Emily Kraus, MD, Clinical Assistant Professor at Stanford Children's Orthopaedic and Sports Medicine Center
Sports injury management often requires a specially concocted recipe unique to the athlete and his or her respective sport, which includes a period of rest or activity modification, rehabilitation, and sometimes surgical intervention. Another consideration in this assessment is gaining a proper understanding of the athlete’s movement patterns and how this may increase injury risk or affect overall performance. If appropriately used, biomechanical analysis can provide a useful extension to a sports physician’s physical exam.
Sports biomechanical analysis has been gaining greater interest and popularity, with cutting edge sports performance centers popping up in major cities across the country. Some target their services to professional athletes, Olympians, or collegiate athletes; while others are appealing to a broader population of different ages and skill levels. Just like any medical intervention, I find it important to understand the potential value in utilizing the particular intervention in your practice, while also recognizing its limitations. Biomechanical analysis is no exception.
The biomechanical analysis examines how mechanical laws can affect the human body, and an important part of this analysis lies within understanding human movement patterns in sport. Examples include the assessment of running or sprinting form, a pitcher’s throwing motion, a golf swing, and jumping or cutting movements. This analysis can be performed qualitatively, identifying movement patterns with a hi-speed camera, or quantitively with image-based motion analysis using video or automatic marker-tracking systems. Qualitative analysis is a faster “quick and dirty” assessment but may provide insufficient detail. Quantitative analysis is more in-depth but requires a skilled biomechanist with a thorough understanding of the motion capture technology, specifically as it applies to different sports. It can also be quite expensive to equip a sports medicine facility with the equipment and expertise needed for quantitative studies.
Biomechanical analysis in sport has multiple potential roles:
1) identifying faulty movement patterns which may put an athlete at risk for future injury
2) evaluating the outcome of treatment (either operative or non-operative) through quantitative assessment
3) longitudinally monitoring progress in rehabilitation and assist in the process of clearance back to the sport
One example where these roles have been heavily studied in clinical practice is in anterior cruciate ligament (ACL) injuries, which comprise 20-25% of all sports-related knee injuries and result in the greatest time lost from sports participation, specifically in young female athletes. Biomechanical analysis has helped identify risk factors that may predispose athletes to ACL injury and has led to specific injury prevention programs, which are being implemented in higher risk sports, such as soccer. Further, the use of a dynamic assessment via biomechanical analysis could play a valuable role in monitoring the rehabilitation progress of post-operative ACL reconstruction patients. One of the challenges in the broad implementation of biomechanical analysis is a lack of consensus to establish ‘‘standard criteria” for return to sports. As a result, physicians often rely on experience and personal judgment to determine an athlete’s readiness to return to sport. The need for an objective biomechanics assessment as part of the criteria to determine return to sport should be explored in future research.
"One of the cornerstones of my practice in the field of sports medicine is “what can I do to maximize an athlete’s function and minimize disability and time away from sport or activity?”
Another example in which qualitative biomechanical analysis can be applied clinically is in the analysis of running form. Fifty percent of runners experience injury yearly, and 25 percent are injured at any given time. Running-related injuries are often multifactorial in etiology, including biomechanical risk factors. Research has shown that certain malalignments seen in runners can predispose them to common injuries such as knee pain, stress fractures, and iliotibial band syndrome. Video analysis of running form has been shown to be a reliable method of assessment of certain variables such as foot strike pattern and pelvic (trunk) drop. There is an ongoing debate as to whether gait retraining can prevent running-related injuries, however running analysis may be an effective tool to identify obvious muscle imbalances or weaknesses in the runner. Technology developments are taking the monitoring and interpretation onto the streets and trails with cutting edge wearable technology. Accuracy of these wearables is continuing to be studied and enhanced.
Sports biomechanics is a fascinating field ripe with the potential to enhance our clinical assessment and management of athletes. I challenge clinicians to maintain an evidence-based mindset in its utility in injury prevention, recovery monitoring, and outcome measurements. I anticipate we will continue to see growth in this field with a variety of different applications to different sports and more unique settings.