Preliminary female cervical spine injury risk curves from PMHS tests. J Mech Behav Biomed Mater 2018 Jul;83:143-147
Date
05/02/2018Pubmed ID
29709826DOI
10.1016/j.jmbbm.2018.04.020Scopus ID
2-s2.0-85046470719 (requires institutional sign-in at Scopus site) 2 CitationsAbstract
The human cervical spine sustains compressive loading in automotive events and military operational activities, and the contact and noncontact loading are the two primary impact modes. Biomechanical and anatomical studies have shown differences between male and female cervical spines. Studies have been conducted to determine the human tolerance in terms of forces from postmortem human subject (PMHS) specimens from male and female spines; however, parametric risk curves specific to female spines are not available from contact loading to the head-neck complex under the axial mode. This study was conducted to develop female-spine based risk curves from PMHS tests. Data from experiments conducted by the authors using PMHS upright head-spines were combined with data from published studies using inverted head-spines. The ensemble consisted of 20 samples with ages ranging from 29 to 95 years. Except one, all specimens sustained neck injuries, consisting of fractures to cervical vertebrae, and disruptions to the intervertebral disc and facet joints, and ligaments. Parametric survival analysis was used to derive injury probability curves using the compressive force, uncensored for injury and right censored for noninjury data points. The specimen age was used as the covariate. Injury probability curves were derived using the best fit distribution, and the ± 95% confidence interval limits were obtained. Results indicated that age is a significant covariate for injury for the entire ensemble. Peak forces were extracted for 35, 45, and 63 (mean) years of age, the former two representing the young (military) and the latter, the automobile occupant populations. The forces of 1.2 kN and 2.9 kN were associated with 5% and 50% probability of injury at 35 years. These values at 45 years were 1.0 kN and 2.4 kN, and at 63 years, they were 0.7 kN and 1.7 kN. The normalized widths of the confidence intervals at these probability levels for the mean age were 0.74 and 0.48. The preliminary injury risk curves presented should be used with appropriate caution. This is the first study to develop risk curves for females of different ages using parametric survival analysis, and can be used to advance human safety, and design and develop manikins for military and other environments.
Author List
Yoganandan N, Chirvi S, Pintar FA, Baisden JL, Banerjee AAuthors
Anjishnu Banerjee PhD Associate Professor in the Data Science Institute department at Medical College of WisconsinFrank A. Pintar PhD Professor in the Biomedical Engineering department at Medical College of Wisconsin
Narayan Yoganandan PhD Professor in the Neurosurgery department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AdultAged
Aged, 80 and over
Biomechanical Phenomena
Cervical Vertebrae
Female
Humans
Materials Testing
Mechanical Phenomena
Middle Aged
Probability
Risk Assessment
Sex Characteristics
Spinal Injuries
