I don’t think I’ve known the ground to be so hard so early in the year. I’m trying not to complain as the weather has been very kind (so far) but the price we have to pay for a dry spring and warmer days, is that the ground is rock hard already and worries surrounding concussion is happening months earlier than normal.
So in this blog we will take a closer look at how horses absorb concussion and what we can do to minimise it.
Of course with the longer days and sunshine, it really is the time of year when we want to be out having fun with our horses. Toby and I have been out to a few dressage, showjumping and eventing competitions through the spring. He won his first elementary and was placed 3rd and 1st in the 2 events we did.
However recently I have been even more selective as to where I run him. If he does run on hard ground he develops windgalls (swellings above his forelimb fetlock joints) for a couple of days afterwards so it is important to be very careful with him.
Concussion can cause lameness, so it’s important to consider your horse’s training routine if you don’t have access to a suitable surface. Competition plans may need to be altered and careful management will be needed to help keep your horse happy, comfortable and sound through the summer months.
Interestingly it's not just hard ground xc we need to consider. Often at a one day event it is the dressage warm-up which is the longest in duration.
Concussion is the impact and jar on a horse’s legs and feet as they strike the ground as he moves. The greater the forces, the further the concussion travels and the greater the effect on the tissues.
4 Factors that Affect Concussion
Impact from different types of surface plays a large part in absorbing concussion. A hard, impacted surface with no give – such as roads, sun baked pasture, or frozen ground can play havoc with your horse’s legs. When you’re training it’s advisable to work on a surface that gives and isn't too deep or too hard.
Force is weight combined with speed and this creates a large amount of concussion on a few square inches of hoof. The shorter the time that the foot is on the ground, the greater the force. For example, in canter, the foot is on the ground for half the length of time compared to walk so concussion forces are greater and need to be absorbed in half the time.
Conformation is especially important in your horse’s front legs because they are subjected to greater concussion than the hind. If legs, joints and feet are strong they can withstand greater concussive forces. The nearer the leg is to ideal conformation, the more easily it will cope. Horses with poor conformation have less chance of absorbing concussion effectively.
Shoeing protects your horse’s hooves and aims to limit the effects of concussion by spreading its effects. A good farrier will balance each foot to allow optimum function of all the structures to ensure the shoe addresses the ground on a level plane. However adding a heavy shoe will also increase forces.
The Structures that Absorb Concussion
The foot, frog, heel, sole and wall of the hoof expand as the foot takes the weight. Inside the hoof capsule, the circulating blood and laminae also cushion impact. A well developed frog and digital cushion is vital for maintaining performance and a healthy hoof.
The pastern joint absorbs most of the impact transmitted upward from the foot. A sloping pastern has more concussion-absorbing qualities than a short, steep pastern. An ideal angle of the forelimb pastern is approximately 45 degrees.
The fetlock, together with the sesamoid bones and its strong ligaments, has an important part to play in shock absorption.
The knee, in which the carpal bones are separated by a layer of cartilage and synovial fluid allow a small amount of movement and are designed to absorb concussion.
The hock in conjunction with the stifle and hip joints absorbs most concussion in the hind limb. There’s less movement in the tarsal bones of the hock than the knee, but the permanent partial flexion of the hock does help to absorb concussion.
The shoulder and elbow – the angle of the humerus in relation to the shoulder and elbow joints (ideally at about 60 degrees) acts like a suspension system. As the foreleg comes into contact with the ground, the joints flex to absorb energy.
The thoracic sling – the muscular and ligament attachments prevent jarring by allowing ‘give’ in the soft tissues reducing the impact when the foot hits the ground.
Well Toned Muscles
Muscles also have an important role to play. If they are tense, more concussion will be taken by the joints putting them under additional strain. Relaxed, healthy, toned muscles ensures forces are distributed more evenly through the body.
Any concussion that isn’t absorbed by the lower hind leg travels up the limb and is ultimately absorbed in the sacroiliac joint. Hence concussion in the hindlegs can contribute to pain in the sacroiliac and lumbar region. If your horse already has sacroiliac or back issues working repeatedly on hard ground is something that should be avoided.
Tips for Avoiding Concussion
Exercise strengthens the body and its structures. Keeping your horse fit and lean will help avoid concussive injuries.
Supple, well-conditioned muscles absorb concussion more readily than tight restricted ones.
Fast work and jumping on hard ground should be limited to reduce the chance of concussion.
Good farriery keeps feet in the best possible condition for absorbing shock.
Reducing the amount of weight carried will limit the effects of concussion.
The information in this blog is an extract taken from the book How Your Horse Moves - A unique visual guide to improving performance. Learn more about this subject and more.
Also learn more about the effect of different surfaces and terrain on the horse and how we can use them within our training programs in the book Posture and Performance.