Interface pressure measurement is widely used to evaluate, for example, compression stockings, compression bandages and pressure ulcer prevention devices. Pneumatic [1], electro-pneumatic [1-3], resistive [2-4] or capacitive [5-6] sensors are usually used. The ideal interface pressure measurement device should be [7-8] small, thin and highly flexible, have a continuous output, be sensitive in detecting the range of pressure as low as 0-100 mmHg, be free from error of measurement on curved surfaces, be free from the effects of temperature and moisture, low cost. Despite sensors developed over the years, to our knowledge, none of them has met all the above criteria. Four “FSA” thin and flexible resistive pressure mapping systems have been designed by Vista Medical (Winnipeg, Manitoba, Canada). The objective of this study is to evaluate the FSA sensor (Vista medical, Winnipeg, Manitoba, Canada) for the measurement of interface of lumbar belts. Lumbar belt is a medical devices used to prevent and treat low back pain. The main mechanical effect of lumbar belts is the pressure applied on the trunk, which can induce a decrease of intervertebral pressure and/or modify morphological curves of the spine