Posture vs conformation – in the bones or in the stance?

Chloe Mabbutt, discusses how to assess a horse’s conformation 

The difference between posture and conformation is very confusing for many people, with the two being heavily interlinked. The key thing to consider is that posture can be altered and conformation cannot. If a horse is standing “correctly”, the conformation is what you will see. If a horse is offloading in some way, such as standing with their hind legs slightly underneath themselves (Figure 1), that is posture, which can be improved/corrected with pain management, physiotherapy such as therapeutic modalities and remedial exercises and, correct shoeing. For example, a horse conformationally, may have a short lumbar spine that cannot be changed but, their spinal alignment (whether it is dipped or roached), can be altered as this is posture.

How to assess

It all starts with simply looking at your horse as they are standing naturally. Take note of how they choose to stand usually before asking them to stand for an official “photo”. By watching how they prefer to stand you can start to assess if they have a specific preference for example, which leg they choose to stand closer to their centre of mass or, if they are often “shuffling” behind and never fully resting one way or the other…

You can then ask the horse to stand square, on a flat, stable surface – a concrete yard is ideal – do not force them to stand square, if they cannot, this is a huge postural discomfort indicator. Now you can take a picture from the front, behind, and each side (Figure 2) as a record to refer back to, and take time to look carefully at their shape. This also means you can draw plumb lines (Figure 1), from the point of buttock straight to the ground and, the top of the shoulder blade (just in front of wither/behind base of neck) straight down to the ground. You can do this for all angles to assess for deviations from the normal; there will be an example later!

Try to make an accurate assessment of proportions and symmetry; muscle mass and how the horse chooses to stand are the easiest to monitor. A horse should stand with their forelimbs in alignment from the top of the shoulder blade (scapula) down to the fetlock; and in the hindlimbs the point of buttock (tuber ischii) and point of hock (tuber calcanei) in alignment, with the cannon bone (metatarsal), running straight down perpendicular to the ground (following green lines in figure 1). Also you should consider proportions – the horse’s shoulder, trunk, and hindquarters should be in equal thirds; one section being bigger than the other causes uneven strain.

However, it is not your job to notice every detail, as a therapist what I would like is for you to tell me of any changes and, to be aware of any limitations I may have asked you to take into consideration.

What can assessing conformation and posture tell us?

Sometimes a horse has relatively good posture but unfortunately, their issues are more conformational; although you cannot change conformation, being aware of issues can ensure you do not push the the horse physically beyond their limits. For example, in Figure 3, this eventing pony has an open stifle angle (upright stifles), which are prone to concussion, and sickle hocks (cannon bone slopes slightly forwards from the hock rather than straight down). The upright stifles make him prone to concussive type injuries. While we cannot change this conformationally, now the owner is aware of the limitations; the pony will not event when the ground is hard. His sickle hocks leave him slightly more prone to tendon and ligament injuries at the back of the limb but, he is also standing slightly camped under in the hindlimbs. By correcting this minor postural issue, it will reduce the strain on the ligaments from being stretched forwards, assisting with force dispersal up the limb during movement and, assisting with his upright stifle conformation. We can also see he is wither high with a nice shoulder angle, meaning he has the foundations for good stride length and is at less risk of forelimb injuries, he has a generally good ventral line (belly line) indicating good core strength, imperative to prevent back pain.

The point of assessment is to notice problems before they escalate, and to be able to do something about it. Figure 4 is another example, this horse at the time had some hindlimb stifle discomfort and, arthritis in the right forelimb pastern. In this image, the hindlimb discomfort caused him to move his hindlimbs closer to his centre of mass for support, changing the joint angles to alter loading and, placing his hindlimbs closer together to act as one pillar of support. This “under” posture causes the pelvis to rotate, raising the tuber sacrale (point of croup), making the horse appear croup high. He was were cranially loading on to his forelimbs to reduce the weight going through his hindlimbs, causing the humerus and scapula to drop and forelimbs to appear camped under. In reality, the trunk and sternum (breastbone) have shunted forwards, again alluding to a croup high posture. Finally, both of these adjustments caused a “shortening” in the spinal space, creating a dipped (lordotic) appearance, alongside the back musculature contracting to create stability, which also creates the lordotic posture. Therefore, it was imperative the owner noticed this incorrect posture to employ the assistance of physiotherapists and vets to assess the issue and, to monitor whether treatment was effective with how the horse’s posture started to change.

