Abstract: Apparatus for absorbing shock, particularly repetitive shocks, comprises a frame and a shock-absorbing component comprising a shape memory alloy (SMA). In one type of apparatus, one or more SMA rings (65) are mounted on brackets (64) on a frame (62, 63) so that shock received by the frame from one direction changes the shape of the rings into ellipses with major chords in a first direction, and shock received by the frame from the opposite direction changes the shape of the rings into ellipses with major chords in a second direction which is at right angles to the first direction. In other types of apparatus, SMA shock-absorbing components (16, 27, 37, 46, 89) are mounted in a frame (11, 12, 13, 14, 15, 17; 21, 22, 24, 25, 26; 31, 32, 34, 35; 41, 42, 43, 44, 45, 47) so that the way in which the shock-absorbing component is deformed is independent of the direction of the shock received by the frame.