CORE CONCEPTS – Part 2
In my last blog I discussed how a rider’s position and posture can affect the horse. This time I will be talking about the horse’s ‘core’ and posture, it’s relevance during training and ridden work and how we can influence it.
What is the horse’s ‘core’?
Firstly, a quick overview of anatomy:
The horse’s anatomy essentially consists of the axial skeleton (skull, vertebral column, ribs and sternum), the appendicular skeleton (forelimbs and hindlimbs), internal organs and soft tissue (muscles, fascia, tendons, and ligaments) which act to support, protect and produce locomotion. When we refer to the horse’s ‘core’ we are essentially referring to the muscle groups of the abdomen, back and sublumbar muscles. The longer, dorsal superficial muscles of the back help to produce side flexion, rotation and extension of the spine, whilst the abdominal muscles aid flexion, along with assisting the short ventral muscles close to the spine and the sublumbar (iliopsoas) to stabilize the back.
If you have studied equine biomechanics in any form you may be familiar with the ‘bow and string’ theory. This is a concept which aims to explain the action of the muscles in relation to locomotion. The bow forms the horse’s vertebral column whilst the string relates to the abdominal muscles. By contraction of the string (abdominals) the bow (back) is flexed. Further flexion is achieved by retraction of the forelimbs and protraction of the hindlimbs. The back becomes extended by protraction of the forelimbs and retraction of the hindlimbs.
This theory has been used during training of the horse in a long, low posture, encouraging the horse to move forward energetically in an attempt to encourage greater protraction (stepping forward) of the hindlimb to aid greater flexion of the back, increase space between the vertebral spinous processes and strengthen the muscles used to support the rider and lighten the forehand.
What affects core activation and stability?
Some horses, like people, have a greater natural ability to activate their postural muscles which enables them to move easily in a balanced, athletic way. Conformation will affect a horse’s ability to activate the core muscles- those with a long back, for instance, will find this more difficult. Age can also be a factor- young, weak horses may have poor core control, whilst older horses may have age related postural changes, joint stiffness and less effective muscle regeneration. These factors should all be taken into consideration with training to include exercises which aid activation of the core muscles.
Horses that are recovering from injury or surgery may also require specific exercises to help optimise strengthening of these muscles during rehabilitation.
The rider is an obvious factor that could affect the ability of the horse to use its core muscles effectively. The ability of the rider to sit in balance on the horse and activate their own core will influence the horse’s posture and core muscles.
As discussed in my last blog, Core Concepts, a crooked rider with muscle imbalance will affect the horse and may result in back pain, as will an incorrectly fitting saddle.
Head positioning can influence spinal posture- an elevated head and neck posture can increase lumbar extension whilst in a lower position can increase sacral flexion. If the horse is asked to work in an advanced head position before it has sufficiently developed strength of the postural muscles the long term effect will be back pain due to overexertion and fatigue of the muscles.
It is felt that poor stabilization of the spine and poor posture may be a factor in development of dorsal spinous process impingement (kissing spine).
We know from human studies that back pain can result in muscle dysfunction of multifidus (one of the spinal stabilizers). Horses with back pain also present with dysfunction of the short interspinous muscles which act as stabilisers and affect the horse’s posture and performance. If not addressed, back pain will result in secondary postural changes, leading to compensatory movement patterns, muscle overuse and asymmetry and continued poor performance.
What can we do to help activation of the core muscles?
There are a number of ways we can influence the horse to activate the core muscles.
-Baited stretches- these can be useful if your horse is on box rest with injury, as well as for maintenance to aid flexibility and core muscle activity.
– Ridden stretches- these can be a useful progression from baited stretches.
– Poles- Walking over poles in hand or ridden exercises will help strengthening and will also aid proprioception (body awareness of limb placement).
– Lungeing aids- Aids can be useful to encourage core activation. The Pessoa and Equiami are popular aids but every horse is different so they may not have the same effect for all.
– Hillwork- Walking up and down hills will help to strengthening of the core muscles as well as the hindlimbs.
– Underwater treadmill – these can be a useful way to improve strengthening, particularly after injury such as tendon strains. However, there is some evidence that they may aggravate existing back pain so probably best avoided for horses with back or hindlimb problems.
If your horse has had an injury it is always best to check with your physio what exercises are appropriate to avoid making things worse.
The important point to consider from these findings are that as riders/ trainers we should have an understanding in how we can influence a horse in order to prepare it to do its job, whether that be hacking or as an elite athlete. We also have a responsibility to ensure we are not a cause of problems through our own imbalances.
If your horse is suffering from performance related issues a qualified physiotherapist will be able to carry out a full assessment to highlight any imbalance/ postural issues and recommend a suitable rehabilitation programme.