Differences in Lower Extremity Kinematics Between High School Cross-Country and Young Adult Recreational Runners.
Mark F Reinking, Nina M Carson, Bridget M End and 3 others
PMID 33604140WHAT IT FOUND
High school cross-country runners showed slightly greater vertical center of mass excursion than young adult recreational runners, suggesting better shock attenuation.
Knee flexion angles were similar between groups. Two-dimensional video analysis produced knee flexion values comparable to prior three-dimensional studies, supporting its clinical use.
Key findings
01Vertical excursion of the center of mass was significantly greater in young adult recreational runners (7.96 cm) compared to high school runners (6.45 cm), a mean difference of 1.51 cm.
02Maximum knee flexion during stance and total knee flexion did not differ significantly between the two groups, contradicting the hypothesis that high school runners would exhibit greater knee flexion.
03The mean maximum knee flexion values found using 2-dimensional analysis were comparable to values previously reported using 3-dimensional analysis, supporting the validity of low-cost 2D methods for clinical screening.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The study used a treadmill rather than overground running, which may alter natural gait mechanics. The sample size was small (25 per group), limiting generalizability. The groups differed in running experience and intensity (competitive cross-country vs recreational), which may confound age-related differences. A single rater performed the analysis, although intra-rater reliability was previously established.
Declared interests
The study was approved by the Regis University Institutional Review Board. No specific funding sources or conflicts of interest were declared in the provided text.
The easy way to misread this
Do not assume high school runners are inherently more efficient at attenuating shock based solely on age. The difference in vertical center of mass excursion was small (1.51 cm) and the groups differed in training status (competitive vs recreational), so this may reflect training adaptations rather than age-related kinematic changes.