An energy absorber according to various embodiments can include a structure having a predetermined cross-sectional profile. A hollow profile is formed within the structure. The pre-determined cross-sectional profile of the structure is configured based on a deceleration-time profile that includes a first period and a second period. The first period is defined by a substantially sharp and linear increase in magnitude of the deceleration of an impact until a maximum deceleration value is achieved. The second period is defined by a rapid decrease in the magnitude of the deceleration.