03/01/2026
𝗦𝗜 𝗝𝗼𝗶𝗻𝘁 𝗗𝘆𝘀𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻 - 𝗧𝗵𝗲 𝗡𝗲𝘂𝗿𝗮𝗹 𝗖𝗼𝗻𝘀𝗲𝗾𝘂𝗲𝗻𝗰𝗲
In my last post we discussed mechanical restriction:
• Ilium inflare
• Ilium outflare
• Sacral axis alteration
𝘕𝘰𝘸 𝘸𝘦 𝘢𝘥𝘥𝘳𝘦𝘴𝘴 𝘸𝘩𝘢𝘵 𝘵𝘩𝘢𝘵 𝘥𝘰𝘦𝘴 𝘵𝘰 𝘵𝘩𝘦 𝘯𝘦𝘳𝘷𝘰𝘶𝘴 𝘴𝘺𝘴𝘵𝘦𝘮.
The sacrum sits between the two ilia, forming the central keystone of the pelvic ring. When the ilium rotates, the sacrum cannot remain neutral - it adapts within the joint interfaces and ligamentous sling.
𝗝𝘂𝘀𝘁 𝗹𝗶𝗸𝗲 𝗶𝗻 𝗵𝘂𝗺𝗮𝗻𝘀, 𝘁𝗵𝗲 𝗲𝗾𝘂𝗶𝗻𝗲 𝘀𝗮𝗰𝗿𝘂𝗺 𝘂𝗻𝗱𝗲𝗿𝗴𝗼𝗲𝘀 𝘀𝘂𝗯𝘁𝗹𝗲 "𝗻𝗼𝗱𝗱𝗶𝗻𝗴" 𝗺𝗼𝘃𝗲𝗺𝗲𝗻𝘁𝘀:
𝘕𝘶𝘵𝘢𝘵𝘪𝘰𝘯:
The base of the sacrum moves ventro-cranially (tips forward/down). This happens during the loading phase of the stride.
𝘊𝘰𝘶𝘯𝘵𝘦𝘳𝘯𝘶𝘵𝘢𝘵𝘪𝘰𝘯:
The base moves dorso-caudally (tips back/up).
This represents one functional axis; multiple planes of sacral motion can be assessed clinically.
𝗦𝗜 𝗱𝘆𝘀𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻 𝗶𝘀 𝗻𝗼𝘁 𝗷𝘂𝘀𝘁 𝘀𝘁𝗿𝘂𝗰𝘁𝘂𝗿𝗮𝗹.
𝗜𝘁 𝗶𝘀 𝗻𝗲𝘂𝗿𝗼𝗹𝗼𝗴𝗶𝗰𝗮𝗹.
In an inflare–outflare torsional pattern, the ilium moves medially at the dorsal aspect and laterally at the ventral aspect.
Not dramatic displacement.
But enough to alter tension, proprioception, and neural signalling.
𝗪𝗵𝘆 𝗧𝗵𝗶𝘀 𝗠𝗮𝘁𝘁𝗲𝗿𝘀 𝗡𝗲𝘂𝗿𝗼𝗹𝗼𝗴𝗶𝗰𝗮𝗹𝗹𝘆:
The sacroiliac region is richly innervated.
𝘐𝘵 𝘤𝘰𝘯𝘵𝘢𝘪𝘯𝘴:
• Dorsal rami of sacral nerves
• Ventral rami contributing to the sacral plexus
• Mechanoreceptors within ligaments
• Nociceptors within joint capsule and fascia
𝙒𝙝𝙚𝙣 𝙢𝙚𝙘𝙝𝙖𝙣𝙞𝙘𝙨 𝙖𝙡𝙩𝙚𝙧, 𝙨𝙞𝙜𝙣𝙖𝙡𝙡𝙞𝙣𝙜 𝙖𝙡𝙩𝙚𝙧𝙨.
1️⃣ 𝗟𝗶𝗴𝗮𝗺𝗲𝗻𝘁𝗼𝘂𝘀 𝗠𝗲𝗰𝗵𝗮𝗻𝗼𝗿𝗲𝗰𝗲𝗽𝘁𝗼𝗿𝘀 & 𝗔𝗳𝗳𝗲𝗿𝗲𝗻𝘁 𝗦𝗶𝗴𝗻𝗮𝗹𝗹𝗶𝗻𝗴
The dorsal sacroiliac ligaments are dense with mechanoreceptors.
