The Myth of Stretching to Prevent Running Injuries:

Evidence-Based Practice in Sports Medicine

By Dr. Laurence N. Benz, P.T.

Do you routinely stretch before you run? If you were to ask almost any physical therapist, athletic trainer or sports medicine physician if you should stretch before you run, you would invariably get a resounding "yes" in most cases. However, if you were to ask for proof that doing so actually decreases the risk of injury, this individual would be hard pressed to show you research that supports the claim that stretching reduces the risk of injury. In fact, several recent studies have shown that stretching does not help prevent injury.

A trend has emerged in medicine known as evidence-based practice (EBP) or evidence-based medicine (EBM). In the simplest terms, EBP is a practice model in which a clinician routinely locates, evaluates and implements the current best evidence in the care of the particular patient they are seeing. In the EBP model, current best evidence is defined by standards that help decrease the subjectivity associated with deciding which evidence is "best" and the use of which is supported patient care. Lest this focus on science and evidence seem a bit cold and removed from the art of medicine, it is important to remember that implementation of current best evidence in the care of a patient is always in the context of the patient's values and the clinical expertise of the provider, two other key tents of EBP.

EVIDENCE-BASED PRACTICE

The roots of modern EBP can be traced to McMaster University School of Medicine in Hamilton , Ontario ( Canada ) and began to become prominent in the 1990s. Most medical profession training programs would agree that healthcare practitioners should be readily able to apply basic EBP skills in their clinical practice. For example, practitioners should know how to ask a meaningful clinical question, be able to search for the answer using any number of computer-based tools and be able to critically evaluate a scientific paper and determine its quality and relevance for clinical practice. Fortunately, this trend is being integrated into many areas of medicine including sports, physical therapy and orthopedic practice, which should result in a significant improvement in medical care. Healthcare professionals should be able to demonstrate evidence to support the interventions they commonly use in practice.

The EBP revolution has been necessitated for a variety of reasons. One of the primary reasons is that insurance companies and regulatory agencies have noted substantial variations and unexplained differences in medical practices and treatment rates between one geographic area of the U.S. and others. The rates of C-sections, use of prescription medication for acute low-back pain and back surgery are just a few of the most commonly cited examples. Substantial work has also been done by the academic community with respect to defining and agreeing on what constitutes the highest quality evidence that can be used to improve decision-making in health care. "Expert" opinion is often not correct, thus you shouldn't be surprised to know that an expert's opinion is the least credible form of evidence. Instead, we should be basing our decision on systematic reviews and randomized clinical trials when this level of evidence exists. Our ability to translate evidence into clinical practice has been facilitated by the rapid growth of emerging technologies that vastly improve our ability to assimilate the growing amounts of published research. The Internet, coupled with the development of robust search engines and databases of published research; meta-analysis; and systematic reviews, have made it more efficient for practitioners to participate in "real-time" EBP for their patients.

It is important to understand what EBP is and what it is not because the terms "evidence-based" and "EBP" have become buzz words that have practically lost their meaning entirely. It is not uncommon to hear so-called "experts" advocate a particular treatment approach, only to find that their "evidence" is limited to several theoretical studies with only esoteric and even imaginative implications for practice. Simply citing published literature, regardless of the study's design or quality, to support whatever treatment approach one may be inclined to use or "works in my patients," does not constitute EBP. Neither does merely understanding the pathophysiologic process underlying a disorder and applying interventions known or suspected to interrupt or modify the process, regardless of the amount of basic science and bench research available.

WHAT CONSTITUTES CURRENT BEST EVIDENCE OR EVIDENCE THAT CAN BE USED TO IMPROVE DECISION-MAKING?

