Sustainable activity across the life span often involves navigating through pain and/or MSK injury. Developing self-care skills to (1) provide reassurance that hurt does not equal harm and activity is not dangerous, (2) improve movement tolerance and competency, (3) gradually increase load capacity, and (4) exposure to variable movement tasks and environments is a crucial component to this process. Movement is the common thread that unites each of them. We can educate through movement, understand through movement, assess and correct through movement, and create resiliency, robustness, and adaptability through movement.
There is a myriad of approaches for correcting dysfunction or “fixing” MSK issues. However, rather than following a technique system, this chapter will lay out four scalable principles used to guide the rehabilitation process. The scalable nature of these principles allows for broad application across the prevention-rehab-performance continuum, yet permits a precision delivery tailored to the specific needs of the individual. These principles serve as a foundation for a personalized, functional approach to patient care.
Modern goals of care align with the principles of the functional approach and include:
The typical “overprotected, underprepared” patient will tend to progress through these goals in order, although this is not always the case.
Immunizing someone against disability requires building up their ability to adapt to stress. In contrast, diagnostic imaging, injections, medications, manual therapy, and physical therapy modalities are merely palliative and do not contribute to the developmental of psychological and physiologic resilience.
The Four Principles
Increase pain tolerance
Numeric rating scale or visual analog scale/yellow flags
Return to participation
Activity volume and intolerances
Principle One: Reassurance Educate patients that hurt doesn’t equal harm, while creating a positive experience with movement.
Principle one is a basic starting point—understand pain and calm things down. However, this can be very nuanced as the “experience” of pain takes on different meanings for different individuals. It may have to do more with building activity tolerance than a merely palliative approach would imply.93
It is the beginning of pain education
because it addresses distinguishing “good pain” from “bad pain.” The essence of a fragilista mind-set is to assume “hurt equals harm,” yet a resilient person knows this is not always true.
Pain is a stress and the manner in which a patient “interprets” that stress could make them feel fragile—for example, under Damocles sword. The HCP’s role is to reassure the patient so they feel they can tolerate the pain and stay active. This is the key step in switching from a reactive, palliative mind-set to a sustainable, resilient one.
Distinguishing between a person’s sensitivity and tolerance is a key first step. In the patient’s history the HCP gains a sense for an individual’s attitudes and beliefs about the relationship of movement and pain as well as hurt and harm (see Appendix 7A
in Chapter 7
). For instance, during ADLs like sit to stand, walking, getting up and down from the floor, bending, etc., a person might say their pain is an 8/10, but they can tolerate it (meaning it doesn’t limit them, nor do they need medication), whereas another person’s pain might be something they can’t tolerate and thus are disabled by it. In other words, sensitivity does not equal disability and tolerance does not mean a lack of sensitivity.
At one end of the spectrum is the fragilista person who is anxious and catastrophizes. At the opposite end of the spectrum is the person who goes “boom and bust” and may believe in the adage “no pain no gain.” This person may simply want to resume their normal activities and therefore want the pain extinguished by any means. In this case they will likely ignore pain’s function as a possible warning sign about a mismatch between the current capacity they have and the required capacity they need. By ignoring “stop rules” and failing to appreciate the “gift of injury” they miss the opportunity to make a training investment that would lead to sustainable athleticism.94
A Buddhist “middle path” is required with respect to pain management and building activity tolerance. This is called the “Goldilocks principle.” Not too much or too little. We want to avoid “letting pain be your guide” and thus doing “too little too late.” But, we must also avoid the pitfall of being a bull in a China shop and “doing too much too soon.” Pain education can guide the appropriate interpretation of the patient’s experience and promote confidence in the return to PA. We can start to screen our patients’ BELIEFS about hurt and harm, ANXIETY, and CONFIDENCE with selected yellow flag questions (see Assessment section).
It is interesting to note that the numeric rating scale (NRS) for pain that has been a “gold standard” for over a generation is now coming under increased scrutiny. Here you see an alternative rating scale that
shows how one feels on a continuum from happy to sad (see Fig. 38.12
). This one shows a traffic light as it relates to movement and whether it is appropriate or not to proceed (see Fig. 38.13
). It is worth considering if we should stop asking patients how much an activity hurts and start asking them only the perceived red light question—“what does it stop them from doing.”
