Sloniewski, K., Reklewski, Z. (2006) Repeatability of the horses

jumping parameters with and without the riders. Livestock Science. [online]

99, pp.125-130 Available through: Science Direct [2.11.12]

Life and Horses (2013) Traditional dressage seat. [photograph]. Life and

Horses. Available through: http://www.lifeandhorses.com/category/all-items-

related-to-dressage/ [13.03.13]

Lovett, T., Hodson-Tole, E., Nankervis, K. (2004) A Preliminary investigation

of rider position during walk, trot and canter. Equine Comparative Exercise

Physiology. 2(2).pp.71-76.

LRGAF (2012) Horses center of mass. [image].The long guild academic

foundation. Available through: http://www.lrgaf.org/articles/saddles21stc2.htm

[12.03.13]

Maslen, A. & Ackland, T. (1994) Radiographic study of skin displacement

errors in the foot and ankle during standing. Clinical Biomechanics. [online]

9(5), pp.291-296. Available through: Science Direct [12.03.13]

47

Meershoek, L., Schamhardt, H., Roepstorff, I., Johnston, C. (2001) Jumping

a horse smaller or equal to 1m , has little effect on COM mass displacement

and subsequently causes little more effect than canter stride. Equine

Veterinary Journal. [online] 33(33), pp. 6-10. Available through: Wiley Online

Library [11.11.12]

Meschan, E., Peham, C., Schobesberger, H., Licka, T. (2007) The influence

of the width of the saddle tree on the forces and pressure distribution under

the saddle. The Veterinary Journal. [online] 173, pp.578-584. Available

through: Science Direct [8.11.12]

Meyers, M. & Stirling, J. (2000) Physical, haematological and exercise

response of collegiate female equestrian athletes. Journal of Sports Medicine

and Physical Fitness. 40, pp. 131-138.

Meyers, M. (2006) Effect of Equitation training on health and physical fitness

of collage females. European Journal of Applied Physiology. 98, pp.177-184.

MIllbry Hill (2013) Wintec VSD Horse saddle. [photograph]. Millbry Hill- for

people who love animals. Available through:

http://www.millbryhill.co.uk/equestrian-530/horse-saddlery-584/horse-

saddles-595/wintec-saddle-saddles-5302.htm [12.3.13]

Moore, G. (2010) General Biomechanics: The horse as a Biological Machine.

Journal of Equine Veterinary Science. 30, pp.379-382

Nauwelaerts, S., Kaiser, L., Malinowski, R. & Clayton, H. (2009) Effect of

trunk deformation on trunk center of mass mechanical energy estimates in

the moving horse. Equus caballus. Journal of Biomechanics. [online] 42, pp.

308-311. Available through Science Direct [1.12.12]

Peak Performance (2013) Body Somatotypes. [image] Peak Performance-

Sporting Excellence. Available through:

http://www.pponline.co.uk/encyc/body-type-training-are-we-slaves-to-our-

body-type-genes-39798 [12.03.13]

Peham, C., Kotschwar, A., Borkenhagen, B., Kuhnke, S., Molsner, J.,

Baltacis, A. (2010) A comparison of forces on the horses back and the

stability of the riders seat in different positions at trot. The Veterinary Journal.

[online] 184, pp. 56-59. Available through: Science Direct [19.11.12]

48

Peham, C., Licka, T,. Schobesberger, H., Meschan, E. (2004) Influence of

the rider on the variability of the equine gait. Human Movement science.

[online] 23, pp.663-671. Available through: Science Direct [1.10.12]

Peham, C., Licka, T., Schobesnerger, H. & Meschan, E. (2004) Influenvce of

the rider on the variability of the equine gait. Human Movement Science.

[online] 23(1), pp. 663-671. Available through: Science Direct [12.10.12]

Pony Club. (2007) The manual of Horsemanship. Thirteenth Edition.

Amersham: Halstan & Co Ltd.

Print, P. (2011) The BHS Complete Manual of Equitation. The Training of the

horse and rider. First Edition. London: Kenilworth Press.

