Dugwayâs Chemical Test Division successfully tests JCAD system on Stryker. Caged in a menacing looking metal grid with intricate sensory equipment attached to all sides the Armyâs M113 NBC RV Stryker vehicle sits on a dusty road at Dugway Proving Groundâs target S grid being readied by its crew for testing....
The following conditions are when secondary curvatures of the spine  develop:   Cervical-when the baby starts to hold its head up   Lumbar-when the baby starts to â¦ walk. 4 people found this useful.
Secondary curvatures are the curves in the spine that develop after birth (when a baby starts to hold its head up). Thoracic and sacral curvatures are the primary curvatures c â¦ ervical and lumbar. 6 people found this useful.