Community-based running measures associated to pain – Abstract

CONTROL ID: 2565373
TITLE: Community-based running measures associated to pain

Author Details
AUTHORS (LAST NAME, FIRST NAME): Suydam, Stephen M.1; Evans, Matt2; Willy, Richard W.3
INSTITUTIONS (ALL): 1. Milestone Sports LTD, Chicago, IL, United States.
2. Physics & Astronomy, University of Wisconsin – Eau Claire, Eau Claire, WI, United States.
3. Physical Therapy, East Carolina University, Greenville, NC, United States.
Student Category – Research Report: Not a Student

Purpose/Hypothesis :
Distance running is a popular recreation demonstrated by more than 2.5 million Americans running half or full marathons, but distance running comes with a high rate of injury(1,2). Prospective and retrospective gait analysis have been performed and suggested that reduced running cadence and increased vertical load rates (VLR) are associated with running-related injuries (3,4,5,6). Despite these assertions, previous studies have only examined these biomechanical relationships in a laboratory setting and may not relate well to running biomechanics during actual training sessions. Emerging wearable technologies may provide the means to examine running biomechanics during community-based runs. Therefore, we sought to perform community based data collections and collect self-reported, lower extremity discomfort metrics to determine if a relationship exists between pain and gait mechanics commonly associated with injury.

Number of Subjects :

Materials/Methods :
77 runners took part in a 13-week marathon training course. Each participant wore a shoe-mounted wearable device that uses a validated, proprietary algorithm to estimate VLR in addition to several spatial-temporal metrics (cadence, duration, distance). VLR is measured minute by minute as low, medium and high (<64bw/s,64-80bw/s,>80bw/s, respectively) based on the derivative of the accelerometery signal from footstrike to peak positive acceleration (MilestonePod, Columbia, MD, USA). VLR is converted to a single number through the equation:
VLR=((3*%high+2*%medium+1*%low)-100)/2 i.e.100% high=100, 100% low=0
Participants submitted a weekly online survey that assessed any lower extremity pain and location (hip/back, knee, lower leg/ankle, foot). Running metrics from the Pod were compiled each week for each user. Χ2logistical fit tests were used to compare occurance of pain that week in each location to weekly distance, cadence, and VLR.

Results :
There were a significant relationships between pain occurrence in the lower leg and the knee and VLR (p=0.001, 0.006 respectively). There was also a significant relationship between distance and lower leg pain (p=0.023). There was no significant associations to hip or foot pain. There was no interaction effects between cadence and VLR.

Conclusions :
Runners with a high VLR were more likely to report a greater incidence of pain occurrences in the knees and lower legs compared with those with lower VLR. Interesting, cadence did not have a significant association with pain in any of the 4 body segments. While increased cadence has been an effective technique in positively altering biomechanics to reduce injury, it is VLR and not cadence that is correlated to pain during running.

Clinical Relevance :
These data suggest that assessing VLR during community-based training runs may provide clinicians with the means to identify runners who may be at increased risk for sustaining injuries to the knee or lower leg. Further, an intervention for runners which reduces their VLR may decrease pain and limit the occurrences of longer term injury. Assessing cadence does not appear to have predictive value for running related injuries.