Senior Managing Engineer Exponent, Inc., United States
Introduction: : Understanding cervical spine loading during routine yet vigorous daily activities provides important context for evaluating the full range of natural, non-injurious spinal motion. Prior studies have reported quantification of cervical loading (such as compression, flexion, extension, and lateral bending) but typically only for a subset of tasks or directions. Furthermore, a comprehensive analysis incorporating anthropometric influences and statistical comparisons across tasks has not been presented in a single consolidated dataset.
This study compiles and analyzes cervical spine loading data from a controlled laboratory study involving 30 healthy adults performing a diverse series of 12 vigorous activities. Some of the cervical loading data have been published previously, including compression, flexion, and extension for four tasks (Vijayakumar et al., 2006) and lateral bending for four others (Isaacs et al., 2019). Several additional tasks and loading directions are reported here for the first time, providing a complete and unified dataset.
While linear head accelerations from these same tests were previously reported by Scher et al. (2005), this poster focuses exclusively on cervical spine loading estimates, offering new insights into natural variability and task-specific differences.
Materials and
Methods: : Thirty adult participants (ages 18–44) completed a series of vigorous, non-injurious daily activities while wearing a validated sensor system to estimate cervical spine loading. The system included MEMS-based triaxial accelerometers mounted to a lightweight, adjustable headband aligned with anatomical landmarks.
Tasks were randomized for each participant to minimize fatigue or order effects. Participants performed synchronization motions prior to each trial to aid in data alignment and sensor verification. Sensor placement and cable routing were verified not to restrict normal head or neck motion. No participants reported discomfort or adverse effects. Twelve distinct activities were analyzed, spanning a range of motions and intensities. The tasks included:
• Looking quickly from left to right • Shaking water from head and ears • Spinning in an office chair • Swatting gnats away • Picking up and moving a soda can • Hopping • Jumping rope • Falling into a chair • Running with abrupt stop • Running stairs • Jumping down stairs • Sitting down on the floor and standing up quickly
Data processing used MATLAB to compute linear acceleration at both the head center of mass and the atlantooccipital junction (AOJ). Cervical spine loading was inferred from the estimated linear acceleration at the AOJ, based on anthropometric scaling (Zatsiorsky, 1985). The Scher et al. (2005) head acceleration results are not repeated here. Previously reported cervical spine loading data from Vijayakumar et al. (2006) and Isaacs et al. (2019) are integrated with additional previously unpublished activities and directions for a complete dataset.
Results, Conclusions, and Discussions:: All 30 participants completed the protocol without issue, and the sensor system did not interfere with task performance. Peak cervical spine loading values are presented as mean ± standard deviation across the cohort.
This poster consolidates previously published cervical spine loading data with new, unpublished results to offer a comprehensive reference for spinal loading during voluntary, vigorous activity. This complete dataset can serve as a valuable benchmark for biomechanical model validation, ergonomic design, and wearable sensor development. Capturing the natural variability of non-injurious cervical spine loading enhances understanding of cervical spine mechanics during dynamic, asymmetrical activities.
Future research may expand this work to include older populations, occupational tasks with added load, and field validation using real-world wearable systems.