Surprisingly, an increase in pain with rehabilitation can be associated with a positive outcome.95
In this emerging paradigm, the meaning of pain is explained in terms of danger instead of sensitivity. In the tendinopathy literature, 0 to 2 is considered safe; 3 to 5 acceptable; and over 5 a high-risk zone (see Figs. 38.14
If a clinician allows pain during activity, it is recommended to follow these two additional steps:
Debrief the following day to see if the patient has experienced any additional pain spikes
Debrief a week later to determine if there is overall progress, no change, or a regression
Figure 38.12 Alternative scale to numeric rating scale.
Figure 38.13 Traffic light system.
Figure 38.14 Pain-monitoring model.
Figure 38.15 Tendinopathy pain model. Adapted from Silbernagel KG, Thomeé R, Eriksson BI, Karlsson J. Continued sports activity, using a pain-monitoring model, during rehabilitation in patients with Achilles tendinopathy: a randomized controlled study. Am J Sports Med. 2007;35(6):897-906.
The need for pain to be avoided or alleviated as much as possible has been challenged, with a paradigm shift from traditional biomedical models of pain toward a biopsychosocial model of pain, which is particularly relevant in the context of performing therapeutic exercise.97
Sturgeon and Zautra write, “Attempts to control a chronic stressor like chronic pain are often counterproductive and can magnify the negative effects of the stressor.”98
Smith’s recent systematic review and meta-analysis of painful exercises versus pain-free exercises for chronic MSK pain concluded that “protocols allowing painful exercises offered a small, but statistically significant, benefit over pain-free exercises in the short-term.”95
We define painful exercises when: exercises are prescribed with instructions for patients to experience pain or where patients are told that it is acceptable and safe to experience pain.97
We know pain is not an accurate assessment of tissue status and that if a patient assumes hurt equals harm it is up to the HCP to discuss with the patient if this is plausible or not. How can this be interpreted? Should such discomfort always lead to avoidance behavior? According to van Vliet et al, paradoxically we might actually increase fear by recommending avoidance of pain! “We hypothesized that engaging in avoidance may (paradoxically) increase rather than decrease pain-related fear (i.e., bidirectionality hypothesis). …These findings may have clinical implications and suggest that allowing avoidance behaviors during treatment may thwart fear reduction.”99
Pain and tissue state are poorly related
Patients often expect or experience increases in pain with exercise, which can cause fear and influence compliance.100
According to Smith et al permitting patients to increase their tolerance or acceptance of pain demonstrated short- to medium-term benefit.95
Sandal et al reported that in patients with persistent knee or hip pain, acute exercise-induced pain flares during an 8-week rehabilitation program are expected.100
Furthermore, these flares were transient and should not influence compliance as the pain flares gradually lessened so that by the end of the program, pain levels were significantly reduced. Therefore, communicating the message that “pain during movement rehabilitation is normal and expected” is likely to reduce fear, prevent catastrophization, and improve compliance with exercise programs.
An example of how to reframe the pain sensitivity/movement tolerance dialogue might be “your shoulder is painful because it has become deconditioned and not used to movement. We need to exercise your shoulder, so it will become strong and conditioned to enable you to do what you need to do.”97
This can change the threat perception101
and allow a new conditioned response to emerge.102
Too often, pain is treated as a purely biomedical problem. It is a biopsychosocial condition.103
According to Darnall, “people who worry more about pain, or who report feeling helpless in the face of it, are at risk of prolonged pain…. Simple pain-science education, cognitive regulation and relaxation skills can help empower patients to reduce pain processing in the brain.” Learning how to distinguish hurt from harm is decisive to help a patient become more functional. Disability does not always have to result from pain. The clinicians’ role in educating patients about coping is decisive in avoiding nocebos such as overly protective “safety” advice rather than more adaptive “coping” advice.104
Developing a Flexible, Agile Mind-set Enhances Function
Taking a pragmatic approach by using functional outcomes to classify exposure behavior will provide clearer rules for distinguishing safety functions (i.e., those that reduce flexible approach behavior) from coping functions (i.e., those that encourage flexible approach behavior).104
Originally developed for treating anxiety disorders, “exposure therapy involves gradually and repeatedly confronting feared stimuli, without engaging in avoidance, escape, or other behaviors that reduce anxiety and/or make the feared situation more tolerable.”104,105
Pain avoidance acts as an emergency brake in rehabilitation because patients become focused on palliative relief, which unfortunately does not address the real drivers of activity limiting pain—over-protection or underpreparation. It is wiser to inform patients that hurt does not equal harm and that an acute increase of pain is a common response to starting exercise in people with chronic or persistent pain.106
Patients should be educated that over time, exercise can decrease pain even if there is an initial increased pain response.106
According to Lima, “A single bout of fatiguing exercise in the presence of a chronic pain condition can exacerbate pain that is characterized by increased phosphorylation of NMDA receptors in the RVM, suggesting enhanced central facilitation. On the other hand, regular exercise promotes pain relief and is characterized by reduced NMDA receptor phosphorylation, suggesting reduced central facilitation. Further regular exercise reduces serotonin transporter expression, increases serotonin levels, and increases opioids in central inhibitory pathways including the PAG and RVM, suggesting exercise utilizes our endogenous inhibitory systems to reduce pain.”
