Dynamic mechanical properties of intact human cervical spine ligaments.

Background Context: Most previous studies have investigated ligament mechanical properties at slow elongation rates of less than 25 mm/s.

Purpose: To determine the tensile mechanical properties, at a fast elongation rate, of intact human cervical anterior and posterior longitudinal, capsular, and interspinous and supraspinous ligaments, middle-third disc, and ligamentum flavum.

Study Design/setting: In vitro biomechanical study.

Whiplash causes increased laxity of cervical capsular ligament.

Background: Previous clinical studies have identified the cervical facet joint, including the capsular ligaments, as sources of pain in whiplash patients. The goal of this study was to determine whether whiplash caused increased capsular ligament laxity by applying quasi-static loading to whiplash-exposed and control capsular ligaments.

Methods: A total of 66 capsular ligament specimens (C2/3 to C7/T1) were prepared from 12 cervical spines (6 whiplash-exposed and 6 control).

Neck ligament strength is decreased following whiplash trauma.

Background: Previous clinical studies have documented successful neck pain relief in whiplash patients using nerve block and radiofrequency ablation of facet joint afferents, including capsular ligament nerves. No previous study has documented injuries to the neck ligaments as determined by altered dynamic mechanical properties due to whiplash. The goal of the present study was to determine the dynamic mechanical properties of whiplash-exposed human cervical spine ligaments.

Multiplanar cervical spine injury due to head-turned rear impact.

Study Design: Head-turned whole cervical spine model was stabilized with muscle force replication and subjected to simulated rear impacts of increasing severity. Multiplanar flexibility testing evaluated any resulting injury.

Objectives: To identify and quantify cervical spine soft tissue injury and injury threshold acceleration for head-turned rear impact, and to compare these data with previously published head-forward rear and frontal impact results.

Effect of rotated head posture on dynamic vertebral artery elongation during simulated rear impact.

Background: Elongation-induced vertebral artery injury has been hypothesized to occur during non-physiological coupled axial rotation and extension of head. No studies have quantified dynamic vertebral artery elongation during head-turned rear impacts. Therefore, we evaluated effect of rotated head posture vs.

Frontal impact causes ligamentous cervical spine injury.

Study Design: Whole cervical spine model with muscle force replication was subjected to simulated frontal impacts of increasing severity, and resulting injuries were evaluated via flexibility testing.

Objectives: To identify and quantify cervical spine soft tissue injury and the injury threshold acceleration due to frontal impact.

Summary Of Background Data: Cervical spine instability may result from automotive collisions.

Evaluation of the intervertebral neck injury criterion using simulated rear impacts.

The Intervertebral Neck Injury Criterion (IV-NIC) is based on the hypothesis that intervertebral motion beyond the physiological limit may injure spinal soft tissues during whiplash, while the Neck Injury Criterion (NIC) hypothesizes that sudden changes in spinal fluid pressure may cause neural injury. Goals of the present study, using a biofidelic whole cervical spine model with muscle force replication, were to correlate IV-NIC with soft-tissue injury, determine the IV-NIC injury threshold, and compare IV-NIC and NIC. Using a bench-top apparatus, rear-impacts were simulated at 3.