Randle, H., Edwards, H. and Button, L. (2010) The effect of rider Position on

the stride and step length of a horse at canter. Journal of Veterinary

Behaviour. [online] 5, pp.219-220. Available through: Wiley Online Library

[15.11.12]

Roberts, M., Shearman, J. & Marlin, D. (2009) A comparison of the metabolic

cost of the three phases of the one day event in female collegiate rider.

Comparative Exercise Physiology. 6, pp.129-135.

Roxanne Wilson (2013) Body shapes [image] Roxanne. Available through:

http://www.roxannewilson.com/body-quiz-what-is-the-most-common-female-

body-shape/ [12.03.13]

Swift, S. (1985) Centred Riding. First Edition. London: R.J. Actford Ltd.

Symes, D. and Ellis, R. (2009) A Preliminary study to rider asymmetry within

equitation. The Veterinary Journal. [online] 181,pp.34-37. Available through;

Science Direct [12.11.12]

Terada, K., Mullineaux. D., Lanovaz, J., Kato, K. & Clayton, H. (2004)

Electromyographic analysis of the rider muscle at trot. Equine Comparative

Exercise Physiology. [online] 1(3), pp. 193-198. Available through: Google

Scholar [12.1.13]

The British Horse Society (2007) Riding Manual. First Edition. London:

Harper Collins Publishers.

49

The Chronicle of the horse (2013) Correct Rider Position. [photograph]. The

Chronicle of the horse. Available through: http://www.chronofhorse.com

[13.03.13]

Tiago, Z., Arruda, D., Bass, K., Flavio, D,. Corte, D. (2011) Thermo graphic

assessment of saddles used on jumping horses. Journal of Veterinary

Science. [online] 31, pp. 625-629. Available through: Science Direct [1.10.12]

Trowbridge, E., Cotterill, J. & Crofts. (1995) The physiological demands of

riding national hunt races. European Journal of Applied Physiology. 70,

pp.66-69.

Westerling, D. (1983) A study of physiological demands of riding. European

Journal of Applied Physiology. 50, pp. 373-382.

Wilmore, J., Costill, D. & Kenny, L. (2008) Physiology of sport and exercise.

Fourth Edition. Champaign: Human Kinetics.

Winfield , J. & Lewis, V. (2012) Saddle and body shape. [online]

http://www.jowinfield.com/wp-content/uploads/2012/01/Riding-in-the-right-

saddle.pdf [17.1.13]

50

APPENDICIES

1.0 BHS Stage 2 riding criteria:

“The learner will be able to ride schooled horses independently and working

as a ride in an enclosed environment. They must be confident and competent

riding horses with and without stirrups in all three paces, and with the reins in

one hand. Their position must be established, showing balance and security

and a degree of ‘feel’. They will be able to build up a rapport and work in

harmony with various types of horse and show an understanding of the basic

principles of riding from leg to hand. They will show an ability to assist the

horse in keeping its balance during a range of school movements. The

learners’ independent, well balanced and secure seat should be established

at this level. This will enable the learner to progress their confidence and

competence in being able to further positively influence the horse’s way of

going.” (BHS, 2012)

And

“The learner will be able to show a secure, independent balanced jumping

position. They must be confident and competent jumping horses over a

course of fences up to maximum of 2ft 6ins (76cm). Their position must be

established, showing balance and security and a degree of ‘feel’. They will be

able to build up a rapport and work in harmony with various types of horse.

They will show an ability to assist the horse in keeping its balance round a

course of fences. The learners’ independent and well balanced jumping

position should be established at this level. This will enable the learner to

develop their skills and ability to jump horses over more difficult fences and

courses.” (BHS, 2012)

2.0 Participant details:

Key:

*Thigh measured: From crease of groin to the top of patella.

