A metal shock absorption element comprising a first metal sheet and a second metal sheet, wherein said first metal sheet is shaped in the form of a longitudinally open metal profile and having a substantially "C"-shaped cross-section and wherein said second metal plate is shaped in the form of a longitudinally open metal profile and having a substantially "C"-shaped cross section, said second metal sheet is inserted in a first longitudinal channel of said first metal sheet, moreover said second metal sheet is made integral in one single piece with said first metal sheet in a plurality of points to create a metal honeycomb structure having a closed cross-section and having a plurality of metal channels, said first metal sheet comprises a first wall, a second wall and a third wall which extend perpendicularly from said first wall, and further comprises a fourth wall which extends perpendicularly to said second wall, and further comprises a fifth wall which extends perpendicularly to said third wall, and wherein said fourth wall and said fifth wall are parallel to said first wall to create said open, substantially "C"-shaped cross-section, and wherein said fourth wall and said fifth wall define a side opening having in particular a transverse width of 10 mm and in particular of 4 mm, furthermore said second metal sheet comprises a first wall, a second wall and a third wall which extend perpendicularly from said first wall, and further comprises a fourth wall which extends perpendicularly to said second wall, and further comprises a fifth wall which extends perpendicularly to said third wall, and wherein said fourth wall and said fifth wall are parallel to said first wall to create said open and substantially "C"-shaped cross-section, and wherein said fourth wall and said fifth wall define a side opening having in particular a transverse width of 10 mm and in particular of 4 mm, characterised in that said first metal sheet comprises a plurality of metal fixing walls which extend from said plurality of walls (1A, 2A, 3A, 4A, 5A) at said first open front end, to fix said shock absorption element to a metal crosspiece, at least a part of said plurality of metal fixing walls are inclined with respect to a direction of extension of said metal honeycomb structure to favour the start of a plurality of programmed folds of said metal shock absorption element, starting from said first open front end. said first metal sheet comprises a first wall, a second wall and a third wall which extend perpendicularly from said first wall, and further comprises a fourth wall which extends perpendicularly to said second wall, and further comprises a fifth wall which extends perpendicularly to said third wall, and wherein said fourth wall and said fifth wall are parallel to said first wall to create said open, substantially "C"-shaped cross-section, and wherein said fourth wall and said fifth wall define a side opening having in particular a transverse width of 10 mm and in particular of 4 mm, furthermore said second metal sheet comprises a first wall, a second wall and a third wall which extend perpendicularly from said first wall, and further comprises a fourth wall which extends perpendicularly to said second wall, and further comprises a fifth wall which extends perpendicularly to said third wall, and wherein said fourth wall and said fifth wall are parallel to said first wall to create said open and substantially "C"-shaped cross-section, and wherein said fourth wall and said fifth wall define a side opening having in particular a transverse width of 10 mm and in particular of 4 mm, characterised in that said first metal sheet comprises a plurality of metal fixing walls which extend from said plurality of walls (1A, 2A, 3A, 4A, 5A) at said first open front end, to fix said shock absorption element to a metal crosspiece, at least a part of said plurality of metal fixing walls are inclined with respect to a direction of extension of said metal honeycomb structure to favour the start of a plurality of programmed folds of said metal shock absorption element, starting from said first open front end.