Author(s): LI, X.1, ZHOU, Y.2, TAN, J.1, LIU, H.2, FAN, Y.1, Institution: BEIJING RESEARCH INSTITUTE OF SPORTS SCIENCE, Country: CHINA, Abstract-ID: 1180

INTRODUCTION:
Running-related injury incidence in novice runners is more than twice that of other amateur runners [1], hindering fitness gains and imposing economic costs. Identifying lower limb injury risk factors in this population is therefore crucial. This study aimed to determine risk factors of running-related injuries in novice runners by assessing baseline lower limb characteristics and biomechanics in healthy novice runners and conducting a 6-month injury surveillance.
METHODS:
This prospective cohort study enrolled 227 novice runners (118 males; mean age: 40.5 ± 11.3 years; height: 169.0 ± 8.57 cm; weight: 65.7 ± 11.9 kg). Inclusion criteria: weekly running distance ≥10 km, ≤2 years of running experience, and no lower limb injury in the 3 months prior. Baseline assessments included anthropometry (lower limb length, Q-angle), isometric hip strength (abduction, adduction, and external/internal rotation) measured by hand-held dynamometer (Hoggan Microfet®2, USA), and active range of motion (hip to ankle). Running biomechanics were collected using a 3D motion analysis system (Qualisys Oqus 12, Sweden, 200 Hz) and 3 force plates (Kistler 9287C, Switzerland, 1000 Hz) at a speed of 12 km/h ±5%. At least five trials per side were averaged for analysis. Participants reported injuries weekly for 6 months. Group comparisons used independent t-tests or Mann-Whitney U tests. Univariate and multivariate logistic regression identified predictors, with performance evaluated by ROC analysis. Analyses were performed in R (Version 4.5.1).
RESULTS:
78 runners (34.36%) sustained injuries. The knee was the most common site (41%). Injured and non-injured groups differed significantly in hip external/internal rotation strength (p<0.05) and in the peak ankle inversion angle during the stance phase and the frontal-plane knee ROM during running (p<0.01). Multivariate analysis identified hip external rotation strength as protective (OR=0.56, 95% CI: 0.33-0.96, p=0.033), while greater frontal-plane knee ROM (OR=1.19, 95% CI: 95%CI:1.02- .39, p=0.026) and greater peak ankle inversion during the stance phase (OR=1.09, 95% CI: 95%CI:1.02-1.17, p=0.008) were risk factors. The model's AUC was 0.657 (95% CI: 0.585-0.723).
CONCLUSION:
Greater peak ankle inversion during the stance phase and frontal-plane knee ROM during running are injury risk factors for novice runners, while greater hip external rotation strength is protective.