Earlier this year, Sarah MacKeigan from Living with Dogs with Disabilities interviewed both Ben Blecha from Wiggleless Braces and Carrie Adrian on the use of back braces to support and encourage mobility. Their discussion was fascinating, touching on discussion points such as spinal traction, muscle fatigue, compensatory and secondary pain and injury, as well as specific pathologies such as IVDD and DM in canines.
Neurological deficiencies or pathologies can lead to a significant reduction in control of mobility in dogs, which can have far-reaching detrimental effects. Wiggleless back braces can be used to support, stabilise and encourage appropriate movement or mobility in dogs with spinal pathologies, such as intervertebral disk disease or degenerative myelopathy.
Continue reading for a condensed summary of their lengthy discussion, as it relates to us as canine rehabilitation therapists.
Why the spine?
Carrie Adrian: The spine is a fascinating area, ranging from the human vertical orientation in a biped to the horizontal spine of the quadruped. We just don’t know a lot about the pathology of the spine. I work with a lot of military working dogs, and watching these dogs retire around the age of seven was heartbreaking. The bond between the dogs and their handlers is unbelievable. There was a particular case a number of years ago who had spinal surgery and was put to sleep shortly afterwards, which really triggered my interest in doing better for these cases. It’s difficult to see these incredibly athletic dogs lose function and mobility as they age. The spine connects everything, and is affected to a degree no matter what the pathology the dog might be suffering from. We still have a great deal to learn about it.
Should we brace or should we not brace?
Sarah: There are so many thoughts and misconceptions around bracing, such as, if we brace, will muscles arophy? Will we lose mobility? There are also many different conditions affecting the spine, and bracing may affect them all differently.
Carrie Adrian: Before you brace a dog, it is very important to know what is going on and why you want to brace them. You will apply a brace for different reasons and for different lengths of time, and it is not always appropriate. Just because there is a brace available on the market, doesn’t mean it is beneficial or appropriate for a specific patient.
When we look at IVDD rehabilitation, type I IVDD needs to be seen and treated by the vet as quickly as possible. In type II IVDD, we are more likely to be using a brace to support these older dogs who have degenerative changes in their spine with pain, but very little or no neurological signs. We have to address pain aggressively before we brace the area, however. If, posturally, the dog has gone into lumbar kyphosis, we should not brace that and force the spine into extension; that would increase the pinch or the compression of prolapsed disk material and lead to more pain.
Arthritis can occur in the spine just as easily as in other joints of the body.
What comes first? Do we see degenerative changes in the spine followed by muscle adaptations to help stabilise, or is there a change in the muscle supporting the spine, leading to degeneration of the spine?
Ben Blecha: This is a question we need to learn more about, but as Carrie said, a dog will go into kyphosis to open up the dorsal rim of the spinal column and alleviate the pain. At the same time, they are closing and compressing the bottom aspect of the vertebrae, which might be adding additional pressure to the disk in a dorsal direction and potentially worsening the prolapse. If we could open the ventral aspect of the vertebrae in traction, could we potentially be encouraging the disk material to sink ventrally again by creating that space?
When we use bracing of the spine, we easily think of the restriction it causes to the lateral flexion, as well as dorso-ventral flexion, but we are also applying circumferencial pressure, which will result in a level of traction in the spine. We don’t yet know how much traction this really creates on an individual level.
In dogs, it’s really important to get the brace tight enough to be able to achieve that traction. If anyone has imaging modalities and wants to investigate this, please get in touch with me so that we can investigate this and try and answer this question.
Carrie Adrian: In human bracing, this is exactly the theory, together with spreading out the pressure across a larger area of the spine. In humans, together with bracing the back, we also do McKenzie extension exercises, where we aim to theoretically push the disk material back into the spinal column.
Inflammation in the spine
Ben Blecha: We don’t speak about inflammation nearly enough, and it’s a very important part of degeneration in the spine, or compression of the spinal cord. Inflammation causes the soft tissues in the vertebral column to expand, leading to compression of those tissues. This is painful, causing compression of the spinal cord and the nerve roots exiting the spine. We need to address the inflammation to reduce the compression and neurological dysfunction that occurs.
Motion vs stability
Ben: With these braces, there is still some available motion – it’s not a rigid plastic brace. Physical therapists always speak about having movement available to strengthen, but that movement has to be controlled and within an appropriate range. If we can get the spine to remain within the appropriate range of motion, we can get the muscles to activate and start to support stability. If the spine and the muscles start to veer in an uncontrolled way outside of that range of motion, then we cannot build strength in that muscle. When we provide stability, together with proprioceptive feedback through the use of a brace, we can control and facilitate a more appropriate proprioceptive feedback mechanism to allow strengthening and retraining of good movement.
