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Centaur Biomechanics Conference, Part 3: Asymmetry of the rider, by Helen Mathie, Physio

Screen shot 2013-06-25 at 20.06.30Asymmetry of the Rider (and its effects on the horse.)
(Helen Matthey is the Physiotherapist to Team GB ParaEquestrian Squad.)

The horse has approximately 200 bones, 700 muscles, 1 brain, and rapid acceleration/deceleration (0-60kmh in seconds.)
The rider has 200 bones, 700-850 muscles, and a highly developed brain.

This can make for two systems working in complete harmony… or carnage!

The rider must have:
A stable base, and the ability to move and control movement, absorbing that of the horse.
The ability to react to dynamic movement, cope with a stumble/spook/rapid acceleration.
The rider must be supple but flexible, not floppy.
A very delicate balance.

Differences in Anatomy –  Male vs Female.

We compete on equal terms despite anatomical and muscular differences.
Males are bulkier with shorter muscles, but longer tendons, which help in the generation of force.
The males’ shoulder girdle is broader, and they have a narrower pelvis than females.
The pelvis shape differs: male is generally narrow and tall, female is short and wide. (But of course there are variations within the sex – some women have a wider, or narrower, pelvis.)
This has an impact on SADDLE FIT.

The femur/tibia length ratio differs. Females tend to have a longer femur and be shorter from knee to ankle, but overall their leg may still be the same total length as a man’s, just the ratio differs.
The thigh bone in particular is usually longer in FEMALES.


How you doin’?

This photo brought a ripple of appreciative laughter from the audience.
The stereotypical male physique. Visually pleasing.
What is appealing about it?
The body proportions. The symmetry.

Certain body types predispose you to be more successful as a rider. E.g. a big heavily-muscled rugby player would be a less ideal shape for riding.

Then we moved onto asymmetry.
Your horse might do a crooked halt because you are weighting one seat bone more than the other.

Do you weight 1 leg more than the other when standing? Most people do, because it is easier.

Get someone to look at you off the horse.
Have someone check your “Q angle” – the line from the quadriceps through the knee. (There are videos on youtube!) There’s usually bigger angle in females, this affects the position of your lower leg against the saddle flap. It may roll the thigh out for comfort, it tightens the hip joint ligaments and decreases pelvic movement.

Hip mobility is important, otherwise it will prevent pelvic movement.

Male vs Female ability to dissociate (move – flex/extend) the pelvis. Women are usually better at this. If you can flex/extend the pelvis you can absorb the horse’s movement better.

Body Proportions:

The pelvis divides the body in 2, the upper and lower body.
short upper body (thorax and back) with a longer lower body (legs) = easier to balance on a horse than the converse, because of levers and the centre of gravity.

Shoulder width to pelvis width ratios.

Arm length re: positioning of hands. Elbow to hip (iliac crest) vs lower thorax length.

William Fox-Pitt is the ultimate example: his very tall upper body is a very long lever, he must have a VERY strong core to stay there and never collapse forward.

Ladies tend to have bigger bottoms!

Someone with a narrower shoulder girdle will struggle to come round their corners more with their shoulders.

Can you keep your elbows on top of your hip bones? Or, if you have shorter arms (or a very long torso), won’t they reach?

The body is designed to MOVE!!!
We are hunter-gatherers.

The incidence of LBP (lower back pain) in children, and the obesity epidemic.

Joints get nutrition from synovial fluid during compression, i.e. whenever they are moved. Lack of this leads to the start of arthritis and stiffness.

Muscles are designed for contraction/extension. Problems of disuse or over-use.

Bones – loading forces maintain bone density, especially for females, especially in later life. Prevent osteoporosis/osteopaenia.

Nervous system – use it or lose it. Muscle memory.

Horses are the same!

We are seeing more and more arthritis due to people living longer.

Requirements of the rider:
Suppleness             Fitness        Strength         Flexibility         Co-ordination         Balance    Stability     Precision           Ability            Psychological State         Hydration          Nutrition        Education    Timing


Injury       Imbalances       Asymmetry
Weak and Long  vs Tight and Short

Common problems:

Collapsing through hip

Back pain (excess spinal movement)

Stiff pelvis (blocked by hip joints)

Fixing arm or leg

Dominance 1 side or the other

Riders will cheat, e.g. collapse Right hip due to weakness, then their right arm will go tight and fixed to compensate.

Tight through hip restricts the hip joint and thus the leg aid becomes confused – lateral work influenced.

