Applied Force During Prone Restraint: Is Officer Weight a Factor?

INTRODUCTION: It has been suggested that law enforcement officer (LEO) weight on the backs of prone subjects may cause asphyxia.

METHODS: Law enforcement officers used their agency-trained "local" single- and double-knee techniques, the "Wisconsin" 3-Point Ground Stabilization, and the Human Factor Research Group Inc single-knee tactical handcuffing techniques, and the weight force was measured.

RESULTS: Forty-one LEOs (36 men, 5 women) participated, aged 38.4 ± 8.3 years, and weighing 96.2 ± 19.4 kg. The double-knee technique transmitted more weight than single knee (P < 0.0001). Wisconsin technique force was lower than other single-knee techniques (P < 0.0001). Double-knee weight was 23.3 kg plus 24% of LEO's body weight. Mean values for local and Human Factor Research Group Inc single-knee were 30.9 and 32.9 kg, respectively. The Wisconsin single knee weight force was given by 15.4 kg plus 9.5 kg for a male.

CONCLUSIONS: A double-knee technique applies more weight force than single-knee techniques. The Wisconsin single-knee technique provides the least weight force of single-knee techniques. Law enforcement officer body weight is irrelevant to prone-force weight with single-knee techniques. With double-knee restraint, it has a modest influence. Our data do not support the hypothesis of restraint asphyxia.