Localised resistance selectively activates the semispinalis cervicis muscle in patients with neck pain

Abstract

The semispinalis cervicis muscle displays reduced and less defined activation in patients with neck pain which is associated with increased activity of the splenius capitis muscle. Exercises to selectively activate the semispinalis cervicis muscle may be relevant for patients with neck pain however the most appropriate type of exercise has not been determined. The purpose of this study was to investigate whether a specific exercise could selectively activate the semispinalis cervicis muscle relative to the splenius capitis. Ten women with chronic neck pain participated. Intramuscular electrodes were inserted into the semispinalis cervicis and splenius capitis unilaterally on the side of greatest pain. After testing the maximal neck extension force, three isometric exercises were performed in sitting: 1. the investigator placed a hand on the patient’s occiput and pushed into flexion asking the patient to resist into extension maximally, 2. the investigator placed the thumb and index finger on the vertebral arch of C2 and pushed into flexion asking the patient to resist maximally, 3. same procedure as for C2 however the resistance was applied at C5. The ratio between the normalized electromyography (EMG) amplitude of the semispinalis cervicis and splenius capitis was computed. The relative activation of the semispinalis cervicis was greater (P < 0.05) than the splenius capitis with resistance at C2 (2.53 ± 2.43) compared to resistance at the occiput (1.39 ± 1.00) or at C5 (1.16 ± 0.85). The results indicate that localized resistance can achieve relative isolation of the semispinalis cervicis muscle. This exercise approach may be relevant for patients with neck pain.