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.
primary curvature of vertebral column. the ventrally concave curve of the fetal vertebral column, retained in the thoracic and sacral regions as the thoracic and sacral kyphoses. See also: kyphosis.