𝘞𝘩𝘦𝘯 𝘵𝘩𝘦 𝘵𝘶𝘣𝘦𝘳 𝘴𝘢𝘤𝘳𝘢𝘭𝘦 𝘮𝘰𝘷𝘦𝘴 𝘮𝘦𝘥𝘪𝘢𝘭𝘭𝘺:
• Ligaments tension asymmetrically
• Joint capsule compression changes
• Afferent input to the spinal cord becomes altered
This affects proprioception, the horse’s internal map of where its pelvis is in space.
The brain now receives distorted positional feedback.
𝗥𝗲𝘀𝘂𝗹𝘁? 𝗠𝗼𝘁𝗼𝗿 𝗼𝘂𝘁𝗽𝘂𝘁 𝗰𝗵𝗮𝗻𝗴𝗲𝘀.
Not because the horse is weak.
But because the nervous system is protecting.........
2️⃣ 𝗦𝗮𝗰𝗿𝗮𝗹 𝗙𝗼𝗿𝗮𝗺𝗶𝗻𝗮 & 𝗡𝗲𝗿𝘃𝗲 𝗥𝗼𝗼𝘁 𝗜𝗿𝗿𝗶𝘁𝗮𝘁𝗶𝗼𝗻
Subtle restriction around S1–S2 does not require visible pathology.
Even mild mechanical narrowing or inflammatory change can:
• Increase nociceptive input
• Reduce motor efficiency
• Alter gluteal recruitment
Chronic low-grade irritation may lead to:
• Delayed firing of multifidi
• Gluteal inhibition
• Hamstring over-recruitment
The stabilisers go quiet.
The larger muscles brace.
3️⃣ 𝗩𝗮𝘀𝗰𝘂𝗹𝗮𝗿 & 𝗟𝗶𝗴𝗮𝗺𝗲𝗻𝘁 𝗟𝗼𝗮𝗱 𝗦𝘁𝗮𝘁𝗲
The sacroiliac region is not only neural, it is vascular.
𝘛𝘩𝘦 𝘴𝘢𝘤𝘳𝘢𝘭 𝘧𝘰𝘳𝘢𝘮𝘪𝘯𝘢 𝘵𝘳𝘢𝘯𝘴𝘮𝘪𝘵:
• Nerve roots
• Segmental vessels
• Venous drainage
When ligament tension becomes asymmetrical, load is no longer evenly distributed.
One side may sit in chronic compression.
The other in persistent tension.
𝘛𝘩𝘪𝘴 𝘮𝘢𝘺:
• Alter neural glide
• Influence local tissue perfusion
• Disturb mechanoreceptor signalling
Importantly, this does not require a visible tear.
Micro-strain and cumulative overload are enough to disturb stability.
The ligaments act as a stabilising sling between pelvis and spine.
If their tension balance is altered, force transfer efficiency reduces.
𝘖𝘷𝘦𝘳 𝘵𝘪𝘮𝘦 𝘵𝘩𝘪𝘴 𝘪𝘯𝘧𝘭𝘶𝘦𝘯𝘤𝘦𝘴:
• Gluteal recruitment
• Lumbar tone
• Hip joint loading
• Distal limb stress patterns
4️⃣ 𝗗𝗶𝘀𝘁𝗮𝗹 𝗟𝗼𝗮𝗱𝗶𝗻𝗴 & 𝗠𝘆𝗼𝗳𝗮𝘀𝗰𝗶𝗮𝗹 𝗖𝗼𝗻𝘁𝗶𝗻𝘂𝗶𝘁𝘆
We also cannot ignore the distal driver.
The superficial dorsal line, described by Elbrønd & Shultz (2015) >> begins in the hind hoof and continues up the limb, through the pelvis, along the spine and into the head.
Altered hind hoof balance (for example negative plantar angles) changes tension along this entire myofascial chain.
