5. SIGNIFICANCE & USE 5.1 The high and often narrow heel of womens shoes frequently break and cause women to fall and become injured. 5.2 This test method will establish a minimum required breaking strength for womens heels to minimize the number of injuries caused by heels that fail during walking. 5.3 Footwear manufacturers must use a heel/outsole attaching method that will resist the heel attachment torque produced by the 500 Newton breaking strength times the distance of the heel height minus the 3/8-inch heel tensile test attachment distance. 5.4 Users of the ref. 2.1 test method, which applies a torque to break the heel/insole attaching, have a 250 in. lb. minimum torque requirement. This is equivalent to the 125-lb.