Changes in Pressure Pain in the Upper Trapezius Muscle, Cervical Range of Motion, and the Cervical Flexion^|^ndash;relaxation Ratio after Overhead Work

Abstract

This study examined the changes in pressure pain in the upper trapezius muscle, cervical range of motion, and cervical flexion-relaxation ratio after overhead work. 14 workers were recruited. Pressure pain in the upper trapezius muscle, active cervical range of motion, and cervical flexion-relaxation ratio were measured in all subjects once before and once after overhead work. The pressure-pain threshold of the left upper trapezius muscle was 8.6 ± 2.5 lb before overhead work and 7.3 ± 2.4 lb after overhead work; that of the right upper trapezius muscle was 8.8 ± 2.9 and 7.3 ± 2.8 lb, respectively, revealing a significant decrease in pressure-pain threshold with overhead work. All cervical range of motion measures decreased significantly with overhead work. The cervical flexion-relaxation ratio on the left side was 1.3 ± 0.2 before overhead work and 1.1 ± 0.2 after overhead work; the respective values for the right side were 1.4 ± 0.5 and 1.2 ± 0.3 before and after overhead work, revealing a significant decrease with overhead work. We postulate that overhead work can reduce the pressure-pain threshold in the upper trapezius muscle and cause changes in the cervical range of motion and cervical flexion-relaxation ratio.

Changes in Neck and Back Pain, Cervical Range of Motion and Cervical and Lumbar Flexion‐relaxation Ratios after Below‐knee Assembly Work

“…Shin et al reported that the cervical FRR on the left side was 1.3 ± 0.2 before and 1.1 ± 0.2 after overhead work; the respective values for the right side were 1.4 ± 0.5 and 1.2 ± 0.3, revealing a similar decrease with overhead work 20) . Lee et al suggested that the cervical FRR is a quantitative way to evaluate the potential for developing neck pain with heavy backpack loads.…”

“…Shin et al reported that active CROM decreased after overhead work 20) . Shin and Yoo reported that active CROM decreased after video display terminal work 21) .…”

Comparison of the thoracic flexion relaxation ratio and pressure pain threshold after overhead assembly work and below knee assembly work

“…Similarly, the thoracic FRR decreased significantly in sequence from pre-work, to overhead work, to below-knee work. Shin et al found that cervical FRRs on both sides decreased significantly after 10 min of overhead work 3 ) . Lee et al found that wearing heavy backpacks decreased cervical FRR 5 ) .…”

Novel Electromyographic Protocols Using Axial Rotation and Cervical Flexion-Relaxation for the Assessment of Subjects With Neck Pain: A Feasibility Study

“…The FRR was found to be reduced after the Sorenson protocol was used to induce neck pain fatigue in 20 healthy participants. The effect of various activities on the cervical FRP has been reported including carrying a backpack, 22 working on a computer, 23 overhead work, 24 visual display terminal work, 25 and below-knee assembly work. 2 Pialasse et al 26 have reported on the effects of load and speed on the cervical FRP.…”