Research suggests that hind hoof imbalance may influence pathology not only within the limb, but into the pelvis, sacroiliac region and caudal thoracic spine, with potential neurological implications along the sciatic pathway.
𝗧𝗵𝗶𝘀 𝗿𝗲𝗶𝗻𝗳𝗼𝗿𝗰𝗲𝘀 𝗮𝗻 𝗶𝗺𝗽𝗼𝗿𝘁𝗮𝗻𝘁 𝗽𝗿𝗶𝗻𝗰𝗶𝗽𝗹𝗲:
𝗦𝗜 𝗱𝘆𝘀𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻 𝗶𝘀 𝗻𝗼𝘁 𝗮𝗹𝘄𝗮𝘆𝘀 𝗰𝗿𝗲𝗮𝘁𝗲𝗱 𝗹𝗼𝗰𝗮𝗹𝗹𝘆.
Which is why collaboration between farriers, veterinarians and practitioners is essential when managing postural and locomotor dysfunction.
𝘛𝘩𝘦 𝘙𝘦𝘴𝘶𝘭𝘵𝘪𝘯𝘨 “𝘗𝘳𝘰𝘵𝘦𝘤𝘵𝘪𝘷𝘦” 𝘉𝘦𝘩𝘢𝘷𝘪𝘰𝘶𝘳𝘴:
Because the brain prioritises protection over performance, movement patterns change.
Not dramatically.
But strategically.
𝗬𝗼𝘂 𝗺𝗮𝘆 𝘀𝗲𝗲:
• “Bunny hopping” in canter > reducing unilateral pelvic rotation that increases shear or tension
• Plaiting behind > narrowing the base of support to increase perceived stability
• Toe dragging > reduced hind limb lift due to altered gluteal recruitment and delayed motor firing
• Resistance to collection > rounding the back increases SI compression, so the horse braces instead
• Scooting sideways in transitions > avoiding the surge of force closure required
These are not random habits.
They are motor strategies.
The nervous system is choosing the movement pattern that feels safest under altered afferent input.
𝗪𝗵𝗮𝘁 𝗢𝘄𝗻𝗲𝗿𝘀 𝗠𝗮𝘆 𝗦𝗲𝗲:
• Loss of engagement
• Crooked transitions
• One-sided difficulty in lateral work
• Reluctance in canter strike-off
• Disuniting behind
• Subtle gluteal atrophy
• “Hunter’s bump” appearance
• Tail slightly off midline
• Reduced impulsion
Often labelled behavioural.
Frequently neurological inhibition secondary to pelvic restriction.
Chronic pelvic torsion can also subtly alter acetabular loading and contribute to secondary hip compensation patterns often mistaken for primary hindlimb pathology.
𝗧𝗵𝗲 𝗞𝗲𝘆 𝗖𝗼𝗻𝗰𝗲𝗽𝘁
Muscles do not switch off randomly.
The nervous system inhibits them when joint input feels unsafe.
If pelvic mechanics distort afferent signalling, motor output adapts.
You cannot strengthen your way out of neural inhibition without first restoring mobility.
Restore mobility.
Rebuild stability.
Increase capacity.
Over the past week I’ve shared a series exploring sacroiliac dysfunction/torsion and its neural consequences.
The response has been significant; thank you for the level of discussion.
Due to demand, I’ll be announcing a small-group, in-person CPD day next week, focused specifically on assessing this.
𝗜𝗳 𝘆𝗼𝘂’𝗱 𝗹𝗶𝗸𝗲 𝗽𝗿𝗶𝗼𝗿𝗶𝘁𝘆 𝗮𝗰𝗰𝗲𝘀𝘀 𝗯𝗲𝗳𝗼𝗿𝗲 𝗽𝘂𝗯𝗹𝗶𝗰 𝗿𝗲𝗹𝗲𝗮𝘀𝗲, 𝘆𝗼𝘂 𝗰𝗮𝗻 𝗷𝗼𝗶𝗻 𝘁𝗵𝗲 𝗹𝗶𝘀𝘁 𝗵𝗲𝗿𝗲:
https://www.helenthornton.com/contact
Image;https://onlinepethealth.com/the-continuum-of-equine-sacroiliac-joint-dysfunction/