Hydro-resistive measurement of dynamic lifting strength

Area of Science:

• Biomechanics
• Human Performance Measurement

Background:

• Accurate measurement of dynamic vertical lift strength and power is crucial for understanding human performance.
• Existing devices may lack safety, robustness, or transportability for diverse applications.

Purpose of the Study:

• To describe a new, safe, robust, and easily transportable device for measuring strength and power outputs during dynamic vertical lifts.
• To detail the device's mechanism for assessing performance across a wide range of lift velocities and forces.

Main Methods:

• A water-filled tube with a piston and adjustable drag system was employed.
• Force was measured using a strain-gauged cantilever, and displacement via a shaft encoder.
• Data acquisition was synchronized using an interfaced computer for velocity and power calculations.

Main Results:

• The device demonstrated high accuracy, with repeatable power measurements across days.
• A slight warming-up effect was observed within a single day's repetitions.
• The drag system allowed for a 100-fold adjustable range, independent of temperature.

Conclusions:

• This device provides a versatile and accurate tool for studying dynamic vertical lifts.
• It enables research into human performance from quasi-isokinetic movements to high-acceleration lifts.
• The system's design facilitates diverse biomechanical and performance analyses.