This study aimed to determine the effect of lower trapezius muscle strengthening exercises on pain, neck disability index (NDI), cervical range of motion (ROM), and lower trapezius muscle strength in patients with unilateral neck pain. Following baseline measurements, the subjects (N=40) with unilateral neck pain were randomized into one of two 5 weeks exercise intervention groups: a experimental group (EG, n1=20) that received strength training of the lower trapezius muscles or a control group (CG, n2=20) that received routine physical therapy program. Each group participated in the intervention for 30 minutes, 3 times a week, for 5 weeks. All participants performed 2 repetitions of each intervention per day. The numeric pain rating scale for pain, NDI, ROM, and lower trapezius strength were recorded both pre- and post-intervention for both groups. Paired t-tests were used to determine significant changes post-intervention compared with pre-intervention and independent t-tests were used to analyze differences in the dependent variables between the 2 groups. After the 5-weeks intervention, both groups experienced significantly decreased pain and disability level (p<.05) and significantly increased cervical flexion, extension, lateral flexion, and rotation ROM (p<.05). The EG that received strength training of the lower trapezius muscles showed greater improvements in pain and functional disability level, cervical rotation, and lower trapezius strength than the CG (p<.05). These results suggest that a lower trapezius strengthening exercises reduce neck pain and neck disability level and enhance cervical ROM and lower trapezius strength level in patients with unilateral neck pain.

Violinists tend to position the neck asymmetrically to hold the violin between the chin and the left shoulder. Asymmetrical neck posture may induce unilateral neck pain. Previous studies have suggested that individuals with unilateral neck pain exhibit reduced muscle strength of the lower trapezius, but no study has investigated violinists with unilateral neck pain. To this end, we recruited 18 violinists with unilateral neck pain for the present study in which the side on which neck pain was experienced, pain duration, and intensity were recorded. Lower trapezius strength was measured bilaterally in each subject using a handheld dynamometer. Significant differences in lower trapezius strength were evident between the ipsilateral and contralateral sides of neck pain (p＜.05). No significant association between neck pain intensity or duration, and the extent of a deficit in lower trapezius strength, was evident (both p＞;.05). The association between the sides of weakened lower trapezius strength and neck pain was significant (p＜.05). In conclusion, violinists with unilateral neck pain exhibited significantly less lower trapezius strength on the ipsilateral compared to the contralateral side of the pain. Unilateral neck pain more frequently involved the left side of the neck, which is used to stabilize the violin during playing. Thus, our study suggests that a possible relationship exists between muscle weakness in the lower trapezius and neck pain.