As a general rule, if exercise is too painful, another exercise can be found. The goal is for pain to be reduced over time; however, mild to moderate pain is typically not a sign of impending harm. Moderately or
severely painful movements should be noted and recorded as baseline mechanical sensitivities. These can be audited within- and between-session to demonstrate progress. Although improvement generally takes time, and flares are a normal part of the process, an investment in gradually increasing exercise or activity tolerance will be a trial of graded exposure to feared stimuli. The goal is simple—to increase activity tolerance via reassurance that:
Education campaigns now need to emphasize a “trust your back” message rather than a “protect your back” message while staying active.107
Even in older patients with severe hip or knee OA, exercise-induced pain is safe.108
During the course of training, pain is ultimately decreased or unchanged, but not worsened. Flare-ups occur but are uncommon. Increased strength, balance, and mobility are achieved during the training period.
Principle Two: Reactivation Gradual reactivation and participation.
After pain education and reassurance about the safety and value of activity, the next progression is to assure that landmarks are in place to guide the reactivation process. Assessment of movement quality gives a parallel functional baseline to complement the pain baseline described earlier. We track both the pain intensity (NRS/VAS) alongside the volume of activity (steps/day; minutes of exertional activities [see Appendix Form A], activity intolerances [Appendix Chapter 8
], etc.). It is the role of pain education
and reassurance to reduce an overprotection
mind-set while the movement exploration and gradual reactivation address underpreparation
Every exercise is a test
When one feels they can tolerate or withstand stress they are at the beginning stages of becoming resilient. It is important to build on the reassurance of Principle 1 by reactivating patients via Principle 2. This reduces overprotection and addresses underpreparation.
It is important to note that although we avoid loading dysfunctional patterns, we also don’t want to create a nocebo by increasing a patient’s worry that they’ll cause damage if an unloaded movement quality isn’t performed perfectly (see Safety discussions earlier and later). Inactivity is the real bogeyman we should be concerned about. The red, yellow, green stop light analogy used earlier, as well as the recognition, education, and discussion of “yellow flags” will help promote empathetic reactivation.
Resumption of near-normal ADLs should follow a few “rules of the road.” Gray Cook says, “move well then move often.” This means that we create an environment with “guardrails” that constrains faulty movement patterns and reactively facilitates motor learning. Once quality improves then volume can increase. This is a necessary prerequisite to adding load or resistance. At this stage most of our exercises involve primarily bodyweight and/or gravity for the resistance.
It is important to realize that static posture does not correlate well with pain, but in preparation for load it is important. So, context is key. We want to gradually expose the person to more challenging tasks (see Principle 3). The tasks should be relatable to the person’s ADLs or demands they are required to perform.
Gray Cook developed a simple scoring schema for the Functional Movement Screen (FMS) that can be applied to both Principles 1 and 2 (see Table 38.2
If there is pain, the movement is given a score of 0. If the movement cannot be completed acceptably, the score is a 1.
If the movement is completed but with acceptable compensations, the score is a 2. If a task can be accomplished with pristine form and technique, it is scored a 3.
Functional Movement Screen (FMS) Scoring According to Cook*
0—any pain that is considered more than a discomfort during a movement or task—MARKER
1—unacceptable dysfunction during a movement or task**—GOAL
2—acceptable dysfunction during a movement or task—THE MUD (ideal for bodyweight)
3—perfect form during a movement or task—COMFORT ZONE therefore add load
*The FMS includes seven tests but the scoring system is scalable to all exercises and tests.
** This category in the FMS is used to signify that the subject is not able to complete the task.
According to Lewit, after an examination of baseline functional integrity or competency “there must be an analysis of what was found… . Treatment (or training
) starts with a ‘dysfunction’ which is likely to be of key importance.110
After this, re-examination of the most important findings follows in order to find out whether some or most of the signs…have reacted or not.” This idea of identifying baselines, intervening, and then reassessing is the hallmark of the scientific method and our CAP or the assess-correct-reassess process. If we can find “within-session” improvement the prognosis is enhanced for “between-session” improvement.
