electrical and electromagnetic control to the valve module 25 which in turn controls the activation or deactivation of the compressor module 21 causing pressure to be sent to or removed from pneumatic pad module 11 having pneumatic modules 31 32 and 41 pneumatic modules 31 32 and 41 are preferably controlled independently of pneumatic module 11 further modules may also be provided such as an extension 42 beyond pneumatic module 32 in this configuration pneumatic modules 31 and 32 provide cushioning below the thighs independent of the buttocks forming a three segment seating cushion the extension pneumatic module 41 is operated separately from the other inflatable modules and can be actuated to extend the right knee to provide exercise and to maintain joint flexibility similarly the extension pneumatic module 42 is also operated separately and can be actuated to extend the left knee the inflation cycles of the pneumatic modules 41 and 42 are controlled by the controller module 12 the extension pneumatic modules 41 and 42 may operate in various manners if a fixed surface 50 is provided behind the pneumatic module 41 42 as shown in fig1 b and especially if the pneumatic module 41 42 has a wedge shape or bellows type extension 51 52 as the pneumatic module 41 42 is inflated and the pressure increases the wedge or bellows will press against the fixed surface 50 causing a physical movement of the front top surface of the pneumatic module lifting.