A humerus provisional reference value (PRV) was developed to help evaluate upper arm injury potential. The proposed PRV is based on humerus bone bending moments generated by testing pairs of cadaver arms to fracture in three-point bending on an lnstron testing machine in either lateral-medial (L-M) or anterior-posterior (A-P) loading, at 218 mm/s and 0.635 mm/s loading rates. The results were normalized and scaled to 50th and 5th percentile sized occupants. The normalized average L-M bending moment at failure test result was 6% more than the normalized average A-P bending moment. The normalized average L-M shear force at failure was 23% higher than the normalized average A-P shear force. The faster rate of loading force. The faster rate of loading resulted in a higher average bending moment overall: 8% in the L-M and 14% in the A-P loading directions. The faster rate of loading gave 3% higher and 11% higher shear forces in the L-M and A-P directions respectively. The differences between the two loading rates and L-M and A-P directions however were not statistically significant. The proposed PRV for the 50th percentile occupant is Fx = Fy = 2.5 kN and Mx = My = 230 N.m. The proposed PRV for the 5th percentile occupant is Fx = Fy = 1.7 kN and Mx = My = 130 N.m. (A)
Abstract