Section 572.165 - Upper and lower torso assemblies and torso flexion test procedure(a)Upper/lower torso assembly. The test objective is to determine the stiffness effects of the lumbar spine (specified in 49 CFR 572.125(a) ), including cable (specified in 49 CFR 572.125(a) ), mounting plate insert (specified in 49 CFR 572.125(a) ), nylon shoulder bushing (specified in 49 CFR 572.125(a) ), nut (specified in 49 CFR 572.125(a) ), spine box weighting plates (drawing 167-2020 Revision A), lumbar base weight (drawing 167-3010 Revision A), and abdominal insert (specified in 49 CFR 572.125(a) ), on resistance to articulation between the upper torso assembly (drawing 167-2000) and the lower torso assembly (drawing 167-3000). Drawing Nos. 167-2000, 167-2020 Revision A, 167-3000, and 167-3010 Revision A, are incorporated by reference, see § 572.160 .(b)(1) When the upper torso assembly of a seated dummy is subjected to a force continuously applied at the head to neck pivot pin level through a rigidly attached adaptor bracket as shown in Figure S2 according to the test procedure set out in 49 CFR 572.125(c) , the lumbar spine-abdomen assembly must flex by an amount that permits the upper torso assembly to translate in angular motion until the machined surface of the instrument cavity at the back of the thoracic spine box is at 45 ±0.5 degrees relative to the transverse plane, at which time the force applied as shown in Figure S2 must be within 88.6 N ±25 N (20.0 lbf ±5.6 lbf), and(2) Upon removal of the force, the torso assembly must return to within 9 degrees of its initial position.(c)Test procedure. The upper and lower torso assemblies are tested as specified in 49 CFR 572.125(c) , except that in paragraph (c)(5) of that section, the initial torso orientation angle may not exceed 32 degrees.69 FR 42602, July 16, 2004, as amended at 70 FR 77338, Dec. 30, 2005