Accurate interpretation of conformation is difficult, as there is a lot of variability between observers, as well as different “requirements for disciplines and breeds. Therefore, to make the measurement more reliable at least, there are some objective methods professionals and, some owners, can employ.

1. Grimace scale – this is something owners and professionals can both use (give it a google!), where pain has been “mapped” on to a horse’s face. So, although not directly posture, the two go hand in hand!
2. Conformation photography – I always encourage my owners to take lots of photos to monitor their horses! Get them to stand as square as possible and take images side on, front on, and from the back. However, bony landmark identification through palpation and skin sticker placement as done by a qualified therapist is more accurate and reliable¹ ². Angle measurement can then be performed by a vet or physiotherapist to determine for accurate assessment and interpretation of findings.
3. Pressure algometry – this is something a professional may use to assess muscle sensitivity more accurately. It assesses mechanical nociceptive thresholds (pain tolerance) and so, can help to determine if a horse is standing a particular way due to a sore muscle and, exactly how sore it is to monitor progress.
4. Stance analysis – stance analysis is available through some hydrotherapy centres or physiotherapists. Force platforms used to assess postural sway in horses have been found valid to analyse balance deficiencies, more so than standard pictorial analysis³.
5. Nevertheless, ideal conformation is a whole other topic and, is dependent on discipline as well as breed. For example, in dressage horses a sloping pelvis will assist with greater collection and, a longer back to improve suppleness⁴, as well as a sloping shoulder angle to create greater stride length and extension⁵; whereas in show jumpers an upright and long shoulder will give greater scapula movement for jumping⁶, and a short back will create less strain through the lumbar area⁷. Therefore, as much as we all love seeing a cob perform dressage…they just don’t cut it at the big levels in the same way as a dressage bred warmblood!

Take home message

Static assessment of animals is of utmost importance as aspects of posture can inform us with regard to pain and, aspects of conformation can give an indication as to future athletic limitations and potential risks for injury⁴. A horse cannot talk so, it is vital we pay attention to these visual cues of their limitations and potential pain. Therefore, ensure you are constantly assessing your horse’s posture and, take their conformation in to account when considering their ridden career. Employing the help of therapists can ensure you always have a trained eye watching your horse for any subtle signs of problems before they escalate!

 More information on this can be found here:  https://fouramigosvetphysio.co.uk/2022/02/horses-breeding-for-sport-or-breeding-to-break/

 References

1. Tabor G, Williams J. 2020. Objective measurement in equine physiotherapy. Comparative Exercise Physiology; 16(1):21–8.
2. Hunt WF, Thomas VG, Stiefel W. 1999. Analysis of video-recorded images to determine linear and angular dimensions in the growing horse. Equine Veterinary Journal; 31(5):402–10.
3. Clayton HM, Bialski DE, Lanovaz JL, Mullineaux DR. 2003. Assessment of the reliability of a technique to measure postural sway in horses. Am J Vet Res; 64(11):1354–9.
4. Van Weeren PR, Crevier-Denoix N. 2006. Equine conformation: clues to performance and soundness? Equine Veterinary Journal; 38(7): 591-596.
5. Weller, R., Pfau, T., Verheyen, K., May, S., and Wilson, A., 2006. The effect of conformation on orthopaedic health and performance in a cohort of national hunt racehorses: Preliminary results. Equine Veterinary Journal, 38: 622-627.
6. Mostafa A.M., Senna, N., Abu-Seida, A., and Elemmawy, Y. 2019. Evaluation of Abnormal Limb Conformation in Jumping Thoroughbred Horses. Journal of the Hellenic Veterinary Medical Society, 70(2), 1533-1540. https://doi.org/10.12681/jhvms.20859
7. Morscher, S., 2010. An analysis of conformation and performance variables in 3 day event horses in Ireland (Thesis). University of Limerick. https://ulir.ul.ie/bitstream/handle/10344/1639/2010_Morscher%2C%20S.pdf?sequence=6