The Relationship Between Arm Swing Asymmetry and Spinal Rotation at Different Levels During Steady Walking in Healthy Individuals

This study aims to investigate how arm swing angles correlate with spinal rotation angles at different levels during steady walking in healthy individuals.

This study recruited 21 healthy males (age 20.2 ± 1.1 years, right-handed). The task involved steady walking on a treadmill at a 4.0 km/h speed. A 3D motion analysis system consisting of 16 cameras was used. Reflective markers were attached to three locations on the tip of a T-shaped stainless steel plate (48 mm [W] x 40 mm [H]), as well as on the first and seventh thoracic vertebrae (T1, T7), the first and third lumbar vertebrae (L1, L3), the second sacral vertebra (S), and the lateral epicondyles of both upper arms. The measured parameters were the sagittal plane rotation angles of the lateral epicondyles of the upper arms (L_Arm, R_Arm) and the horizontal plane rotation angles of the upper thoracic vertebrae (T1_T7), lower thoracic vertebrae (T7_L1), upper lumbar vertebrae (L1_L3), and lower lumbar vertebrae (L3_S). A t-test was used for statistical analysis to compare the average difference in arm swing angles between the left and right arms. Pearson's correlation coefficient was used to examine the relationship between arm swing angles and the rotation angles of T1_T7, T7_L1, L1_L3, and L3_S. The significance level was set at 5%.

The average difference in arm swing angles was −4.50°, with L_Arm showing significantly higher values than R_Arm. A significant positive correlation was found between L_Arm and L3_S in the relationship between arm swing angles and spinal rotation (p 0.01, r = 0.56). In contrast, no significant correlation was found between R_Arm and spinal rotation angles.

This study revealed a relationship between arm swing angles and spinal rotation in healthy individuals during steady walking. A strong positive correlation was found between L_Arm swing and L3_S rotation angles. However, no correlation was found between R_Arm and any of the spinal rotation angles. These results suggest that the asymmetry in arm swing, with L_Arm being dominant during steady walking, is associated with increased lower lumbar spine rotation.

This study suggests the potential effectiveness of therapeutic interventions that utilize the interaction between arm swing and spinal rotation at different levels.