Rehabilitation approaches for chronic muscle conditions
06 Mar, 2019
An earlier article (https://www.fullstride.com.au/blog/how-long-does-it-take-for-a-dog-to-recover-from-a-muscle-injury ), discussed neuroplastic changes observed in the nervous systems of human and animals with chronic, painful musculoskeletal conditions. This article reviews treatment approaches that address both neurological changes and musculoskeletal damage to return the animal to optimal performance levels.
Traditional approach to rehabilitating muscle conditions
The traditional treatment approach to acute musculoskeletal conditions is to consider the condition from a structural perspective. This approach assumes that an injury changes the mechanics of muscles and connective tissue. These changes affect the function of the muscle which impacts sensory receptor activity and transmission. The structural rehabilitation approach assumes neurophysiological changes are secondary to the injury and will normalise when the injury is resolved.
Further, this approach views pain as a result of musculoskeletal damage which is localised around the site of the injury. Once the tissue is healed, it is assumed the pain will be resolved.
Applying this mindset, the practitioner identifies the source of the dysfunction at the site of the injury and works to restore function. For example, a dog injures their cruciate ligament. The traditional treatment approach would centre on restoring function (strength, flexibility and co-ordination) to the stifle and more generally the hind quarters.
This approach has proven effective in humans and animals with acute injuries to improve local tissue however it fails to address the following:
- Changes in motor control – Despite tissue healing, motor control changes have not spontaneously resolve themselves, which predispose the animal to recurrence of symptoms.
- Changes in perceptual processing including changes in perception threshold of noxious stimuli (central sensitization) and symptoms being observed in the contralateral limb.
Rehabilitation approach that targets changes in the central nervous system
Treatment that targets neuroplastic changes are more effective in treating chronic musculoskeletal injuries than protocols that address only the muscle tissue damage. Rehabilitation approaches that address neural changes have been shown to restore function and decrease pain in human and animal subjects.
Externally paced resistance training
This treatment approach applies a combination of resistance training and motor control exercises to restore muscle strength and resolve the neurological changes that have accompanied muscle damage. The effectiveness of this treatment approach to address neuromuscular changes requires exercises to activate muscles using the cortical and subcortical regions of the brain. In human studies, externally paced resistance training (isometric muscle contractions) was found to be the most effective in restoring muscle function and motor control. Strength training component of this protocol seeks to improve muscle architecture and rebuild muscle strength while external pacing addressed the cortical muscle control to improve muscle recruitment patterns and soft tissue loading. Additionally, this treatment approach modulated soft tissue pain. In the human studies of this treatment approach, external pacing was provided using visual cues or a metronome.
For dogs, resistance training can be provided using exercise bands, balance or wobbly boards and weight shifting exercises.
Motor skill training
There is evidence that motor skill training can restore movement performance and reduce pain associated with muscular disorder. In a study of rats with evidence of neuroplastic changes associated with musculoskeletal disorders, the level of functional recovery was directly correlated with the ability of the rats’ primary motor cortex to re-express movement sequences that were abolished by the soft tissue injury. In human studies, novel motor skills training has been shown to increase representation of the trained muscle in the primary motor cortex (M1) of the brain and improve task performance.
Neuroplastic changes in (M1) can occur over a short training period. Some studies have shown changes occurred after only 15 minutes of training. There are however multiple stages of motor skill acquisition. In the initial, fast learning stage, considerable improvement in performance is observed in a short period. The next stage involves slower learning with performance gains acquired over several training sessions.
To be effective in addressing neuroplastic changes, motor skill training should focus on executing movement components, not a full sequence of movements. This type of training compared with strength training requires greater skill, focussed attention and precision. In animal studies, increased complexity of the motor skill task correlated with increased representations of the trained muscle (s) in the primary motor cortex. Further, slowly increasing the complexity of motor skill tasks over the duration of the rehabilitation period, encouraged cognitive effort and enhanced cortical neuroplastic changes.
With motor skill training, the emphasis is on the quality of the training rather than the quantity. The number of repetitions should be limited to avoid fatigue and pain. Focus on form, the ability to perform the task correctly and gradual functional progressions in terms of volume and intensity over the course of the rehabilitation period should be maintained.
Current research on effective rehabilitation approaches for humans and animals with chronic musculoskeletal disorders indicate that it is necessary to address both affected soft tissue and the neural changes observed with these changes. The traditional, structural approach while effective in restoring muscle strength does not directly address neuroplastic changes resulting in the persistence of pain and motor control issues. Rehabilitation approaches that target neural changes including motor skill training and externally paced resistance training, appear to be effective in restoring pre-injury movement function and decreasing pain.
Full Strides provides canine remedial massage treatments to support your dogs’ rehabilitation plan. For qualified canine and equine massage therapists in your local area please see the practitioner listing at www.saena.com.au .
Until next time, enjoy your dogs.
Boudreau, S. A., Farina, D., & Falla, D. (2010). The role of motor learning and neuroplasticity in designing rehabilitation approaches for musculoskeletal pain disorders. Manual therapy, 15(5), 410-414.
Millis, D.L, Levine, D & Taylor R.A (ed) (2004) Canine Rehabilitation and Physical Therapy, Elsevier Inc, Missouri USA
Pelletier, R, Higgins, J, Bourbonnais, D (2015) “Addressing neuroplastic changes in distributed areas of the nervous system associated with chronic musculoskeletal disorders.” Physical Therapy, Vol. 95, No. 11, Nov 2015
Rio, E, Kidgell, D, Lorimer Moseley, G, Gaida, J, Docking, S, Purdam, G and Cook, J (2016) “Tendon neuroplastic training: changing the way we think about tendon rehabilitation: a narrative review.” British Journal of Sports Medicine, Feb 2016, 50 (4): 209 – 215