Neurological physical therapy should never be easy! As avid readers of my blog ;) you are already well aware that in order for the brain to achieve neuroplastic changes, rehabilitation efforts need to be of a high intensity. If you are reading this and have no idea what I'm referring to, feel free to check out a previous post on neuroplasticity. An abundance of research supports this need for high intensity rehabilitation for those who have suffered a stroke, brain injury, or spinal cord injury, or those who have been diagnosed with a neuro-degenerative disease such as Parkinson's or Multiple Sclerosis. This intensity may start as early as your stay in the hospital, but more often begins once in an in-patient rehabilitation setting. However, multiple studies have shown, that typical physical therapy in these settings achieves only 3-7 minutes per session of high intensity training (1). So what constitutes "high intensity" and what should I (as a patient of physical therapy) expect from a high intensity PT session?
High Intensity Gait (Walking) Training
High intensity gait training can mean walking (or running) at at a higher speed, increasing your heart rate, or adding a particular type of challenge such as, walking on uneven surfaces or navigating around and over obstacles. In recent studies, intensity has been measured in percentage of heart rate reserve (HRR) or rate of perceived exertion (RPE).
Heart Rate Reserve
Heart Rate Reserve (HRR) is the difference between your heart rate max (HRM) and your resting heart rate (HR). High intensity training means achieving anywhere between 60-80% of your HRR. This is calculated by taking a specific percentage of your HRR and adding back in your resting heart rate using this formula:
70% of HRR = Resting HR + [(HRM - Resting HR) X 0.7]
HRM can be calculated one of two ways, with the latter seemingly more accurate:
220 - your age
208 - (0.7 x your age)
So if you are 65 years old and your resting heart rate is 70 beats per minutes (bpm), your HRM would be 163 bpm (using the second equation). And high intensity exercise would be achieving a heart rate between 126 bpm and 144 bpm.
Rate of Perceived Exertion
Rate of Perceived Exertion (RPE) is a measure used to indicate how hard a person feels they are working. It's a subjective measure calculated on a 20-point scale (although 10 point scales have been adapted for ease of use). High intensity in this measure means working between a 15-18 RPE. At this intensity you should feel a little uncomfortable and short of breath, but able to speak one sentence.
Multiple studies have shown that patients post-stroke engaged in High Intensity Gait Training achieve higher levels of walking independence, increased walking speed, and increased walking distance than those engaged in traditional physical therapy care (2). In fact, high intensity walking, not only improves walking, but also has been shown to improve balance, functional mobility (like getting in/out of a chair or transferring to a toilet), and endurance (4). All these improved without explicitly practicing those skills!
High Intensity Balance Training
High intensity doesn't just apply to walking. You can practice high intensity balance training. A clinical instructor once told be that if the patient doesn't feel like they are about to fall, then the activity isn't challenging enough. This has stuck with me ever since....just ask any of my patients! Of course, ensuring patients are safe is of priority, so I challenge my patients by using an overhead harness (image right). That way, I can get them to the point of falling and allow their body to adapt and learn how to prevent the fall, without them being at risk of having an actual fall. And the research supports this! Perturbation-based balance training is a type of exercise that practices reactive balance. Reactive balance is the balance strategy our body reflexively uses to prevent a fall when a sudden, unexpected force (or perturbation) occurs. An example of this might be, suddenly being nudged by someone in the supermarket and your ability to maintain your balance. Other types of reactive balance include your ability to maintain your balance when you slip on ice, or trip over an object. Perturbation-based balance training has shown to reduce the number of falls and overall fall risk in older adults and people with Parkinson's Disease (4). In fact, just a single session of perturbation-based balance training can improve reactive balance significantly for up to 1 year (5)! Maybe we should have fall prevention tune-ups, similar to regular teeth cleaning at the dentist???
What Can I Expect from High Intensity PT?
Expect to sweat! When engaged in high intensity PT, long gone are the days of casually chatting with your therapist while riding a recumbent bike. If you can carry on a conversation easily while performing your exercises, your exercises are not intense enough! That doesn't mean there isn't time for rest breaks and having fun with your therapist. It just means more time is dedicated to getting the intensity required to make neuroplastic changes.
Sessions at Whidbey Dizziness & Balance will look different from patient to patient, depending on their abilities and overall therapy goals. Some activities will be walking on the treadmill in the overhead harness (to prevent falls) at a fast pace, on an incline, or even sideways or backwards! Some activities will involve walking overground, stepping over/around various obstacles, or going outside to walk on variable terrain. We are currently in the design phase of an outdoor terrain park at Whidbey Dizziness & Balance to do just this (see below)!
Is It Safe?
When implemented by a trained healthcare professional, high intensity gait training is safe. A physical therapist with advanced training in high intensity gait training will perform a thorough evaluation of your medical history, co-morbidities, medications, and current condition. They can then determine if you are a good candidate for high intensity gait training. Just to ensure my patient's safety, I take the additional step of contacting your primary provider or cardiologist to ensure there are no concerns. During a high intensity session, my patients wear a continuous heart rate monitor, so I can design activities which keep them in a safe, yet optimal, heart rate zone for neuroplastic changes to occur. Vitals are monitored before, after, and sometimes during a session. This is why you should discuss the appropriateness of high intensity gait training with a healthcare professional before starting!
References
DiPasquale J, Trammell M, Clark K, et al. Intensity of usual care physical therapy during inpatient rehabilitation for people with neurologic diagnoses. PM&R. 2022; 14(1): 46-57.
Hornby TG, Holleran CL, Hennessy PW, Leddy AL, Connolly M, Camardo J, Woodward J, Mahtani G, Lovell L, Roth EJ. Variable Intensive Early Walking Poststroke (VIEWS): A Randomized Controlled Trial. Neurorehabil Neural Repair. 2016 Jun; 30(5): 440-50.
Moore JL, Nordvik JE, Erichsen A, Rosseland I, Bø E, Hornby TG; FIRST-Oslo Team. Implementation of High-Intensity Stepping Training During Inpatient Stroke Rehabilitation Improves Functional Outcomes. Stroke. 2020 Feb; 51(2): 563-570.
Mansfield A, Wong JS, Bryce J, Knorr S, Patterson KK. Does perturbation-based balance training prevent falls? Systematic review and meta-analysis of preliminary randomized controlled trials. Phys Ther. 2015 May; 95(5): 700-9.
Liu, X., Bhatt, T., Wang, S. et al. Retention of the “first-trial effect” in gait-slip among community-living older adults. GeroScience. 2017; 39: 93–102.