Objective: The objective of this study was to evaluate the neuromuscular activities of neck muscles in five different postures of the head and neck during book reading.
Introduction: The cervical spine is a highly sensitive region of the body due to its extensive range of motion, numerous vertebrae, and the involvement of multiple muscles. Daily activities, such as reading books, often require the frequent use of the head and neck, making it crucial to investigate the neuromuscular control in these postures.
Methods: Twenty-three subjects participated in this study and assumed five different head and neck angles (-10°, 0°, 10°, 20°, and 30° relative to the vertical axis) while reading a book. Ten Vicon motion capture cameras recorded marker trajectories from the head and trunk. A musculoskeletal model of the head and neck was created in OpenSim, a software package for biomechanical simulations. The inverse kinematics, inverse dynamics, and static optimization tools in OpenSim were utilized to estimate cervical joint angles, joint moments, and muscle activations, respectively.
Results: The comparison of joint torques revealed significant differences in torque distribution among different neck vertebrae in various postures. Furthermore, increasing neck flexion during book reading led to an increase in torque applied to all cervical vertebrae. Analysis of muscle activity demonstrated that the activation patterns of different neck muscles varied with head and neck angles in different postures.
Conclusion: This study employed musculoskeletal simulation to accurately quantify kinematic and kinetic parameters in various head postures during book reading. It provided detailed insights into the neuromuscular activities of neck muscles in these postures. The findings from this study can be utilized in the design and development of ergonomic tables and accessories, promoting improved ergonomics, and reducing the risk of musculoskeletal disorders.