Neck Muscle Endurance in Nonspecific Patients With Neck Pain and in Patients After Anterior Cervical Decompression and Fusion

ObjectiveThe purpose of this study was to investigate differences in ventral and dorsal neck muscle endurance (NME) among men and women with nonspecific neck pain (NP) or cervical disk disease (who had anterior cervical decompression and fusion [ACDF]) and healthy controls (C). Another purpose was to investigate changes in NME after intervention.MethodsNeck muscle endurance was measured in patients with NP (n = 78) and ACDF (n = 25) before and after the treatment period, and their results were compared to each other and to sex-specific reference values from controls (n = 116) at both the individual and group levels.ResultsPatients had significantly decreased (P < .01) NME compared with control subjects, except for ventral NME in female patients with NP before treatment and male patients with ACDF after treatment. Female patients with ACDF had lower ventral NME than female patients with NP (P < .01). Among the patients, 35% to 100% had NME disability, with most of them having a lower rate than the 95% confidence interval of controls. Female patients with NP and male patients with ACDF showed improvement (P < .05) after treatment. Flexion/extension ratio in patients with NP (P = .36), but not in patients with ACDF (P < .0001), returned to normal levels after treatment. There was a significant negative correlation (P < .02) between NME and Neck Disability Index in both patient groups, except for ventral NME in patients with NP before treatment.ConclusionMany patients had impairment in NME before and after treatment. This suggests that additional exercise of specific training for NME should be incorporated into the rehabilitation program, which may improve treatment outcome.