Movement Assessment: Screening, Performance, and Injury Prevention

Ian McKeown

Craig Liebenson

LEARNING OBJECTIVES

After reading this chapter, you should be able to:

Explain the purpose of movement assessment.
Describe how movement screening can lead to a healthy lifestyle.
Identify how movement screening can establish risk.
Describe how to use a movement assessment as part of a training system.
Explain how to design and apply a movement screen.

“As to methods there may be a million and then some, but principles are few. The man who grasps principles can successfully select his own methods. The man who tries methods, ignoring principles, is sure to have trouble.

–HARRINGTON EMERSON

Introduction

Health professionals have for a long time assessed fundamental movements deemed necessary for healthy living or athletic optimization. Historically, assessment of movement has been in isolation, investigating areas of stiffness or weakness, primarily measuring isolated strength or range of motion. These investigative tools of isolated movements are well established in pain and injury management. However, the qualitative and quantitative assessment of movement has evolved over time away from isolated strength, local muscular endurance, and range of motion tests, toward the assessment of the critical fundamental abilities underpinning the healthy life of the athlete, patient, or client often manifested in common fundamental movements of squatting, lunging, hinging, pushing, and pulling (twisting, stopping, starting, change of direction, jumping, and landing). The use of the single leg squat to assess hip control, trunk strength, and ankle proprioception, or the overhead squat to assess thoracic extension, hip control, and lower limb mobility is just an example popularized as functional movements to be readily assessed.

The methods of assessment can, and should, vary depending on the principles of the assessor, demands or activities the individual is exposed to in their environments, clinical status, and the practical intervention that will be the result of the assessment. Conjecture arises in this area when a one-method-fits-all mentality is adopted and when certain methodologies are scrutinized in areas that the original decision process did not consider.

At this early stage in movement screening research, there are large ranging viewpoints on what should and shouldn’t be considered. This is largely determined by the practitioner’s area of interest or expertise. Variation of viewpoints and presentation of data across each of the tools is only promoting the need for more work to be done in movement science and should be encouraged. Speculation around the efficacy of movement screens and other assessments in the literature at present is caused by attempting to utilize methods that the tool was not specifically aimed at addressing or making assumptions on the cause of differentiation in the movement far beyond the scope of the assessment criteria—for example, for injury risk or as surrogate of functional demands.

The aim of this chapter is to highlight the need for careful consideration relating to the requirements of each practitioner and to communicate the various schools of thought that are used to guide principles of contemporary practice and research literature. Additionally, the authors’ intent is to outline the purpose, limitations, and provide guidelines to optimize movement assessment and screens in the future.

Why Should We Assess in the First Place?

“If we do not assess something, we cannot get better at something…”

“You can’t manage what you can’t measure…”

Mobility, strength, balance, and fitness are critical to health but the assessment of these qualities in isolation is considered too far removed from the daily demands of living and function to provide a true indication of ability and risk of injury. The coordinated and graceful aggregate of limbs in motion is ultimately crucial for long-term health and functional ability within the demands of the performer’s physical demands; however, assessing movement in isolation without proper context can be as limited as isolated mobility or strength tests. The commonly used phrase is to coach movement, not muscles and if we are to deliver on this phrase and coach the movement not the muscles, we must therefore also assess human movement in this way. This has led to the development of several movement screens or assessments. The exception to this phrase is in diagnosis and rehabilitation where tissue integrity is crucial to triage orthopedically. The assessment of movement can be utilized to evaluate the patient/athlete as they perform relevant activities (exercises, activities of daily living or otherwise), exposing any apparent risky movement behaviors or substandard levels of ability that would be required for their lifestyle or sport.

The aim of the practitioner should be to improve upon the current movement ability (motor control and capacity) of their patient or athlete. The training program should be designed to ensure risk of injury is mitigated and the patient or athlete has the foundational ability required to build capacity for a healthy lifestyle and/or performance-oriented goals. Within the athlete population this is taken to the next step where the demands of their lifestyle and as such their sport will depend upon a higher level of foundational ability that is closely aligned with the demands of the training and competition of their particular sport. Movement assessment should be utilized in
this instance to critically evaluate the fundamental movements required of the patient/athlete and that individual changes over time to the prescribed training are in line with their training demands. This principle of assessment provides a secondary layer to the system, firstly to gauge the fundamental movement ability but secondly provide a reference for the learning of the patient to the fundamental tasks or abilities. This is particularly useful in youth and development-level athletes and patients where long-term athlete pathways ideally include the foundational movements required for sporting demands as plotted against maturation. However, it is equally important for the “average Joe,” “weekend warrior,” or elderly person who inevitably lacks the general physical preparation to engage in long-term athletic participation.

In order to understand these changes, assessment must be reliable. The level of reliability required will depend on the practitioner and how the information will be used; however, it is advised to strive for the highest standard of care in all elements of your practice, therefore seeking to understand the smallest worthwhile changes and the typical error derived from repeated assessments of assessments at different times of day or pre/post therapy or training to be calculated. Besides measuring actual changes over time, assessments should also be used for determining return to activity or sport landmarks.

