Selective activation of intra-muscular compartments within the trapezius muscle in subjects with Subacromial Impingement Syndrome. A case-control study

Aim. This study investigates consequences of chronic neck pain on muscle function and the rehabilitating effects of contrasting interventions.Methods. Women with trapezius myalgia (MYA,n=42) and healthy controls (CON,n=20) participated in a case-control study. Subsequently MYA were randomized to 10 weeks of specific strength training (SST,n=18), general fitness training (GFT,n=16), or a reference group without physical training (REF,n=8). Participants performed tests of 100 consecutive cycles of 2 s isometric maximal voluntary contractions (MVC) of shoulder elevation followed by 2 s relaxation at baseline and 10-week follow-up.Results. In the case-control study, peak force, rate of force development, and rate of force relaxation as well as EMG amplitude were lower in MYA than CON throughout all 100 MVC. Muscle fiber capillarization was not significantly different between MYA and CON. In the intervention study, SST improved all force parameters significantly more than the two other groups, to levels comparable to that of CON. This was seen along with muscle fiber hypertrophy and increased capillarization.Conclusion. Women with trapezius myalgia have lower strength capacity during repetitive MVC of the trapezius muscle than healthy controls. High-intensity strength training effectively improves strength capacity during repetitive MVC of the painful trapezius muscle.

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A case-control study of trapezius muscle activity in office and manual workers with shoulder and neck pain and symptom-free controls

International Archives of Occupational and Environmental Health ◽

10.1007/bf00383127 ◽

1995 ◽

Vol 67 (1) ◽

pp. 11-18 ◽

Cited By ~ 49

Author(s):

O. Vasseljen ◽

R. H. Westgaard

Keyword(s):

Neck Pain ◽

Muscle Activity ◽

Case Control Study ◽

Trapezius Muscle ◽

Case Control ◽

Shoulder And Neck Pain ◽

Control Study

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Acromiohumeral distance and supraspinatus tendon thickness in people with shoulder impingement syndrome compared to asymptomatic age and gender-matched participants: a case control study

BMC Musculoskeletal Disorders ◽

10.1186/s12891-021-04885-3 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Donald J. Hunter ◽

Darren A. Rivett ◽

Sharmaine McKiernan ◽

Suzanne J. Snodgrass

Keyword(s):

Linear Regression ◽

Case Control Study ◽

Supraspinatus Tendon ◽

Case Control ◽

Impingement Syndrome ◽

Shoulder Impingement Syndrome ◽

Shoulder Impingement ◽

Tendon Thickness ◽

Acromiohumeral Distance ◽

Control Study

Abstract Background Shoulder impingement syndrome (SIS) is the most common form of shoulder pain. Conservative and surgical treatments for SIS are often not effective. One such surgical intervention is subacromial decompression, aimed at widening the subacromial space (SAS). A better understanding of the changes in the SAS may help explain the relative ineffectiveness of current interventions. Objective: To measure the acromiohumeral distance (AHD) and supraspinatus tendon thickness (STT) in people with SIS using a case control study. Methods The AHD and STT of 39 participants with SIS ≥3 months and 39 age, gender and dominant arm matched controls were measured using ultrasound imaging. Between-group differences for AHD and STT were compared using t-tests. A linear regression was used to determine if there was a relationship between AHD and STT measures, with group as a covariate. Results Compared to controls (mean age 55.7 years, SD 10.6), individuals with SIS (mean age 57.1 years, SD 11.1) had a significantly larger AHD (mean difference 2.14 mm, 95% CI 1.21, 3.07, p < 0.001) and STT (mean difference 1.25 mm, 95% CI 0.60, 1.90, p < 0.001). The linear regression model indicated an association between AHD and STT (β = 0.59, 95% CI 0.29, 0.89, p < 0.01, R2 = 0.35, n = 78), suggesting that as STT increases in size, so does the AHD. Conclusion Individuals with SIS had a larger AHD and greater STT than controls. These results suggest the SAS is already wider in people with SIS and that the symptoms associated with SIS may be more related to an increased STT than a smaller SAS.

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