Gray Cook explains that “pain & dysfunction, regardless of their origin, alter motor control. That is why initially we focus on training the most dysfunctional, non-painful pattern.”109
Even though finding the “weak link” is crucial, labeling it the source of pain can put too much attention on “corrective exercise” when our goal is to address overprotection and underpreparation. Each HCP has to “thin-slice” the balance between investment in general reactivation and a specific “thing” being the cause of pain.
By focusing on movement competency, we can improve the quality of one’s movement patterns as a nonthreatening graded exposure designed to build tolerance and self-efficacy. However, it is important to avoid the common trap of overcorrecting. As discussed in Principle 1, although we want to identify painless dysfunctions hypothetically correlated to a person’s symptoms, we don’t want patients to become overprotective. Excessive messages with reference to “safety” should be avoided while emphasizing how adaptive a person’s “coping” abilities are.104
Psychological agility or flexibility on the part of the patient is an important trait to support.104
What Dr. Lewit means is that if you continue to try to improve motor control, it is a never-ending process. It is far more efficient to find the “weakest link” and raise one’s floor dysfunction. The metaphor “you are only as strong as your weakest link” can be a helpful construct that gives the patient something that they can work on where they can expect to see regular progress. This is a more optimistic approach than worrying about magnetic resonance imaging (MRI) findings which “you have to learn to live with.”
If we look at how a person with a neurologic impairment learns to perform a sit to stand or prehensile tasks, individual motor control factors taught in a “blocked” manner do not result in better skill acquisition than offering environmental or task constraints that promote more variability (see Chapter 5
We should always ask ourselves what is the goal and if our training is going to be the most efficient and safest way to achieve that goal.
Why Do We Choose a Certain Test?
We often start with what test, but we should be asking why we are testing. Is it to evade or react, to maintain velocity, change model, or is it perceptual-cognitive?
—Tim Suchomel, PhD
Once we have a foundation in movement competency, the next step is to progress to adding strength (see Fig. 38.17
). Competency is defined as a collection of skills for a predefined purpose. The “predefined purpose” here is the acceptable execution of the fundamental movement patterns in order to then add load. If we add load on top of dysfunction, we continue to create unnecessary compensations. It should be noted that although standards have been developed to grade competency in movement, ultimately, these are subjective measures.
Figure 38.17 Foundational requirements. Reproduced from Liebenson CL. Functional Training Handbook. Philadelphia, PA: A: Lippincott; 2014.
The starting point for the development of competency in a particular pattern will vary depending on the movement literacy, the ability to execute basic motor skills, and what an individual brings to the table. High physical literacy (PL) and qualities of agility, balance, and coordination will likely translate to faster development of competency in a particular pattern. The concept of movement literacy is nested to Principle 4, MV, in that an individual who is literate in a variety of movement environments will be more adaptable and have a variety of options for completing a given task.
Another issue that pertains to both Principles 1 and 2 is that as a general rule making patients autonomous, establishing an internal locus of control, and building self-efficacy is the goal. Consistent with the scientific evidence, both education and self-care are deemed high-value care,69
whereas passive care approaches like manual therapy or physical therapy modalities are considered low-value care.69
If we realize the downside risk of patient dependency from passive care, then there is no problem using it as an adjunctive therapy. The key is that it is not our front-line “default” strategy, and even when used, the goal is to return to promoting independence and self-care.
Principle Three: Resilence Find the hardest thing you do well and gradually increase resistance (strength) training.
The third principle is to build load capacity through resistance training. Basically, to progress from desensitization (Principle 1), to establishing a foundation in body weight movement integrity (Principle 2), to building load tolerance by adding resistance (Principle 3). In effect, if Principles 1 and 2 are mastered, the patient has learned to move well and then added volume—“first move well, then move often.” This is a prerequisite for Principle 3 that involves finding “the hardest thing you do well.”
Building strength is challenging for a number of reasons (see Table 38.3
). First, it produces soreness and many people prefer to avoid this, resulting in insufficient intensity to cause tissue adaptation. Second, when proper intensity is employed, it is a weapon and a recovery phase is needed before loading again. Often the recovery phase is too short or not supported properly (e.g., sleep, manual therapy). In this case, the individual is not in a state of readiness or preparedness for the next training session, and thus fails to benefit from the training stimulus. Third, excessive correctives or blocked practice is utilized, thus depriving the person of the necessary stress to create a transferable change.
