against the user 39 s back and has a silhouette which is similar to that of the above described protection device 1 b a reinforcement element 31 made of rigid material is superimposed on the background 30 and fixed thereto e g by riveting said reinforcement element has the same concavity as the background 30 to which it is coupled and has a series of equidistant humps 32 which are arranged transversely and alternated with flat portions 33 the transverse humps 32 act as cages for locating elongated impact cushioning pads 34 which can contain open cell polyurethane 35 or simply compressed air the impact cushioning pads 34 comprise an outer case 36 which is provided with a suitable inflation valve 37 in order to pressurize the interior so that in use they act as cushioning elements for any impacts due to accidental falls in order to protect the backbone at the flat portions 33 and near to the lateral edges of the reinforcement element 31 there are in case of coupling by means of riveting holes 38 in which rivets 39 are inserted each flat portion 33 of the reinforcement element 31 can also have a through opening 40 which is formed at the median portion thereof for lightening and.