Effects of short break neck stretching on neck pain and surface EMG median frequency changes in office workers

Abstract

Introduction: Chronic neck pain is a very common complaint among computer users and considered to be a serious work-related musculoskeletal disorder (WRMSD). Chronic neck pain causes sick leave, poor performance, poor quality of life and burdens the economics of the country. Treatment and prevention, therefore, of chronic neck pain among computer users are necessary.

Objective: To study and compare the effects of 4-week short break neck exercise between stretching exercise and relaxation breathing exercise on pain level (VAS), surface EMG median frequency (MF) and the neck disability index score (NDI) in chronic neck pain female office workers who are prolonged computer users.

Participants: The volunteers were 60 Thai female office workers with chronic neck pain from using computer more than 4 hours per day (8.18 ± 2.22) and aged between 25 - 35 years old (29.12 ± 2.99). These participants had not been treated by physiotherapy and/or medicine program.

Methods: Sixty volunteers were divided into 2 groups equally. They were 1) Stretching group stretched neck muscle 30 seconds for 3 times in both upper trapezius (UT) and cervical erector spinae (CES), 2) The breathing exercise group did diaphragmatic deep breathing for relaxation 5 minutes. VAS, MF, and NDI were used as parameters.

Results: VAS pain score in both groups reduced significantly after 4 weeks of exercise. The stretching group reduced VAS from 48.80±18.41 to 26.30±22.22 (p<0.001) and the breathing group reduced VAS from 42.83±22.20 to 19.33±20.37 (p<0.001). The initial surface EMG MF of all neck muscles in both groups was shifted toward lower frequency which indicated fatigue pattern. Only the left UT and the left CES in the stretching group showed no fatigue after training. There was significant (p<0.001) improvement of NDI score in both groups. The stretching group was 5.81 ± 6.29% (13.26 ± 8.81 to 7.44 ± 4.86) and the breathing group was 3.61 ± 0.79% (12.78 ± 10.59 to 9.16 ± 10.33).

Conclusion: The effects of stretching or breathing exercise as a short break exercise at work twice a day in 4 weeks program provided decreased pain level and increased quality of life. The stretching exercise potentially improved muscle fatigability of the neck muscles in the non-dominant side.