Understanding Equine Myofascial Lines: Fascia, Movement & Performance
Your horse's body doesn't move as a collection of individual muscles.
Every stride requires muscles, joints, fascia and the nervous system to work together to create and control movement. From the hindlimb pushing against the ground to the movement travelling through the pelvis, back and towards the forehand, different structures must coordinate to produce balanced and efficient locomotion.
One of the ways we can understand these connections is through equine myofascial lines.
Myofascial lines describe chains of anatomically connected muscles and fascial structures running through the horse's body. Rather than looking at each muscle individually, they provide a model for considering how different regions may work together during posture and movement.
This whole-body perspective is particularly relevant to equine osteopathy, where assessment is not limited to the area in which stiffness or tension first presents.
What Is Fascia?
Fascia is connective tissue found throughout the body. It surrounds, separates and connects muscles and other anatomical structures, forming a three-dimensional network rather than existing as isolated sheets.
Importantly, fascia isn't simply passive "wrapping" around the muscles.
Histological research in horses has demonstrated distinct superficial and deep fascial layers. Researchers have found that equine deep fascia is relatively thick and closely attached to underlying muscle, while superficial and deep fascia merge within the extremities. Blood vessels and nerves have also been identified within associated fascial tissues.
Research into the equine forelimb has similarly demonstrated innervation within deep fascia and retinacular tissues, adding to our understanding of fascia as a biologically active component of the musculoskeletal system rather than simply structural packaging.
More recent research into the equine thoracolumbar spine also describes fascia as an important component of support and movement and discusses the potential proprioceptive significance of the thoracolumbar fascia.
What Are Myofascial Lines in Horses?
The concept of equine myofascial kinetic lines was investigated anatomically by researchers Vibeke Sødring Elbrønd and Rikke Mark Schultz.
Their early research investigated whether interconnected myofascial pathways comparable with those proposed in humans could be identified anatomically in horses.
In a 2014 study, five myofascial kinetic lines were dissected in 22 horses:
Superficial Dorsal Line
Superficial Ventral Line
Lateral Line
Spiral Line
Functional Line
The researchers identified anatomical continuity along these pathways.
Further research published in 2015 expanded this work using dissections from 26 horses. The authors adapted the human model to account for the considerable anatomical and biomechanical differences between a biped and a quadruped, proposing an equine-specific model for understanding interconnected movement.
Later research investigated deeper myofascial pathways. A 2021 comparative dissection study involving 44 horses described three profound lines comparable with those described in humans and an additional equine line, expanding the anatomical model beyond the superficial pathways.
This is particularly interesting because it provides another way of thinking about equine anatomy: not simply as individual muscles producing isolated actions, but as interconnected structures contributing to whole-body movement, posture and stability.
The Superficial Dorsal Line – The Topline
The Superficial Dorsal Line travels along the dorsal aspect of the horse and connects structures from the hindlimbs through the back and towards the head.
Functionally, the line has been proposed to contribute to extension through the vertebral column and flexion of the hindlimbs.
From a practical perspective, this highlights the relationship between what happens through the hindquarters, back, neck and head.
Rather than viewing the horse's "topline" as simply the long muscles visible either side of the spine, the myofascial model encourages us to consider how structures throughout the chain interact during movement.
This becomes particularly relevant when considering posture, back movement and the way a horse coordinates its body during ridden exercise.
The Superficial Ventral Line – Supporting the Ventral Body
Running along the ventral aspect of the horse, the Superficial Ventral Line provides another interconnected pathway between the limbs and trunk.
Elbrønd and Schultz describe the superficial ventral and dorsal pathways as having opposing functional relationships: while the dorsal line is associated with spinal extension and hindlimb flexion, the ventral line contributes to spinal flexion and hindlimb extension.
This shouldn't be interpreted as one line simply switching on while another switches off. Equine movement requires coordinated activity between many muscular and fascial structures.
Instead, it demonstrates how movement through the trunk cannot be separated completely from movement of the limbs.
The Lateral Lines – Bending and Stability
The Lateral Lines run along either side of the horse and provide another useful way of considering movement through the trunk.
Lateral movement is required whenever a horse bends through its body, negotiates a circle or coordinates movement where one side of the body is being used differently from the other.
For a ridden horse, left-to-right symmetry is rarely absolute. Horses naturally have preferences and asymmetries, just as riders do.
However, a significant or changing difference between the two sides can provide useful information during an osteopathic and movement assessment.
This is why difficulty bending shouldn't automatically be attributed to a single "tight muscle". Joint mobility, muscular strength, coordination, pain, training and movement throughout the rest of the body may all influence what we see.
The Spiral and Functional Lines – Connecting Movement Across the Body
The Spiral and Functional Lines are particularly interesting when we consider movements requiring coordination across different areas of the body.
These pathways connect structures diagonally and across regions of the horse rather than simply following the top, underside or lateral aspect of the body.
That makes them relevant when considering the rotational and diagonal components involved in equine locomotion.
A horse changing direction, bending, transitioning between gaits or coordinating the limbs during canter requires considerably more than simple forwards and backwards movement.
The whole body must continually organise forces generated by the limbs while maintaining balance and controlling movement of the trunk.
The myofascial model gives us one anatomical framework through which these relationships can be considered.
Protraction and Retraction Lines – Moving the Limbs
Protraction describes movement of the limb forwards, while retraction describes its movement backwards relative to the body.
Both are fundamental to locomotion.
The horse must be able to bring the limb forwards effectively and then coordinate its movement as the foot contacts the ground and the body progresses over it.