**Calf measured: posterior tibiofemoral joint crease to heal.

51

3.0 Additional Equipment:

1× tripod

2× Stirrup leathers & irons

2× Pack of reflective markers

1× Tape measure

2× Laptops

1× Camera (8mp)

No. Age Height (cm) Inside leg (cm) Thigh* (cm) Calf** (cm) Discipline:

1

20 171 79 38 48 SJ

2

21 172 80 38.5 48 E

3

21 181 84.5 41 47.5 SJ

5

21 181 86 41 49 SJ

7

18 179 81.5 39.5 50.5 SJ

8

23 185 85.5 43.5 51 HACK

9

21 184 86.5 44 51 SJ

10

22 178 81.5 44 46.5 HUNT

SD

5 14 2.59 2.23 1.81

Average: 20.88 178.88 83.06 41.19 48.94

52

4.0 Participant permission Slips & Information Booklet.

Participant Participation Form:

Title of Investigation:

An investigation into the effect of saddle design on rider lower leg position

when using the light seat.

Participant

Name:……………………………………………………………………………

Address:………………………………………………………………………………

…………………………………………………………………………………………

……………………………...........

Contact Number/s:………………………………………………………

Email Address:……………………………………………………………

I in the capacity of the rider, herby give my permission

(Name)………………………………….. To participate in the stated study,

where I will ride the mechanical horse through different gaits in two different

saddles and will partake in the following procedure:

I understand that data collected will be stored and used in par with Data

Collection Act 1998 and that data collected will be monitored by our

supervisor to enable any individuals to be removed from the study at our

request.

53

If you are under 18 years of age, you must be granted permission from a

parent/guardian before participating in the study. Therefore, before you

partake in the study permission should be gained.

(Please circle appropriate answer)

I am aged 18 or older: Y/N

I am aged under 18: Y/N (if under 18 please fill in the following)

I as the parent/Guardian of (Name)……………………………………….. herby,

give permission for (Name) to partake in the stated study.

Signature of parent/Guardian:

……………………………………………………………

Please read the following and tick in the designated boxes:

I understand that all data will be kept in accordance with the Data Protections

Act 1998 and that it will be kept anomalous and used only for this dissertation

study.

I understand that I can withdraw from the study at any given time, without

reason.

I have no past of present injury that will hinder my ability to participate in the

study. Therefore I declare myself fit to ride.

I am a competent rider that can ride to a minimal level of BHS stage 2 or

equivalent:

Please sign to agree with terms and conditions of the study above:

Sign………………………………………………………………………Date…/…./

….

Print……………………………………………………………………………………

….

54

Participant Information booklet:

Name: Amanda Purchas

Supervisor: Vicki Lewis

Contact Details: amanda.bashar@btinternet.com / 07824306297

Dissertation title:

An investigation into the effect of saddle design on rider lower leg position

when using the light seat.

Invitation to participate:

My name is Amanda Purchas; I am currently undertaking a degree in Bsc

Equine Sports Science at Hartpury Collage (UWE) and I would like to invite

you to participate in my dissertation study. For you to gain full benefit from

the participation in the study and to allow you to decide with confidence; it is

important that you understand the reasons for the proposed dissertation

study.

Please do not hesitate to contact me regarding and concerns or queries

throughout the data collection process. Please take time to read the

following. Please remember there is no pressure to partake in the study and

that you may leave the process at any given time. Thank you for your time.

The purpose of the study:

The purpose of my study is to determine if the General Purpose (GP) saddle

less forward cut allows for the rider to optimally shorten their stirrup length for

show jumping with reference to the ‘light seat’ and whether the GP saddle

can correctly accommodate the lower leg position without interfering with the

correct riding posture. Conversely, I will investigate if the show jumping

saddle exaggerated design better accommodates the ‘light seat’ as it

suggests. I will also investigate whether there is any difference in lower leg

stability in both the GP saddle and show jumping saddle.

What data and data type will be collected?

I will collect body segment angles, by using body markers (Placed on top of

clothing on pre-determined points) I will also collect data on lower leg stability

using markers placed on the hip and heal. All of the described data will be

collected in the form of video. This data will then be analysed using Dartfish

video anaylsis software.

55

Leg length and stirrup length will be recorded throughout the study.

Do I have to take part?

No. All invited participants will only partake in the study under their own

choice there will be no pressure to partake and the individual regains the

right to leave the study at any time.

