Interrater, Test-retest Reliability of the Y Balance Test. A Reliability Study including 51 Healthy Participants

International Journal of Exercise Science 16(4): 182-192, 2023. The aim was to determine the relative and absolute interrater, test-retest reliability of the Y-Balance Test (YBT) in a sample of healthy and active adults aged 18 to 50 years. The sample consisted of 51 healthy and active participants, 30 men and 21 women with a mean age of 28 ± 7 years. The YBT was performed on the right leg in the three test directions. Test and retest of the YBT were performed with a median interval of 15 days. The method for data collection was in line with the Y Balance Test Lower Quarter Protocol (YBT-LQ). The test was conducted by raters previously inexperienced in the use of the YBT. The relative reliability was reported as Intraclass Correlation Coefficient (ICC(2,1)). The absolute reliability was reported as Standard Error of Measurement (SEM) and Minimal Detectable Change (MDC). The ICC ranged from 0.79-0.86. SEM ranged from 2%-4%, indicating the measurement error at group level and MDC ranged from 5%-11%, indicating the measurement error at individual level. The YBT showed good relative and absolute reliability. The YBT is therefore considered suitable at both group and individual level in physically active populations

A Comparison of Hip Muscle Mass, Muscle Power, and Clinical Outcomes with Long-Term Follow-Up in Patients with Metal-on-Metal Hip Arthroplasty Compared to Metal-on-Polyethylene Hip Arthroplasty

(1) Background: Metal-on-metal (MoM) total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA) was presumed to provide superior functional outcomes compared to metal-on-polyethylene (MoP) THA. (2) Methods: We compared muscle mass, power, step test asymmetry, and patient-reported outcomes between MoM THA/HRA and MoP THA. A total of 51 MoM THA/HRAs and 23 MoP THAs participated in the cross-sectional study at a mean of 6.5 (2.4–12.5) years postoperatively. Muscle mass was measured by Dual energy X-ray Absorption (DXA) scans and muscle power in a Leg Extensor Power Rig. Step test asymmetry was obtained with an Inertial Measurement Unit (IMU). The patients completed the Harris Hip Score (HHS) and the Copenhagen Hip and Groin Outcome Score (HAGOS). (3) Results: The MoM THA/HRA group had a greater inter-limb difference in hip muscle mass compared to the MoP THA group (p = 0.02). Other inter-limb differences in muscle mass and power were similar (p > 0.05). Muscle mass of the thigh and calf area and muscle power in both legs were higher in MoM THA/HRA compared to MoP THA (p p = 0.03). HHS and HAGOS scores were similar between groups (p > 0.05). (4) Conclusion: Overall, we could not verify the hypothesis that MoM THA/HRA contributes to superior functional outcomes compared to MoP THA