Table 38.3 Challenges to Developing Strength
The basic training elements (BTEs) are foundational patterns such as squat, lunge, hinge, push, pull, and carry and can be used as a framework for the introduction of load (see Table 38.4
These are important for getting up and down from chairs or the floor, lifting, carrying, running, throwing, etc. Disability is on the rise and responsible for the growing gap between health span and life span. In order for this gap to shrink, maintaining the ability to squat (frailty prevention) and lunge (fall prevention) is crucial.
Sports Medicine Model Is for Everyone
If someone has knee pain from working at a desk versus knee pain from being a pro athlete…we view the faulty squat pattern the same
—(Craig Friedman, vice president of the performance innovation team, EXOS Performance Center at Mayo Clinic)357
Foundational patterns or BTEs are scalable for load, making them ideal for adding recoverable stress to cause adaptation. Some people contend they are not athletes so they don’t need to train. However, underpreparation is a major determinant of injury risk.71
Similarly, with an adult population becoming physically active between 40 and 60 years, it has been shown to reduce premature death from any cause by up to 35%.114
In addition to the BTEs, other foundational movement characteristics such as change of direction ability, landing ability, and deceleration/acceleration mechanics are important building blocks of function.
Table 38.4 Basic Training Elements
Squat—Getting up and down from chairs. An essential athletic strength foundation and key for prevention of frailty.
Lunge—Single leg tasks. Essential in most sports and related to fall prevention.
Hinge—Bending forward to pull from the ground. Trains lower body power.
Push—Reaching, pushing, or throwing objects. Builds upper body power.
Pull—Grasping and lifting or pulling things toward us. Relevant in modern society to offset consequences of prolonged sitting and balance the tendency to push more than pull.
Carry—Moving forward such as in gait. A basic functional task needed for everyday life.
How much? Adding load increases the RPE.
As RPE increases, NRS/VAS should go down. This will reinforce to the patient that they are becoming more resilient. The goal is to cause adaptation. Sufficient intensity at or near one’s threshold is required to cause this adaptation. Darwin said, “It is not strongest of the species that survives, nor the most intelligent, but the one most responsive to change.”115
There is a sweet spot where stress causes adaptation. Above that level external load is a poison, below that level there is only atrophy (see Fig. 38.18
). The sweet spot is the zone of supraphysiologic overload (Goldilocks Principle).
Too often we create a cycle of rehabilitation purgatory by managing patients away from load and thus dooming them to be unprepared for future stress (see Load Management
section). Thus, it is said “your comfort zone is a cage. It’s a beautiful place but nothing new grows there.” People should be reassured that their body is built to last not to break. Principle 3 reinforces for people that they are not fragile. It’s not the activity that’s harmful it’s the activity you’re not prepared for. Our responsibility is to build up the general physical preparation (GPP) for sustainable success.
This sustainable goal is an essential distinguishing hallmark of intelligent coaching versus a “boot camp” approach. Mel Siff said, “To me the sign of a really excellent routine is one which places great demands on the athlete, yet produces progressive long-term improvement.” He goes on to say, “Any fool can create a program that is so demanding that it would virtually kill the toughest marine…but not any fool can create a tough program that produces progress without unnecessary pain.”
Finding and staying within this sweet spot is the art of a great coach. According to McArdle, Katch, and Katch, “There is an appropriate level of stress whereby the system will adapt. Below this level, little or no change will occur.”116
In rehabilitation where we often go wrong is not loading soon enough or strong enough: “The intensity must be high enough so that a specific physiologic system is stressed at or near its present maximum capacity in order to cause the system to adapt, thereby improving performance.”
How long? After a sufficient training stimulus there is normally postexercise soreness, fatigue, and need for recovery.
This is followed by supercompensation and then a new fitness baseline (see Fig. 38.19
). If, however, a person is loaded again too soon before recovery has occurred, not only do they fail to make gains, but they often regress or get reinjured (see Fig. 38.20
). It is helpful to include recovery strategies such as adequate sleep, hydration, manual therapy, cryotherapy chambers, and recovery pumps, to enhance or even shorten the recovery phase.
The problem of overcorrecting as discussed in Principle 2, a danger of expecting perfect movement patterns is we remain in “rehab purgatory.”
