Department of Paralympic Sport, Wrocław University of Health and Sport Science, Wrocław, Poland.
Department of Health Science and Technology, ExerciseTech, Aalborg University, Aalborg, Denmark.
J Sport Rehabil. 2024 Aug 1;33(7):542-548. doi: 10.1123/jsr.2023-0389. Print 2024 Sep 1.
The study aimed to investigate the effects of the level of contraction during isometric shoulder abduction at different abduction angles on muscle thickness and stiffness of the shoulder girdle in asymptomatic individuals.
Measurement properties study.
Biomechanics and motion analysis lab.
Twenty individuals volunteered to participate in this study.
The subjects were tested for morphological and mechanical properties, expressed by thickness and stiffness of the supraspinatus tendon and muscle, and upper trapezius muscle. Moreover, acromiohumeral distance was also evaluated using B-mode ultrasound and shear-wave elastography.
The thickness and stiffness of the supraspinatus and upper trapezius muscle were assessed at 3 angles of abduction (0°, 60°, and 90°) and 3 levels of contraction (0%, 10%, and 20% of the maximal voluntary isometric contraction) using ultrasonography with shear-wave imaging. Moreover, the acromiohumeral distance was measured to establish the occupation ratio during passive movement.
The supraspinatus and upper trapezius muscle thickness and stiffness were significantly greater at 60° shoulder abduction compared with 0°, and 90° compared with 60°, as well as significantly greater at 20% maximal voluntary isometric contraction compared with 0% and 10% maximal voluntary isometric contraction. Thickness and stiffness were significantly greater in the supraspinatus compared with the upper trapezius muscle at all 3 angles of shoulder abduction for all 3 level of contractions. The acromiohumeral distance decreased significantly from 0° to 60° and from 60° to 90°.
Morphological and mechanical properties of the supraspinatus and upper trapezius muscles depended on the relative level of muscle contraction and the angle of shoulder abduction.
本研究旨在探讨在不同外展角度的等长肩外展过程中收缩程度对无症状个体肩部带肌厚度和刚度的影响。
测量性能研究。
生物力学和运动分析实验室。
20 名个体自愿参加本研究。
通过超声剪切波成像评估冈上肌腱和肌肉以及上斜方肌的厚度和刚度，来测试受试者的形态和力学特性。此外，还通过 B 型超声和剪切波弹性成像评估肩峰肱骨关节间距。
使用超声剪切波成像在外展 0°、60°和 90°的 3 个角度和 0%、10%和 20%最大自主等长收缩的 3 个水平下评估冈上肌和上斜方肌的厚度和刚度。此外，还测量了被动运动时的肩峰肱骨关节间距，以确定占用率。
与 0°和 90°相比，60°肩外展时冈上肌和上斜方肌的厚度和刚度显著更大，与 0%和 10%相比，20%最大自主等长收缩时的厚度和刚度也显著更大。在所有 3 个肩外展角度和 3 个收缩水平下，冈上肌的厚度和刚度均显著大于上斜方肌。在所有 3 个收缩水平下，肩峰肱骨关节间距从 0°到 60°以及从 60°到 90°显著减小。
冈上肌和上斜方肌的形态和力学特性取决于肌肉收缩的相对水平和肩外展角度。