If you would like to partake in the study a permission form highlighting the

terms and agreements of the study will be forwarded to yourself and

returned.

Are there any pre-requisites for partaking in the study?

Yes. I will require you to ride at a minimum level of BHS stage 2 or

Equivalent, this will allow me to standardise my population sample as it

means all riders should have a competent riding posture.

I will also require a long leg to body ratio this will make data analysis easier

and 27-33inch inside leg length.

Is there any specification on clothing or equipment to be worn or

brought?

Yes. In order to make data analysis easier on myself and increase the

accuracy of the study, participants will be required to wear tight dark clothing;

preferably blue or black. They will also be required to wear correct riding

boots and to bring and wear a fitted helmet. Gloves may be worn but they will

remain as an optional item.

What Process will I under go in the study:

After signing the Participant permission form and understanding the

requirements of the study the participants will undergo the following:

Step 1:

Leg length measured:

- Inside leg length

- Thigh length

- Calf Length

Height measured.

Step 2:

56

Using sticky paper markers (glue used will be machine washable) I will mark

up your:

- Hip

- Knee

- Ankle

- Toe

- Heal

- Shoulder

- Ear (marker will be placed in line with ear on on the hat)

Step 3:

After putting on a fitted riding hat; mount mechanical horse in the show

jumping saddle and shorten/lengthen stirrup length to jumping length.

(Stirrup length will be recorded)

- To ensure the stirrup length does not impair your position, I will

analyse your position to ensure that your position meets the

guidelines stated in the BHS- Equitation manual.

- This will involve:

o Visually analysing the alignment of body segments

o Ensuring you are sat correctly in the saddle

Step 4:

Complete 5 minuet warm up on mechanical horse; in all four gaits, using both

a mix of the light seat, deep seat and rising seat.

Step 5:

1) A static photo of you in the deep seat will be taken and then in the light

seat.

2) 1 video will be recorded of you in a steady canter gait in the light seat

for duration of 1minuit.

Step 6:

Dismount from mechanical horse, and GP saddle will be swapped for the SJ

saddle. The same stirrup length will then be transferred onto the GP saddle.

57

You will mount into the different saddle.

Step 7:

I will then ask you if you feel the need to alter your stirrup length. I will then

carry out the same analysis of your position as stated prior in addition to

ensuring that your leg is sat correctly into the saddle i.e:

- Your knee does not extend that of the knee flap.

- You are sat correctly in the seat of the saddle.

If by strict analysis I determine that the stirrup length does not allow for you to

sit in the saddle correctly and impairs the correct riding posture; I will alter

your stirrup length until all required saddle and postural requirements are

met. However, this will occur after repeating steps 4 & 5.

If stirrup length is to be altered a 3

rd

cycle of step 4 & 5 will be completed with

the altered stirrup length.

Step 8:

I will then debrief ; which will include what will now happen with your data as

well as ensuring that all information gained will be kept and stored in the

correct manor.

Are there any risks to the study?

Yes. However, the risks are small. As I require you to be a competent rider,

who can ride at a minimum of BHS stage 2 or equivalent and you will be

riding a mechanical horses whos motion is predictable and controlled, the

risk of a falling off the mechanical horse is low. However, the following safety

measures will be made:

- A Gym mat will surround the mechanical horse, to prevent

concussive forces if you were to fall.

- You will be required to where a fitted hard hat.

- A emergency stop button is present on the mechanical horse in the

case of an incident.

- You will be allowed any reasonable time acclimatise to the motion

of the mechanical horse.

To prevent an exercise strain injury a 5 minute warm-up on the horse will be

allowed.

58

Are there any drawbacks to the study design?

Yes. By using the mechanical horse it allows me to standardise the speed

and gait of the ‘horse’, however the motion of the mechanical horse does not

100% mimic a real horses motion therefore, it may lack a degree of

comparability.

I will also have to use one standard saddle size, meaning that the saddle

may not fit each of the riders perfectly; however, I hope to overcome this by

standardising the thigh length of the riders.

What if something goes wrong?

