THE GAP BETWEEN RESEARCH AND CLINICAL PRACTICE FOR INJURY PREVENTION IN ELITE SPORT: A CLINICAL COMMENTARY

Abstract

As clinicians strive to apply evidence-based principles, team-based practitioners have identified a large gap as it relates to published research, ideal applications of evidence-based practice, and actual clinical practice related to injury prevention in elite sport within the United States. For rehabilitation professionals, especially those intimately involved in the research of injury prevention, the solution often seems quite clear and defined. However, preventing injury by implementing the latest recommendation from the most recent prospective study on the using the FIFA 11 + warm-up, a Copenhagen Adduction exercise, or a plyometric drill with elite athletes may not be as effective as was seen among the cohort used in the study. In addition to extrapolating research, clinicians face additional challenges such as variance among professions, schedule density, and off-season contacts with athletes. There is an inherent difficulty in the application of research to practice in elite sport as it relies on the teamwork of not only the practitioner and athlete, but the entire sporting organizational structure and those involved in athlete participation. The purpose of this clinical commentary is to explore the difficulty with application of research in clinical practice and to discuss potential strategies for improving carry over from research to clinical practice.

INTRODUCTION

The multi-factorial impact of sporting injury often goes underappreciated. As previously documented in the literature, the effects of injury impact the athlete, medical personnel, organizations, and other supporting individuals intimately involved in an athlete's health and success.¹ This impact pertains to, but is not limited to, the global health, wellness, and financial success of the individual athlete as well as the competitive and professional success of all vested parties who are connected to the athlete.^2,3 The resultant pressures and anxiety placed on athletes, medical professionals, as well as coaches, agents, family, athletic directors, and sporting management are well documented, and likely are heightened in an age of instant information.^4,5 To reduce these adverse events, the importance of injury prevention has become of mainstream focus, as nearly every injury is now documented, scrutinized, and information is increasingly desired withi the public domain.⁶ From video analysis on social media, estimations regarding time loss by commentators, and media questions relating to the competitive abilities of an individual, information available to the general public about athlete's personal health information is at an all-time high. Injuries in elite sports are commonly critiqued from various perspectives, even to the possible detriment of the physical health and mental wellness of an athlete.^7-9

WHAT IS INJURY PREVENTION AND IS IT POSSIBLE?

To prevent, is “to keep from happening”, as defined by Merriam-Webster. While this is a noble goal in musculoskeletal injury, the nature of sport and injury leads clinicians to attempt to find practical ways to manage and reduce risk. General prevention and ‘load management’ methods often rely on the removal of exposure, which is not advantageous to sporting population.^2,10 After all, avoiding loss of participation is the goal of prevention. Risk reduction strategies are likely to be a more realistic strategy for the common goal.^11,12 In considering risk reduction as it relates to athletic injury, the paradigm is best defined as a complex systems approach.¹³ Numerous interrelated factors may contribute to an injury, and these can be moderated or mediated by internal and external factors. These factors are constantly in a state of dynamic flux, and can be altered by the slightest change in sleep, diet, or stressors, let alone prior injury or increased competitive exposure.^14-16

REVIEWING THE EVIDENCE

At the time of this review, the authors suggest that there are areas with significant limitations regarding the current body of evidence. These issues range from the carry-over of evidence-based intervention to evidence that may or may not be applicable.¹⁷ The issues with the current body of evidence can be for a myriad of reasons including limited descriptions in the research to limitations in population carry over.

It is well established that properly dosed exercise intervention is a gateway to injury risk reduction. However, the details regarding exercise dosing (frequency, intensity, type, time) and exercise choice is often elusive. Frequently, the exercise dosing information is poorly described in various systematic reviews by reducing it to the simplest of terms. For example, proprioceptive training for ankle sprain reduction is recommended by the National Athletic Training Association to be performed for 5-30 minutes, 1-5 times a week, for a duration of four weeks or the full duration of competitive season.¹⁸ Within the review, there is no definition of which method of proprioceptive exercise is preferred for the intervention.

Perhaps the most frequently described injury prevention methods relate to the knee, specifically, the anterior cruciate ligament. Interestingly, this is the only injury prevention topic published within the JOSPT Clinical Practice Guidelines (CPG).¹⁹ The likely populations shown to benefit from the CPG are primarily adolescent females, in particular those playing soccer, volleyball, and handball.^19,20 While the concern of such a catastrophic injury is warranted, in select populations such as the National Basketball Association and the National Football League, Major League Baseball, and the National Hockey League, this injury accounts for less than 2% of all injuries, rendering these clinical practice guidelines less applicable to the athletes in these leagues.^21,22

While injury is an unfortunate event within any population, it is accepted that playing at greater levels of competition and skill put an individual at greater risk. There is a greater need for risk reduction strategies at elite levels in addition to guidelines published for other populations.²³ While those who participate in elite sport often have decreased mortality, the long-term effects of sports injuries have high potential to negatively impact the individual and the health care system long after their playing career is done.^24-26

At this time the soft tissue injury literature primarily focuses on hamstring and adductor strains. Additionally, elite sports research studies are commonly focused on soccer, rugby, and Australian rules football athletes. In muscle injury studies that involve team sport, there is a common reliance on publications from professional, semi-professional, and amateur sports leagues in within Europe and Australia. With these two biases, including a focus on specific muscle injuries and specific populations, it is imperative that clinicians understand the dangers that come with generalizing the outcomes that are described relative to a given sport, at a defined competition level, and that address a specific body region. When the study populations shift from professional to semi-professional and to sub-elite youth athletes, it makes the application of research inherently challenging. In the United States, team-based studies usually come from collegiate level sports, and often are a combination of varying sports or a range of different tiers of athletic level (Division 1-3). Homogenous injury prevention literature from major American professional sports or major Division 1 sports is scarce.

