Scapular force: Couple ratios in healthy shoulders – An observational study reflecting typical values

South African Journal of Physiotherapy

Field Value
Title Scapular force: Couple ratios in healthy shoulders – An observational study reflecting typical values
Creator Briel, Sonia Olivier, Benita Mudzi, Witness
Subject Education-Physiotherapy scapular stability; force couple ratios; stabilising muscles; shoulder
Description Background: Scapular stability is primarily maintained through the action of the scapular stabilisers and not through bony stability. The values of the force couple ratios of the scapular stabilisers remain largely unknown.Objectives: To determine typical scapular force couple strength ratios in the pain-free shoulders of healthy female and male participants.Methods: This was a quantitative cross-sectional study. The muscle strength of the serratus anterior upper and lower fibres, the upper, middle and lower trapezius and the rhomboids (in both shoulders) were determined in kilogram force (kgf) using a handheld dynamometer. The ratios of the force couples of the scapulae of both shoulders of the participants were calculated. Participants (both female and male) with healthy shoulders were recruited from the general public (a local university, schools, church groups and sport clubs). We mainly utilised descriptive analysis. Statistical significance was set at 5%.Results: Force couple ratios were as follows (means, with SD). Dominant arm in women: upper trapezius:lower trapezius 3.63 (0.97); serratus anterior lower fibres:lower trapezius = 1.97 (0.27); middle trapezius:serratus anterior upper fibres = 0.40 (0.10); serratus anterior lower fibres:rhomboids = 1.41 (0.21); lower trapezius:rhomboids = 0.74 (0.17). Dominant arm in men: upper trapezius:lower trapezius = 2.70 (0.72); serratus anterior lower fibres:lower trapezius = 2.15 (0.45); middle trapezius:serratus anterior upper fibres = 0.47 (0.12); serratus anterior lower fibres:rhomboids = 1.40 (0.31) and lower trapezius:rhomboids = 0.17 (0.6).Conclusion: Specific force couple strength ratios were determined, between and within the nondominant and the dominant arms of the shoulders of healthy women and men.Clinical implications: Scapular stability is mainly maintained through the optimal force couple balance of the scapular stabilisers.
Publisher AOSIS
Contributor none
Date 2022-07-25
Type info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion — cross-sectional observational study
Format text/html application/epub+zip text/xml application/pdf
Identifier 10.4102/sajp.v78i1.1619
Source South African Journal of Physiotherapy; Vol 78, No 1 (2022); 7 pages 2410-8219 0379-6175
Language eng
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Coverage — — Between 18-35 years of age, females and males, all races
Rights Copyright (c) 2022 Sonia Briel, Benita Olivier, Witness Mudzi