Standing Exercises for the Back
By Dr. Meg Hammond, DVM
Many of the horses rehabbing at VRSVA are lead through a series of exercises to strengthen the back 5 times per week. But why? They’re not in work. They might not have back problems. Why do we spend so much time doing this for them? Why is this so important?
There is a strong correlation in horses between lameness and back pain. Lameness can ignite back pain; back pain can exacerbate lameness. A horse on stall rest and nothing else will lose muscle tone through the back and limbs. Muscles provide support and stabilization to the joints they surround. This is especially true of the back.
As the hind limbs drive a horse forward, the abdominal muscles and the muscles on either side of the back contract to stabilize the spine. In a comfortable back, there is supple flexion and extension through the spine as the horse moves, absorbing the concussion created as the limbs impact the ground. The multifidus muscle is primarily responsible for this stabilization. It attaches between the individual vertebrae in the back to support healthy movement of the spine. During a period of stall confinement and also in primary back pain, muscle fibers within the multifidus muscle can atrophy, creating asymmetry and instability within the back. Other muscles within the back become rigid and tight in attempt to brace the spine. This fuels the cycle of discomfort and inhibits performance.
In humans, loss of the multifidus muscle fibers has been shown to occur within three days after acute injury and interestingly, these fibers do not come back after the injury has resolved. Physical therapy with specific exercises targeted at reactivation of this important muscle help to restore comfort and prevent reoccurring injury. The same is thought to be true of horses. The multifidus muscle atrophies with injury, but it can also atrophy with disuse (stall rest, lameness) and it doesn’t easily return.
A study out of Michigan State (N.C. Stubbs et al) evaluated the use of several dynamic mobilization type exercises and their effect on the cross sectional area of the multifidus muscles in horses that had previously been in work, but are now on rest. The exercises were performed five times per week for a period of three months. All of the horses in the study had a significant increase in the size of the multifidus muscles on both the left and right, and those with initial asymmetries in these muscles developed more symmetry as well!
This is big. We know how important the multifidus muscle is to maintain comfort and appropriate movement within the spine. We know horses on rest often lose muscle tone. The horses in this study were taken out of work and only performed standing stretch and hold type exercises, and their multifidus muscles grew in size!
This is why we take the time to perform these exercises on our rehab horses. We’re not just resting your horse — we are putting them through a rehabilitation program to help their injury heal quicker and stronger and to keep the rest of their body conditioned, comfortable and poised to go back into work.
Dynamic Mobilization Exercises for Multifidus Activation:
Most horses can benefit from these exercises. You can do these at home! All exercises are typically performed with a small treat to encourage willing motion. It is key that the horse is brought into position and that the position is held for 5-10 seconds. Exercises that combine movement with a hold are best at activating the type II fibers which can atrophy in back pain. Each exercise is repeated 3-5 times, 5 times per week.
Cervical flexions: The chin is brought to the underside of the chest. The chin is brought as far as comfortably possible between the limbs at the level of the carpus. The chin is brought as far as comfortably possible between the limbs at the level of the front fetlocks.
Cervical extension: The neck is extended and the chin is brought as far forward as comfortably possible.
Lateral bending: The chin is brought to the left and right sides near the location of the girth. The chin is brought to the left and right sides toward the location of the hip. The chin is brought to the left and right sides toward the hock.