In the veterinary profession, it is currently normal practice to prescribe crate rest, stable rest or restricted activity to our patients for varying lengths of time after surgery or injury. Unfortunately, it is also true that many dogs and horses lead lives where their movement is permanently restricted.
Rest, or a restriction of movement, can seem like the best thing to do for a patient following an injury or surgery, but there are many negative side effects following rest that can be severely detrimental to our patients over time.
In a recent webinar with Dr Maira Rezende Formenton, she shared her insights on immobilisation syndrome with our Onlinepethealth Small Animal Members. In view of how frequently crate rest is prescribed for our patients, the insights she shared at this webinar were shocking, to say the least.
Here are some of the concepts from her webinar I would like to share with you:
- Who is affected by immobilisation, and how quickly can negative effects be seen?
- Which body systems are affected by immobilisation?
- How can we reduce or reverse the effects of immobilisation?
When animals rest
Rest or restricted activity can be prescribed for many reasons, or may be enforced on our animals as a result of the lifestyle or management programme they are a part of. Whether their activity is restricted post-injury or surgery, or whether it is restricted as a result of their lifestyle, the effects are serious and detrimental to their long-term health.
In humans, the effects of rest can be seen within seven days, while in animals the effects may be seen as quickly as after one day.
I am sure you’re thinking, ‘There’s a big difference between resting and complete immobility,’ and certainly, you are right. Our bodies need rest as much as they need stress to remain in balance – without one or the other, the entire homeostasis is disrupted. The problem is that rest if often prescribed out of that balance, without the necessary movement to maintain the health of the entire body.
Body systems affected
Every body system is affected by bed rest, including the cardiorespiratory system, immune system, digestive system, integumentary system, nervous system and musculoskeletal system. All of these systems experience negative effects as a result of a lack of mobility.
Let’s discuss some of the effects to the systems that we most often work with.
The nervous system is relevant not only when it comes to the rehabilitation of neurologically impaired dogs, but also in the control of pain in every patient we see, and in motor control. Complete rest, or a lack of activity, can affect both of these areas. Firstly, there will be a decrease in general sensory perception, leading to a loss of proprioception, a compromise of motor control, leading to uncoordinated movement and clumsiness, decreased nerve conduction speeds, and an increase in the perception of pain, which can progress to neuropathy or central sensitisation.
Instead of helping us with goal number 1 – decrease pain – rest will have the opposite effect and increase the patient’s perception of pain.
Similarly, rest may cause a lack of coordination and increased clumsiness in patients that will increase their risk of future injury or carrying themselves with incorrect postures and incorrect muscle recruitment or movement patterns.
When we consider the effect of immobilisation on a joint or cartilage, we need to bear in mind that the integrity and health of cartilage is completely reliant on movement, as movement activates the synovial pump that supplies nutrition to the cartilage. A lack of movement results in decreased production of synovial fluid, a lack of nutrition in the cartilage and chondrocytes, and degeneration of the extracellular matrix.
Muscles are subject to rapid atrophy when immobilised, with a loss of type-I muscle fibres and changes to the muscle on a cellular level. The effects on muscle are easily reversed with re-mobilisation, but can take a great deal of time.
Ligaments and tendons are likewise subject to changes in their mechanical properties when subjected to rest.
The health of bone, too, is extremely dependant on the stresses placed on it. Bone will adapt to changes in stress fairly quickly – whether there is an increase or decrease in stress. When our bones are no longer subject to outside forces, calcium leaches out of the bone, leading to a loss of mechanical strength and an increased risk of fracture.
Movement really is life – every body system depends on movement to function not only optimally, but in balance.
Who is subject to immobilisation?
When it comes to our patients, our first thought goes to those that have just undergone orthopedic surgery, and have been prescribed restricted activity or crate rest. For these patients, the key needs to be controlled activity, not a complete lack thereof.
They must be able to move around wherever they are being kept, and need to be allowed or facilitated in movement multiple times per day to prevent the side-effects of immobilisation, and to facilitate healing.
The second group of patients that comes to mind are those that have suffered a neurological deficit and are unable to ambulate. In these cases, it is essential that we facilitate movement through regular repositioning, range-of-motion exercises, facilitated weight bearing and walking. The more often the patient can be facilitated to move, the better we will be able to reduce the effects of immobilisation, as well as improving their chances of healing.
Our third group is the geriatric patients that are ‘slowing down’, sleeping more and moving less. For these patients as much as for every other group, it is essential that we allow and encourage movement as much as possible through the course of each day, while managing their pain.
But there is another group of patients that can easily be forgotten – healthy dogs and horses whose lifestyle is extremely sedentary. By nature, dogs and horses are not sedentary animals, but when they are confined to small spaces, a lack of social interaction and a lack of intentional exercise, they can also be subject to immobility syndrome. It is essential that we recognise these limitations to their health, and address them as much as is possible.
Treating and preventing immobilisation syndrome
Dr Maira shared four rules of re-mobilisation during her webinar. These are well worth repeating – and doing:
- Respect the displacement of the stress-strain curve.
- Respect the deficit in motor control.
- Respect the degree of pain the patient is experiencing.
- Never restrict motion to the point that immobilisation syndrome is induced.
We have spoken about most of these points in the paragraphs above, but we have not yet touched on the stress-strain curve. In essence, when a tissue is immobilised, the stress-strain curve lowers for that tissue, leading to an increased risk of injury as the breaking point of that tissue is now much lower than it was before. We must be aware and respectful of this lowering as we slowly rebuild the structural strength and integrity of that tissue.
When it comes to pain, we know that these patients will have a heightened pain perception, and very likely movement will be painful for them. We need to be very considerate of this, and provide them with the appropriate analgesia during this period.
If I have piqued your interest about immobilisation and got you thinking about alternative ways of managing your patients during recovery from injury, please let me know! And if you would like more information on the research that supports what I’ve discussed, and the various techniques and strategies you can use for your patients, be sure to watch our webinar on Immobilisation Syndrome in the Small Animal Members’ portal.
Webinars in our Onlinepethealth Library: