About The Riding X-Ray

The working trot has a 0.76-second stride, covering about 2.51 m. Its stiff-pelvis sitting-rider example loses seat contact for about 58% of a stride, while the following rider has no airborne interval under the model’s contact criterion. The default jumping sequence crosses a 1.10 m fence.

• Watch the correct riding first, then pick a mistake under “Show me”. The page moves to the gait where that mistake shows, draws the correct rider as a blue outline for comparison, and explains what happens, why, and how to fix it.
• Under “What the horse does”: the gait, its paces (collected to extended), circles to either side, and the jump.
• Sound is off when the page opens. Turn it on to hear the hoofbeats: each one sounds as the hoof lands in the picture, so you can hear the rhythm of each gait.
• Slow it down (0.1x) or use “Freeze at” to stop at a key moment. “Show the data” opens the footfall chart, the saddle motion and the numbers.
• Drag to turn the view. Keys: 1-4 views, space pause, L joint names, arrows step while paused. “Copy link” copies a link to exactly what you are looking at.
• Each explanation is marked with where it comes from: “studies” (published measurements), “model” (worked out by the page’s own model), “mechanics” (worked out from basic physics) or “riding instruction” (what coaches teach). “est.” marks an estimate.

• The horse moves by measured joint angles and footfall timing from published gait studies, with its hooves kept planted on the ground while they carry weight. Each change is checked frame by frame for hooves that slide or sink, joints that separate and sudden jerks.
• The rider is a small physics model, with springs and dampers at the seat, hips and spine, fitted to measured riders. The consequences of each mistake (where the weight goes, how hard the rider lands) come from that model, not from a script.
• The rising trot was timed against measured horses and their rider; the saddle motion matches measurements on dressage horses; the hoofbeats follow 19 recorded horses, and their sound is built from measurements of how a hoof rings when it lands.
• About 150 studies, books and rule books were read for it; the main ones are listed below. Everything runs in your browser from rules and data: no AI model, no recordings.

• One horse (a warmblood, about 1.65 m at the withers), scaled to the other body types, and one rider (1.70 m, 70 kg).
• The bones are simple shapes generated in code, not scans. Proportions and joint ranges follow the sources below.
• Only the relaxed end of the hip slider is calibrated to measured riders; stiffer settings are what the model predicts.
• Estimated: the canter’s saddle motion, the rising-trot height, the two-point seat, and the gallop’s footfall timing (its joint curves reuse the canter’s).
• Circles: the measured back bend is for a 5 m circle and scaled for 10 m (estimate), as is the pelvis turning in. Inside steps are shorter because the inside hooves run on a smaller circle. The back sways side to side once a stride (walk 15°, trot 7°, measured; canter 10°, estimate); its timing is an estimate. No gallop on circles.
• The hoofbeats are those of shod hooves on a firm arena; the picture shows no particular footing.

• How much a horse bends “along the circle”. Riding teaches an even bend from poll to tail; measured backs bend only a few degrees, and most of the look comes from the neck and the lean. Toggle “Textbook arc” to compare.
• Neck bend on circles depends on how it is measured (with or without correcting for the lean); the page uses the uncorrected numbers, which are likely too large.
• Whether the ribcage swings out between the shoulder blades on a circle: anatomically possible, not measured in moving horses.

• This is an illustration for learning and curiosity. It is not riding instruction, veterinary or medical advice, and it cannot judge your horse or your riding. Riding is a risk sport: learn with a qualified instructor and wear a helmet.
• The models are simplified, and studies measure a handful of horses and riders; real horses and riders differ. It is provided as it is, without any warranty, and we accept no liability for decisions made from it.

Numbers are taken from these studies and cited; figures and text are not reproduced. Where only the abstract was read, it says so.

Footfall timing

1. [R22] Rhodin, Smit, Persson-Sjodin, Pfau, Clayton et al. 2022. Timing of vertical head, withers and pelvis movements relative to the footfalls in different equine gaits and breeds. Animals 12:3053. link — walk and trot footfalls
2. [C11] Clayton HM 2011. Canter rhythms, oddities, and illusions. USDF Connection. link — canter footfalls
3. [S09] Starke, Robilliard, Weller, Wilson, Pfau 2009. Walk–run classification of symmetrical gaits in the horse. J R Soc Interface 6:335. link — duty factors
4. [H16] Hobbs, Bertram, Clayton 2016. Diagonal dissociation and moderate changes in speed in trotting horses. PeerJ 4:e2190. link — trot diagonal timing
5. [HC19] Hobbs & Clayton 2019. Collisional mechanics of the diagonal gaits of horses over a range of speeds. PeerJ 7:e7689. — trot stance and swing
6. [SG23] St George, Clayton, Hobbs et al. 2023. EMG and kinematic comparison of the leading and trailing fore- and hindlimbs of horses during canter. Animals 13:1755. — canter leading and trailing legs
7. [W06] Witte, Hirst, Wilson 2006. Effect of speed on stride parameters in racehorses at gallop in field conditions. J Exp Biol 209:4389. — gallop stance times (abstract)
8. [P08] Parsons, Pfau, Wilson 2008. High-speed gallop locomotion in the Thoroughbred racehorse I. J Exp Biol 211:935. — gallop stride frequency (abstract)
9. [BG09] Bertram & Gutmann 2009. Motions of the running horse and cheetah revisited. J R Soc Interface 6:549. link — gallop footfall order

