What do Physical Therapists Do: Installment #3 - We Strength Train

© creativecommonsstockphotos - ID 96113980

In the first installment of "What Do Physical Therapists Do? We Look at Mechanics," I described an experience with a patient who came to Seattle Children's with doctor's orders to do a biomechanical assessment to clear him for return to sport and discussed how it is our job to be "movement specialists."  In the second installment, "What Do Physical Therapists Do? We Listen," I touched upon the biopsychosocial model and the importance of considering the psychological stressors in addition to the internal biological influences on pathology.

Today I'm back with the third installment: "What Do Physical Therapists Do? We Strength Train."  I don't mean that we necessarily pump iron... although I do like to lift heavy things from time to time. Earlier this week, for example, I carried my ~50 pound kayak overhead about 1/4 of a mile to put it into the water... some overhead pressing would probably make that a bit easier.  It would be even cooler if I could suitcase carry it - but so far I'm not able to.  Some of my PT coworkers lift. Others do yoga, or ride horses, or ski, or hike, or play hockey, or lacrosse.  In general we're an active group which helps us to better understand how the body moves.  I once had a clinical instructor tell me that I should try out (or at least watch) any activity available so I could best understand where frequent injuries in that activity could come from and see the things the body is capable of.  It led me to take a snowboarding lesson and watch sumo wrestling - talk about immensely different ways for the body to move!  But that's not what this is about... I'm talking about what we do for our patients.

A common (and essential) physical therapy treatment is exercise.  Exercise covers a wide variety of topics, so the focus today is on strength training.  I'm not here to debate whether or not soft tissue work improves mobility of tissues or has neurological effects or changes the chemical composition of body tissues.  I believe all of these things happen to some extent and know there is debate in the literature on this topic.  Regardless of how soft tissue treatments are applied and what is happening in the body, after some mobility work is completed we need to load our patients. Here's why this is a problem:

Physical therapists guide their patients in strength training exercises but, in my opinion, we barely touch on the basic principles of resistance training and we certainly did not apply them sufficiently in PT school.  Earlier this week, I passed the Certified Strength and Conditioning Specialist (CSCS) exam by the National Strength and Conditioning Association (NSCA). "Certified Strength and Conditioning Specialists are professionals who apply scientific knowledge to train athletes for the primary goal of improving athletic performance."  Some of my patients are not participating in athletic endeavors, but all humans are athletes and all athletes are humans - so we need to treat them as such.  (I can't remember where that line came from - it's not mine, though).  So physical therapists serve a similar role as strength coaches in many ways.

While preparing for the CSCS exam, I was overwhelmed by how much I didn't know. When checking the literature for articles about physical therapists and strength training, I came upon this 2016 article entitled "Periodization and physical therapy: Bridging the gap between training and rehabilitation."  The paper also presented the basics of resistance training and the similarities and differences between physical therapy rehabilitation programs and strength and conditioning programs.

Both physical therapists and strength coaches apply the General Adaptation Syndrome.  "Physical activity is better described as a physiological stressor... when physical activity is properly dosed in individuals who possess the physiological capacity to respond acutely, homeostasis is restored."  The idea is that the body has a baseline set point that it normally operates at and a threshold beyond which it cannot properly recover.  Exercise is one type of stressor following which the body moves away from its set point, towards a threshold, and needs to have processes available to return to baseline.  There are baseline settings for numerous things in the body, all of which can be influenced by exercise including: fluctuation in blood pH, stimulus of hormonal changes and immune responses, changes to the cardiovascular and respiratory systems, altered hydration status, potential tissue damage... the list of is extensive.  The body is generally amazing in its ability to adapt and respond to this variety of changes to return the body to its resting state.   However, if the stresses are too high, injury, illness, or death (at extremes) can occur.  The goal from physical therapy and from strength training is to operate within the boundaries of applying stress so the body can adapt to and recover without over-reaching.

How do you structure this into patient/client programs in a way that makes their threshold improve so they can do more work or lift more weight over time?  Both Physical Therapy and Strength Training use the concept of progressive overload described in Essentials of Strength Training and Conditioning as "progressively placing greater-than-normal demands on the exercising musculature - applies to training to increase bone mass as well as training to improve muscle strength."  For example, we start with a movement pattern such as the squat, and we train it as a movement with just body weight and then progressively load it with dumbbells or barbells and we fluctuate the variables of our training volume and intensity so that the body has time to adjust and adapt and learn.  This means that the homeostasis set point and the thresholds from the general adaptation syndrome are flexible and can be improved with the possible exception of someone who has reached their full genetic potential.

With consideration for progressive overload, strength trainers design training programs for their clients.  In my opinion, based on my observations in numerous clinics over the past 3.5 years, this is where the two fields diverge and physical therapists don't use the same principles.  When planning for resistance training, we can consider four target outcomes: 1) strength gains, 2) improved power, 3) muscle hypertrophy, 4) muscular endurance.  Programming for a specific target outcome means varying the volume (reps/sets), the load (percentage of maximum able to be lifted), frequency of training, and rest breaks.   To target these outcomes, those variables have been studied and summarized as follows:

Target Outcome	Reps per set	Sets	Percentage of 1RM	Rest
Strength	< 6	2-6	> 85	2-5 mins, full recovery
Power	1-2 or 3-5	3-5	depends but >75	2-5 mins, full recovery
Hypertrophy	6-12	3-6	67-85	30 sec - 1.5 mins
Endurance	> 12	2-3	< 67	< 30 sec

Also important to consider is Matveyev's model of Periodization which considers the preparatory phase (basically off-season), transition period (changing over from off-season to in-season), and competition periods, but the preparatory period is broken down into three more sections: hypertrophy and endurance early on, moving into a basic strength phase, and then more of a sport specific strength and power phase.  So understanding how to vary the volume and align it with time on the field or court is essential.  But in the PT clinic, we don't usually program or progress in this manner.  We may consider similar rep schemes and progressive resistance, but we don't typically use loads of this magnitude because we're rehabbing people who either can't or should not yet be lifting loads of that intensity.  At the end of the day, we're all loading up our patients/clients.

Lastly, consider teaching a person a new task such as a squat.  At first, regardless of reps and sets selected, the initial changes that person will experience will be the brain learning how to squat.  This is the same for any activity - your body needs to learn the pattern and get the neurons linked together before you can experience significant muscle gains, improvement in function, and changes in strength.  They may feel stronger or that the task is easier, but these initial changes are neuromotor.  In the context of pain, people move differently and their neuromotor patterns change.  So, since about 99% of the patients I treat are in pain, I'm basically coaching them to make neuromotor changes and as they go through that work, their symptoms resolve, and they're done with physical therapy (because insurance dictates this).  Thus, they have so much remaining potential for strength gains, endurance training, hypertrophy, power, agility, and all the physiological benefits that remain for a strength coach to guide them.  I'm a little bit jealous that I don't generally get to observe these adaptations in my patients, but I get to see them in my own training.