A cycloidal vibration module comprises a motor 16 with a body 18 and end caps 20, 22 with a fan 24a, 24b and an eccentric weight 26 mounted at each end of a shaft 25 outside the end caps 20, 22, a pair of clamshell housings 12, 14 and a plurality of elastomeric rings 34 around the motor clamped between the motor 16 and housings 12, 14. The housings 12, 14 define a plurality of lugs 98 comprising slots 101 suitable for receipt of a frame. The motor module can be used in vibration therapy and the prevention and treatment of ulcers. The lugs 98 may be defined by two lug halves, one on each housing half. There may be four lugs 98. The rings 34 are disposed between the end caps 20, 22 and the housing 12, 14. The end caps 20, 22 and rings 34 may comprise first and second circumferential ridges and grooves 32, 36, 38, 40. The caps 20, 22 and housings 12, 14 may have windows (90 fig 6) to permit air flow. The body 18 of the motor may be cup shaped with one open end. The motor module may be incorporated into a chair, bed and/or mattress.
