Structure and Function of the Upper Trapezius and Its Role in Chronic Shoulder Pain: an Investigation of Kinematics, Morphology, Muscle Quality and Activation Distribution
NCT Number: NCT06472349
Status: RECRUITING
Study Type: OBSERVATIONAL
Conditions: Chronic Shoulder Pain
Sponsor: National Yang Ming Chiao Tung University
Sex: ALL
Age: ADULT
Enrollment: 100
Study Design: Observational Model: |Time Perspective: p
Start Date: 2023-12-12
Completion Date: 2025-12
Locations: National Yang Ming Chiao Tung University, Taipei, 11221, Taiwan

Summary:
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.

Primary Outcome Measures: 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., During the procedure|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., During the procedure
Secondary Outcome Measures: Oscillation frequency, The oscillation frequency (Hz) of the muscle obtained from the myotonometer will represent the muscle tone, During the procedure|Dynamic stiffness, The dynamic stiffness (N/m) of the muscle obtained from the myotonometer will represent the muscle tone, During the procedure|Mechanical stress relaxation time (ms), The mechanical stress relaxation time (ms) of the muscle obtained from the myotonometer will represent the muscle tone, During the procedure|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., During the procedure|Muscle thickness change at rest and in contraction, The muscle thickness at rest, during arm raise at 90o abduction, during 2-kg abduction, during 4-kg abduction, and the change (%) between the latter three and at rest., During the procedure|Muscle fat quantification, The upper, middle and lower trapezius muscle fat quantification indicate the muscle fat infiltration., During the procedure|Muscle / fat fraction, The upper, middle and lower trapezius muscle / fat fraction indicate the muscle fat infiltration., During the procedure|Echo intensity, The echo intensity of the upper, middle and lower trapezius muscle obtained from the musculoskeletal sonography., During the procedure|Pain intensity, The score obtained from the VAS scale and NRPS scale during the most painful movement represent the pain intensity of the chronic shoulder pain group., During the procedure|Disability level, The FLEX-SF score and DASH score will indicate the disability level of the subjects., During the procedure|Craniovertebral angle, The cranial-vertebral angle will indicate the level of forward head posture., During the procedure