Clinical analysis for isometric strength of the neck muscle in patients with cervical disorder

120 cases of normal group and 46 cases of cervical disorder group were evaluated for their isometric strength of neck muscles by the author's originally proposed method. The results obtained were as follows. 1. The control group showed the highest strength in neck extension, followed in order by lateral bending, flexion, and rotation. Male controls possessed almost twice as much strength as female controls of the same generation. 2. Most of the cervical disorder cases showed relative weakness in extension, which was commonly noticed in the cases with prolonged duration of symptoms or with restricted mobility of the cervical spine in the sagittal plane. 3. A group of cases perfprmed posterior decompression surgery showed relative weakness in etension than a group of anterior interbody fusion in the period of 3-6 months after surgery. The findings on CT scanned in this period suggested degenerative changes of the postrior paraspinal muscles, which was suspected to be the cause of weakness in extension.