Centro de Investigação em Reabilitação (CIR), Escola Superior de Saúde, Instituto Politécnico do Porto, Porto, Portugal.
Centro de Investigação em Actividade Física, Saúde e Lazer (CIAFEL), Faculdade de Desporto, Universidade do Porto, Porto, Portugal.
Proc Inst Mech Eng H. 2024 Mar;238(3):288-300. doi: 10.1177/09544119241228082. Epub 2024 Feb 25.
Muscle stiffness had a crucial role in joint stability, particularly, at the shoulder complex. Although changes in upper trapezius muscle stiffness have been described for shoulder pain, contradictory findings have been obtained. Also, existing data regarding scapular muscles are, majorly, about trapezius. Myotonometry is a method used to assess stiffness; however, the reliability values of scapular muscle stiffness through this method have not been assessed in shoulder pain conditions. The present study aims to compare scapular muscles' stiffness (trapezius, serratus anterior, and levator scapulae) between subjects with and without chronic shoulder pain and to evaluate the related test-retest reliability. Twenty-two symptomatic and twenty-two asymptomatic subjects participated in a cross-sectional study. The dynamic muscular stiffness of scapular muscles, at rest and during an isometric contraction, was measured bilaterally with myotonometry, in two moments. The differences in bilateral averaged values between symptomatic and asymptomatic subjects and the effect of the group (group presenting pain in the dominant or non-dominant side, and asymptomatic group) and of the limb (unilateral painful or asymptomatic limb, and bilateral asymptomatic limbs) were investigated. Test-retest intra-rater reliability was determined. An effect of the group was observed at rest, for middle trapezius stiffness, and during contraction, for middle and lower trapezius stiffness. For middle trapezius, increased values were observed in the group presenting pain in non-dominant side comparing to both groups or to group presenting pain in dominant side. The intraclass correlation coefficient, majorly, ranged between 0.775 and 0.989. Participants with pain in the non-dominant side presented an increased middle trapezius' stiffness. Globally, high reliability was observed for scapular muscles dynamic stiffness.
肌肉僵硬在关节稳定性中起着关键作用，尤其是在肩部复合体。尽管已经描述了肩部疼痛时上斜方肌僵硬的变化，但得到的结果却相互矛盾。此外，关于肩胛骨肌肉的现有数据主要是关于斜方肌的。肌振器是一种用于评估僵硬的方法；然而，在肩部疼痛情况下，通过这种方法评估肩胛骨肌肉僵硬的可靠性值尚未得到评估。本研究旨在比较有和无慢性肩部疼痛的受试者之间的肩胛骨肌肉（斜方肌、前锯肌和肩胛提肌）的僵硬程度，并评估相关的测试-再测试可靠性。22 名有症状和 22 名无症状受试者参加了横断面研究。使用肌振器在休息和等长收缩时测量双侧肩胛骨肌肉的动态肌肉僵硬，在两个时刻进行测量。比较了症状组和无症状组之间双侧平均值的差异，以及组（优势侧或非优势侧出现疼痛的组和无症状组）和肢体（单侧疼痛或无症状的肢体和双侧无症状的肢体）的影响。测试-再测试的内部测试者可靠性被确定。在休息时观察到组的影响，对于中斜方肌僵硬，在收缩时对于中斜方肌和下斜方肌僵硬。对于中斜方肌，与两个组或优势侧出现疼痛的组相比，非优势侧出现疼痛的组的中斜方肌僵硬值增加。组内相关系数主要在 0.775 到 0.989 之间。非优势侧疼痛的参与者表现出增加的中斜方肌僵硬。总体而言，肩胛骨肌肉动态僵硬具有很高的可靠性。