Mirrors are very useful, also someone on the ground.

The horse always likes to step under the weight of the rider.

Pain & Dysfunction – why?

Direct trauma:
Fractures. Conservative vs surgical management.
Soft tissue injuries.
Head injuries.

Overuse injuries – strains and sprains

Accumulation of micro-trauma over time.

Pain/inflammation/structural fatigue = weakness

Pain – difficult to quantify because it is personal.

Fracture x-ray – after a kick from a young horse. A top trainer/rider, badly broken lower leg.
Left with that leg shorter, she is managing the ongoing problem by wearing a heel wedge, having regular soft tissue support. Regular maintenance is required because of the compensation.

Neck and Back pain.

Spinal anatomy – C7, T12, L15, Sacrum. 7 cervical vertebrae. Atlas, Axis, C3-C7.

Headaches – block at C2-C3, which is where the back of a riding hat sits. The head position when in the forward/jumping seat (head forced back further than it would be with torso upright).

Falls – whiplash – the neck is the most mobile segment of the spine, therefore it is likely to get injured. Neck pain can affect balance and visual ability.

Muscle imbalances & problems.

Natural curves of the spine.

Some people are naturally very lordotic (have a stronger curve to their back).

Core stability.
Muscular and neurological control arond the lumbo-pelvic region to enable function.
Natural muscular corset, supporting the lumbar spine.
Anteriorly: Rectus Abdominus, Internal/External Obliques, Transverse Abdominus.
Posteriorly: Multifidus, Q L, Longissimus.

These are all usually working overtime.
Usually over-compensating.

Need to activate and use them with correct breathing control.

Shoulder Pain.
Ball and socket joint, designed to place the hand in space. But, it sacrifices stability for mobility.
Rotator-cuff musculature, complex joint biomechanics: humerus, scapula, clavicle.
Impingements/tears common. Problems after trauma, e.g. clavicle fractures due to muscle imbalance, capsular restrictions.

It shows: on a circle, not coming round with outside shoulder, blocking.

Short arms = shoulder pain.

Groin pain.
Especially eventers and show-jumpers.
Because of the gripping mechanism, tightness, gripping to stay on!
Don’t want the muscles constantly in tension – adductor muscle problems.

Show-jumpers tend to be older guys and those muscles are not as lengthened and strong as their female counterparts’.
This affects the way you have your leg on.

Muscle Imbalances.

Thoracic rotation, for example if your core is not good.
Tightness in hips – piriformis and gluteals over-active.
You will grip more if the saddle is not right for you.

Adductor tightness – influences pelvis, seat rises out of saddle, tension.

Hamstrings in show-jumpers and jockeys are very very tight, because they are riding very short.

Weighting of seat-bones.
Sit on your hands – are you even? Or not? Can you even feel it?

Symmetry vs Asymmetry – why?

More aesthetically pleasing people, like supermodels, are very symmetrical.

Equal sides, even application of body parts, even weight distribution.

Impact of asymmetry on the horse:
Uneven maintenance of contact, restricting hands, gripping hips/buttocks/thighs, which restrict the thorax of the horse and the muscles under the saddle.
Tense knees
Asymmetric weight distribution

Atlas-occipital joint and/or Temporomandibular joint restriction
Spinal restriction
Alteration of rhythm, hollow side
Weakened: Ventral serrate, lat dorsi and transverse abdominals – these are the horse’s CORE, they need to be activated.

!!!Para riders are often a lot MORE symmetrical than average riders because they work on it so much!!!

Physio: prevention. Regular treatment, intervention, early detection.


Direct injury treatment

Rehab – graded return to functional activity

Core stability, flexibility, fitness, lifestyle, team approach.

Peak performance = the sum of many parts.

Nutrition – effect of toxins. Smoking, alcohol.
Hydration – clear thinking.
Low blood sugar – not a good thing.

Fitness for purpose – cardiovascular, respiratory, as well as muscles, tendons, ligaments, nervous system.

Training/coaching input
Psychological/emotional states

Physio/soft tissue support

Strength and conditioning

Identification of the structural problem

Aim to: strengthen the long and weak, lengthen the short and tight.

Create a balance, but must be appropriate.

Rider vs Horse – harmony… the horse will mirror the rider over time.
Good to put another rider on and get their feedback.


It is easier to treat and resolve an acute problem before it becomes chronic.

Prevention vs Management of injuries.

Riding – the ultimate challenge.








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