Relatively high chronic loads when they are slowly reached are associated with decreased injury risk and improved performance.117
The kryptonite of this resilience building process is overcorrection. According to Wulf, “Precise movement correction by strength coaches & PTs, for instance during trunk control exercises, are thus not so much a sign of professional expertise as a sign of ignorance about how movements are controlled. Well-intentioned but misapplied expertise can often be highly damaging.”118
Figure 38.18 Load versus frequency.
Figure 38.19 Supercompensation.
Figure 38.20 Improper recovery frequency. Gabbett, TJ. The training—injury prevention paradox: should athletes be training smarter and harder? Reprinted with permission from Soligard T,Schwellnus M, Alonso JM, et al. How much is too much? (Part I) International Olympic Committee consensus statement on load in sport and risk of injury. Br J Sports Med. 2016;50(17):1030-1041.
Kill your darlings.
It is very tempting to correct every dysfunction. But, according to Carmen Bott, “By stepping in to ‘solve’ the client’s problems, the enabler takes away any motivation for the client to take responsibility for his or her own actions. Without that intrinsic motivation, there is little reason for the client to change. We must go beyond telling them their form is terrible and how it will cause this or that….”119
Well-meaning trainers who know not to load dysfunction can be tempted to overcorrect. This along with overprotection from the clinician leads to chronic “rehabbers.”
The acute:chronic workload ratio71
Various repetition maximum (RM) for standard exercises (i.e., squat, bench press, military press, one-arm row)
Endurance metrics (Sorensen, side plank, etc.) (see Chapters 10
Readiness (e.g., recovery)—Wellness questionnaire120,121,122
Principle Four: Variability Constraints-based training to enhance performance and build anti-fragility.
The most important attitude to have when helping patients regain activity tolerance and develop resilient habits is to focus on their goals (e.g., relatedness) and create a program that matches their needs. This requires that we leave aside thinking it is about our program, but instead focus on their profile.
Although some degree of specificity is needed in order to provide sufficient intensity to cause an adaptation, it is only through variability that the recovery occurs, which is the prerequisite for that adaptation. It is perhaps best to view specificity in training as a “proxy” for transferability.123
Valle says, “Sport specific is a direct pipeline for rehearsal of the sport or just general training that is closer to demands than other options.”
I don’t know what “sport specific” is, since the term is a vague one.123
When we begin with the end in mind, it becomes clear why “overcorrecting” and even continuing to build strength in the gym beyond certain preferred baselines can reach a point of diminishing returns. The goal of training is transferability and resilience, not strength or motor control for itself. To this end challenging patients’ ability to problem-solve in novel, unpredictable situations is more likely to prepare them for optimal performance. As a result, confidence or self-efficacy will rise.
Confidence is the cornerstone of great performance and it comes from one place—what you say to yourself.
—Michael Gervais, PhD
Realizing with humility that there is not one correct path is the essence of Principle 4. The blind men and elephant metaphor applies well here. Rather than focusing on the pain generator alone, the goal is to view the problem in the context of upstream psychological and social determinants of health as well as through the lens of regional interdependence (see later). A failure of descending inhibitory modulation can amplify pain signals. Poor social support can also reduce self-efficacy. Similarly, if a source of biomechanical overload above or below a symptomatic area is dysfunctional addressing, this can enhance recovery.
In truth, there seems to be no optimized pre-determined planning path. There is only the informed exploration of a dynamically changing landscape.124
A good example of what Kiely means within the context of periodization of training or rehabilitation is the use of conjugate periodization. Conjugate refers to the utilization of multiple methods of training in order to optimize results. For instance, variation in training stimulus allows greater load to be used over a longer period of time without injuring the athlete. In fact, the options to prevent injury are volume (Principle 2), load (Principle 3), and variability (Principle 4).125
This certainly relates to training in multiple planes (sagittal, transverse, and frontal), as well as stances (bilateral, unilateral, and split).
There is no one single “right” way to move, which may be why motor control training is not always effective3
(Low). According to Hamill et al, “Several studies have now demonstrated an association between reduced coordination variability and orthopedic disorders or overuse injuries.”127,128
Dovetailing with the discussion in Principle 1 about excessive “safety” behaviors versus more agile adaptive, coping ones, Seay et al demonstrated that coordinative variability measures are able to discriminate129
between runners with LBP,
those recovered from LBP,
and those who never experienced LBP.
Coordinative variability of trunk-pelvis transverse plane relations were greatest in those never injured, smallest in those with back pain, and in between these values for those who had “recovered” from injury.127,129
Life is unpredictable, thus MV should be a hallmark of rehabilitation and coaching in order for preparedness to match demands. The goal of training is to improve movement quality and tissue resilience under the demands at the outer edge of what a person might encounter. One avenue to this is by challenging a person’s problem-solving ability under novel and unexpected circumstances.
