Prior research has explored factors influencing muscle activation, including muscle thickness, fear avoidance beliefs (kinesiophobia), and somatosensory integration. In individuals with chronic shoulder pain, various characteristics impacting symptoms and treatment outcomes have been identified, such as psychosocial factors, fear avoidance, central sensitization, somatosensory impairments, and brain morphology changes. These shared characteristics affecting both muscle activation and chronic shoulder pain may potentially modulate upper trapezius muscle activation during functional movements in patients with chronic shoulder pain. Notably, there remains a gap in the literature concerning investigations into the upper trapezius muscle's morphology and quality, fear avoidance, central sensitization, somatosensory impairments, and their interplay with upper trapezius muscle activation in chronic shoulder pain patients.
To address these gaps, this study aims to: this study aims to: 1) compare different methods of measuring clavicular kinematics using an electromagnetic tracking system; 2) establish the reliability and validity of measuring muscle thickness and fat infiltration through ultrasound and magnetic resonance imaging; 3) compare shoulder kinematics, muscle activation, muscle morphology, and muscle fat infiltration in individuals with chronic shoulder pain with matched healthy controls; 4) explore the correlation between the factors that may influence upper trapezius muscle activation, including basic data of the subjects, muscle morphology, and muscle fat infiltration.
Chronic shoulder pain group
18-50 years old18-50 years old
unilateral and non-traumatic shoulder pain
pain duration longer than 3 months
history of significant shoulder trauma, such as fracture or ultrasonography clinically suspected full thickness cuff tear
recent shoulder dislocation in the last 2 years
diagnosis of adhesive capsulitis characterized by a gradual and painful loss of both active and passive ROM in all shoulder planes, primarily external rotation
shoulder pain originating from the cervical spine by using Spurling's neck compression test
Community Sample
Cohort
Cross-sectional
Not listed
Shoulder kinematics
The scapular kinematics will be assessed, including scapular internal/external rotation, upward/downward rotation, and posterior/anterior tilt angle. Clavicular kinematics will be evaluated by measuring clavicular protraction/retraction, elevation/depression, and posterior rotation angle.
Muscle activation
The average root mean square (RMS) value collected from surface EMG and outcomes collected by high-density EMG including average root mean square (RMS) value in whole/upper/lower regions, the RMS value distribution, and position of the barycentre of RMS distribution in different humeral elevation angles and different isometric shoulder and scapular tasks will be the outcome measures related to muscle activation.
Oscillation frequency
The oscillation frequency (Hz) of the muscle obtained from the myotonometer will represent the muscle tone
Dynamic stiffness
The dynamic stiffness (N/m) of the muscle obtained from the myotonometer will represent the muscle tone
Mechanical stress relaxation time (ms)
The mechanical stress relaxation time (ms) of the muscle obtained from the myotonometer will represent the muscle tone
Muscle thickness and cross-sectional area
The upper, middle and lower trapezius muscle thickness and cross-sectional area obtained from MRI and the upper, middle and lower trapezius muscle thickness obtained from musculoskeletal sonography.
Click on the lead sponsor to view all of their trials.
