Validation of a Sensor-Based Dynamic Ski Deflection Measurement in the Lab and Proof-of-Concept Field Investigation

Area of Science:

• Sports Engineering
• Biomechanics
• Materials Science

Background:

• Ski deflection is crucial for alpine skiing performance.
• Segmental and temporal curvature characteristics of skis are gaining attention.
• A previous PyzoFlex® prototype showed high reliability in quasi-static tests.

Purpose of the Study:

• To evaluate an enhanced PyzoFlex® prototype's performance in dynamic settings.
• To assess the prototype's reliability and validity during skiing-like simulations and field tests.

Main Methods:

• Twelve sensor foils were integrated onto a ski.
• Sensors were calibrated and subjected to simulated bending and edging on a robot at varying speeds.
• Reliability was assessed using Change in Mean (CIM), Coefficient of Variation (CV), and Intraclass Correlation Coefficient (ICC 3.1).
• Validity was determined by comparing sensor data with measurements from an optoelectrical system (Qualisys).

Main Results:

• High reliability was observed across bending cycles (ICC 3.1 > 0.999) and velocities (ICC 3.1 = 0.997).
• Criterion validity showed a strong correlation (r = 0.98).
• Accuracy and precision were -0.003 m⁻¹ and 0.047 m⁻¹, respectively.

Conclusions:

• The enhanced PyzoFlex® prototype is stable, robust, and waterproof.
• It provides plausible ski curvature data in dynamic conditions.
• The prototype is a strong candidate for smart ski equipment due to its proven reliability and validity.