Restrictions in stride length or changes in protraction and retraction can have many possible causes, including pain, joint mobility, muscular function, neurological control, hoof balance, conformation and training.
For that reason, seeing a shortened stride doesn't allow us to diagnose a particular myofascial restriction.
However, considering the interconnected structures involved in limb movement can help us avoid viewing the problem as belonging exclusively to one joint or muscle.
The Deep Myofascial Lines – Stability and Postural Control
The later research into deep myofascial kinetic lines is particularly relevant when considering postural stability.
The 2021 dissection research described deep dorsal, ventral, adduction and abduction pathways and proposed their involvement in locomotion, stabilisation and posture.
This links particularly well with developing research into spinal function.
A 2025 review of the functional anatomy of the equine thoracolumbar spine discusses the importance of spinal musculature, neuromotor control and fascia in relation to equine back function and rehabilitation. The authors highlight that back pain can alter muscular activation patterns and that rehabilitation needs to consider neuromotor control rather than simply strengthening muscles indiscriminately.
For riders, this is relevant to concepts such as postural control and self-carriage.
Building a stronger topline isn't simply about making the visible epaxial muscles larger. The horse needs appropriate coordination between deeper stabilising structures, larger movement-producing muscles, the limbs and trunk.
Why Does This Matter for Equine Performance?
Understanding myofascial connections helps demonstrate why an apparent problem in one area of the horse doesn't necessarily exist in isolation.
For example, an owner might notice:
reduced suppleness on one rein;
changes in stride length;
difficulty maintaining bend;
reduced impulsion;
changes in transitions;
asymmetrical muscle development;
difficulty maintaining balance;
reduced quality of movement; or
a general change in performance.
These signs cannot be attributed to a particular myofascial line based on observation alone.
There may be many possible explanations, including training, weakness, fatigue, saddle fit, hoof balance, musculoskeletal pain or veterinary conditions.
However, the anatomical connections demonstrated within the myofascial research provide another reason to assess the horse globally rather than automatically focusing treatment on the area where the problem appears.
Myofascial Lines and Equine Osteopathy
The concept of myofascial lines fits naturally with the whole-body principles of osteopathy.
During an osteopathic assessment, I don't want to simply locate the tightest muscle and treat it.
I want to understand how the horse is moving, where mobility may have changed, which tissues appear under additional tension and whether other regions may be influencing the pattern I am seeing.
This may involve considering:
Joint mobility → muscular and fascial tension → posture → movement → compensation → workload.
Treatment can then be tailored to the individual horse using appropriate osteopathic techniques, which may include joint mobilisation alongside soft tissue and fascial approaches.
It is important, however, to distinguish between anatomical evidence for myofascial connections and clinical evidence for myofascial treatment.
The dissection studies demonstrate anatomical continuity between structures. They don't prove that "releasing" a particular line will resolve a specific performance problem, prevent injury or directly improve performance.
That distinction is important when using research to inform treatment.
Fascia, Compensation and the Whole Horse
One of the most useful lessons we can take from myofascial anatomy is that where we see the problem isn't necessarily the only area worth considering.
A horse's body continually adapts to workload, terrain, training and changes in physical function.
If movement changes in one region, other areas may alter the way they work in response. Over time, this can contribute to a more complex pattern involving several structures rather than one isolated muscle.
That is why my osteopathic approach combines palpation and hands-on assessment with observation of the horse's movement and consideration of their wider history.
Their discipline, training, previous injuries, fitness, conformation and recent changes in performance all provide context.
What Does the Research Actually Tell Us?
Research into equine fascia has developed considerably, but it remains a relatively young field.
The anatomical evidence supports the existence of fascial continuity and identifiable myofascial kinetic pathways in horses. Histological studies have also demonstrated that equine fascia has distinct structural characteristics and contains vascular and neural elements.
More recent work has continued to explore the role of fascia in spinal function and rehabilitation. The 2025 review of equine thoracolumbar anatomy describes fascia as a complex three-dimensional network and discusses its possible contribution to support, movement and proprioception.
However, there is still considerably more to learn about exactly how these fascial connections function dynamically in the living horse and how specific manual treatments influence them.
For me, that makes myofascial research valuable not because it gives us a simple explanation for every problem, but because it reinforces something fundamental to osteopathic practice:
the horse's body is interconnected, and movement is best considered as a whole-body process.
Research & Further Reading
Elbrønd, V.S. & Schultz, R.M. (2014) – Myofascial Kinetic Lines in Horses
Foundational equine research identifying five interconnected myofascial kinetic lines through anatomical dissection of 22 horses.
Read the researchAhmed, W. et al. (2019) – A Comparative Multi-Site and Whole-Body Assessment of Fascia in the Horse and Dog
Detailed histological investigation into the structure and organisation of equine fascia.
Read on PubMedElbrønd, V.S. & Schultz, R.M. (2021) – Deep Myofascial Kinetic Lines in Horses
Dissection research involving 44 horses, expanding the original model to include deeper myofascial pathways associated with locomotion, posture and stability.
Read the researchHarrison, L.M. et al. (2025) – Functional Anatomy of the Equine Thoracolumbar Spine Related to Equine Back Rehabilitation
A recent review exploring spinal anatomy, muscular function, neuromotor control and rehabilitation of the equine back.
Read the research
Research into equine fascia and myofascial kinetic lines is continuing to develop. These studies support our understanding of fascial anatomy and connectivity, but do not establish that dysfunction within a particular myofascial line causes a specific performance problem.