MV can be introduced by altering constraints—environmental, individual, or task
(see Fig. 38.22
)—so that movement is spontaneously challenged and improved. This is termed Dynamic Systems Theory (DST
) and is covered in detail later. Such automatic changes are said to occur as a result of creating a central nervous system (CNS) attractor state.130
For instance, adding an overhead reach to a lunge may make posture more lordotic. Judging if this is a good or bad change is up to the clinician. A person who slouches when they lunge may benefit, whereas a person who tends to hyperextend their lumbar spine may be better with some other constraint.
Figure 38.22 Three aspects of Dynamic Systems Theory.
This movement change should be successful/productive (what the coach/clinician seeks), or else it is just random. Example:
Overhead squat can change the attractor state in a post-anterior cruciate ligament (ACL)/knee pain and/or erector spinae dominant weightlifting squat
Lateral squat can add the attractor state to laterally move under load in a rugby player (and others)
One-legged squat can change the attractor state to increase a one-legged vertical jump in a basketball player
In this way, as a result of problem solving the movement challenge on their own, there is greater likelihood of residual adaptation and transferability to sport or ADLs (see Fig. 38.23
). Willy and Meira studied neuromuscular reeducation of patients with patellofemoral pain and found that if asked to squeeze their glutes, there was diminished valgus alignment during the landing phase of running.131
But, if they were told to imagine a large window between their knees, the same result was achieved with
more efficiency—as measured with electromyography activation of co-contraction patterns. Additionally, the motor control gains persisted over time.
“The concept of the human beings as complex dynamic systems changes the mechanical view of athletes and the adaptation process based on the computer metaphor. This change in paradigm affects training proposals stemming from classical training theories and leads to a demand for its principles to be updated…. The concept of the correct or right response has been fundamentally changed by the new paradigm. According to the research results obtained by applying DST to the study of human movement, the athlete does not need to know the solution of a new task beforehand”.132
More strategies translate to an enhanced ability to successfully accomplish the movement goal and cope with change. This has been referred to as invariant results through variant means, which is also referred to as functional variability.80,133
The antifragile model described by Taleb succinctly encapsulates the fourth principle.134,135
The goal is optionality. Health care mirrors financial investments where we don’t want to “put all our eggs in one basket.” This diversification applies to rehabilitation as well as to the development of fundamental movement skills in children where early diversification and play is preferred over early specialization. The same is true for strength training where variability is a key ingredient to maximize recovery after intensity has been increased in specific exercises. Optionality is one of the weapons in the antifragile armamentarium. This enables a biologic system to benefit from stress.
The “fragilista” patient requires Principle 1’s emphasis on coping. As a vulnerable patient learns that not every hurt equals harm, they are less likely to feel “fragile” like glass and can better tolerate pain. The next step is to be able to tolerate stress. This occurs first in Principle 2 by adding volume on top of a base of movement competency. In this way they build activity tolerance. As one can tolerate increases in volume of low-load activity, they are prepared for the addition of intensity—Principle 3. By “slow-cooking” load tolerance a more robust or resilient person emerges who can bounce back from adverse situations—like phoenix. Finally, by adding variability in Principle 4, the person can now even benefit from stress—like bone that gets stronger in response to weight-bearing load. This is the antifragile person.
Is there one right (e.g., best) way to train or move? According to Hamill, the best way is variable and would depend on the context, in other words, the required capacity or demands and the current capacity or competency. Being able to handle both expected and unexpected demands truly makes a person antifragile and thus as Hamill says, “higher variability state of a coordinative structure is the healthy state while the lower variability state is the unhealthy or pathological state.”
An innovative approach to enhance motor learning is by the use of gamification principles. Game theory is a way to keep people engaged through behavioral constraints and nudges. Gamification in its simplest form is the utilization of game-like elements to enhance engagement. In rehabilitation, it involves applying elements of game playing to prescriptive exercise to encourage compliance, motivation, and adherence.
The addition of the typical elements of game playing to other types of activities to increase engagement.
When introducing a training stimulus, nearly everything will work in the short term to achieve gains, but inevitably a plateau will be hit. Variability (Principle 4) is at least as valuable as intensity (Principle 3) to catalyze further progress. Michael Merzenich says, “Stereotypy is the
enemy…you really want to exercise the brain with a VARIETY of movements, a VARIETY of actions. A VARIETY of challenges.”137
The healthier a system is, the greater degrees of freedom to execute movements it will have.
