2. Data acquisition

2.1 Accelerometric data

Raw data is generally collected by an accelerometer located either on a smartphone or on a dedicated connected object. The advantage of using a smartphone is that a user's data can be collected unobtrusively using an application, without the need for additional hardware. It should be noted, however, that the user is likely to change the position of his or her smartphone quite frequently; the use of a dedicated platform has the advantage of being able to position and fix the sensor at a precise point on the body. The type of equipment usually used in studies is described in table 1 .