The hock joint is a complex joint, comprising of several articulations between the tibial bone, tarsal bones and the third metacarpal bone.

The joints within the hock joint:

• The tarsocrural joint, which is the articulation between the distal aspect of the tibia and the proximal aspect of the tarsal bone. The tarsocrural joint is the joint of highest motion, capable of flexion and extension, accounting for 90% of the range of motion.  
• The proximal intertarsal joints is the articulation between the distal surface of the talus bone, the proximal surface of the central tarsal bone, the first and second fused and the fourth tarsal bone (the first row of tarsal bones).
• The distal intertarsal joints is the articulation between the distal surface of the central tarsal bone and the proximal surface of the third tarsal bone (second row of tarsal bones).
• The tarsometatarsal joint is the articulation between the third and the fourth tarsal bones and the proximal aspect of the third metacarpal bone.
• The proximal intertarsal, distal intertarsal, and tarsometatarsal joints are plane joints and are capable of only small amounts of gliding (shear) movement and account for the remaining 10% of range of motion.
• The talocalcaneal joint is the curved articulation between the planter surface of the talus bone and the craniodistal surface of the calaneous bone.

There is outward rotation of the third metatarsal bone during the swing phase, followed by a small inward rotation during stance, when the hock is compressed. As a result, during gallop the hindlimbs swing outside the forelimbs as the tarsus flexes and then move back toward the midline as the tarsus extends before landing, avoiding contact with the abdomen.
 
The hock joint is much lower than people expect, as shown in the images, and that’s why it is so important to know your musculoskeletal anatomy and exactly where the articulating bones are, in order to assess the functionality of the joint, perform stretches and mobilisations that affect the joint and apply modalities in the most effective way.

The hock joint is most commonly affected by osteoarthritis and this most commonly occurs within the distal intertarsal joints and the tarsometatarsal joints as their function is to absorb concussive forces during locomotion.

​How can I help?

• Photizo light therapy to the distal tarsal joints to relieve joint pain and reduce inflammation.
• Massage will help to relieve tension and secondary discomfort caused by hock joint pain and compensatory postural changes. 

As the lockdown is lifting and competitions are starting up again, I thought it would be the perfect opportunity to share my top tips on how to prepare your horse for competition. 

Tip 1: Tapering your exercise

• Reducing the exercise intensity of your horses workload at least one week prior to the intense competition can help to restore glycogen stores in the muscle and allow for full muscle tissue repair (Marlin et al., 2013) before the competition. The benefits are hugely recognised in human sports and can be a useful tool to implement into your horses training programme.
• This can be done by including only light schooling, hacking and/or lunge work in the week prior to the competition. 

Tip 2: Full body massage and treatment should be booked in at least a week prior to the competition to relieve any discomfort. 

Tip 3: Pre-event massages 3-5 hours prior to competitions.

• Relax the muscles, improve muscle tone and prepare the body for exercise to maximise performance. 

Tip 4: Arrive at least one hour before the competition and hand walk your horse once you arrive at the venue.

• Transporting your horse in a lorry or trailer can put a lot of stress and fatigue on the musculoskeletal system as the horse uses isometric and eccentric muscle contractions to stabilise themselves and to brace against the movements.
• Travelling can also be a stressful experience for most horses and heart rate is reported to remain elevated for up to 30 minutes after unloading (Tateo et al., 2012) especially with those with less travelling experience (Padalino, 2015).
• Did you know that approximately 1 hour in the trailer/horse box is reflective of 20 minutes of trotting in terms of muscular effort?
• Hand walking for 5/10 minutes once you arrive at the venue can help the horse to relax and loosen up the muscles that have been supporting them in the trailer and arriving an hour prior to the test will give them enough time to rest before being asked to work and perform their best for you.
• Any journey over 3 hours would require at least 2 hours (or overnight) of recovery as a result of minimal muscle damage and for elevated muscle enzymes to return to normal (Tateo et al., 2012).

Tip 5: Massage within the 24 hours post competition.

• Aid muscle recovery, lactic acid removal and prevent muscle soreness

Muscle soreness and stiffness, commonly referred to as Delayed Onset Muscle Soreness (DOMS), can occur between 12-72 hours post exercise. This is caused by: 

• Mechanical stress placed on muscle and tissue (esp. during eccentric action) resulting in micro-tears within muscle fibres that causes disarrangement of sarcomeres.
• Triggers immune response releasing histamine and prostaglandins.
• Also causes oedema (accumulation of fluid), inflammation inside muscle compartment, and increase pain sensations.

Good luck to all of my clients and to anybody who is starting to compete with their horses again and I hope these tips are helpful. 