Carrie: A lot of people are afraid of neurological disease. There is a big push against bracing because it may lead to more and more muscle atrophy as time progresses. What we are talking about here, more commonly, is a 4-,6- or 8-week period where we are working to stabilise the spine. We are reducing the range of motion to protect the spine from uncontrolled, ataxic motion. We are not applying a rigid brace, but it does control the range of motion to allow the area to heal.
The bottom line of physical therapy is that we have to be able to manage the tissue we are dealing with, within a healing timeframe. In bracing a dog, we help to stabilise the spine while it heals, and we take some strain off of the muscles that are likely fatigued from having to work harder. We use the brace to our advantage in the static phase, while still doing exercise and physical therapy with the dog, until we can start to move into dynamic work and slowly wean the dog out of the brace.
Fatigue in neurological conditions
Sarah: Dogs with neurological conditions will also often fatigue a lot faster. When we stabilise the spine, there is a lot less wasted energy because the dog isn’t moving in these great big areas. It therefore helps to protect the muscles from fatigue.
Ben: People will often claim that bracing causes weakness – to me, if it causes weakness they are using it incorrectly. Muscle fatigue is really interesting to me, because most of us consider muscle fatigue in relation to training, when we want to train muscles to the point of fatigue to strengthem them. But when we overfatigue a muscle, it also goes backwards and becomes painful for an extended period of time. In neurological dogs, the muscles are much weaker and are more prone to overfatigue.
In your physical therapy practice, you spend a great deal of time exercising the muscles just the right amount so that they can strengthen. But then Dad comes home from work and plays fetch with the dog for another hour, tipping the muscles into overfatigue. Using a brace in those times when life throws ‘extras’ at the dog helps to hold the dog in that place where they are not going to overfatigue the muscles. This helps them to rehabilitate more quickly.
Bracing for degenerative myelopathy
Carrie: There is a big difference between muscle fatigue in an elite athlete and muscle fatigue in a dog with a neurological dysfunction such as DM. In these cases, the nerve-to-muscle connection isn’t working any more. We cannot strengthen the dog – we can’t make something work that isn’t there anymore. We cannot make the dog better, but we can try to minimise or slow the degeneration. We don’t want to work these dogs to fatigue, because we don’t want to increase the detrimental effects on the muscle.
When we watch dogs with DM, there is a severe lack of control in the rear end and through the spine; the entire hindquarter has a tendency to swing in an uncontrolled manner from one side to the other. This movement is extremely inefficient and will cause fatigue much more quickly. With a brace, the spine and core area are much more controlled, allowing dogs to control their limbs more effectively and efficiently. There is a saying that we often use: proximal stability for peripheral mobility. Basically, we want to control and stabilise the core as much as possible to allow better, more controlled ambulation of the limbs.
Sarah: Is there an ideal timeframe when a brace should be introduced for DM dogs?
Carrie: Introducing back braces with these large dogs with DM is a very new concept that we have really only started exploring in the last year, year and a half. We are still learning, but what we are seeing is that there is a period of time where the brace is helping with the proximal control. As the disease progresses, the brace begins to overstimulate and become detrimental to supporting ambulation – this is usually when the thoracic limbs start to become affected.
Sarah: If we want to help with respiration and keeping the dogs upright as long as possible, we need to stimulate and strengthen the core area.
Carrie: Absolutely. The wiggleless back brace is definitely providing proprioceptive feedback and circumferential pressure that stimulates and supports the diaphragm and the abdominal muscles, or the msucles of respiration.
Ben: As this condition progresses, there is so much that goes into it, and multiple questions that we don’t have answers to. Even if there is only a three-month window, there is a huge improvement to their quality of life and improvement of function.
Carrie: We are all about improving function, and if the brace is improving their function, then that is great. Might it also be slowing the progression of the disease? There are still many questions.
Sarah: Secondary injuries in DM are also a common problem as a result of the lack of control of the limbs. With the back brace, there may be a prevention of secondary injury component that we need to consider.
Carrie: Everyone says that DM is not painful, but if we look at the compensation that is occurring as a result of the lack of stability and abnormal movement patterns, something has to give! There will be compensatory pain and dysfunction that occurs as a result of the abnormal and uncontrolled motion as a result of DM.