Segment Coordination Variability Differs by Years of Running Experience

Abstract

Running is a popular activity that results in high rates of overuse injury, with less-experienced runners becoming injured at higher rates than their more-experienced peers. Although measures of joint kinematics and kinetics and ground reaction forces have been associated with overuse running injuries, similar differences across levels of running experience have not been found. Because running is a motor skill that may develop with experience, an analysis of segment coordination and its variability could provide additional insight into why injury incidence decreases with increasing experience.

Purpose: The purpose of this study was to determine if less-experienced runners have different segment coordination and lower segment coordination variability compared with their more-experienced peers.

Methods: This retrospective analysis included 20 more-experienced (≥10 yr running) and 21 less-experienced (≤2 yr running) runners. Sagittal thigh versus shank and shank versus foot segment coordination and coordination variability were calculated using a modified vector coding approach as individuals ran on a treadmill at preferred pace. Coordination and its variability were compared between groups during terminal swing and early, mid, and late stance for both segment couples.

Results: Segment coordination was similar between less- and more-experienced runners. Less-experienced runners had lower segment coordination variability compared with more-experienced runners for both the thigh versus shank and shank versus foot couples. This lower variability occurred during early and mid stance.

Conclusions: Runners appeared to attain stable segment coordination patterns within 2 yr of consistent running, but had lower coordination variability compared with individuals who had been running for 10 or more years. These results suggest that assessment of movement patterns and their flexibility may help inform injury prevention or treatment strategies for less-experienced runners.

FIGURE 1—

Exemplar vector coding methods. Left-hand graph shows a sagittal thigh vs shank angle-angle plot during stance over multiple strides. Curved arrow indicates direction of gait cycle progression. Inset demonstrates phase angle (θ) calculation between gait cycle points. Right hand graph shows angle ranges for phase angle patterns. The phase angles exemplified in the inset would fall into the 157.5° to 202.5° proximal phase pattern.

FIGURE 2—

Comparison of segment coordination between less-experienced runners (dashed lines) and more-experienced runners (solid lines). *Significant difference between groups during terminal swing and early stance for the shank vs foot couple. Although there were these significant group differences, coordination pattern (color + key) did not differ between groups.

FIGURE 3—

Comparison of segment coordination variability between less-experienced runners (black box and whiskers) and more-experienced runners (gray box and whiskers) for gait cycle phases of interest. Circles indicate individual data points. *Significant difference between groups.