Evaluating a New Standardized Protocol for the Single-Leg Horizontal Hop for Distance Test

Abstract

Background: Single-Leg Horizontal Hop Test (SLHD) is one of the common tests in most clinical settings that assess strength, power, and agility in the lower extremity post injury. In such cases, SLHD does not show good reliability owing to the implication of existing protocols, and a new standardized protocol was developed to improve the reliability.

Objective: This study aimed to establish the test-retest reliability of the SLHD using a newly standardized protocol for the measurement of lower limb strength and power in a healthy population. The current study also aimed to determine, with a proposed protocol, the absolute and relative reliability of the SLHD, including the calculation of the SEM and MDC for the SLHD.

Methods: Thirty-five university-educated females participated, providing descriptive statistics for the variables of age, weight, body height, and BMI. The SLHD was measured twice in a standardized way. The assessed IC correction was via the Intraclass Correlation Coefficient (ICC). Test-retest agreement for the measured variables was analyzed using Passing-Bablok regression and Bland-Altman analysis. SEM was determined according to the following formula: SEM = SD * √(1 - ICC). The Minimal Detectable Change (MDC) of 95% was calculated using the formula: MDC95 = 1.96

Results: Test–retest reliability showed an excellent ICC of 0.98 (95% CI: 0.95 to 0.995). SEM and MDC were very low at 1.18 cm and 3.1628 cm (95% CI: 2.5653–. There were no significant differences between the test-retest values, according to regression analysis reported by Passing-Bablok (regression equation: y = -1.301 + 0.991x) or Spearman's correlation coefficient, which was r = 0.991 (P < 0.001). The Bland-Altman analysis confirmed the agreement: the mean difference was 0.1886 cm (95% CI: -0.3700; 0.7471) with the 95% LoAs ranging from -2.9985 to 3.

Conclusion: The study highlighted the importance of controlling confounding variables, such as hydration and nutritional status, to ensure accurate measurements. While the findings are promising, they are primarily applicable to healthy, university-aged females and may not extend to other populations. Future research should investigate the Minimum Clinically Important Difference (MCID) in diverse groups to further validate the SLHD. Overall, this study supports the use of the SLHD protocol in clinical and research settings for monitoring lower extremity function and detecting meaningful changes in performance.