Reliability of the Strain Gauge in Assessing Isometric Strength in Leg Extension
Abstract
Muscular performance is a key indicator of overall health and is associated with benefits such as a healthier cardiovascular profile and a lower risk of metabolic diseases. This study aims to evaluate the reliability of isometric strength measurement in the lower limbs using a Chronojump® strain gauge in university students, providing evidence on the repeatability and reliability of this evaluation method. The research was conducted using an observational cross-sectional descriptive design with repeated measurements. A total of 49 students from the University of Sonora participated, with an average age of 20.32 ± 2.83 years, including 28 women and 21 men. The participants’ maximum isometric strength was assessed on a multi-station gym machine using a Chronojump® strain gauge. The results showed excellent repeatability values for both bilateral and unilateral evaluations (ICC between 0.983 and 0.986). It is concluded that the Chronojump® strain gauge is a reliable instrument for measuring isometric strength in the lower limbs, demonstrating high reliability in both bilateral and unilateral assessments. It is recommended that future research increases the sample size and incorporates statistical analyses such as the standard error of the mean and the minimal detectable change to identify significant differences resulting from interventions.
References
Candia-Luján, R., Núnez Escudero, B.A., Santa Cruz, K.I.C., De León Fierro, L.G., Esther Carrasco-Legleu, C., y Candia-Sosa, K.F. (2018). Similar bilateral asymmetry index of lower limbs muscle strength expressions in university students. Retos - Nuevas tendencias en educación física deporte y recreación, (33), 34-36. https://doi.org/10.47197/retos.v0i33.52934
Chen, B., Liu, L., Bin Chen, L., Cao, X., Han, P., Wang, C., y Qi, Q. (2021). Concurrent Validity and Reliability of a Handheld Dynamometer in Measuring Isometric Shoulder Rotational Strength. Journal of sport rehabilitation, 30(6), 965-968. https://doi.org/10.1123/jsr.2020-0021
Deysel, G., van Aswegen, M., y Kramer, M. (2024). Assessing quadriceps strength in patellofemoral pain patients: A study on the reliability and validity of a low-cost strain-gauge for clinical practice. PloS One, 19(5), e0298570. https://doi.org/10.1371/journal.pone.0298570
Grootswagers, P., Vaes, A.M.M., Hangelbroek, R., Tieland, M., van Loon, L.J.C., y de Groot, L.C.P.G.M. (2022). Relative Validity and Reliability of Isometric Lower Extremity Strength Assessment in Older Adults by Using a Handheld Dynamometer. Sports health, 14(6), 899-905. https://doi.org/10.1177/19417381211063847
Hartog, J., Dijkstra, S., Fleer, J., van der Harst, P., Mariani, M.A., y van der Woude, L.H.V. (2021). A portable isometric knee extensor strength testing device: test-retest reliability and minimal detectable change scores of the Q-Force ӀӀ in healthy adults. BMC musculoskeletal disorders, 22(1), 966. https://doi.org/10.1186/s12891-021-04848-8
Martínez Pérez, J.A., y Pérez Martin, P.S. (2023). Coeficiente de correlación intraclase [Intraclass correlation coefficient]. Semergen, 49(3), 101907. https://doi.org/10.1016/j.semerg.2022.101907
Monsalves-Álvarez, M., Solis-Soto, MT, Burrone, MS, Candia, AA, Jofré-Saldía, E., Espinoza, G., Flores-Opazo, M., Puebla, C., Valladares-Ide, D., y Jannas-Vela, S. (2024). Community strategies for health promotion and prevention of chronic non-communicable diseases with a focus on physical activity and nutrition: the URO/FOCOS study protocol. Frontiers in public health, 11, 1268322. https://doi.org/10.3389/fpubh.2023.1268322
Naimo, M.A., Varanoske, A.N., Hughes, J.M., y Pasiakos, S.M. (2021). Skeletal Muscle Quality: A Biomarker for Assessing Physical Performance Capabilities in Young Populations. Frontiers in physiology, 12, 706699. https://doi.org/10.3389/fphys.2021.706699
Parada Rivera, I. (2024). Relació entre la propulsió inicial màxima i manegot de rotadors en jugadors d’elit de rugbi en cadira de rodes [Trabajo de Grado. Ciències de l'Activitat Física i de l'Esport, Universitat Pompeu Fabra]. https://repositori.tecnocampus.cat/handle/20.500.12367/2830
Patel, A.V., Hodge, J. M., Rees-Punia, E., Teras, L. R., Campbell, P. T., y Gapstur, S. M. (2020). Relationship between Muscle-Strengthening Activity and Cause-Specific Mortality in a Large US Cohort. Preventing chronic disease, 17, E78. https://doi.org/10.5888/pcd17.190408
Pereira-Rodriguez, J.E., Mercado-Arrieta, M.A., Quintero-Gómez, J.C., Lopez-Flores, O., Díaz-Bravo, M., y Juárez-Vilchis, R. (2020). Efectos y beneficios del entrenamiento de fuerza en pacientes con cáncer: revisión sistemática de la literatura. Universidad Médica Pinareña, 16(3), e498. https://revgaleno.sld.cu/index.php/ump/article/view/498
Portilla-Cueto, K., Medina-Pérez, C., Romero-Pérez, E.M., Hernández-Murúa, J.A., Vila-Chã, C., y de Paz, J.A. (2022). Reliability of Isometric Muscle Strength Measurement and Its Accuracy Prediction of Maximal Dynamic Force in People with Multiple Sclerosis. Medicina (Kaunas, Lithuania), 58(7), 948. https://doi.org/10.3390/medicina58070948
Ríos Riquelme, M.A., Marín Guajardo, C., Loro Ferrer, J.F., Cofré Boladós, C.J., y Castillo Paredes, A. (2024). Efectos de los ejercicios isométricos sobre el rendimiento, fuerza, potencia o aptitud en jóvenes y adultos: Una revisión narrativa. Retos, 61, 1290-1297. https://doi.org/10.47197/retos.v61.109779
Sahu, P.K., Goodstadt, N., Ramakrishnan, A., y Silfies, S.P. (2024). Test-retest reliability and concurrent validity of knee extensor strength measured by a novel device incorporated into a weight stack machine vs. handheld and isokinetic dynamometry. PloS One, 19(5), e0301872. https://doi.org/10.1371/journal.pone.0301872
Wang, Z., Bridgeford, E., Wang, S., Vogelstein, J.T., y Caffo, B. (2024). Statistical analysis of data repeatability measures. International Statistical Review. https://doi.org/10.1111/insr.12591
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