The highest level of evidence to support a particular treatment is randomized controlled trials and systematic reviews of randomized controlled trials. Despite the various criteria for evaluating the validity of these studies, the common thread is that they involve human subjects and measure clinically meaningful outcomes in patients. When evidence of this type is not available, then practitioners may indeed have to rely on lower levels of evidence. When this is the case, EBP principles dictate that due pause is warranted with regard to the conclusions we draw and the confidence we have in our expected patient outcomes. The unfortunate reality is that high-quality evidence is often available, yet practitioners either are unaware of the evidence or have made a conscious decision to ignore its implications for improving the care of their patients.

There are a number of reasons why EBP should be important to all practitioners. Although a practitioner's bedside skills may improve with time and experience, the quality of care may just do the opposite! A recent systematic review on physician performance published in Annals of Internal Medicine demonstrated decreasing performance with increasing years in practice. In other words, physicians and other medical practitioners who have been in practice longer are at risk for providing lower-quality care than their so-called "less-seasoned" peers in large part due to not integrating EBP into their clinical practice. In addition, the sheer volume of medical literature and its exponential growth makes the way we have traditionally attempted to remain abreast of current literature obsolete. For example, general physicians would need to examine 19 articles a day, 365 days a year just to stay current in their awareness of current evidence related to their practice! Although commonly touted as a solution to bridge the gaps between first professional education and current evidence, traditional continuing education has not been shown to be effective either, largely because much of the information communicated in this medium is based on "expert advice" that only serves to lead us further astray. These considerations, coupled with the fact that medical practice today consists of an environment where resources are dwindling and consumer expectations and knowledge are higher than ever before, make for quite a dilemma, especially considering that most practitioners are unlikely to set aside more than 15-30 minutes a week for general reading and study.

At Kentucky Orthopedic Rehab Team's (KORT) physical therapy centers, we have embraced this change and taken active steps to make sure EBP care is experienced by every patient who presents to a KORT facility for care. To this end we have collaborated with industry experts to develop and publish several position papers on the most supported physical therapy treatments for the most common conditions seen by physical therapists - low back, neck, knee and shoulder pain. In addition, our continuing education, professional development and training activities have focused on enhancing the clinical skills of our therapists related to applying these evidence-based interventions in the care of their patients.

STRETCHING AND PREVENTING INJURIES

The myth of stretching to prevent injuries is an excellent example of how EBP has evolved over the last several years, especially given there is scientific agreement as to the hierarchy of evidence and the differing implications for practice with each level of evidence. To be fair, two studies were published in the 1980s concluding that stretching before exercise reduces injuries. However, both studies permitted co-interventions, meaning that other treatments besides stretching were allowed. This makes it impossible to determine whether the favorable effects on injury prevention that were observed in these studies could be attributed to stretching or some other aspect of treatment. In addition to these two studies, a variety of experts have generally been favorable to stretching. These studies and expert opinions would be classified as "C" level within the nomenclature of EBP.

To the contrary, "A" level evidence consists of randomized controlled clinical trials, meta-analyses and systematic reviews. A meta-analysis that analyzed various studies over a six-year period (1997-2002) related to the impact of stretching on prevention of sports injury concluded that stretching was not beneficial for preventing injury. The results of additional studies including 12 trials with 8,806 runners analyzed the effectiveness of stretching, the results of which corroborated the conclusion that stretching does not apparently prevent injury. Rather, research has instead shown that factors such as higher levels of fitness and greater strength are more important elements in the prevention of running injuries.

This is just one example of a commonly accepted health care myth that is taken as fact; numerous other examples exist. Now, isn't it easy to see why EBP is so important? The EBP practitioner, combined with an informed consumer, can result in more appropriate recommendations for clinical practice to promote optimum health and wellness for all involved the sports medicine circles.

Dr. Benz is president/CEO of Kentucky Orthopedic Rehab Team (KORT). He holds a master's and doctorate in physical therapy as well as an MBA and is board certified in orthopedics (OCS) and clinical electrophysiology (ECS). For a complete list of references used in this article or a more information on evidence-based practice in medicine, please contact him at larry@kort.com or www.kort.com.