The Dose Makes the Medicine: Exercise Rehabilitation
A statement I hear in clinic quite often is “I tried rehab; it didn’t work”. And yet, when it comes to musculoskeletal pain, such as low back pain, shoulder pain, neck pain or knee pain for example, exercise is always included as a first line therapy (1,2,3). Despite exercise being a relatively safe and effective method for pain and injury management, ‘the dose makes the medicine.’ Here is your starting point for exercise prescription.
Disclaimer: in the presence of pathology, trauma or acute injury, the management may differ. Be sure to refer to an appropriate healthcare provider for the management of anything that may fall outside your scope of practice.
Why not just rest it?
Despite it often being our instinctual first thought, absolute rest is not recommended in most conditions. Even major surgeries incorporate loading and movement in many cases the day of the operation. Absolute rest often results in no improvement or worsened outcomes (4).
But what if it hurts to exercise?
This is where exercise prescription and dosing are crucial.
As previously discussed in previous articles, it is important to understand that pain is not always an indicator of tissue damage, but rather a perception of threat. I do not mean to say that pain one may be experiencing is not a tissue injury, but rather that it’s more complex than that. In these cases, exercise probably will not cause any further damage when dosed appropriately. The goal of rehabilitation is twofold – to increase physical capacity, and to desensitize (5,6).
Have you ever been in a hot tub before? When you first put your hand in the hot water you must pull your hand out. Ouch! Your body just recognized a threat and went back to safety. But, if you put your hand back in the water, it is suddenly tolerable. The water did not change – you did. Our bodies can adapt quite quickly to painful stimuli, and with repeated exposure can reduce the degree of pain experienced. (5)
During the rehab process, being pain-free with exercise is often not a realistic short-term goal. For this reason, we follow the “traffic light” method to help us auto-regulate discomfort (8). if you need more information on this idea, read this article here. Our goal is for discomfort to be tolerable with exercise. It is important to help manage the individual’s expectations and regularly reassure that hurt does not equal harm. It is okay to feel some soreness. Sore but safe! I refer to this range as, “tolerable discomfort,” which falls roughly between a score of 0 to 3 out of 10 on a subjective numeric rating scale. This is also considered the “Green Zone” for the traffic light analogy. (7)
There are a few variables we can manipulate to modify a training program:
Volume: defined as the product of sets and reps. (Sets x Reps) = Volume. For example, 3 sets of 10 reps would have a total volume of 30 for that exercise. Volume can be measured per exercise, per training session or by total weekly accumulation (3 sets x 10 reps x 3 training sessions) = 90.
Tonnage: defined as the product of sets, reps, and load. In weight training, this is the weight lifted. I.e. (3 sets x 10 reps x 50lbs) would have a total tonnage of 1500lbs.
Frequency: this is the total number of times a particular exercise is trained during a particular time period (e.g. 3 times per week, or 20 times per month). Generally, increased frequency can increase total volume and tonnage across a period of time, which reduces recovery time between bouts, thus increasing overall fatigue. (citation may be needed here)
Intensity: this is the training load i.e. the weight lifted or the pace of the exercise. This can be measured objectively by a percentage of 1 rep maximum (RM) or by percentage of maximal heart rate. It can also be subjectively characterized by Rating of Perceived Exertion (RPE). RPE is an estimation of the difficulty of the exercise based on how the individual is feeling. RPE is a useful tool because it accounts for variance in energy levels and fatigue from day-to-day, which allows for a more customizable approach to training.
Interestingly, the Borg RPE Scale was initially scaled from 6-20 as a correlate of heart rate; as a healthy 20-year-old would have a resting heart rate of approximately 60 beats per minute (BPM), and a maximal heart rate (HR) of approximately 200 BPM (8). This is in contrast to a basic RPE scale which is typically rated on a scale of 1-10. This basic RPE scale has value in resistance as well as aerobic training.
