Validity and Test-Retest Reliability of a Novel Push Low-Cost Hand-Held Dynamometer for Knee Strength Assessment during Different Force Ranges

• Published in: Diagnostics (Basel) Vol. 12; no. 1; p. 186
• Main Authors: Macedo, Maria de Cássia, Souza, Matheus Almeida, Ferreira, Kariny Realino, Campos, Laura Oliveira, Souza, Igor Sérgio Oliveira, Barbosa, Michelle Almeida, Brito, Ciro José, Intelangelo, Leonardo, Barbosa, Alexandre Carvalho
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 13.01.2022; MDPI
• Subjects: Agreements; Injuries; isometric contraction; knee assessment; Load; muscle strength; Software; Statistical analysis; Validity; United States > US; muscle strength; isometric contraction; knee assessment
• ISSN: 2075-4418; 2075-4418
• DOI: 10.3390/diagnostics12010186

The objective was to assess the instrumental validity and the test–retest reliability of a low-cost hand-held push dynamometer adapted from a load-cell based hanging scale (tHHD) to collect compressive forces in different ranges of compressive forces. Three independent raters applied 50 pre-established compressions each on the tHHD centered on a force platform in three distinct ranges: ~70 N, ~160 N, ~250 N. Knee isometric strength was also assessed on 19 subjects in two sessions (48 h apart) using the tHHD anchored by an inelastic adjustable strap. Knee extension and flexion were assessed with the participant seated on a chair with the feet resting on the floor, knees, and hips flexed at 90°. The isometric force peaks were recorded and compared. The ICC and the Cronbach’s α showed excellent consistency and agreement for both instrumental validity and test–retest reliability (range: 0.89–0.99), as the correlation and determination coefficients (range: 0.80–0.99). The SEM and the MDC analysis returned adequate low values with a coefficient of variation less than 5%. The Bland–Altman results showed consistency and high levels of agreement. The tHHD is a valid method to assess the knee isometric strength, showing portability, cost-effectiveness, and user-friendly interface to provide an effective form to assess the knee isometric strength.