Chronic low back pain changes the latissmus dorsi and gluteus maximus muscles activation pattern and upward scapular rotation: A cross-sectional study

Abstract

BACKGROUND: Patients with chronic low back pain (LBP) have an impaired dynamic spinal stability, which may lead to arm injuries. OBJECTIVES: To examine the latissimus dorsi and gluteus maximus muscles activation pattern and the upward scapular rotation in patients with chronic LBP. METHODS: Sixty-one right-handed males were divided into two groups: chronic LBP group (n= 31) and healthy controls (n= 30). The electromyography (EMG) activities of the right and left latissimus dorsi and gluteus maximus were recorded. The upward scapular rotation in different shoulder positions (neutral, 45∘, 90∘, 135∘ abduction and end range) was measured in both groups. RESULTS: The LBP group has a bilateral significant increased EMG of latissimus dorsi (p< 0.05) and significantly decreased EMG of gluteus maximus (p< 0.05) compared to the control group, without significant differences between the right and left sides (p> 0.05). There was a significant increase in upward scapular rotation in the LBP group relative to the control group in all shoulder abduction positions on both sides. The left side upward scapular rotation was more significant than the right (p< 0.05). CONCLUSION: Chronic LBP increased the latissimus dorsi muscle activities and decreased the gluteus maximus activities. It furthermore increased the upward scapular rotation in different shoulder abduction positions.