Movement variability is the oil of the CNS.138
Dynamic Systems Theory
When restoring function and enhancing performance, the DST model gives us a process-driven approach rather than one that follows a rigid system. In DST, there are three basic avenues to influence the patient’s function—environment, task, or individual.132
Each of these is a constraint on MV or freedom. In a nutshell, the practitioner can guide movement exploration by manipulating constraints.
According to McKeon, “the need for a theoretic construct to aid in decisions associated with program design, evaluation, and progression has grown. The dynamical systems theory (DST) provides such a framework.”133
By using a constraints-based approach to motor learning or skill acquisition, the practitioner has options to guide performance in a specific direction. “This interplay of the environment, the task, and the organism, each with their own constraints on how the movement can and cannot be performed, creates a conditional framework within which movement can be usefully and contextually performed.”139
According to DST, the behavior of the motor control system is controlled by (a) the person’s health, (b) the task being performed, and (c) the environment in which a movement is carried out. According to McKeon, “The nervous system is free to develop and change strategies as it interacts with the environment.” Patterns emerge, “on the basis of demands imposed by the movement goal.”133
The nervous system accomplishes tasks via “spontaneous (goal-oriented) self-organization.”
We should think in terms of140
The environment in which the movement is carried out
The movement or task being attempted or performed
The individual performing the challenge
a. Ways to think about environmental constraints
According to Winkelman, “the first teacher you meet is all around you—it is called the environment.”141
van Ryssegem says “if you want to change movement, then change the environment. No foam rolling needed. The brain can figure it out in mere seconds—allow pattern emergence.”130
When a movement pattern changes (for the better) while using an implement (cable, band, dumbbell, vibration platform, etc.), the attractor state comes from the environment. Think environment as anything outside of the body itself (van Ryssegem personal correspondence).
I don’t tell my guys where certain movements should happen. Set up the environment and let them figure it out.142
An example of coaching by modifying the environment is having a person squat while facing near a wall. In this instance, if someone has a tendency to slump forward or bend excessively from their waist by standing near the wall it will allow them to “figure out” how to keep their back straighter during squatting. Because the person learns this on their own it is more likely to be retained and transfer to later activities and skills.
Simply emphasizing short-sided games for athletes or outdoor play for children is an excellent way of changing the task or environment to facilitate motor learning, skill acquisition, and problem-solving ability. According to Frisch, “Kids need more play time outside or actual activity inside…. A modern kid plays less than kids in the past…. Kids should be playing and having fun, not being taught how to play tennis. If they are young enough to play on a slide or jungle gym, leave the organized sports alone. Sports are not fun if you are on the bench, not interacting during a game, or not good at them. Free play allows for kids to climb trees, build a snow fort, and even make up their own games.”143
b. Ways to think about task constraints
Changing a task is probably the simplest and most common way coaches and clinicians change how movements occur, for instance, shifting from squatting on two legs, to split stance, or single leg. The emphasis is typically on BOS and COG. Tasks can be
made harder by decreasing the BOS holding objects overhead. This makes progressions and regressions very simple by altering these constraints.
Giving a Good Task Is Better Than Cueing
c. Ways to think about individual or organism constraints
Injury can significantly hinder the bodies’ ability to accomplish movement goals. An injured area will restrict degrees of freedom available to the nervous system to accomplish a task. This leads to a constraint. For instance, if you broke your dominant arm, involuntary reaching tasks will be constrained. The new pattern isn’t “wrong,” you merely chose the most efficient pattern available.
According to Falsone, other ways to influence the organism are to “close both eyes or turn the head, track a moving object, perform cognitive tasks while moving, or do an unrelated upper-extremity activity while performing a lower body movement.”144
The goal of rehabilitation from the perspective of DST is to restore the bodies’ ability to cope with change during the execution of movement goals. According to McKeon, “The clinician can utilize the principles of the purposeful manipulation of task and environmental constraints to guide the progression of rehabilitation, which makes it possible to tailor a program to a patient’s ability to achieve movement goals and restore sensorimotor system freedom.”133
Life is full of surprises. Certainly, we should expect the unexpected and in the clinic and gym we should prepare people for the most difficult passages of play or what they may face.117
According to Glasgow et al, “Given that many sports take place in highly variable environments, the identification of effective strategies to widen the range of conditions under which athletes can safely and effectively execute sport-specific skills should be a priority.”82