Subclassification of recreational runners with a running-related injury based on running kinematics evaluated with marker-based two-dimensional video analysis.

OBJECTIVES: To explore whether homogeneous subgroups could be discriminated within a population of recreational runners with a running-related injury based on running kinematics evaluated with marker-based two-dimensional video analysis. DESIGN: Cross-sectional. SETTING: Research laboratory. PARTICIPANTS: Fifty-three recreational runners (15 males, 38 females) with a running-related injury. MAIN OUTCOME MEASURES: Foot and tibia inclination at initial contact, and hip adduction and knee flexion at midstance were measured in the frontal and sagittal plane with marker-based two-dimensional video analysis during shod running on a treadmill at preferred speed. The four outcome measures were clustered using K-means cluster analysis (n = 2-10). Silhouette coefficients were used to detect optimal clustering. RESULTS: The cluster analysis led to the classification of two distinct subgroups (mean silhouette coefficient = 0.53). Subgroup 1 (n = 39) was characterized by significantly greater foot inclination and tibia inclination at initial contact compared to subgroup 2 (n = 14). CONCLUSION: The existence of different subgroups demonstrate that the same running-related injury can be represented by different kinematic presentations. A subclassification based on the kinematic presentation may help clinicians in their clinical reasoning process when evaluating runners with a running-related injury and could inform targeted intervention strategy development.

Two-dimensional video analysis can discriminate differences in running kinematics between recreational runners with and without running-related knee injury.

OBJECTIVES: To determine whether two-dimensional video analysis could discriminate running kinematics between recreational runners with and without a running-related knee injury. DESIGN: Case-control. SETTING: Research laboratory. PARTICIPANTS: Forty-two recreational runners (5 male-13 female injured; 7 male-17 female non-injured). Running-related knee injury was defined as the presence of anterior or lateral knee pain, resulting in altered running activity for at least one week. MAIN OUTCOME MEASURES: Foot and tibia inclination at initial contact, and lateral trunk position, contralateral pelvic drop, femoral adduction, hip adduction, knee flexion and ankle dorsiflexion at midstance were measured with two-dimensional video analysis during running. Participant characteristics (sex, age, body weight, body length, body mass index, running volume before injury, running speed) and two-dimensional measured angles were compared between groups. RESULTS: No significant differences in participant characteristics between groups were identified (P > .05). The injured group ran with greater contralateral pelvic drop (P = .035), femoral adduction (P = .021) and hip adduction (P = .001) at midstance, and significantly smaller foot inclination at initial contact (P = .031). CONCLUSION: Two-dimensional video analysis can discriminate kinematics between runners with and without running-related knee injury. Greater contralateral pelvic drop, femoral adduction and hip adduction at midstance may provide running retraining targets for runners with running-related knee injury.

Biomechanical Risk Factors Associated with Running-Related Injuries: A Systematic Review.

BACKGROUND: Running is a popular form of physical activity with many health benefits. However, the incidence and prevalence of running-related injuries (RRIs) is high. Biomechanical factors may be related to the development of RRIs. OBJECTIVE: This systematic review synthesizes biomechanical risk factors related to the development of RRIs in non-injured runners. METHODS: PubMed, Web of Science, CINAHL, Embase, and SPORTDiscus were searched in July 2018 for original peer-reviewed prospective studies evaluating potential biomechanical factors associated with the development of RRIs. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Two reviewers independently assessed articles for inclusion and methodological quality. Due to methodological heterogeneity across studies, a narrative synthesis of findings was conducted, rather than a meta-analysis. RESULTS: Sixteen studies, including 13 of high quality and three of moderate quality, were included. A large number of biomechanical variables were evaluated, producing inconsistent evidence overall. Limited evidence indicated greater peak hip adduction in female runners developing patellofemoral pain and iliotibial band syndrome, but not for a mixed-sex population of cross-country runners sustaining an RRI. The relationship between vertical loading rate and RRIs was inconsistent. Other kinematic, kinetic and spatiotemporal factors were only studied to a limited extent. CONCLUSIONS: Current prospective evidence relating biomechanical variables to RRI risk is sparse and inconsistent, with findings largely dependent on the population and injuries being studied. Future research is needed to confirm these biomechanical risk factors and determine whether modification of these variables may assist in running injury prevention and management.