Spinal cord and brain injury protection: testing concept for a protective device.

STUDY DESIGN: Test development for a device that could prevent both brain and spinal cord injuries during motorcycling and horseback riding. OBJECTIVE: The objective of this study was to develop a method and test a concept device that could protect against both spinal cord (SCI) and brain injuries (BI). SETTING: St Louis, Missouri, USA. METHODS: A Hybrid III dummy (that is, head, neck and torso) was used as a pendulum bob during three test conditions: (1) no protection, (2) standard motorcycle helmet and (3) SCI and BI test structure (SCIBITS). Triaxial accelerometers, a C1 force transducer and a video system were used to collect data as the dummy axially impacted a rigid barrier at speeds ranging from 10 to 605 cm s(-1). SCIBITS consisted of a fused fiberglass thoracic jacket/head shield unit. Separation between the dummy head and the head shield permitted freedom of head movement within safe limits as impact forces to the head shield were transferred from the head and neck to the upper thorax. The BI threshold was 200-300 g, and the SCI threshold was 3010 N. RESULTS: The SCIBITS protected against spinal cord injury, whereas the motorcycle helmet did not. The helmet protected against BI and the SCIBITS provided partial protection. CONCLUSIONS: The experiments describe the efficacy of an impact testing system utilizing an instrumented dummy suspended as a pendulum bob. The equipment will facilitate the design and construction of a functional device for protection against both SCI and BI in relation to both motorcycling and horseback riding.