Changes in Neck Muscle Thickness Due to Differences in Intermittent Cervical Traction Force Measured by Ultrasonography

Abstract

[Purpose] Many patients receive intermittent cervical traction in a daily treatment setting. However, unified settings for traction force, duration, and direction have yet to be determined. Therefore, an objective index is required to determine changes in traction conditions or to indicate its effectiveness. [Subjects] Fifteen healthy males volunteers participated in this study. [Methods] The thickness of the trapezius and splenius capitis muscles before and during traction were measured using ultrasonography at three traction forces: 5, 8 and 11 kg. [Results] Significant differences in muscle thickness were observed at 11 kg in the trapezius, and at 8 kg and 11 kg in the splenius capitis muscles. The muscle thickness ratio of the trapezius muscle showed a significant difference between 11 kg and 5 and 8 kg, and between 5 kg and 8 and 11 kg, as well as between 8 kg and 11 kg for the splenius capitis muscles. [Conclusion] Differences in muscle direction between the trapezius and splenius capitis muscles may account for the contrasting results obtained at the 8 kg traction force. This finding suggests that cervical traction must be performed considering the effects on different neck regions.

Changes in cervical muscle activity according to the traction force of an air-inflatable neck traction device

“…Recently, Katsushi 4 ) proposed that a traction force of a low intensity, such as 5 kg or 8 kg, did not significantly change the thickness of the upper trapezius; however he reported that a traction force of a high intensity at 11 kg might significantly decrease muscle thickness. In other words, when a relatively high traction force is given, changes in the upper trapezius may be triggered.…”

“…Katsushi 4 ) administered intermittent cervical traction in a reclining wheelchair composed of traction for 20 seconds and resting for 10 seconds with the cervical flexion angle at 10 degrees; meanwhile, we used the same sitting posture as that in a hospital but traction device’s cervical flexion angle was uncontrollable. Therefore, the differences between the two studies’s results are considered to have emerged from differences in the traction positions, cervical flexion angles, or types of traction devices.…”

“…The air-inflatable neck disk traction device is a traction unit used in a sitting posture, and muscle activity is regarded as differing according to traction posture. Katsushi 4 ) minimized the contraction of the muscles around the neck during traction by positioning the head of the subject on the headrest in a reclining wheelchair. Moreover, Jette et al 11 ) had their subjects rest for 5 minutes prior to traction, thereby reducing the influence of gravity on the muscles.…”

“…The sampling frequency was set at 1,000 Hz and the obtained EMG signals were processed with a 60 Hz notch filter and a 50–500 Hz bandpass filter. The muscles used for the muscle activity analysis were the splenius capitis and upper trapezius 4 ) . The subjects were placed in a prone position at the corner of a bed, a 2 kg sandbag was placed behind their head, and the head was extended.…”

“…Previous studies have verified the traction effect by analyzing radiological images 2 ) or evaluating the activity 3 ) or thickness of the muscles 4 ) around the vertebrae during traction. Once traction force is provided, the space between the vertebrae will be enhanced 5 ) .…”