The present disclosure provides a support device including a body interface layer resting against a user's body, a core adjacent the body interface layer with a plurality of independently acting micro coils surrounded by an enclosure layer, a stabilizing layer more rigid than the enclosure layer and the body interface layer, and an outer layer adjacent the stabilizing layer and which rests against an external surface such as a seat back when the device is in use. The body interface layer includes a curvilinear or parabolic profile with its inflection point toward a central region of the device and tapering toward lateral ends thereof. The body interface layer is thickest toward its intermediate portion which aligns with a central row of the spiral biasing devices, the body interface layer thinner outer intermediate regions aligning with outer spiral biasing device rows, providing for a consistently distributed pressure against the body.