Horse skeleton and joint curves

1. [S25] Shaffer, Medjaouri, Swenson, Eliason, Nicolella 2025. A markerless approach for full-body biomechanics of horses. Animals 15:2281. link — joint angle curves (read from its Fig. 8 and adjusted; CC BY 4.0), rest pose
2. [Pa22] Pagliara, Marenchino et al. 2022. Fetlock joint angle pattern and range of motion. Vet Sci 9:456. link — fetlock curves
3. [Ho00] Hodson, Clayton, Lanovaz 2000. The forelimb in walking horses: 1. Kinematics and ground reaction forces. Equine Vet J 32:287. — walk forelimb key moments (abstract)
4. [B95] Back, Schamhardt, Savelberg, van den Bogert et al. 1995. How the horse moves: 1. Forelimb kinematics. Equine Vet J 27:31. — trot forelimb (abstract)
5. [Ma08] Matsuura et al. 2008. Influence of equine conformation on rider oscillation. J Equine Sci 19:9. link — bone lengths, standing angles
6. [Ah25] Ahmad et al. 2025. Evaluating forelimb and hindlimb joint conformation of Morna racehorses. Vet Sci 12:20. link — standing joint angles
7. [vB24] van Bijlert, Geijtenbeek, Smit, Schulp, Bates 2024. SHADOWFAX horse model. Integr Comp Biol 64:694. link — joint structure (read, files not used)

Back, saddle and rider

1. [By19] Byström A 2019. The movement pattern of horse and rider in different degrees of collection. PhD thesis, SLU, Acta Univ Agric Sueciae 2019:32. link — saddle and rider pelvis motion, walk and trot
2. [By18] Byström et al. 2018. Lateral movement of the saddle relative to the equine spine in rising and sitting trot. PLoS ONE 13:e0200534. link — saddle sideways sway
3. [F01] Faber et al. 2000–2001. Thoracolumbar kinematics (bone-fixed markers). Am J Vet Res 61:399, 62:757; Equine Vet J Suppl 33:145. — back bend and twist per gait (abstracts)
4. [Pf05] Pfau, Witte, Wilson 2005. Displacement data during cyclical movement using an inertial sensor. J Exp Biol 208:2503. — trunk motion at speed (abstract)
5. [Cl23] Clayton, MacKechnie-Guire, Hobbs 2023. Riders’ effects on horses — biomechanical principles with examples from the literature. Animals 13:3854. link — rider targets, stiff vs supple riders
6. [Mü14] Münz, Eckardt, Witte 2014. Horse–rider interaction in dressage riding. Hum Mov Sci 33:227. — professional vs novice pelvis (abstract)
7. [Wi09] Winter DA 2009. Biomechanics and Motor Control of Human Movement, 4th ed., Wiley. Table 4.1. — rider segment lengths, masses and centres of mass
8. [WT09] Williams, Tan, Usherwood, Wilson 2009. Pitch then power: limitations to acceleration in quadrupeds. Biol Lett 5:610. link — how hard a horse can stop and speed up

