The primary aim of this study therefore is to investigate the effects on pain and disability of an emphasized exercise program targeting the deep neck extensor semispinalis cervicis and a general exercise program for all neck extensor muscles in patients with chronic neck pain. As a secondary aim , the effect of both exercise programs on activation pattern of two neck extensor muscles was investigated with electromyography (EMG). The investigators hypothesized that both exercise programs would have similar effects on pain alleviation and pain related disability, but that the emphasized exercise program for the deep semispinalis cervicis would improve its activation more compared to the general exercise program. The results of this study will be relevant for designing effective rehabilitation/training programs for patients with chronic neck pain.