Zanesljivost in veljavnost poenostavljenega protokola meritev moči sprednjih in zadnjih stegenskih mišic : magistrsko delo

Oder, Bine (author), Spudić, Darjan (mentor)

Namen magistrskega dela je bil preveriti zanesljivost in veljavnost poenostavljenega protokola meritev največje moči sprednjih in zadnjih stegenskih mišic. Za poenostavljen protokol, primeren za uporabo v praksi, smo uporabili tlačno-natezni senzor (T-N senzor) s povezovalnim trakom. Za referenčni protokol pa smo uporabili izometrično opornico, ki se uporablja kot zlati standard tovrstnih meritev in je bil uporabljen za preverjanje veljavnosti. V presečno raziskavo je bilo vključenih 26 študentov Fakultete za šport (starost 23,9 ± 2,2 leta; telesna višina 176,6 ± 10,6 cm; telesna masa 75 kg ± 13,9 kg). Vzorec je vseboval 18 preizkušancev moškega in 8 preizkušank ženskega spola. Protokol meritev je obsegal tri največja hotena izometrična naprezanja (iztega/upogiba kolena), najprej v 90°, nato pa še v 60° kolenskega kota z levo oziroma desno nogo. Za oceno relativne zanesljivosti rezultatov treh ponovitev je bil uporabljen intraklasni korelacijski koeficient (ICC) skupaj s 95-% intervalom zaupanja. Absolutno zanesljivost pa smo ocenjevali s koeficientom variance (CV) in standardno napako merjenja (SEM). Rezultati so pokazali dobro do odlično zanesljivost v primeru izometrične opornice (ICC: 0,775–0,963; CV: 3,58–10,99) z majhno variabilnostjo in nekoliko slabšo zanesljivostjo v primeru leve noge (ICC: 0,775–0,891; CV: 6,40–10,99). Poenostavljeni protokol s T-N senzorjem je prav tako pokazal dobro do odlično zanesljivost (ICC: 0,867–0,967; CV: 3,23–5,87) vseh spremenljivk. Za oceno veljavnosti meritev smo primerjali rezultate med protokoloma glede na kot upogiba v kolenu (60° in 90°), pri čemer je bila uporabljena dvostranska analiza variance (ANOVA) za ponovljene meritve, ki je pokazala statistično značilne razlike med protokoloma, pri čemer smo z izometrično opornico izmerili večje vrednosti maksimalne moči v primerjavi s T-N senzorjem. Prav tako smo ugotovili, da je bilo pri večini spremenljivk prisotno tudi statistično značilno razlikovanje med koti, zlasti pri merjenju maksimalne moči upogiba kolena. Povezanost in razlike v rezultatih moči med instrumentoma za vsak položaj merjenja in med položajema merjenja za vsak instrument smo še dodatno izračunali s Pearsonovim koeficientom korelacije in Bland-Altmanovo statistiko. S slednjima smo potrdili visoke korelacije med instrumentoma, a je kljub temu prišlo do sistematičnih razlik med njunimi rezultati, kar nakazuje omejeno primerljivost absolutnih vrednosti med instrumentoma. Naša raziskava kaže, da je T-N senzor s povezovalnim trakom zanesljiva metoda za merjenje mišične moči v praksi, vendar rezultati v večini primerov niso enaki rezultatom meritev na izometrični opornici, zato v prihodnje priporočamo konsistentno uporabo enega instrumenta za spremljanje moči iztegovalk in upogibalk kolena v praksi.

• Language: Slovenian
• Keywords: izometrična opornica, tlačno-natezni senzor, maksimalna moč kolena, zanesljivost, veljavnost
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FŠ - Faculty of Sport
• Year: 2025
• PID: 20.500.12556/RUL-167942
• COBISS.SI-ID: 236561155
• Publication date in RUL: 21.03.2025

Secondary language

• Language: English
• Title: Reliability and validity of a simplified protocol for measuring anterior and posterior thigh muscles strength

Abstract

The purpose of the master's thesis was to present and verify the reliability and validity of a simplified protocol for measuring the strength of the anterior and posterior thigh muscles. For the simplified protocol, suitable for practical use, we used a load-cell sensor (L-C sensor) with a fixed connecting strap. As a reference protocol, we used an isometric chair dynamometer, which is used as the gold standard for such measurements and was used to verify the validity. 26 students of the Faculty of Sport were included in the cross-sectional study (age 23.9 ± 2.2 years; body height 176.6 ± 10.6 cm; body weight 75 kg ± 13.9 kg). The sample consisted of 18 male and 8 female subjects. The measurement protocol consisted of three maximum voluntary isometric contractions (knee extension/flexion), first at 90° and then at 60° of the knee flexion angle with the left and right legs. The Intraclass corelation coefficient (ICC) was used to assess the relative reliability of the three replicate results, along with a 95% confidence interval. Absolute reliability was assessed using the coefficient of variance (CV) and standard error of measurement (SEM). The results showed good to excellent reliability for the isometric dynamometer (ICC: 0.775-0.963; CV: 3.58-10.99) with low variability and slightly lower reliability for the left leg (ICC: 0.775-0.891; CV: 6.40-10.99). The simplified protocol with the L-C sensor also showed good to excellent reliability (ICC: 0.867-0.967; CV: 3.23-5.87) for all variables. To assess the validity of the measurements, we compared the results between the protocols according to the angle of knee flexion (60° and 90°), using a two-way analysis of variance (ANOVA) for repeated measures, which showed statistically significant differences between the protocols, where the isometric dynamometer showed higher strength values compared to the L-C sensor. We also found that there was a statistically significant difference between the results obtained at different knee flexion angles for most variables, especially when measuring knee flexion strength. The correlation and differences in the strength results between the instruments for each measurement position and between the measurement positions for each instrument were additionally calculated using the Pearson correlation coefficient and the Bland-Altman statistics. The latter confirmed high correlations between the instruments. Nevertheless, there were systematic differences between their results, indicating limited comparability of the absolute values between the instruments. Our study shows that the L-C sensor with a connecting strap is a reliable method for measuring muscle strength in practice, but the results are not the same as the results obtained with the isometric dynamometer, so in the future we recommend the consistent use of one instrument for monitoring the strength of the knee extensors and flexors in practice.

• Keywords: isometric dynamometer, pressure-tension sensor, maximal knee strength, reliability, validity