Abstract: A mattress construction includes upper and lower structures defining generally parallel planes, and coil springs operatively connected to such structures and located between those planes, and with:(a) at least one of the upper and lower structures including a first grid,(b) and band apparatus extending at the periphery of the mattress and connected with the first grid to interact therewith and transmit force for tensioning the grid.The mattress construction also enables treating of a patient having a spinal condition for which traction is recommended by suspending the patient's body to extend generally horizontally on a "trampoline" grid mattress surface which interacts with the mattress border perimeter structure to create a surface lift and therefore stretch reflex on the patient's body.