You've got this! 

References: 

Marlin, D., and Nankervis, K. (2013) Equine Exercise Physiology. USA: Blackwell Publishing. 
​
Padalino, B. (2015). Effects of the different transport phases on equine health status, behavior, and welfare: A review. Journal of Veterinary Behavior: Clinical Applications and Research. 10(3), 272-282.

​Tateo, A. Padalino, B., Boccaccio, M., Maggiolino, A., and Centoducati, P. (2012) Transport stress in horses: Effects of two different distances. Journal of Veterinary Behaviour: Clinical Applications and Research. 7, 33-42.

Neck muscles:

​Dorsal neck muscles such as the rhomboids and splenius contract isometrically and eccentrically to control the extension and lengthening of the neck into a contact and to resist gravity, as well as supporting the weight of the head and neck. These muscles work extremely hard to maintain a consistent elevated outline during dressage and this increases as you ask your horse to perform more advanced or elevated movements or to hold the contact for longer durations.
The goal is to strengthen these muscles, but not overwork them. Here are some key tips on how to work these muscles correctly, sustainably and to avoid fatigue and/or muscular damage.

• Your horse should always be encouraged to engage their neck muscles freely, without resistance.
• Improving self-carriage and impulsion from the hindquarters
• Developing the dorsal and ventral muscular chains collectively to create balance
• Regular breaks and long and low exercises to allow the horse to stretch these dorsal neck muscle, to relax and avoid fatigue.
• Avoid working young or immature horses (this includes those who are moving up a level as well as horses who are unaccustomed to working in a contact and those changing disciplines) in a consistent outline for long durations, they should be allowed to stretch every five minutes and the duration of contact work should be increased gradually and within your horses’ physical capabilities.

 
Training methods, which restrain the horse into a contact, will exacerbate the strain on these dorsal muscles as they resist the forces placed on them. This in turn can lead to breakdown of the dorsal muscular chains and further disruption in the ventral chain. This has been explained in the diagram below. 
​
Useful reading:
https://dressagetoday.com/instruction/develop-dressage-horse-topline-bridge-sue-blinks
Horse Movement: Structure, function and rehabilitation by Gail Williams & Alexa McKenna. 

Dressage requires a lot of strength and gymnastic ability from the horse. The musculoskeletal system works extremely hard to produce the common dressage movements we ask from them. The hindquarters provide the propulsive forces to push the horse forward into the contact, the back provides a ‘bridge’ for which these forces are smoothly transmitted through to the forehand and the neck is then able to elevate and effectively maintain the correct frame. This collection of muscles working together to create this bridge, and what is commonly referred to as the topline, is known as the dorsal extensor chain. For the horse to work efficiently, the ventral flexor chain, commonly known as the core muscles, must also be strengthened to provide stability and flexion of the vertebral column and hip. These two chains must work in harmony to establish self-carriage and if one muscle is not working efficiently, the horse will fail to carry themselves correctly and this can lead to poor posture, poor performance and discomfort.

Here are some common areas of musculoskeletal pain which can affect the dressage horse that every dressage rider should be aware of:

• Neck muscles – maintaining the elevated contact and/or resistance against training aids or the riders hands
• Ventral flexor neck muscles - incorrect riding and/or overworking.  
• Thoracolumbar region of the back – supporting the weight of the rider and transferring impulsion from the hindquarters, weakness from lack of core engagement and/or ill-fitting saddle. 
• Iliopsoas muscle – stabilisation of the lumbar spine and maintaining correct back posture, as well as a major contributor to hip flexion and the horse bringing the hindlimb underneath themselves.
• Hamstring muscle group – This muscle group is typically affected by other sources of pain and hold secondary tension and become tight as the horse is not recruiting the muscle effectively – Primary sources of pain include, but not limited to, hock arthritis, lumbosacral and sacroiliac back pain.
• Hock joint – for dressage, the horse is asked to carry more weight behind than it naturally does  and this increased loading on the hock joints can lead to cartilage degeneration and osseous changes. These joints take considerable loads during common dressage movements and this increases as they are asked to collect.
• Core muscles – Maintaining back flexion and stabilisation, as well as supporting the rider.  

 
My next blog post will look into these areas in more detail and factors which can affect the functionality of these areas,  so keep your eye peeled. 

There are many products out there which use static magnetic fields designed to provide a range of health benefits to your horse. These include magnetic rugs, hock boots, fetlock boots and leg boots.

What do they do?

The magnets within the products are thought to relax capillary walls and the surrounding soft tissue. This essentially would lead to an increase in blood flow and oxygen supply, which aids recovery and healing.

