MECHANISMS ASSOCIATED WITH RUNNING INJURIES 471

Abstract

The purpose of the study was to investigate the relationships between (a) frontal plane kinematics, (b) sagittal plane kinematics and (c) ground reaction impact forces (GRIF) during distance running to gain a better understanding of lower extremity function and underlying mechanisms which might be implicated as possible precursors to injury. Ten subjects ran under two perturbed conditions (speed changes and obstacle heights) to facilitate increases in GRIF. Lower extremity sagittal and rear view video (200Hz) and force platform (1000Hz) data were collected simultaneously to examine selected joint kinematics in conjunction with the GRIF. Finally, the biomechanical results were compared with the results from an orthopedic examination of the subjects. All data were evaluated using a single subject analysis with baseline adjustments before, between and after all perturbations. Significant GRIF differences were observed for 51.7 and 86.7% of the speed and obstacle perturbations, respectively. Furthermore, the total number of significant comparisons between time to maximum pronation and time to maximum knee flexion were 85 and 47.5% of the speed and obstacle perturbations, respectively. The experimental design also produced increases in slope differences (152.47 to 187.99 deg/sec) between the rearfoot and the knee angle mean ensemble curves. These results suggested that increases in GRIF facilitated temporal disruptions between pronation/supination of the ankle and flexion/extension of the knee. Significant correlations (0.857 and 0.798) between the subjects' rankings on the orthopedic examination and the biomechanical evaluations predicting susceptibility of injury suggested that incorporating various meaningful functional components into a properly designed study may allow for an enhanced understanding of mechanisms associated with running injuries.