THREE-DIMENSIONAL QUANTITATIVE ANALYSIS OF THE TRAJECTORY OF THE FOOT WHILE RUNNING

Exercising the leg in a manner similar to running is theorized to have the potential effect of increasing performance and reducing occurrence of injuries in running athletes. Development of an exercise device that can help facilitate this method of specificity training could be beneficial to the sports community and should be investigated. Understanding the trajectory of the foot during the running gait is primary to further pursue this concept. 26 running athletes of varying characteristics participated in this study. Each subjects sex, age, weight, height, leg length, activity level and participation amount in their respective sport was recorded. Retro-reflective cameras captured the three-dimensional trajectory of each subjects right leg while running at speeds of 2, 3.8, 4.52 and 5.36 m/s for 10-15 seconds on a treadmill, respectively. The range of foot movement in each cardinal plane was determined for each speed. An ANCOVA revealed that leg length was the most determinate factor in trajectory range differences among subjects. Subjects were subsequently divided into quartiles based on leg length where further analysis revealed that foot displacement increased vertically and horizontally in the sagittal plane with increases in speed while trajectory in the third plane remained constant and substantially less in magnitude