In this series of articles brought to you in conjunction with Equitop Myoplast we are going to take a look at understanding horse muscle and how you can assess topline and muscle condition (pt 1) and then in the second installment we will look at what exercises will help your horse build muscles and what nutrition is required to build muscles.
The muscle cover of competition horses is often scrutinised as a sign of ﬁtness and desirable appearance; but do we really know what we are looking for when assessing this and why? And what is the best way to get equine muscles in optimal condition? This article takes a look at equine muscles in more detail and offers advice on how to ensure your competition horse is ﬁt for his job.
Horses have evolved over millions of years to become a very athletic species. They have elongated limbs with little ﬂeshy coverage which act as lightweight but strong levers that propel the body efﬁciently across the ground. Their power comes from the muscle groups covering the fore and hindquarters, stabilised by the muscles of the trunk and the neck.
Muscles range in size and function throughout the body: From the huge powerhouse muscles of the hindquarters to the tiny but precise structures that control the movement of an eyeball or the opening of the larynx at full exercise. Regardless of size, each muscle is given an anatomic name although it is also common to describe groups of muscles that work together to produce a single function e.g. the ‘gluteals’ or the ‘quadriceps’.
Each muscle bundle is surrounded by connective tissue that separates it from its neighbours and is made up of many thousands of muscle ﬁbres – each representing one specialised, elongated cell. These muscle ﬁbres contain ﬁbrils made of protein that contract to shorten the muscle. This process requires a constant supply of energy, manufactured in the muscle cells themselves from oxygen and glucose in the bloodstream.
Muscles require a huge blood supply which is why the function of the muscular, respiratory and circulatory systems are inextricably linked.
Movement of the limbs is created by this shortening of muscle proteins creating a ‘pull’ on the ﬁbrous extension of the muscle body, the tendon. Tendons are incredibly strong and elastic structures that are attached to the bones of the limbs and trunk: moving the limbs or giving postural support.
How can I assess topline and muscle condition?
We all want our horses to be healthy, ﬁt and well prepared for whatever activities we ask of them. We dedicate an enormous amount of time to training and improving performance, so how do we know if our hard work has paid off?
Looking at your horse when it is standing still is a good time to evaluate his topline. Don’t forget that a well-developed topline doesn’t just look good! The muscles of the neck, back and croup stabilise the core, give elevation to movement, enable your horse to carry himself in an outline and are key in preventing fatigue and therefore injury. It is a common mistake to look for a rounded outline of the crest of the neck and mistake it for muscle, when more often than not a well-deﬁned crest actually represents fat! Muscle is only present below a structure called the nuchal ligament. To ﬁnd the nuchal ligament, feel behind the poll for a thick rubber band like structure running down to the withers (see ﬁgure 3). As you get further from the poll, the ligament becomes further and further away from the base of the mane. Anything above this ligament is not muscle, just fat. This should obviously be minimal in a ﬁt athlete. Below the ligament, the muscles of the neck should be ﬁrm and well deﬁned. The epaxial muscles of the back run on either side of the supraspinous ligament – the line down the middle of the back. They should be well developed, giving a rounded appearance.
The trot is an ideal pace at which to evaluate the locomotor or ‘powerhouse’ muscles of the fore and hindquarters. Again they should be well deﬁned. If these areas look rounded but you cannot identify individual muscles moving it is likely that there is a layer of fat covering whatever muscle may or may not be present. This is a common mistake – to confuse ‘condition’ with muscular ﬁtness.
The hindquarters should appear proportionally larger than the forequarters, transmitting the power required to establish a light forehand. A natural, balanced outline with good elevation gives an indication that the core muscles and topline are working effectively.
In part two of this series we will look at what exercises will help your horse build muscles and what nutrition is required to build muscles.