Electromyograhic Analysis of Neck Muscle Fatigue in Patients With Osteoarthritis of the Cervical Spine

Abstract

Median frequency parameters of myoelectric signals were studied in 25 patients with osteoarthritis of the cervical spine and in 25 normal subjects. The median frequency parameters included initial median frequency and slope of the median frequency during 20%, 50%, 80%, and 100% of maximum voluntary contractions (MVC). The subjects performed sustained, isometric constant-force contractions of forward and backward bend of the cervical spine. The median frequency signals were obtained from the anterior (sternocleidomastoid) and posterior (upper trapezius) neck muscles. The results showed that at moderate and high forces (i.e., 50%, 80%, and 100% MVC) the anterior neck muscles in patients with osteoarthritis of the cervical spine fatigued faster than those of normal subjects. The posterior neck muscles in patients fatigued faster compared to normal subjects at high force levels (i.e., 80% and 100% MVC). This indicates a higher fatigue of the anterior and posterior neck muscles associated with arthritic changes of the cervical spine. Rehabilitation programs must consider these muscular changes to obtain optimal outcomes.