An instrumented footbar for evaluating external forces in Pilates

Area of Science:

• Biomechanics
• Exercise Physiology
• Rehabilitation Engineering

Background:

• Pilates exercise intensity is typically subjective, relying on instructor experience.
• Accurate force measurement is needed for objective exercise assessments and inverse dynamics (ID) analyses.
• The Pilates reformer's footbar force magnitude and direction are currently unquantified.

Purpose of the Study:

• To develop and describe a novel device for measuring force exerted on a Pilates reformer footbar.
• To quantify the magnitude and direction of footbar forces during Pilates exercises.
• To compare device-measured forces with forces estimated via spring parameters.

Main Methods:

• Commercial load cells were integrated into a Pilates reformer's footbar.
• A device was constructed to measure the direction and magnitude of applied force.
• A volunteer performed standardized footwork exercises with varying parameters (speed, load, foot position).

Main Results:

• The developed device successfully measured the magnitude and direction of footbar forces.
• External forces estimated from spring deformation were significantly different (P < .001) from device-measured forces.
• This indicates that estimations based solely on spring parameters are imprecise.

Conclusions:

• The novel load cell device provides accurate and objective force measurements for Pilates exercises.
• This technology enables precise quantification of forces for inverse dynamics analyses.
• Objective force data can enhance exercise assessments and research in Pilates and related fields.