To the authors’ knowledge, no successful injury prevention programs have been rigorously examined and published within the major American professional sporting leagues. This lack of high-level evidence could be due to several factors, one of which is the cultural differences in sports clubs’ recognition of research and the application of this information into common sporting practice. High performance problems and questions are not unique to any sport or country, but the methods in which these are tackled is significantly different from sport to sport and region to region. The significant limitation in resources for proper investigation are not unique to any specific leagues, organizations, or their collective bargaining agreements.¹ Embedded research programs, that are intimate within the sporting league and organization, as common in aforementioned cultures, would improve the quality of evidence for practitioners and care for athletes downstream.

REVIEWING CLINICAL PRACTICE

Currently, practicing clinicians are best served by loosely translating evidence from different populations whose demographics, sporting demands and potential mechanisms of injury are different.

For example, the current best evidence for reducing hamstring strains relies on recommendations of eccentric training, proper pre-season sport specific training, and appropriately dosed high speed running.²⁷ However, in basketball, a hamstring injury may have a deceleration mechanism of injury, with demands of the sport never achieving max speeds as mechanisms found in other field based sports. Additionally, athletes are exposed to congested schedules (>three contests per week average, situations of back to back contests, three games in four nights) which decreases recovery time and minimizes secondary prevention opportunity.²⁸ When considering muscle damage and fatigue variables associated with competition and eccentric exercise combined with inadequate physiologic time to recover between contests, when can a clinician safely dose sprinting and Nordic hamstring exercises?^28-34

Current evidence recommending secondary prevention via “load management” pathways allows training modifications in preparation for weekly to bi-weekly contests, while still considering the performance demands placed on the athlete.^31,34 This is not pragmatic in many of the professional sporting leagues as it relies on universal adherence from athletes, clinicians, coaches, in addition to league and team scheduling decisions.

Proper high load pre-season training is reported to decrease the risk of injury.^14,16,23 However, in many professional leagues, a period of sport-specific training is not mandatory for the athletes, and thus this stimulus is often missed leading in to the highest risk period. In particular, these high-risk periods include pre- and early season competition where the athlete's prior training stimulus may be unknown.^23,35

Pathways for in-season loading for positive training adaptations are possible, but are often limited by athlete time, engagement, and allotted team time instituted by the respective leagues, organizations, and dependent on the priority of coaching staff.³¹

If an athlete voluntarily chooses to participate in such recommended training, there is a question as to whether a specific injury prevention program would be superior to appropriately dosed general training.^36,37 Specific exercises can be integrated within a warm-up program and be defined as a “prevention program”.³⁸ However, these exercises are commonly dosed as recommended within common strength and conditioning programs without the distinction of being a “prevention program.” How are clinicians in elite sport expected to differentiate an “injury prevention program” from current best practice across the strength and conditioning field which includes all the related variables? These variables include athlete engagement, staff communication, appropriate programming and dosing.

A practical recommendation would be for improved coordination in hiring, developing, and programming between athletes, medical providers, performance and sporting coaches, and management. A cohesive group would allow for the application of evidence-informed constructs required to achieve a protective exercise stimulus. This common ground is difficult to achieve currently due to the often-siloed realms of injury prevention, strength and conditioning, sports science, and sporting activity.

A VIEW FROM THE FIELD

Regardless of the proposed program, adherence and dosing are common pitfalls to the success of risk reduction. Recent studies have proclaimed astounding success and failure in their ability to reduce injury occurrence.^17,38 However, a commonality is that the optimal volume of training is often not achieved, with reports of adherence ranging from 15 to 32 percent.^17,38 Once again, this issue is often best related to institutional buy-in, as well as athlete engagement.^39,40 Even in the most well supported populations and recommendations, as seen in ACL prevention models, adherence to programming is poor, with key stakeholders being identified as a limiting factor.²⁰

A culture that promotes health and well-being requires collaboration among all parties regarding health recommendations. This culture is heavily influenced not just by the athlete and performance staff, but also by the coaching, management, and representation responsible for additional demands on their livelihood.^1,41 It is important to remember that key participants of athlete health involve the athlete themselves, as well as those who control the athlete's sporting exercise experience. Engagement and leadership among all parties has been directly tied to health outcomes.⁴¹

While current research continues to support avenues of active strategies to reduce injury risk, current practice does not facilitate a means for implementation of evidence-based practice. Time and effort would best be served to focus on systemic education, implementation and application of not only current recommended exercise strategies, but also avenues for institutional understanding and collaboration between all vested parties.⁴⁰ On a short term, practical level, developing a shared vision, communicating effectively, and facilitating shared-decision making are strategies all necessary to implement current-best practice models. Long term development includes embedding researchers/research groups into sporting populations, clubs, and leagues who are equipped to challenge current practice and systematically. address pragmatic clinical questions. These strategies would best focus on athlete health in the present, while also developing long-term integrated research-based avenues to improve upon where elite sports practice stands today.^1,42