Comparison of Kinematic and Electromyographic Patterns During Cyclic Neck Motions in Asymptomatic Young and Middle-Age Adults

This is the authors' abstract. We don't add key points for this paper.

The purposes of this study were to investigate the activation of neck muscles during movement of the head from the neutral position to the maximum points and back to the neutral position. The experiment was designed to compare between groups. There were in total 26 subjects: 11 in the young group (mean age 24.3 years old) and 15 in the middle-age group (mean age 55.9 years old) were recruited. The active ROM, velocity, and surface EMG activities of the left and right sternocleidomastoid (SCM) muscles were recorded during repetitive cervical movements in the six directions of flexion/extension, right/left rotation and side-bending. The data were evaluated with repeated-measures analysis of variance (ANOVA). The active ROM and maximum force in both flexion and extension were significantly lower for the middle-age group than for the young group. However, the integrated EMG values for the left and right SCM muscles during movement of the head to and from the maximum points of the ROM in three cardinal planes were significantly greater in the middle-age group than in the young group. Whether these over-activation of SCM is related to degeneration of the cervical spines requires further investigation.