An adjustable lumbar spine assembly for a crash test dummy comprising: an upper member adapted to be operatively connected to an upper thoracic portion of a spine of the crash test dummy; a lower member adapted to be operatively connected to a lower thoracic portion of the spine of the crash test dummy; an upper abdomen interface connected to said upper member and adapted to be connected to an upper abdomen portion of the crash test dummy; and an adjustment mechanism cooperating with said upper member and said lower member to allow adjustment about a lateral axis extending through a first fastener between said upper member and said lower member of a predetermined number of different and varying fixed joint angles about the lateral axis between said upper member and said lower member wherein, said adjustment mechanism comprises the first fastener to pivotally connect said upper member and said lower member together, characterized in that said upper member has an upper wall and a pair of side walls extending downwardly from said upper wall, that said lower member has a lower wall and a pair of side walls extending upwardly from said lower wall, that said first fastener extends through said side walls (38, 60) of said upper member and said lower member, that each side wall of said upper member includes a plurality of first apertures and a second aperture extending through said side walls, that each side wall of said lower member includes a plurality of first apertures, second apertures and third apertures extending through said side walls, and that the first fastener is a shoulder bolt extending through the second apertures (47, 64), and that said adjustment mechanism comprises a second fastener extending through one of said first apertures of each of said first side walls of said upper member and also extending through one of said first apertures of each of said second side walls of said lower member to fix said upper member and said lower member in one of said joint angles. an upper member adapted to be operatively connected to an upper thoracic portion of a spine of the crash test dummy; a lower member adapted to be operatively connected to a lower thoracic portion of the spine of the crash test dummy; an upper abdomen interface connected to said upper member and adapted to be connected to an upper abdomen portion of the crash test dummy; and an adjustment mechanism cooperating with said upper member and said lower member to allow adjustment about a lateral axis extending through a first fastener between said upper member and said lower member of a predetermined number of different and varying fixed joint angles about the lateral axis between said upper member and said lower member wherein, said adjustment mechanism comprises the first fastener to pivotally connect said upper member and said lower member together, characterized in that said upper member has an upper wall and a pair of side walls extending downwardly from said upper wall, that said lower member has a lower wall and a pair of side walls extending upwardly from said lower wall, that said first fastener extends through said side walls (38, 60) of said upper member and said lower member, that each side wall of said upper member includes a plurality of first apertures and a second aperture extending through said side walls, that each side wall of said lower member includes a plurality of first apertures, second apertures and third apertures extending through said side walls, and that the first fastener is a shoulder bolt extending through the second apertures (47, 64), and that said adjustment mechanism comprises a second fastener extending through one of said first apertures of each of said first side walls of said upper member and also extending through one of said first apertures of each of said second side walls of said lower member to fix said upper member and said lower member in one of said joint angles.