Claimed benefits from commercially available products

• Maintained circulation
• Reduced muscle tension
• Aids recovery of muscle fatigue
• Tissue oxygen supply
• Can help to maintain the overall wellbeing of your horse.
• Reduce scar tissue
• Reduce inflammation
• Reducing swelling
• Reduce stiffness
• Reduce muscle cramps
• Aid arthritis
• Increases blood flow, helps to relieve stiffness and reduce filling in horse's legs

Let’s look at the research…
An early research paper looked into the “Effect of a static magnetic field on blood flow to the metacarpus in horses” by Steyn et al., [2000]. They used 6 healthy horses and a commercially available magnetic wrap was placed onto one metacarpal of each horse and a control wrap was placed on the contralateral limb for 48 hours. They found no significant difference in blood flow between the control wrap and the magnetic wrap.

So what does this mean?

This research cannot disprove that the magnetic wraps are effective in providing health benefits to the horse, however they can conclude that potential health benefits do not arise from an increase in blood flow. The researchers suggested a potential reason for this could be that the magnets within the wraps provide a weak magnetic field, potentially caused by the arrangement and flexibility of the magnetics and/or the wraps do not fit directly to the limb surface and therefore may not be strong enough to expose the underlying blood vessels to the magnetic field.

A more recent research paper looked into the effect of magnetic blankets (rugs), titled “Does a magnetic blanket induce changes in muscular blood flow, skin temperature and muscular tension in horses?” by Edner et al., [2015]. They used 10 horses and a commercially available magnetic rug was placed on each horse for 60 minutes and then a placebo rug on the consecutive day. On each day, local skin temperature, muscle blood flow, behaviour of the horse and mechanical nociceptive threshold were measure before, during and after each condition.  Blood flow in the back muscles, skin temperatures, MNTs and behavioural traits did not differ between active and placebo magnetic blankets. They also found that skin temperature increased similarly during the magnetic rug and placebo rug treatment.

So what does this mean?

This research, in support of the previous research, found that magnetic rugs do not result in significant differences in back muscle blood flow or skin temperature. The research suggests that the magnetic rugs may not result in significant changes to affect muscle relaxation or reduce tension.
 
My opinion – I feel very passionate that anything you do or use with your horse is backed up by research. There doesn’t seem to be much research out there currently to support the use of magnetic products or to support the claims made by the companies and so I personally would not invest in these products for the time being until more research has been conducted to provide clinical evidence of how effective they are. Please check out the research behind products to make your own educated opinion and whether you would like to use these for your horses.  

Research paper 1: https://pubmed.ncbi.nlm.nih.gov/10997160/
Research paper 2: ​https://beva.onlinelibrary.wiley.com/doi/abs/10.1111/evj.12291

During a massage session, some of you may have noticed that I regularly refer to ‘knots’ and ‘sore spots’ in the muscle. This is known as myofascial trigger points (MTP).

MTPs are hyperirritable spots located in a taut band in the muscles. The taut bands are localised bands of hardened muscle within the softer muscle, that run parallel to the muscle fibres. The theorised cause of taut bands states that muscle injury can lead to excessive release of acetylcholine, stimulating excessive release of calcium in the muscle and the subsequent shortening and sustained contraction of the muscle fibres.

These areas can be painful on palpation and elicit a local twitching of the muscle as the taut band rapidly contracts as a result of the manual stimulation. MTPs in the muscle can result in weakness due to the reduction in contractile forces, as well as irregular recruitment and activation patterns in the muscle during movement.
 
Causes:

• Muscular overuse
• Eccentric contraction with unconditioned muscles (e.g. high workload with a young horse)
• Excessive eccentric contractions (long period of intensive exercise e.g. jumping for hours, asking the horse to perform advanced dressage movements repetitively).

 
Eccentric contractions are high-power contractions, where a muscle lengthens as a result of external force. This requires a vast amount of muscular effort.
 
Commonly affected muscles:

• Pectoral muscles
• Brachiocephalicus
• Triceps
• Neck paraspinal muscles
• Gluteus and hip muscles
• Muscles in the thoracolumbar and sacroiliac region.

 
This essentially means that several or even just one session of intense training for your horse may lead to the development of these irritable painful trigger points in the muscle and, if not resolved, can become increasingly uncomfortable, lead to referred pain in other areas of the body (as the affected muscles may ‘shut down’) and your horse may struggle to cope with training.
 
Typically, because these areas are painful, your horse may show behavioural signs during riding as a response and their performance may decrease as they are unable to effectively recruit the right muscles, especially if there are several affected muscles. Aversion behaviours are common in horses with MTPs, for example, when your horse is reactive to the girth being attached. This is because the girth will result in uncomfortable pressure on MTP, eliciting a response from the horse.
 
