ANALYSIS OF DESIGNED LUMBAR STABILIZATION EXERCISES THAT CAN BE PERFORMED IN THE SITTING POSITION BY ELECTROMYOGRAPHY AND ULTRASOUND IMAGING

D. Inoue¹, H. Ozaki², A. Sakaguchi³, R. Tsukagoshi³, K. Kawaguchi³

Background: Lumbar stabilization exercises (LSE) are exercises to improve core motor control and reduce pain in patients with low back pain. However, some of these exercises, such as Side-bridge and Birddog, may not be performed properly because they are difficult for patients with low activity levels. Therefore, we thought that LSE in sitting can be performed safely and easily even for patients with low activity levels, but few studies have reported such exercise so far.

Purpose: This study aimed to quantify muscle activity and thickness during exercise in newly designed LSE and compare them to conventional LSE.

Methods: 23 healthy men (mean±SD height,173.3±5.5cm; body mass,64.6±7.5kg), whose ages ranged from 20 to 22 years, participated in this study. We designed two LSE that can be performed in the sitting position.“Abdominal Expansion (AE)” is performed by lightly drawing in their lower abdomen below the navel, pushing in the flanks with both thumbs and expanding the flanks laterally to push back with them. “Hip Flexion with Arm Resistance (HFAR)” is performed by vertically resisting the proximal front thigh with their arm, and keep the hip flexed against it. Both exercises are performed with the trunk in neutral spine alignment. The activities of trunk muscles during exercise were investigated to compare the newly designed LSE with conventional LSE (Draw-in, Prone-bridge, Side-bridge, Bridge, and Birddog). Surface electromyography and ultrasound (B-mode, 7.5 MHz linear transducer) were used to calculate the muscle activities of rectus abdominis, external oblique, transverse abdominis / internal oblique, erector spinae, multifidus, rate of change in thickness of transverse abdominis and preferential activation ratio. Electrodes were placed following the SENIAM guidelines and previous studies. Statistical analysis was performed to compare the designing and conventional LSE. Significance was defined as p<0.05.

Results: AE (median;0.02 [IQR;0.01 to 0.05]) and HFAR (0.01 [-0.01 to 0.04]) showed the higher preferential activation ratio of transverse abdominis compared to Prone-bridge (-0.01 [-0.04 to 0.00]) and Side-bridge (-0.01 [-0.03 to 0.01]) (all p<0.05). In addition, the muscle activity of transverse abdominis / internal oblique was higher in AE (60.7%MVIC [51.3 to 106.9]) than in Side-bridge (21.8%MVIC [16.5 to 28.3]) and Birddog (36.5%MVIC [25.5 to 50.5]), and higher in HFAR (37.0%MVIC [32.3 to 55.5]) than in Side-bridge (all p<0.01). On the other hand, the muscle activity of multifidus was lower in AE (12.8%MVIC [7.0 to 18.5]) and HFAR (7.9%MVIC [5.9 to 13.2]) as compared with Bridge (38.5%MVIC [32.8 to 45.5]) and Birddog (33.7%MVIC [26.8 to 42.8]), but higher than that in Draw-in (2.9%MVIC [1.4 to 4.8]) and Prone-bridge (2.5%MVIC [2.1 to 4.0]) (all p<0.01).

Conclusion(s): We found that AE and HFAR can promote preferential transverse abdominis activity and simultaneous contraction of multifidus. These results suggest that AE and HFAR can apply to patients with low back pain similar to conventional LSE. Furthermore, AE and HFAR are exercises in a sitting position, which may be easy to perform even for patients with low activity levels.

Implications: AE and HFAR may apply to patients with low back pain and low activity levels.

Funding, acknowledgements: This study was unfunded.

Keywords: lumbar stabilization exercise, sitting position, trunk muscles

Topic: Musculoskeletal: spine

Did this work require ethics approval? Yes

Institution: Hyogo University of Health Sciences

Committee: The Ethics Review Committee of Hyogo University of Health Sciences

Ethics number: No.18025