Electromyographic Activity of the Scapulothoracic Muscles during Arm Abduction with Loading in Women with Forward Head Posture and Healthy Women

Abstract

Background and Objective: One of the most common postural abnormalities which is seen in 60 percent of patients with neck and shoulder disorders is Forward head posture. The purpose of current study was the comparison of contribution ratio in scapular rotator muscles over dominant and non-dominant arm abduction on loading in women with and without Forward Head Posture. Materials and Methods: In this case-control study 18 women with Forward Head Posture and 14 healthy women were studied. The subjects were matched based on weight, height, age, dominance of upper extremity and voluntarily participated. The contribution ratio of Serratus Anterior, Upper and Lower Trapezius muscles were recorded by surface electrodes during arm abduction with loading. Results: The independent t-test results revealed that the upper trapezius muscle activity ratio of dominant arm in subjects with forward head posture is significantly greater than healthy ones (P= .011), whereas the significant difference was not revealed in non-dominant arm. There were also no significant differences in Serratus Anterior muscle (p>.05) and Lower Trapezius muscle (p>.05) ratio between the groups. Conclusion: Because of the changes in contribution ratio of Upper Trapezius, a simple assessment of head posture through the shoulder muscles can provide useful information for the examiner to decide on prescription of corrective exercises for patient.