Active Voice: Can Gait Retraining Reduce Risk of Developing Overuse Running Injuries?
By Bradley J Bowser, Ph.D., and Irene S. Davis, Ph.D., PT, FACSM, FAPTA, FASB

Bradley J Bowser, Ph.D. Irene S. Davis, Ph.D., PT, FACSM, FAPTA, FASB
Viewpoints presented in SMB commentaries reflect opinions of the authors and do not necessarily represent positions or policies of ACSM.

Bradley J Bowser, Ph.D., earned his doctoral degree at the University of Georgia before completing postdoctoral training in the Running Injury Research Lab at the University of Delaware in Newark, Delaware. A member of ACSM, Dr. Bowser is currently an associate professor and director of the Biomechanics Research Laboratory at South Dakota State University in Brookings, South Dakota. His research focuses on lower extremity biomechanics.

Irene S. Davis, Ph.D., PT, FACSM, FAPTA, FASB, is an ACSM member and professor in the Department of Physical Medicine and Rehabilitation at Harvard Medical School in Boston, Massachusetts, and is director of the Spaulding National Running Center. Dr. Davis’ research focuses on mechanical factors that influence running-related injuries, the effectiveness of interventions to minimize risk of such injuries and strategies to improve post-injury rehabilitation.

This commentary presents Dr. Bowser’s and Dr. Davis’ views on the topic of the research article that they and their colleagues had published in the December 2018 issue of
Medicine & Science in Sports & Exercise® (MSSE).

Based on the Physical Activity Guidelines for Americans, adults need at least 150 to 300 minutes of moderate-intensity aerobic activity each week. Running is among the most popular forms of aerobic activity. More than 16.9 million Americans train for and compete in more than 30,000 races each year. Unfortunately, reports indicate that more than 75 percent of these runners will sustain a running-related injury, with 50 percent of those being reoccurrences.

Although multifactorial in nature, poor running mechanics increase risk for development of overuse running injuries. For example, vertical impact peaks, vertical loading rates and peak tibial shock have been linked to a variety of injuries including tibial stress fractures, plantar fasciitis, iliotibial band syndrome and patellofemoral pain syndrome. More compelling is a recent paper reporting that runners demonstrating high vertical loading rates have nearly a three-fold greater risk of developing a running-related injury compared to runners with low loading rates.

Strength training, improving range of motion and rest are often used as treatments for running-related injuries. However, these modalities alone do not address the underlying cause(s) of the injury sustained. Failure to address the causes may explain the high prevalence of reoccurrences. Retraining to correct faulty running mechanics is one way to address this problem.

In our study, as reported in the December 2018 issue of MSSE, we examined the short- and long-term effects of a gait retraining program using real-time feedback to reduce impact loading in runners. Vertical loading was evaluated on 19 runners who exhibited high tibial shock. Vertical loading measurements on these runners were obtained at six different time points (baseline, post-control, post-retraining, and at one, six, and 12 months post-retraining). The control period consisted of eight sessions of treadmill running over two weeks, during which running time was progressed from 15 to 30 minutes. This was followed by eight sessions of gait retraining over two weeks, using the same progressive treadmill protocol. For the retraining sessions, participants received real-time feedback of their tibial shock. The real-time tibial shock curves were displayed on a computer screen mounted in front of the treadmill. Runners were instructed to try to keep their tibial shock peaks under a designated threshold. Feedback was gradually removed over the eight training sessions to help the runners internalize the new motor program.

Following the control period, there were no significant changes to any ground reaction force variables. However, post-retraining, tibial shock, vertical impact peak and vertical loading rates were all significantly reduced. These findings suggest that reductions in vertical loading were a result of the retraining and not simply running on a treadmill. Of even greater importance is the lasting effect of the retraining sessions. Changes in running mechanics that do not persist over time will have limited impact on reducing injury risk and reoccurrence. However, runners in our study demonstrated that the significant reductions found post-retraining will persist for at least 12 months.

Our findings indicate that two weeks of gait retraining aimed at reducing load rates can be a powerful way to help reduce injuries in runners.