My best friends from college nicknamed me Yurtle the Turtle. This moniker manifested after hours spent cheering for me in my cross-country races while also joining me for leisurely (they would say SLOW) strolls across campus. They teased and marveled how one could run fast, yet walk so slow. We’ve laughed about this many times and I’ve also reflected on the continuum of speed, with respect to rehab, and when it’s beneficial to slow things down.
trailing on the path
When it comes to speed and velocity, both measurements of the rate something moves, the majority of us are biased to thinking “how fast” instead of “how slow.” I use speed and velocity interchangeably here but there is a difference. Speed is a measurement of how fast something moves while with velocity we measure speed with a direction in mind.
There are a number of scenarios when decreasing the velocity of human movement directs us toward better long-term outcomes. The following are examples of when I intentionally slow things down with patients and why I choose to do so.
When it comes to breathing we want our breath rate to be efficient and adaptable to our physiological context. Slow breathing leads to positive physiological effects on a number of systems including our: Respiratory, Cardiovascular, Cardiorespiratory and Autonomic Nervous Systems. (1)
The psychological and physiological effects of breath rate are readily felt in our day to day lives. Ever find yourself intentionally slowing your breath down when you feel a little anxious? I bet the answer is yes. However, do you do it through your nose with mouth closed? Perhaps not.
The topic of slow breathing could be a whole blog post, even a book, so I’m going to focus on one aspect: Nasal breathing, and why slow is a crucial component.
Nasal breathing is a part of many breath practices and can be used therapeutically to promote and reinforce things like oral rest posture, tissue perfusion, performance and overall relaxation.
Taking quick breaths in and out of your nose feels differently than doing it slowly. Go ahead and try it.
Different, right? But how come? Assuming there are no structural abnormalities or other issues like allergies we can use physics to partially explain.
The type of airflow that occurs in the nasal cavity is dependent on several things including flow rate. Slow rates of nasal inspiration produce laminar flow while higher rates of flow trend toward turbulent flow. This is not black and white and the variability of flow type is highly dependent on structure so think in grey here.
May the flow be with you
Image from https://emedicine.medscape.com/article/874822-overview
Per the Hagen-Poisseuille equation, resistance to air flow in a tube is influenced by flow rate. Airway resistance is low during laminar flow, when flow rates are slower. When flow rates increase (eg. intense exercise) the air becomes more turbulent leading to more resistance.
While there is definitely a role for turbulent airflow in the nasal cavity this increased resistance is likely one factor as to why intentionally slowing down your breath rate (to less than 10 breaths/minute) is key to developing the ability to nasal breathe and reap the associated benefits.
Orofacial Myofunctional therapy (OMT) is gaining attention for its focus on the upper airway with respect to breathing, sleep and overall health and wellness.
Slowing down certain OMT exercise has helped my patients with two of the common patient struggles I see.
The first difficulty is the ability to coordinate tongue movements in absence of facial compensations. When learning to coordinate tongue and mouth movements, it’s not always about learning what to turn “on” but what to turn off. There is no doubt that visual feedback with a mirror is helpful but slowing down the movements helps a ton.
The second challenge most people encounter is becoming aware of and elevating the posterior aspect of the tongue to achieve a proper oral rest posture .
If this is a coordinative issue and not a mobility or structural problem, I have people do a cheesy grin/smile swallow. While performing this exercise I stress having them do a slow swallow with an almost pause mid-swallow.
Maybe I’ll start calling it the Thompson tempo TUT swallow ;)
Manipulation of cadence (step rate) is a key variable when treating running related injuries because increasing cadence results in shorter ground contact time. Less ground contact time results in less loading of the hip and knee joints (2) as well as less stress and strain on the Achilles tendon. (3) While this is important for some patients, others might need a different approach.
Slowing down cadence to increase ground contact time can help improve tolerance to limb loading and normalize someone's gait pattern after injury or surgery, especially after a period of non-weightbearing.
Encouraging someone to load the musculoskeletal system and the somatosensory system helps gain a perception of control. One can do this in a number of ways including use of a metronome.
When gait retraining is progressed to running and agility drills, we can also benefit from a brief period of movement deceleration for learning and improving coordination. Slowing down drills such as high knees, A skips and B skips, helps both the individual teaching the drill, and the client, recognize asymmetries not apparent at higher speeds.
It’s fun to watch how the best practice for treating patients with tendinopathy has evolved over the years. We now know that loading intensity is key.
Time under tension (TUT) refers to a method of manipulating exercise tempo - the rate at which each rep is performed - to affect the amount of time muscles are under tension.
Heavy Slow Resistance Training, is an application of TUT, that has gained favor in the strengthening phase of rehab for patients with tendon pain. Several studies (4,5) demonstrate that HSRT protocols with slow concentric and eccentric phases result in improved outcomes compared to protocols emphasizing the old gold standard of Alfredson’s eccentric protocol.
The mechanistic reasoning for why this approach works is varied. Many argue that it develops tendon capacity and neural adaptations. Others note a possible cortical link using external pacing via a metronome, an approach called Tendon Neuroplastic Training.
You can't feel things as well when you move quickly. Slowing down a particular movement to promote sensation at reference points helps express more control, develop precision and eliminate compensations. In the feedback loop of learning, slowing down movement helps gain awareness of these factors.