Trigger point therapy during a massage session can help to relieve and resolve these sore spots and your horse will start to feel much more comfortable and ready for the demands of training. It is important to remember that tension and MTPs can develop very quickly (from just one intense training session!!) and so regular maintenance massages are crucial in keeping your horse in top form and feeling their best.
 
Interval training is also a good way to allow your horses muscles to recover and rest during a training session, and is less likely to cause fatigue. I would recommend (and practice with my own horses) a break every 15 minutes during your training session for 5 minutes of walking on a long rein so the muscles can stretch. This may help to prevent the development of MTPs but this may not always be avoided.


http://www.revistas.usp.br/bjvras/article/view/164351/161980

The latissimus dorsi is a non-weight bearing back muscle.

Origin: The supraspinous ligament from the 3rd thoracic vertebra via the thoracolumbar fascia.

Insertion: into the teres major tuberosity of the humerus.

Function: The muscle is responsible for shoulder flexion and retraction of the forelimb.

Soreness: Because the horse, naturally, does not need to support weight over their back, this muscle and other back muscles are typically weak and require a lot of strengthening to support the weight of the saddle and rider. Tension can build up relatively quickly as a result of regular training, rider weight and balance, ill-fitting saddles and those are 'cold backed'. 

Long and low, core stabilisation and pole work exercises can help to engage and strengthen this muscle. Forelimb extension stretches can aid in relaxing this muscle and improve the compliance of the muscle. Pole work exercises that I would suggest for this muscle would be raised outside poles on a curve and it is particularly useful for horses who are weaker on one side.   

The triceps is a large muscle comprising of three heads; long, lateral and medial.

Long head

Origin: the rear border of the scapula.

Insertion: Olecranon (elbow) of the ulna.

Function: Flexes the shoulder under concentric contraction 

Lateral head

Origin: The lateral border of the humerus.

Insertion: Olecranon (elbow) of the ulna.

Function: Extend the elbow joint

Medial head

Origin: The medial border of the humerus.

Insertion: Olecranon (elbow) of the ulna.

Function: Extend the elbow joint.
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Soreness: When this muscle is tight, the skin may twitch when it is being palpated, the horse may have a shortened stride and/or jump flat as shoulder flexion may be affected. A tight band of fibres and/or tightness throughout the whole muscle is usually felt when this muscle is stressed, which can be released with massage techniques such as cross fibre friction during an appointment.

​Shoulder extension stretches will aid in reducing tension in this muscle and improving the range of movement. 

Origin: The scapula at the supraglenoid fossa.

Insertion: into the radial tuberosity of the radius.

Function: The muscle is responsible for extension of the shoulder joint, flexion of the elbow joint, adduction of the forelimb and stabilisation of the shoulder. This muscle works as an antagonist with the triceps brachii muscle. The biceps brachii, alongside the pectoral muscles, aid in supporting the shoulder during lateral movements and producing a smooth quality of movement. This muscle also acts as a catapult to help reduce muscular effort to pull the forelimb forward.

Soreness: Discomfort and tightness in this muscle may affect the horses co-ordination and the horse may struggle with lateral movements. You may also find that the horse becomes difficult to shoe as the muscle is aggravated with the limb is in flexion for a long period of time.

Massage would help to relieve tension in the muscle and restore the fluidity of the gait. Forelimb retraction stretches will aid in improving range of movement and reduce build up of tension. 

The pectoral muscles are comprised of the anterior pectoral muscles and the posterior pectoral muscles.

Anterior pectoral muscle

Origin: The sternum

Insertion: into the humerus.

Function: This muscle draws the forelimb forwards, adducts the forelimb and cushions the limb on landing. Under concentric contraction, it aids in shoulder extension.

Soreness: Repetitive concussion can cause damage to this muscle due to responsibility of cushioning the limb on landing. On palpation, the horse may object to pressure as the area may be tender and trigger points can be felt as tight knots against the sternum. This muscle is often stressed more with green and juvenile horses and those ridden on the forehand.

Posterior pectoral muscle

Origin: The rear aspect of the sternum.

Insertion: Into the medial side of the humerus, subclavius muscle, 4th to 9th ribs and the abdominal tunic.

Function: This muscle draws the forelimbs backwards and forms part of the thoracic sling, which attaches the forelimb to the ribcage with the subclavius muscles.

Soreness: If a horse has tension in this muscle, they may be sensitive to palpation between the limbs or they may resist the thoracic lift. During exercise, the horse may struggle to reach during lateral exercises (leg yielding, half pass etc.) on the affected side as the adduction ability of the muscle will be reduced.