Influence of Step-Width Manipulation on Running Biomechanics

Our research focus on how step width affects lower limb biomechanics during running. We explore how changes in step-width impact joint loading, stability, and muscle coordination. Its ultimate goal is to help runners improve performance and reduce injury risk by finding their ideal step width.

Techniques of motion capture have evolved rapidly with the rapid development of technologies and advanced interdisciplinary approach. For example, the transitional marker-based motion capture in the lab, AI-driven markerless techniques with video data and wearables. These techniques assist in the analysis of human motion on the different scenarios.

In sport biomechanics, technologies like markerless motion capture, wearable device, and biomechanical simulations are advancing research. Markerless systems analyze nature movements while a wearable like IMUs and smart ace provide continued time series data. Biomechanical models and AI-enabled process data processing, helping researchers optimize performance and reduce injury risks with individualized strategies.

In the current study, we would like to investigate the variation of running step width on lower extremity biomechanics. However, the perturbed step-width conditions in the well-designed lab may not be replicable in the real scenario surrounding environment. Our future research will explore how step width impacts lower limb biomechanics across different populations, including female runners and older adults.

We will study the long-term effects of step width adjustments on performance and injury prevention and use machine learning to develop a personalized strategies for optimizing running biomechanics. To begin, open the tracking software and allow the eight infrared cameras to initialize. Then, switch to camera mode and expand the system resources panel on the left.

Select all eight cameras. Adjust the settings in the left panel under Properties. Set the flash intensity to 0.95 to 1, gain to 1x, and grayscale mode to auto.

Under Centroid Fitting, set the threshold to 0.2 to 0.4, the minimum circularity ratio to 0.5, and the maximum blob height to 50. Position the T frame with markers at the center of the motion capture area. Reselect all eight cameras from the toolbar on the left.

Perform calibration in the tools panel on the right. Select the five marker wand and T frame calibration object from the T frame list. Now under the Calibrate Cameras option, click on the Start button.

Move the T frame back and forth within the capture range while matching the swinging height to the camera's focal height. Stop when the blue lights on the camera stop flashing. Switch the view to a 3D perspective and place the T frame back at the center of the motion capture area.

Click on the Start button under the Set Volume Origin option in the right panel. Next, to prepare the pressure platform, synchronize embedded force plates at 1000 hertz. Connect the platform to the PC for data collection.

For timing system preparation, place a single beam electronic timing gate on a tripod to record participants'running speed as they pass over the force plates. Launch the tracking software. Select New Database from the toolbar.

In the Data Management section, choose New Patient Classification. Then, New Patient. And finally, click on New Session to set up a participant information database.

Instruct the participant to stand with their feet shoulder width apart, ensuring one foot is positioned on the force platform. Arms are held parallel to the shoulders and their gaze is directed straight ahead. Click on Go Live in the left toolbar.

Then, use the split horizontal button in the View interface and select Graphics to view trajectory counts. Then, click on Start to begin data collection and hold the position for 10 seconds. Click on Stop to complete the static capture.

Instruct the participant to walk naturally along a straight pathway with two force platforms, placing the left foot on platform A and the right foot on platform B.To evaluate the trial's success, check if the time to complete one run falls between 0.95 to 1.05 seconds at 3 meters per second, or between 0.76 to 0.86 seconds at 3.7 meters per second. Instruct the participant to run at a speed of 3.7 meters per second on a straight pathway with two force platforms. To measure the preferred step width, mark the force platforms with different-colored tapes corresponding to five step-width conditions.

Instruct participants to walk straight while focusing ahead. The hip abduction and abduction angles during running demonstrated consistent patterns across varying step widths and speeds, corroborating findings from recent running studies.