Reliability, Usefulness, and Validity of Field-Based Vertical Jump Measuring Devices

Area of Science:

• Sports Science and Biomechanics
• Human Movement Analysis
• Performance Measurement

Background:

• Accurate measurement of jump height is crucial for assessing athletic performance and training adaptations.
• Field-based devices offer practical alternatives to laboratory equipment for jump height assessment.
• Evaluating the reliability, usefulness, and validity of these devices is essential for applied practitioners.

Purpose of the Study:

• To examine the test-retest reliability, usefulness, and validity of three field-based devices (Optojump, Output Capture, Push-Band 2.0) for measuring jump height (JH) during a countermovement jump (CMJ).
• To compare the performance of these devices against a criterion measure (force plate).
• To determine if the devices can detect the smallest worthwhile change (SWC) in CMJ performance.

Main Methods:

• Twenty-eight field sport athletes (21 male, 7 female) performed three CMJs.
• Jump height data were simultaneously recorded using a force plate, Optojump, Output Capture, and Push-Band 2.0.
• Reliability was assessed using intraclass correlation (ICC) and coefficient of variation (CV); usefulness by comparing typical error (TE) with SWC; and validity through ANOVA, Pearson correlation, and Bland-Altman analysis.

Main Results:

• All three devices demonstrated excellent reliability (ICCs ≥ 0.80, CV ≤ 10%) in assessing CMJ height.
• Optojump and Output Capture were rated as "good" for detecting SWC (SWC > TE).
• Output Capture showed acceptable validity, while Push-Band 2.0 exhibited systematic bias. Optojump also showed systematic differences, potentially due to device placement.

Conclusions:

• Despite excellent reliability across all devices, Optojump and Output Capture are recommended for practitioners.
• These devices provide a cost-effective, reliable, and valid method for assessing the smallest worthwhile change in CMJ performance in applied settings.
• Practitioners should be aware of potential systematic biases with certain devices like the Push-Band 2.0 and consider device-specific factors for Optojump.