2011 Annual Conference

BARNETT, JULIE

The purpose of this pilot study is to describe the incidence of different running styles (forefoot, midfoot, rearfoot landing) among a group of recreational runners training for a marathon. In an extensive review of literature performed, no investigations with normative values were found related to this topic.  This preliminary investigation was undertaken to add to the body of knowledge related to running styles, shoe characteristics (shoe age and shoe changes) during training and existence of injury.  It is anticipated that results from this investigation will allow for further research lines related to biomechanical assessment of running styles and identification of relevant variables that can contribute to the incidence of injury and injury prevention.

439 runners ranging in age from 18-65 were filmed within this investigation however, not all runners completed all questionnaires.  A smaller cohort comprised the second sample of runners (73% female, 27% male) who completed the questionnaires (n=56). Recruitment was done during the initial meetings for marathon training sessions sponsored by a local running store. 

There were two aspects of data collection during this investigation. The initial segment occurred during the first 3 training sessions where filming of runners was done as well as the  initial questionnaire regarding age, gender, current injuries and shoe age were distributed for completion.  Initial analysis will provide proportion values for running style.  Participants were given an identifying number and this number was written with a grease pencil on the lower extremities in accordance standard triathlon racing procedures. Instructions were reviewed with all participants about running along cones demarcating the filming zone in order to obtain video of their running style.  A 200 meter length after the first mile of the training route was marked with red cones and served as the filming area. Runners ran along this area and had a posterior and lateral video view taken of their lower extremities with three video cameras placed along the lateral border and 1 along the posterior border of the path. 

PROCEDURES ORDER: 1) Flyers announcing the investigation were placed at a local running store that for a third year sponsored the USA Fit training regimen.  2) Investigators presented the project at the Introductory Training Session consent forms were distributed to interested participants with questions answered. 3) The  “running shute” with cameras for filming was set prior to the start of the second training session. Filming and questionnaire completion were done on the initial training session with similar opportunities at the third and fourth training sessions. 4) Participants were reminded to complete subsequent surveys every 2 months for a total of 4 surveys completed.

Video footage was assessed by two physical therapists experienced in biomechanical analysis of the lower extremity for elite and recreational runners.  The zoom and frame capture features of the video footage were used to identify the running style with agreement needed by two investigators.  A descriptive analysis was done to begin establishment of normative data from a large cohort or recreational runners.  Data that was recorded and summarized to describe this sample included:  Running style, age, gender, shoe age, shoe brand and existence of injury.   Further assessment regarding existence of injuries during the duration of training to marathon date are pending at this time.

Initial Results:  Out of 439 recreational runners, video footage demonstrates that 95% were rearfoot strikers (n=417), 2.5% were midfoot strikers (n=11) and 2.5% were midfoot strikers (n=11).  Assessment of questionnaires reveals that of the 52 rearfoot strikers upon initial investigation 32 of 52 runners presented with lower extremity pain while of the remaining runners in this group, 3 forefoot strikers and 2 midfoot stikers had no lower extremity pain. The majority of runners 62.5% upon inception of training had shoes that were less than 6 months old (n=35).  The most commonly used shoes were Asics and Brooks brands followed by New Balance and Reebok shoes.

Initial findings demonstrate that 95%, a large majority of shod runners are rearfoot stikers.  Recreational runners who have sought to participate in an organized marathon training program utilize relatively new shoes with combination last options. Future investigations should continue to focus upon large cohort comparisons of recreational runners because these are the populations typcially seen by health care practitioners.  Additional factors for investigation should include ground reaction forces of differing runing styles and correlation of potential predisposing injury factors such as running style and shoe brand components.  Greater incentives in future investigations are needed to facilitate questionnaire completion

There is a great deal of interest and discussion in the current popular culture regarding barefoot running and changing running styles. Current research is scant with quantification of foot strike patterns done with only with elite runners.  As most clinicians work with the scores of recreational runners who look to emulate the styles of elite successful runners, there is a dearth of information available regarding running style norms for runners.  The exploration of norms for running style is imperative due to the potential for injuries that can be associated with running style but also for identification of related contributory factors to injury such as training errors, prior injury history and shoe age. Though it is possible that attempts to change natural running styles could be contributing to training errors, it is difficult to assess this question without the preliminary normative data and specific variable identification for specific investigation. Successful completion of this preliminary descriptive and future correlational investigation will lead to future randomized controlled trials regarding cause and effect of running styles and potential injury factors.