People have the distinct advantage of being able to control the amount of exercise and physiotherapy they do because they can communicate when things start to hurt. Unfortunately, a horse cannot say during a training exercise, “hey, I think that’s enough for today” and relies on the handler or rider to assess how a session is progressing. This means anyone undertaking a rehabilitation program with their horse needs to have a good grasp of assessing pain and inflammation and be able to monitor subtle changes so that the exercises can be refined if necessary.
Working closely with an experienced veterinarian or physiotherapist is important to enable an objective assessment of pain levels and establish guidelines that can be followed to monitor these levels. Types of assessments can include clinical parameters such as heart and respiratory rates, lameness assessments, and functional examinations including flexion tests. There are some more technical methods available to assess pain, however, most of these are unavailable for general use and not included here.
Core strength is vital for good posture, balance, and stability of the limbs so that movement can occur in an effective and efficient manner. Therefore, maintaining good core strength is one of the key issues we need to address when trying to restore health and function to a horse that has injured part of its musculoskeletal structure.
The “core” for a horse consists of the its axial skeleton, ribs and sternum, the abdominal muscles, sub-lumbar muscles, epaxial muscles, and the musculature (thoracic sling muscles and pelvic stabiliser muscles) that help attach the limbs to the spine. By providing strength and stability, the core structures allow the limbs to propel the body forward. If the core is weakened or becomes imbalanced, then movement quality is compromised. Postural stability is important and research has shown that exercises that work on the small muscles that stabilise the vertebrae along the spine (multifidis muscles) and help to increase the size and strength of these muscles, greatly increase the body’s ability to maintain this stability.
Proprioception is the sense of knowing where your body is positioned when standing and throughout movement. It relies on an interaction between nerves and muscles to tell the brain where limbs are placed and what needs to be activated to maintain that position or move to another. When areas are injured, some of these neuromuscular inputs are affected because of pain and loss of movement, and it becomes important to get these areas back functioning properly to restore normal movement. For example, with an injury that causes the horse to feel pain on joint flexion of a particular joint, the brain learns to exercise without flexing that area fully and relies on flexing another area more to attain similar movement, which can lead to imbalances in body motion. By retraining the body and establishing good proprioception, the body’s movements become more rhythmic and able to perform more efficiently whilst reducing the risks of future injury.
Range of movement is a term used to describe the full range a joint can move when it goes from full extension to full flexion. When joints are injured, their range of movement is usually reduced by either pain, inflammation, or a physical impediment. If this is not addressed in an appropriate manner or in a timely fashion, the range of movement tends to decrease, which results in loss of quality of movement. In its extreme form this can result in joints that have no perceivable flexion or extension, which in turns leads to other areas further up in the limb becoming injured as they are overloaded (over-stretched) to compensate for the lack of movement in the restricted joint. This loss in range of movement is commonly seen in front fetlocks which, when healthy and uninjured have a huge range of motion, but when continually pounded and chronically inflamed become stiff and resistant to flexion.
Many tendon injuries repair with scar tissue that is formed by collagen fibres laid down in an unorganised manner that reduces the quality of the repair. By instigating a rehabilitation exercise program, these fibres become orientated in a more linear fashion in response to the direction the loads on the tendons are placed under, greatly improving the quality of the repair.