Abstract: This paper presents a method to calculate spatiotemporal parameters using a chest-worn accelerometer. Accuracy was compared with an optical system that consists of a walkway of transmitting and receiving bars (Microgait, Optogait, Bolzano, Italy). To this purpose, seventeen healthy male wore a smart shirt based worn accelerometer performing five meters of walkway delimited by five meters of optical bars OptoGaitT for three times. Spatiotemporal parameters such as gait cycle and gait phases were analysed and compared using the two systems. Smart shirt based on chest-worn accelerometer revealed to be a non-intrusive way of calculating gait cycle, phases and sub-phases. In addition, the inverted pendulum model based on chest body-worn accelerometer revealed to be a good model for calculating step length variation and consequently the speed. Our results, are in line with previous literature presenting an average of 60.24 % of stance phase, 39.75% of swing phase, a foot flat subphase of 17.60%, a terminal stance subphase of 21.42%, a pre-swing subphase of 10.65%, a step length of 0.74 m for an average speed of 1.37 m/s using the smart shirt.