Muscle activation during selected strength exercises in women with chronic neck muscle pain

BACKGROUND AND PURPOSE: Muscle-specific strength training has previously been shown to be effective in the rehabilitation of chronic neck muscle pain in women. The aim of this study was to determine the level of activation of the neck and shoulder muscles using surface electromyography (EMG) during selected strengthening exercises in women undergoing rehabilitation for chronic neck muscle pain (defined as a clinical diagnosis of trapezius myalgia).

SUBJECTS: The subjects were 12 female workers (age=30-60 years) with a clinical diagnosis of trapezius myalgia and a mean baseline pain intensity of 5.6 (range=3-8) on a scale of 0 to 9.

METHOD: Electromyographic activity in the trapezius and deltoid muscles was measured during the exercises (lateral raises, upright rows, shrugs, one-arm rows, and reverse flys) and normalized to EMG activity recorded during a maximal voluntary static contraction (MVC).

RESULTS: For most exercises, the level of muscle activation was relatively high (>60% of MVC), highlighting the effectiveness and specificity of the respective exercises. For the trapezius muscle, the highest level of muscle activation was found during the shrug (102+/-11% of MVC), lateral raise (97+/-6% of MVC), and upright row (85+/-5% of MVC) exercises, but the latter 2 exercises required smaller training loads (3-10 kg) compared with the shrug exercise (20-30 kg).

DISCUSSION AND CONCLUSION: The lateral raise and upright row may be suitable alternatives to shrugs during rehabilitation of chronic neck muscle pain. Several of the strength exercises had high activation of neck and shoulder muscles in women with chronic neck pain. These exercises can be used equally in the attempt to achieve a beneficial treatment effect on chronic neck muscle pain.