Accurate testing of knee braces involves many obstacles to understand the true impact and effectiveness of the brace. One such obstacle involves the brace in a cadaver setting as it requires addressing the tissue interface with the brace. As the cadaver tissue has no muscle tone to simulate the stiffness of contracted muscle a tissue analog was developed to simulate the in vivo brace-tissue interface. Determination of the target tissue properties involved indentation testing of both male and female college athletes. Indentation was made at the locations of brace cuff contact at the proximal thigh and distal calf of the right leg. Indentation was made for the tissue alone and as a composite with the brace cuff.

Linear approximations were made to determine the stiffness value at each trial and location. Statistical analysis determined the anterior thigh and calf were of similar stiffness values. The anterior thigh and calf were significantly more stiff than the posterior thigh and male subjects had a higher stiffness for all locations and levels of contraction than female subjects, p<0.05. A composite polyethylene foam model was constructed with stiffness values similar to female subjects. The model was verified to be statistically similar in stiffness to the female subjects, p<0.05. The model was applied to a cadaver knee for testing and the brace compliance was similar to in vivo tissue compliance. All expected relative motion with the brace versus unbraced knee were seen with the application of 225 N of anterior force. The unbraced knee had more anterior translation than the braced and the anterior cruciate ligament deficient knee had as much as twice the anterior translation than the anterior cruciate ligament intact knee.