If at any stage you feel that you have any concerns with any part of the study

please do not hesistate to contact me at: amanda.bashar@btinternet.com or

my supervisor at: vicki.lewis@hartpury.ac.uk .

What will happen with my information?

All document associated with yourself and all study data will be stored in line

with regulations stated by the Data Protections act 1988. It will be used for

this study and this study only and will be disposed of appropriately after the

full completion of the dissertation study.

You will remain the right to claim any data regarding yourself at any point in

the study and may request the findings of the study.

What will happen with the results and dissertation findings?

They will be presented to Hartpury collage (UWE) within the completed

dissertation and will be stored both manually and electronically. I hope to

publish my findings and if such scenario occurs the dissertation will be

presented in an appropriate journal.

How do I sign up?

Email me at: amanda.bashar@btinternet.com and I will send you the

participant permission documents which can be filled in and handed in on the

day of research.

When will I know when the study is taking place?

I will email you with the time and dates of the collection after you have

verbally confirmed your attendance.

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If you have a Facebook account you will have been likely invited to ‘Mandy’s

Dissertation’ Event; I will post information regarding times and changed to the

data collection schedule. If you do not have Facebook the same information

will be passed onto yourself by email.

Where will the data collection be held?

The Therapy yard.

Hartpury Collage

Gloucester Road

Hartpury

Gloucester

GL19 3BE

Thank you for your interest and time! I hope to see you soon.

Many thanks

Amanda Purchas

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5.0 Test Specifications:

(To be used in conjunction with data collection to ensure stirrup length is

SUITABLE and DOES NOT impair the riders ability to sit correctly in the

saddle or sit with the correct riding posture)

Saddle:

1) Ensure the rider’s seat bones are set in the deepest part of the saddle

seat.

2) Ensure the rider’s knee does not overlap the saddle flap and the knee

is set into the knee role of the saddle.

3) The thigh of the rider should run parallel to the cut of the saddle flap.

Rider Position:

1) Ensure riders body aligned in accordance to BHS equitation guidelines

as seen visually below. (Vertical line should be visually seen starting

from the ear to the shoulder, elbow, hip, knee and ankle)

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6.0 Statistacle output:

Kolmogrov-Smirnov Test for normality output :

1) Overall LLD – SJ saddle

2) Overall LLD– GP DIFF saddle

3) SL used in SJ saddle.

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4) SL used in GP saddle.

5) Negative LLD in SJ saddle.

6) Negative LLD in GP DIFF saddle.

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7) Positive LLD- SJ saddle

8) Positive LLD – GP DIFF saddle

9) Body segment Angles. GP & SJ saddle.

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Paired T-test outputs. Key: (Red- No sig diff/ Pink- Near but no sig diff/ Green- sig diff)

10) Positive LLD – SJ and GP DIFF saddle.

Paired Samples Test

Paired Differences

t

df

Sig. (2-tailed)

Mean

Std. Deviation

Std. Error Mean

95% Confidence Interval of the

Difference

Lower

Upper

Pair 1

SJPOS - GPDIFFPOS

1.68250

3.00711

1.06318

-.83151

4.19651

1.583

7

.158

11) Negative LLD- SJ and GP DIFF saddle.

Paired Samples Test

Paired Differences

t

df

Sig. (2-tailed)

Mean

Std. Deviation

Std. Error Mean

95% Confidence Interval of the

Difference

Lower

Upper

Pair 1

SJNEG - GPDIFFNEG

-2.98500

3.36670

1.19031

-5.79963

-.17037

-2.508

7

.041

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12) Overall LLD- SJ Vs GP DIFF saddle.

Paired Samples Test

Paired Differences

t

df

Sig. (2-tailed)

Mean

Std. Deviation

Std. Error Mean

90% Confidence Interval of the

Difference

Lower

Upper

Pair 1

SJO - GPDIFFO

-1.30250

1.77039

.62593

-2

An investigation into the effectiveness of saddle design and its influence on rider lower leg position when using the light seat. Amanda Purchas 18th March 2013

Abstract and Figures