The objective of the study was to compare myoelectric manifestation in neck muscle endurance and fatigue characteristics during sub-maximal isometric endurance test in patients with cervical radiculopathy and asymptomatic subjects. An additional goal was to investigate associations between primary neck muscle endurance, myoelectric fatigability, and self-rated levels of fatigue, pain and subjective health measurements in patients with cervical radiculopathy. Muscle fatigue in the ventral and dorsal neck muscles was assessed in patients with cervical radiculopathy and in an asymptomatic group during an isometric neck muscle endurance test in prone and supine. 46 patients and 34 asymptomatic subjects took part in the study. Surface electromyography signals were recorded from the sternocleidomastoid, cervical paraspinal muscles and upper and middle trapezius bilaterally during the endurance test. Subjective health measurements were assessed with questionnaires. The results showed altered neck muscle endurance in several of the muscles investigated with greater negative median frequency slope, greater variability, side imbalance, lower endurance time and higher experience of fatigue amongst the cervical radiculopathy patients compared with healthy subjects. Endurance times were significantly shorter in both prone and in supine positions between the patients in comparison to asymptomatic subjects. During the neck muscle endurance test, fatigues in the upper trapezius muscles during the prone test and in the sternocleidomastoid muscles during the supine test were of greater significance than self-perceived pain, fatigue, disability and kinesiophobia in predicting neck muscle endurance (NME).
NME testing in the primary neck muscles appears to be an important factor to take into account for rehabilitation.