The following section explores the various reasons to use a movement screen or movement assessment as seen from various professions and environments. Commentary is also provided on the key considerations a health/fitness professional must deliberate on before a screen or assessment is implemented.

Screening and Assessment

There is a fundamental problem with screening that leads to over-reaching. Let’s say you have a test for a disease that is very specific—such as for breast or prostate cancer. So that of every 100 positive results for the disease, 90 are true results (the patient has the disease) and 10 are false (the patient does not have the disease).¹ Thus, these tests have specificities around 90%. Now, imagine the diseases are fairly rare with incidence rates of about 1%. So if we screen 1,000 people we will get 20 positive results. Ten of these will be true positives, and 10 will be false positives (due to the inaccuracy of the test). Counterintuitively, a 90% specific test has an accuracy (positive predictive value) of only 50%.

Tracking down true positives from false positives would quickly overwhelm a sports medicine and S&C staff. Plus, athletes may be unnecessarily alarmed by false positives. In the case of prostate cancer, treating patients based on the screening results is now believed to have more downside risk than is balanced by the upside benefit of treating those who actually have the condition. Thus, screening is not without costs. It is best if it is used to frame training goals rather than making excessive claims regarding injury prevention outcomes.

Movement Screening As an Entry Point to Healthy Lifestyle

The first utilization of a movement screen is to establish an entry point for exercise or training. Similar to how a doctor uses a blood pressure test to evaluate basic cardiovascular function before someone would be cleared to start walking on a treadmill, a movement screen can be used to establish an individual’s general competency of fundamental movement patterns that would be required to start exercising. Just because you pass a blood pressure test does not mean you could go straight out and run a marathon, the same goes for a movement screen. Similarly, a female who demonstrates excellent movement competency while performing a bodyweight squat, lunge, for example, may lack strength to control her knees while landing from a drop jump. The initial screen of bodyweight movement was simply a tool to establish baseline competency.

If you fail a movement screen it doesn’t mean you can’t succeed in sport or activity. Most athletes are highly skilled at their sports. They have developed a “reflexive” ability to succeed at an elite level. For instance, many NBA players are instinctive on the court yet lack fundamental movement skills.

When combined with a thorough analysis of demands, past injury history and treatments, alongside goals, concerns and other key performance indicators (KPIs), passing the basic entry point evaluation allows the fitness professional to confidently start to program for a patient or client. And if constructed intuitively, the screen will provide information as a starting point for programming and addressing areas of weakness or discrepancies in movement. The movement screen in this instance can inform the rehab, fitness, or S&C professional of areas that need work and can form the basis of their rehab/fitness program going forward and as such begins to illustrate the importance of developing a screen or assessment as part of the overall training process.

It is important to note that every person has different demands and require different capacities.² Similarly, with respect to the minimal motor control requirements for individuals with different
injuries, precision requires individualized assessment matched to the needs analysis. Therefore, any “screen” is fraught with overwhelming validity issues that must be overcome in order to justify its efficiency or lack thereof.³ For this reason, knee experts⁴ vary in their screens versus low back specialists.⁵ Further, general preparation phase (GPP) needs (bench, squat, dead lift, vertical leap, horizontal jump, short sprint speed) will be very different from specific physical preparation (SPP) in an elite athlete which will be sport, position, age, injury history, and even body type specific. Dan Pfaff, one of the world’s premier elite sprint coaches, says, “my screen is watching practice.” EXOS athletic performance coach Nicole Rodriguez states, “We need real-time assessment/intervention in the training/sport environment.” Due to the goal of skill acquisition—at all levels of athletic literacy—assessments should be “reverse engineered” from a demand profile. Ecological validity is a cornerstone of the specificity principle.⁶ This is equally true for assessment as training.

In order to avoid the “silo mentality,” a patient or athlete-centered management style is encouraged. Some screens will certainly provide rudimental value because of their universal language, thus facilitating communication across providers and sports. However, the individual’s KPIs and personal history will always trump the generalist goal of scalability precisely because the functional needs of each individual are unique. As Dan John says, “the goal is the goal.” None of the foregoing is to imply that a scalable, generalist approach is without merit only to be transparent regarding the expert “gold standard.” In fact, the great advantage of a minimum scalable standard is that it is scalable, regardless of its predictive capability.

The Functional Movement Screen (FMS) by Cook et al⁷ is an example of an entry-level screen that can be used as part of a larger training system. The premise of the FMS is that the seven tests used within the screen are the fundamental movements of human ability and so should be the very bottom level of assessment; the entry point to exercise. Therefore, it has been proposed that the FMS be used across the population as a starting point for training.

Movement Screening As a Tool to Establish Risk

Further to being used as an entry point for training (and transition from rehabilitation to performance training), the purpose of many movement screens is to identify risk factors for injury. Corrective strategies are put in place to address these risk factors. Attempting to address assumed causes of poor movement or risk factors directly through corrective exercises is quite one-dimensional in its approach.³ Contemporary training programs should incorporate these correctives into the exercise selection, aiming to appease the identified areas for improvement alongside long-term performance improvements. Exercises that only aim to correct should be minimized in favor of creating an entire program or programs that not only clean up areas that require correcting but also provide a training stimulus to increase the capacity of the patient/athlete. Ideally, all training strategies are chosen to address the needs identified during the screen/assessment such that desirable movement behaviors can be engrained. Screening helps to categorize the low-lying fruit or the weak link that is specifically disturbing the skill needed by the individual’s preferred activity. This is responsible for bringing the person closer to a “tipping point” where rehab may fail, training itself may precipitate an injury, or performance will suffer.

