Preliminary study of neck muscle size and strength measurements in females with chronic non-specific neck pain and healthy control subjects

Neck muscle weakness and atrophy are two common causes of pain and disability among office workers. The aim of this study was to compare the strength of the neck extensor and flexor muscles and the size of the semispinalis capitis muscle (SECM) in patients with chronic non-specific neck pain (CNNP) and healthy subjects. Twenty female office workers (10 patients with CNNP and 10 healthy subjects) participated in this study. The strength of the neck extensor and flexor muscles was measured by an isometric device and the SECM size was measured by ultrasonography. Neck muscle strength, size of the SECM and the ratios of neck strength to body weight, neck extensor strength to SECM size, SECM size to body weight and neck flexor to extensor strength were all significantly lower in patients compared to controls (P < 0.05). In conclusion, neck strength, the size of the SECM and the ratio of neck muscle strength to SECM size appear to be useful parameters in appraising patients with CNNP.