The subtleties that matter in exercises aren’t always readily perceived by clinicians or clients at faster speeds. In fact a pause added to a slow flow can be secret sauce.
The importance of symmetrical loading is important to consider when we look at the statistics of re-injury rates in post-op ACLR patients. Individuals post- op ACLR often demonstrate significant asymmetries with loading in squatting, lateral step-downs, stair climbing, single leg hopping and jumping. (6, 7, 8) While this altered loading has been linked to quadriceps weakness we don’t know if it is the altered loading contributing to quadriceps weakness or vice versa. (9)
Most clinics don’t have the force platforms or motion capture systems that can examine movement to the degree performed in research labs. And while that type of feedback, or the use of apps like Coach’s Eye or Dartfish, is beneficial, slowing down the movements helps develop interoceptive awareness so control isn't dependent on external feedback.
Both graded exercise and graded exposure are approaches that can be used in physical therapy and often incorporate slower movements.
Graded exposure is an approach used to expose a patient to movements and/or situations that they fear. Graded exercise on the other hand, is a method of manipulating a variety of variables to improve movement patterns and increase exercise tolerance in rehab.
Slowing down movements in these approaches helps decrease threat and increases tolerance. While we may be affecting physiology here the main goal is an adjustment in perception of control on the part of the patient.
For a patient whose nervous system is sensitive to movement, slowing down the Clinical Neurodynamic assessment helps for several reasons:
1. To prevent a flare up
2. To allow the clinician to feel resistance to movement
3. To allow the patient time to sense when and where they feel symptoms
4. To determine whether the response is an “overt” or “covert” response, thereby distinguishing whether the sensations felt are relevant to the patient’s present complaints.
This approach to structural differentiation allows you to make better clinical decisions when choosing the appropriate intervention. It makes sense that if this approach works in assessing the mechanical sensitivity of the nervous system then a similar approach would work with your interventions.
And yes, a slow down can and should be applied to other manual assessments as well.
The thing I want you to take away from this post is that there are several benefits to slowing down movement. Evolution teaches us that we need to have options in order to adapt. Velocity is one variable we can manipulate to thrive.
Increased time to complete a task allows for increased attention and awareness. Greater self-efficacy develops as one explores movement and builds trust. Slow movement serves an important stepping stone in movement control and slow breathing can positively affect physiology.
When cueing for “slow” it often helps to be specific. “Slow down” doesn’t help as much as “I want to you to descend for the count of 4 seconds.” Alternatively one might ask the movement to be "as slow as needed to feel in control."
Rehab from injury, motor learning, and skill acquisition are all processes. What is best at certain stages may differ as one moves toward their intended goals. There will be times when you need to increase your breath rate, swallow fast and move your mouth/tongue quickly. You'll never gain power if you only move slow and you'll likely miss something if your manual assessments are too quick.
Logically we don’t always want to walk slow. But then again the long term effects from many leisurely strolls across campus may be more impactful than PRs that are made to be broken.
#velocity #speed #slow #motorcontrol #clinicalneurodynamics #myofunctionaltherapy #tendinopathy #heavyslowresistance
References
1. Russo MA, Santarelli DM, and O’Rourke D. The physiological effects of slow breathing in the healthy human Breathe. 2017 Dec; 13(4): 298–309
2. Heiderscheit BC, Chumanov ES, Michalski MP, Wille CM, Ryan MB. Effects of step rate manipulation on joint mechanics during running. Med Sci Sports Exerc. 2011 Feb;43(2):296-302.
3. Lyght M, Nockerts M, Kernozek TW, Ragan R. Effects of Foot Strike and Step Frequency on Achilles Tendon Stress During Running. J Appl Biomech. 2016 Aug;32(4):365-72.
4. Malliaras P, Barton CJ, Reeves ND, Langberg H. Achilles and patellar tendinopathy loading programmes: a systematic review comparing clinical outcomes and identifying potential mechanisms for effectiveness. Sports Med. 2013 Apr;43(4):267-86.
5. Beyer R, Kongsgaard M, Hougs Kjær B, Øhlenschlæger T, Kjær M, Magnusson SP. Heavy Slow Resistance Versus Eccentric Training as Treatment for Achilles Tendinopathy: A Randomized Controlled Trial. Am J Sports Med. 2015 Jul;43(7):1704-11
6. Neitzel JA, Kernozek TW, Davies GJ. Loading response following anterior cruciate ligament reconstruction during the parallel squat exercise. Clin Biomech (Bristol, Avon)
7. Gokeler A, Hof AL, Arnold MP, Dijkstra PU, Postema K, Otten E. Abnormal landing strategies after ACL reconstruction. Scand J Med Sci Sports. 2010;20(1):e12–9
8. Orishimo KF, Kremenic IJ, Mullaney MJ, McHugh MP, Nicholas SJ. Adaptations in single-leg hop biomechanics following anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2010;18(11):1587–93
9. Chmielewski TL, Asymmetrical Lower Extremity Loading After ACL Reconstruction: More Than Meets The Eye. J of Ortho & Sports Phys Ther 2011 41:6, 374-376
Photo credits
From Thao Le Hong at Unsplash
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