Suboptimal movement strategies that are adopted in particular tasks have been associated with injury. For example, knee valgus positions in jumping and landing have been well documented to increase the risk of anterior cruciate ligament injury in female athletes.⁸ Similarly, poor lumbo-pelvic control during heavy lifting has been implicated in disc injuries in power lifters.⁵ The concept behind compromised movement patterns leading to injury is that this movement signature exposes tissues to inordinate loading forces and lengths, elevating their risk of injury. Movement screens therefore attempt to identify these priority movements and assess the strategies employed considering if they are unsafe or safe to continue.

Movement patterns that are deemed to be risky may be addressed with appropriate training and coaching strategies by engraining desirable behaviors, thereby reducing injury or reinjury risk. Risky behaviors can be identified through a range of screening assessment methodologies such as the FMS or through specific tests for particular common injuries. As an example, the FMS has been reported to be used by 66% of professional soccer clubs in a recent survey as an injury prediction tool. However, this is despite the apparent lack of scientific research to support the claims as an injury prediction tool.⁹ Interestingly from McCall et al, a further 16% of clubs in the cohort surveyed adapted the FMS or similar to produce their own specific range of tests. This is in agreement with another previous survey this time across multi-sports at Olympic or professional level showing that although aware of the FMS, practitioners would prefer to use their own movement assessment.¹⁰

Other movements have been used as tests to assess particular provocative or apparent risky movement behaviors such as landing in valgus, or similar single leg squatting with a valgus knee pattern. Used to predict against certain or specific injurious events, these tests can be very useful especially in at-risk populations or when returning from a specific injury.³ Bahr points out that in many instances, even with reliable screening, decisions to intervene in at-risk individuals may be unsuccessful due to intervention side effects outweighing the benefits (mammogram and prostate treatments). Also it may be that it is simpler to provide a low-risk, low-cost, time-efficient preventive strategy to all people in a group without risk stratification.¹¹ The use of movement screens to predict injury risk does not yet have the evidence to comprehensively support its use.¹²^,¹³^,¹⁴^,¹⁵ Janda who pioneered screening for faulty movement patterns primarily saw them as a secondary rather than primary prevention strategy. So not for health promotion or injury prevention but to guide rehab and prevent recurrences.¹⁶ The FMS is the most popular in the research literature by far, but conjecture still remains over whether this screen can predict injury.¹³^,¹⁵^,¹⁷ The FMS was not originally designed as an injury prediction tool but has been misrepresented and used in research designs nevertheless.¹⁸ The concept of formal movement assessment is a relatively recent development in the scientific literature; at this stage, the research has not yet caught up with the width and breadth of the use of movement assessment in contemporary practice. In many cases the formal movement screen as used by experienced coaches does not exist, supporting the use of different approaches to screening and assessment. Experienced coaches will favor observation of sports performance as the primary movement assessment. As valid a measure as this is for experienced coaches in certain sports, research into injury and sports performance requires more rigor and investigation in qualifying and quantifying movement, therefore illustrating the need for continual scrutiny and development of movement assessment methodologies and their relationships to injury and performance.¹⁹^,²⁰ Since the first presentation of Cook’s system, many more have followed suit in presenting their movement assessment tools for peer review.²⁰^,²¹ This can only be seen as a positive for this area of research and evidence-informed practice.

Although movement screens are being used by most practitioners to help to identify risky behaviors, there is still work to be done in this area in order to confidently utilize movement as a predictor of injury.²² Studies to date have shown indifferent relationships between movement ability scores and injury prevalence.¹²^,¹³^,¹⁷^,²³ The unclear effects can be put down to this research being relatively new in the area and the level of complexity of the screening task not being aligned with the typical functional demands placed on the body alongside the multifactorial and complex nature of injury mechanisms. As the environmental and task constraints change (e.g., elevated speed, load, duration, etc.), a performer may adapt their movement behaviors, either in a desirable or undesirable manner. For this reason, to assess behaviors, it may be prudent to design the screen/assessment much that it reflects the physical demands of the performer (lifestyle, sport or otherwise).³^,²⁴

The “disconnect” between the level of assessment complexity (including speed, load, etc.) and the daily tasks will likely not provide the information required to identify areas of injury risk. With further investigation and higher quality data, it is expected that the relationship between injury risk and movement ability will become stronger.¹⁷^,²⁰^,²² It will be important to identify the specific patterns of interest such that a range of tasks and relevant demands can be used to establish the performers’ behaviors. Assessments comprising single tests and uniform demands will undoubtedly offer little insight into the behaviors adopted outside of the training environment. Future research must consider improving upon reliability of scoring as well as the level of assessment criteria used to ensure the scientific rigor improves this area of research providing accurate and meaningful information for the practitioner.

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