Protection device for sports activities, comprising: at least a localization unit adapted to detect the positioning data of the user; at least a detection unit adapted to detect the movement data (A, M, W) of the user and comprising a detection sensor of the acceleration of said user; at least a communication unit, operatively connected to said localization unit and to said detection unit and adapted to send/receive said positioning data and movement data (A, M, W) to/from at least an external module, a data processing unit adapted to process said movement data (A, M, W) and said positioning data for obtaining information on the sports activity of said athlete, said processing unit comprising means for the acquisition of said movement data (A, M, W) associated with said detection unit, first processing means (22, 23) adapted to use at least part of said movement data (A, M, W) in combination with a first mathematical model based on the recognition of the static phase and of the oscillation phase of a single leg descriptive of said movement of said user to obtain first output data comprising at least velocity synthesis data and corrective acceleration parameters adapted to provide first indications on the sports activity of the athlete or adapted to be reused for subsequent processing operations, wherein said first processing means (22, 23) comprise a first preliminary unit adapted to process at least part of said movement data (A, M, W) to obtain first input data (Z, H, S) adapted to implement said first mathematical model, wherein the first preliminary unit processes the data detected by said sensor relating to the opening angle which the leg traces on the sagittal plane, wherein the data processing of said first preliminary unit permitting detecting and defining at least three points of the walk based on said first input data (Z, H, S) and referred to: - the moment the user is stopped; - the moment the heel touches the ground; and - the moment the foot is resting on the ground and the leg is perpendicular to the support plane. at least a localization unit adapted to detect the positioning data of the user; at least a detection unit adapted to detect the movement data (A, M, W) of the user and comprising a detection sensor of the acceleration of said user; at least a communication unit, operatively connected to said localization unit and to said detection unit and adapted to send/receive said positioning data and movement data (A, M, W) to/from at least an external module, a data processing unit adapted to process said movement data (A, M, W) and said positioning data for obtaining information on the sports activity of said athlete, said processing unit comprising means for the acquisition of said movement data (A, M, W) associated with said detection unit, first processing means (22, 23) adapted to use at least part of said movement data (A, M, W) in combination with a first mathematical model based on the recognition of the static phase and of the oscillation phase of a single leg descriptive of said movement of said user to obtain first output data comprising at least velocity synthesis data and corrective acceleration parameters adapted to provide first indications on the sports activity of the athlete or adapted to be reused for subsequent processing operations, wherein said first processing means (22, 23) comprise a first preliminary unit adapted to process at least part of said movement data (A, M, W) to obtain first input data (Z, H, S) adapted to implement said first mathematical model, wherein the first preliminary unit processes the data detected by said sensor relating to the opening angle which the leg traces on the sagittal plane, wherein the data processing of said first preliminary unit permitting detecting and defining at least three points of the walk based on said first input data (Z, H, S) and referred to: - the moment the user is stopped; - the moment the heel touches the ground; and - the moment the foot is resting on the ground and the leg is perpendicular to the support plane. - the moment the user is stopped; - the moment the heel touches the ground; and - the moment the foot is resting on the ground and the leg is perpendicular to the support plane.