Beginning the program:
To find an appropriate place to start, we want to find exercises that the person can tolerate (in the green zone). If the individual is already training for a sport or exercising recreationally, we can keep things similar, and manipulate the variables mentioned above to make their program more conducive to recovery. If they are not currently exercising, start with an activity that they enjoy or find meaningful. For example, if they are an older adult who has difficulty getting on and off of a chair, then a squat variation is a great option. If they are a manual labourer then deadlifts, rows, and carries may be a good choice. Try to include the individual in this decision-making process as it will help them understand why they are training a specific way. This shared decision-making will help show the individual the value of the exercise prescribed.
How can we modify and progress load?
Same exercise, modified: – One option we have is to modify the exercise to be more comfortable. We could change the stance of someone with knee pain to a position that makes a squat more tolerable, or we could shorten the stride length of a runner’s gait. These exercises can then be progressively loaded to increase capacity with the intention of desensitizing the individual.
Reduce intensity: – Reduce the total load. This reduces the total tonnage while keeping the volume the same. If someone can tolerate the exercise well with no pain at less weight, they can fare well with a progressive increase in load. The same goes for a runner. If they can tolerate the same distances with a slower pace, then that can be progressively increased.
Shorten the Range of Motion (ROM): If an individual is having pain at the bottom of the squat or aggravation with deadlifting from the floor, swap in shallower box squats or block pulls. In a clinical setting, this may mean picking something up at knee height. The other training variables can be left unchanged, and a slow return to a full range of motion can offer an avenue of progression.
Change the tempo: Performing exercises slower increases total time that the muscles are under tension (providing a training stimulus). However, it also reduces the total Power (Power = Force x Velocity) acting on the sensitive tissues, making it more tolerable.
Isometrics? – Sure. They offer the slowest tempo of all tempo parameters and often are a starting point for very acute cases. However, just giving a patient with shoulder pain a list of isometric exercises and calling it a day is about as useful as kinesiotape on an elephant’s ass. The person most likely needs to move their arm again, so progressing passed isometrics to include full ROM by means of concentric/eccentric movement is typically necessary. Keep thinking long term, goal-oriented programming.
Some people may be frustrated by the rehab process and want to get back to their sport of choice sooner, which can potentially re-aggravate these symptoms. Always remember to educate them, in order to manage expectations and reassure them to trust the process. As long as there is progression in their training and they are consistent, they are moving in the right direction.
Others may simply not be doing enough to allow for adaptation to occur. However, if the total training volume/intensity is increasing over time, eventually they will catch up.
“Many patients don’t need anything special, just a greater intensity or longer duration of rehabilitation” – Dr. Jim Eubanks
Have questions about how to program for rehab, want to get into the nuance, or are dealing with a persistent injury? Contact us! We’re here to help.
1. Bernstein, Ian A., et al. “Low Back Pain and Sciatica: Summary of NICE Guidance.” BMJ, vol. 356, Jan. 2017, p. i6748. www.bmj.com, doi:10.1136/bmj.i6748.
2. Côté, Pierre, et al. “Management of Neck Pain and Associated Disorders: A Clinical Practice Guideline from the Ontario Protocol for Traffic Injury Management (OPTIMa) Collaboration.” European Spine Journal: Official Publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society, vol. 25, no. 7, July 2016, pp. 2000–22. PubMed, doi:10.1007/s00586-016-4467-7.
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6. George, Steven Z., and Giorgio Zeppieri. “Physical Therapy Utilization of Graded Exposure for Patients with Low Back Pain.” The Journal of Orthopaedic and Sports Physical Therapy, vol. 39, no. 7, July 2009, pp. 496–505. PubMed, doi:10.2519/jospt.2009.2983.
7. Kolski, Melissa C., and Annie O’Connor. A World of Hurt: A Guide to Classifying Pain. Thomas Land Publishers Incorporated, 2015.
8. Perceived Exertion (Borg Rating of Perceived Exertion Scale) | Physical Activity | CDC. 17 Sept. 2020, https://www.cdc.gov/physicalactivity/basics/measuring/exertion.htm.
9. Bunzli, Samantha, et al. “Making Sense of Low Back Pain and Pain-Related Fear.” The Journal of Orthopaedic and Sports Physical Therapy, vol. 47, no. 9, Sept. 2017, pp. 628–36. PubMed, doi:10.2519/jospt.2017.7434.