Force measurements during running on different instrumented treadmills

Area of Science:

• Biomechanics
• Sports Science
• Human Movement Analysis

Background:

• Kinematic and kinetic analysis are crucial for understanding running forces.
• Instrumented treadmills are commonly used, but may not accurately reflect over-ground running forces.
• Differences in force measurements can be attributed to treadmill design and setup.

Purpose of the Study:

• To compare ground reaction forces during over-ground running with those on different instrumented treadmills.
• To develop a theoretical model to correct for discrepancies in treadmill-based force measurements.
• To enhance the accuracy of running dynamics research using instrumented treadmills.

Main Methods:

• 11 participants performed running trials on three distinct instrumented treadmills and over-ground at various speeds (2.7, 3.6, 4.5 m/s).
• Ground reaction forces were measured using force plates and instrumented pressure insoles.
• A three-degree-of-freedom mechanical model was developed to explain and correct force measurement differences.

Main Results:

• Significant differences were observed in vertical ground reaction forces between the tested treadmills and over-ground running.
• A mechanical model, incorporating a force plate, treadmill, and dynamic masses, explained the discrepancies between insole and treadmill force measurements.
• The developed model shows potential for correcting erroneous force data from instrumented treadmills.

Conclusions:

• Instrumented treadmill force measurements differ from over-ground running, necessitating correction.
• A validated mechanical model can improve the accuracy of running force data obtained from instrumented treadmills.
• This research offers a method for researchers to approximate true running forces, enhancing biomechanical studies.