Paces and the correct riding position

1. [Cl94] Clayton 1994. Comparison of the stride kinematics of the collected, working, medium and extended trot in horses. Equine Vet J 26:230. — speed and stride of each trot pace
2. [Cl95] Clayton 1995. Comparison of the stride kinematics of the collected, medium, and extended walks. Am J Vet Res 56:849. — walk paces
3. [No17] Northrop, Martin, Holt, Hobbs, Hall 2017. Limb kinematics between collected and lengthened trot in dressage horses. Equine Vet J 49:648. link — joint angles per trot pace
4. [CH19] Clayton & Hobbs 2019. Biomechanical gait classification of collected trot, passage and piaffe. Animals 9:763. link — collected trot and passage timing
5. [We09] Weishaupt et al. 2009. Kinetics and kinematics of the passage. Equine Vet J 41:263. — passage speed and rhythm (abstract)
6. [Ay16] Ayers 2016. Evaluating the extravagant trot. USDF Connection, March 2016. link — forearm and hind cannon parallel in an extension
7. [AHA23] Arabian Horse Association 2023. Equitation Manual, Hunter/Jumping Seat (USEF / EC rules). link — hands, leg, two-point and jumping position
8. [GM07] George Morris clinic notes, Chilliwack 2007 (Canadian Pony Club). link — jumping position
9. [Te06] Terada, Clayton, Kato 2006. Stabilization of wrist position during horseback riding at trot. Equine Comp Exerc Physiol 3:179. — how still the hands stay (abstract)
10. [Cl22] Clark, Williams, Wilkins et al. 2022. Trunk kinematics of experienced and novice riders during rising trot on a simulator. J Equine Vet Sci 104163. link — rising trot height and trunk angle

Circles, leads and diagonals

1. [By21] Byström, Hardeman, Serra Bragança et al. 2021. Differences in equine spinal kinematics between straight line and circle in trot. Sci Rep 11:12832. link — back bend and lean on a circle
2. [E23] Egenvall, Engström, Byström 2023. Back motion in unridden horses in walk, trot and canter on a circle. Vet Res Commun 47:1831. link — lean and neck bend per gait
3. [Pf12] Pfau, Stubbs, Kaiser, Brown, Clayton 2012. Effect of trotting speed and circle radius on movement symmetry. Am J Vet Res 73:1890. — lean shortfall (abstract)
4. [Cl12] Clayton, Kaiser, Lavagnino, Stubbs 2012. Intersegmental vertebral motion in cervical lateral bending. Am J Vet Res 73:1153. — where the neck bends (abstract)
5. [PS18] Persson-Sjodin et al. 2018. Influence of seating styles on head and pelvic vertical movement symmetry in horses ridden at trot. PLoS ONE 13:e0195341. link — rising-trot timing, correct diagonal
6. [Ho25] Horan & Pfau 2025. Effects of jockey position and surfaces on horse movement asymmetry and horse-jockey synchronisation during trotting exercise. PLoS ONE 20:e0324753. link — when the rider rises and sits against the horse (one rider)
7. [Sy17] Sydnor C 2017. The importance of posting diagonals. USDF Connection. link — the riding-school rule

Hoof sound

1. [Lf24] Laffi, Raimondi, Ferrante et al. 2024. The rhythm of horse gaits. Ann N Y Acad Sci 1543:86. link — recorded hoofbeat rhythm of 19 horses, checked against the page
2. [Be93] Benoit, Barrey, Regnault, Brochet 1993. Comparison of the damping effect of different shoeing by the measurement of hoof acceleration. Acta Anat 146:109. — how the hoof rings after impact (abstract)
3. [Bu97] Burn, Wilson, Nason 1997. Impact during equine locomotion: techniques for measurement and analysis. link — which frequencies carry the impact
4. [Ho24] Horan, Coburn, Kourdache et al. 2024. Hoof slip duration at impact in galloping Thoroughbred ex-racehorses. PLoS ONE 19:e0311899. link — the hoof sliding after landing (abstract)
5. [Tu10] Turchet, Serafin, Dimitrov, Nordahl 2010. Physically based sound synthesis and control of footsteps sounds. Proc DAFx-10. link — how footstep sounds are synthesized

Built with three.js (© 2010-2026 three.js authors, MIT License) and Vite. The full licence texts of the software in this page are in third-party notices.

The horse, rider and tack are generated in code: no third-party 3D models, images or sounds.

Not connected with Horses Inside Out (Gillian Higgins) or with any organisation whose publications are cited; citing them implies no endorsement.

The studies give measurements; turning them into a horse and rider that move together is LifeVen LLC’s own work:

• The joint curves for every gait and pace, built from several studies and fitted to the footfall timing, with the corrections and offsets that keep the hooves planted on this skeleton.
• The trunk lowering, saddle and back motion per gait, and the circle and jump motion.
• The rider model, its springs and dampers fitted to measured riders, and what each mistake does.
• The muscle timing gathered from the studies, and the hoofbeat sound built from impact measurements.

These data and parameters are available under CC BY-NC 4.0: use them in research and teaching with the credit “The Riding X-Ray by LifeVen” and a link to this page. For commercial use, please write to hello@lifeven.com.

• © 2026 LifeVen LLC. All rights reserved in the page, its code, pictures and text; the third-party software, data and models listed above keep their own licences.
• You are welcome to use it and share it. When you share screenshots or recordings, please credit “The Riding X-Ray by LifeVen” and link to this page.
• Please do not copy the page or its code and publish it as your own.