Issue:
A city bus struck a canopy providing shade at a construction site; one of the tent support poles hit a crossing guard allegedly injuring her back.  Did the canopy support pole cause an acute back injury?

Results:
Based on testing of an exemplar canopy and a careful review of the evidence, medical records, and witness statements, Northstar Biokinetics determined that the bus was traveling normally through a restricted flow construction area when it contacted a guy line connected to the SW canopy post; the canopy was subsequently deformed and drug by the bus.  The low mass and unconstrained bottom edge of the post resulted in maximum impact forces to the crossing guard on the order of 14 lbs (spread out over a 1-inch square aluminum post).  Northstar Biokinetics concluded that the forces from the canopy pole strike were insufficient to cause the back injuries claimed by the crossing guard; more than likely, based on a review of the medical records and descriptions in testimony, the guard’s physical, work-related activities and pre-existing degenerative conditions caused her back symptoms.