§ 572.75 - Lumbar spine, abdomen, and pelvis assembly and test procedure.

§ 572.75 Lumbar spine, abdomen, and pelvis assembly and test procedure.

(a) Lumbar spine, abdomen, and pelvis assembly. The lumbar spine, abdomen, and pelvis consist of the part of the torso assembly designated as SA 106C 50 and 60 on drawing SA 106C 001, sheet 2, and conform to each applicable drawing listed on SA 106C 001, sheets 12 and 13.

(b) Lumbar spine, abdomen, and pelvis assembly response requirements. When the lumbar spine is subjected to a force continuously applied according to the test procedure set out in paragraph (c) of this section, the lumbar spine assembly shall -

(1) Flex by an amount that permits the rigid thoracic spine to rotate from the torso's initial position, as defined in (c)(3), by 40 degrees at a force level of not less that 46 pounds and not more than 52 pounds, and

(2) Straighten upon removal of the force to within 5 degrees of its initial position when the force is removed.

(c) Lumbar spine, abdomen, and pelvis test procedure. The test procedure for the lumbar spine, abdomen, and pelvis is as follows:

(1) Remove the dummy's head-neck assembly, arms, and lower legs, clean and dry all component surfaces, and seat the dummy upright on a seat as specified in Figure 42.

(2) Adjust the dummy by -

(i) Tightening the femur ballflange screws at each hip socket joint to 50 inch-pounds torque;

(ii) Attaching the pelvis to the seating surface by a bolt D/605 as shown in Figure 42.

(iii) Attaching the upper legs at the knee joints by the attachments shown in drawing Figure 42.

(iv) Tightening the mountings so that the pelvis-lumbar joining surface is horizontal; and

(v) Removing the head and neck, and installing a cylindrical aluminum adapter (neck adapter) of 2.0 inches diameter and 2.60 inches length as shown in Figure 42.

(3) The initial position of the dummy's torso is defined by the plane formed by the rear surfaces of the shoulders and buttocks which is three to seven degrees forward of the transverse vertical plane.

(4) Flex the thorax forward 50 degrees and then rearward as necessary to return the dummy to its initial torso position, unsupported by external means.

(5) Apply a forward pull force in the midsagittal plane at the top of the neck adapter so that when the lumbar spine flexion is 40 degrees, the applied force is perpendicular to the thoracic spine box.

(i) Apply the force at any torso deflection rate between 0.5 and 1.5 degrees per second, up to 40 degrees of flexion.

(ii) For 10 seconds, continue to apply a force sufficient to maintain 40 degrees of flexion, and record the highest applied force during the 10 second period.

(iii) Release all force as rapidly as possible, and measure the return angle 3 minutes after the release.