Razlike med spoloma v sili, proizvedeni med kraniocervikalnim upogibom in retrakcijo glave : magistrsko delo

Breznik, Jerneja (author), Dolenec, Aleš (mentor), Majcen Rošker, Živa (comentor)

Cilj magistrskega dela je bilo preverjanje razlik med spoloma v sposobnosti razvoja največje hotene izometrične sile (MVIC) ob izvedbi retrakcije glave in kraniocervikalnega upogiba pri asimptomatski in telesno aktivni populaciji (n = 52). Meritve so se izvajale s pomočjo fiksirane opornice z vgrajenim natezno tlačnim senzorjem, poleg meritev sil pa smo s pomočjo brezžičnega EMG sistema merili še električno aktivnost mišic sternocleidomastoideus in trapezius, ki ni smela presegati 15 % MVIC, s čimer smo spremljali ustreznost izvedbe gibov. Na podlagi izmerjenih sil smo za posamezni spol izračunali še indeks ali razmerje med retrakcijo glave in kraniocervikalnim upogibom. Statistična analizo smo izvedli pri stopnji tveganja 5 %. Ponovljivost meritev smo izračunali z intraklasnim korelacijskim koeficientom (ICC). Razlike med spoloma v proizvedeni sili in razmerju sil smo izračunali z Mann-Whitneyevim rang testom. Rezultati kažejo, da so moški uspeli proizvesti 16 % večjo silo ob izvedbi retrakcije glave kot ženske (36 N, p = 0,01), pri čemer je bila pri ženskah prisotna nekoliko večja aktivacija levega trapeziusa (0,87 %, p = 0,04), aktivacija desnega sternocleidomastoideusa pa je bila nekoliko večja pri moških (2,22 %, p = 0,02). Ob izvedbi kraniocervikalnega upogiba so moški uspeli proizvesti 32 % večjo silo kot ženske (25 N, p = 0,03), aktivacija površinskih mišic pa se pri tem gibu med spoloma ni razlikovala. Razmerje med silami ob izvedbi retrakcije glave in kraniocervikalnega upogiba se ni statistično razlikovalo med spoloma (p = 0,18), opazna pa je tendenca nekoliko višjih vrednosti razmerja pri ženskah (1,85) v primerjavi z moškimi (1,5). Tendenco povečanega razmerja pri ženskah pripisujemo predvsem zmanjšani sposobnosti razvoja sile kraniocervikalnih upogibalk. Predvidevamo, da so pri ženskah mehanske obremenitve kraniocervikalnega predela veliko bližje njihovi največji kapaciteti kot pri moških, zaradi česar bi lahko bile ženske bolj nagnjene k pojavu patologij vratnega predela.

• Language: Slovenian
• Keywords: kraniocervikalni upogib, retrakcija glave, anteriorni nagib glave, razlike med spoloma, indeks
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FŠ - Faculty of Sport
• Year: 2022
• PID: 20.500.12556/RUL-137066
• COBISS.SI-ID: 111651331
• Publication date in RUL: 01.06.2022

Secondary language

• Language: English
• Title: Gender differences in force production during craniocervical flexion and head retraction

Abstract

The goal of this dissertation was to determine gender differences in maximal voluntary isometric contraction (MVIC) force production during cranio-cervical flexion and head retraction in asymptomatic and physically active population (n = 52). Measurements were conducted using a fixed stand integrated with a stretch-pressure sensor. Concurrently, muscle activity of sternocleidomastoid and trapezius was measured using a wireless electromyographic (EMG) recording system. It was used to monitor the adequacy of performing the desired movements, as such activity should not exceed 15 % MVIC. The measured forces were then used to calculate the index or ratio between head retraction and cranio-cervical flexion. Statistical analysis was performed with a 5 % risk level. Measurement reproducibility was calculated using an intra-class correlation coefficient (ICC). Gender differences/disparities in exerted force and the force ratio was calculating using the Mann-Whitney rank test. Based on the results male subjects were capable of producing 16 % higher forces during head retraction as compared to female subjects (36 N, p = 0,01). Interestingly, female subjects exhibited a slightly higher activation of the left trapezius muscle (0,87 %, p = 0,04), while the activation of right sternocleidomastoideus muscle in males was higher (2,22 %, p = 0,02). During cranio-cervical flexion, males produced 32 % higher forces than females (25 N, p = 0,03), with no observable differences between genders in superficial muscle activation. While no statistically significant differences between the ratio of head retraction and cranio-cervical flexion forces were detected between genders (p = 0,18), the slightly higher ratio of 1,85 and 1,5 for females and males, respectively, should be noted. We ascribe the tendency of higher index values with females to lower force production capability of the cranio-cervical flexors. Thus, as females are probably a lot closer to their maximal mechanical loads of the cranio-cervical region compared to males, this could lead to a higher risk of development of idiopathic neck pain disorders.

• Keywords: craniocervical flexion, head retraction, forward head, gender differences, index