The Effects of Increasing Mass Unloader Knee Orthosis and Two Kinds of Silicon and Polyethylene Pad on Pistoning Movement during Walking

Introduction: knee orthosis is used in different cases and can be seen pistoning movement in all orthosis. the purpose of this study was to evaluate the effects of increasing mass knee brace and two kinds of silicon and polyethylene (pe) pad on pistoning movement during walking, on health subject. material and methods: a total of 20 healthy volunteers, including 10 men and 10 women, with an average age of 24.65 years, participated in this study. subjects used unloader knee brace with pe and silicon pad, with and without weights in four phases, and at each phase, they engaged in 10 minutes’ walk. before and after each phase, using a video camera, the brace displacement on limb was measured with a marker. finally, the pistoning movement of the orthosis on the knee was measured using the kinovea software. results: this study showed significant differences between the four tests (p < 0.050). the mean migration of the orthosis with silicon pads in both genders was lower, compared to the average migration of the orthosis in the three other cases (0.65 cm), and the amount of migration knee brace with silicon pad with weights, pe pad, pe pad with weights was 4.1 ± 1.6, 3.1 ± 1.4, 6.3 ± 1.8 cm, respectively. an inverse relationship existed between the level of comfort and orthosis migration. orthosis with silicon pad demonstrated the highest level of comfort and orthosis with pe pad, with weight showing the lowest level. conclusion: the results showed that the use of silicone pads inside the brace construction, as well as lighter than knee brace, reduced migration, and increased comfort level. moreover, compliance to knee braces was improved.