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Online edition:ISSN 2434-3404

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Evaluation of cervical muscle strength in healthy adults using a newly devised cervical myodynamometer *

In the orthopedic field, cervical muscle strength has been evaluated mainly by manual muscle testing with grading from one to six. To date, objective numerical measurement of cervical muscle strength has not been used. We developed a new myodynamometer for measuring cervical muscle strength, and used it to measure cervical muscle strength in healthy adults. The apparatus is composed of a manual muscle dynamometer, GT-10 (OG, Giken). The isometric strength of cervical flexion and extension can be measured with the subject in a sitting position and the head fixed in the neutral cervical position. A total of 247 healthy adult volunteers, comprising 120 males, ranging in age from 18 to 29 years old ; average 23.1 ±2.3 years old and 127 females, ranging in age from 18 to 27 years old ; average 21.7 ± 1.7 years old were enrolled in the study. Each subject was seated in a chair with a back and fixed with safety belts. Two manual myodynamometer (GT-10) were attached to the forehead and the occiput with the neck in a neutral position. Then the subject was asked to conduct cervical flexion and extension with maximum his/her strength. The maximum values were adopted as the cervical muscle strength. The mean strengths of the neck flexor muscles in the male and female subjects were 151.0 ±40.2 N and 64.7 ±16.7 N, respectively, and the strengths of the neck extensor muscles were 246.1 ±46.1 N and 129.4 ±27.5 N, respectively. The new cervical myodynamometer was calibrated twice ; before and during the measurement. The accuracy of measurement was ± 4.9 N for less than 196.0 N and ±3% for 196.0 N or higher. The same measurements were repeated one week later in 85 male subjects and 53 female subjects to confirm the reliability. The results indicated that the myodynamometer and the method of measurement were useful. The height, body weight, grip strength, strength of back muscles, and the neck circumference of the subjects were measured, and their history of sports activity was investigated. The relationships between these parameters and cervical muscle strength were analyzed. No significant relationship was observed between any of these parameters and cervical muscle strength in the female subjects. A weak correlation between cervical muscle strength and body weight or neck circumference was observed in male subjects. A one-way analysis of variance showed significant differences in the strength of the neck extensor muscles depending on the history of sports activity in both male and female subjects. (Accepted on October 16, 2000) Kawasaki Igakkaishi 26(4) : 237-247, 2000

Author
Chujo T.
Volume
26
Issue
4
Pages
237-247
DOI
10.11482/KMJ-J26(4)237-247.2000.pdf

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