Segment coordination and variability among prospectively injured and uninjured runners

ABSTRACT

Coordinative variability (CAV) and underlying coordinative patterns are potential running-related overuse injury (RROI) mechanisms, but prospective analyses are needed. This study compared lower limb CAV and coordinative patterns between prospectively injured and uninjured runners. Knee, shank, and ankle kinematics were collected for 39 recreational runners at the beginning of a 6-month follow-up period. Subjects were classified as injured (n=21) or controls (n=18) based on RROI incidence during follow-up. CAV was quantified using modified vector coding. Time spent in each coordinative pattern category was quantified using binning frequency analysis. Coordinative patterns were classified as mechanically unsound if underlying joint/segment motions opposed anatomically allowable running motion. Wilcoxon Rank-Sum tests compared CAV and binning frequencies between groups within different stance portions for knee-shank, shank-ankle, and knee-ankle couplings (α≤0.05). During initial-stance, the injured group displayed significantly greater knee-ankle CAV (effect size (ES)=1.1), knee-shank CAV (ES=0.97), and greater frequency of mechanically unsound knee-shank (ES=0.72) and shank-ankle (ES=0.63) motion. During mid-stance, the injured group displayed lower frequency of mechanically sound knee-ankle motion (ES=0.31). In late-stance, the injured group displayed greater shank-ankle CAV (ES=0.11). Mechanically unsound coordinative patterns along with greater knee-ankle and shank-ankle CAV potentially lead to RROI.

KEYWORDS:

• Running injury
• vector coding
• coordination variability
• lower extremity
• coordination patterns

Acknowledgments

The authors thank Shane Murphy, PhD, Jacob Vollmar, Ashley Nguyen, Kellee Hanigan, DPT, PhD, Bernadette de Leon and Jim Maciukenas, PhD for their contribution to the present study. The study was funded by the School of Public Health–Bloomington Faculty Research Grant Program.

Disclosure statement

The authors declare no conflict of interest or professional relationships with companies or manufacturers who may benefit from this research. The results of the study are presented clearly, honestly, and without fabrication, or inappropriate data manipulation.

Additional information

Funding

This work was supported by the Indiana University, School of Public Health-Bloomington [n/a].