A large number of people take time off work each year due to back pain but our horses do not get a choice as to whether they work each day or not. It is therefore our responsibility as their carers to recognise any problems which may be causing them pain.
Horses are like people some cope with discomfort and soldier on while others develop 'man flu'. Either way the earlier we can recognise discomfort the sooner we can help our equine friends.
By understanding how something works it is easier to see how things can go wrong. A greater level of understanding of the horses anatomy can also help us to prevent back pain occuring in the first place.
The horses spine is made up of 7 cervical vertabrae, 18 thoracic vertabrae, 6 lumber vertabrae, 5 sacral vertabrae (fused), and 15-22 coccygeal vertabrae form the tail. The spinal column houses the spinal cord and nerves exit between the vertabral joints. Misalignments of the vertabrae can cause narrowing of the gaps where the nerves leave the spinal column and thus irritate or interfere with the nerve root. This does not then allow for optimal conditions when messages need to be sent along the nerve fibres. For optimal conditions the bones need to be moving freely with no restriction within their natural range of motion.
All bones are joined by a fairly inelastic tissue called ligament. The other type of tissue that attaches to bone is tendon and this is the type which is, at its other end, attached to muscle. Muscle spasm usually starts near the junction between the muscle and tendon and not in the centre of the muscle. This means that as spasm tightens the muscle it also puts pressure along the tendon. This in turn restricts the movement of the bone to which it is attached and misalignment and stiffness is caused.
All bones have a pair of muscles attached that work antagonistically, that is that as one contracts and flexes the joint the other will lengthen. Both muscles at all times are in use as the one that is becoming longer and allowing the joint to flex has to hold a certain amount of tension for control of the amount of flexion created. If spasm occurs in one of these muscles it will also affect its antagonistic pair. If one muscle is in spasm and therefore shorter than normal the other has to compensate and lengthen accordingly. This can eventually create more strain in the muscle that was not originally injured and in worse cases can cause the pain and stiffness to spread to both sides of the joint.
It is advisable therefore to have your horses back checked regularly to prevent minor stiffness turning to pain. How regularly your horse is treated will depend on his work load and conformation but usually every 3-6 months is recommended.