Aim: To analyze the stress distributions of monolimb and traditional prosthesis using finite element method, and discuss the stress damping of the monolimb. Methods: Based on the real geometrical shapes of the monolimb and the traditional prosthesis designed for the same below-knee amputee, two three-dimensional finite element models were established. Contact between the limb stump and the socket was taken into the consideration of setting the coefficient of friction as 0.5. The loads corresponding to the stance subphase of Heel Off were applied to compare the stress distributions of the monolimb and the traditional prosthesis. Results: (1) The-monolimb and the traditional prosthesis demonstrated the similar stress distributions of sockets and the high stress of the border sections between the sockets and the prosthetic shanks. However the stresses of the posterior and anterior area of border sections in the traditional prosthesis were 47.2% and 60.7% higher than those in the monolimb (16.1 MPa, 17.8 MPa; 23.7 MPa, 28.6 MPa). And the high stress area in the monolimb was obviously smaller than in the traditional prosthesis, in which the area extended from the anterior and posterior ends to the lateral surface. (2) The stress distributions of the soft tissues were also similar in the two models. And both the maximum normal stresses and the maximum shear stresses located at the distal anterior of soft tissues in two models. The maximum normal and shear stresses of the stumps in the traditional prosthesis were 581.2 kPa and 178.7 kPa, respectively; while the values in the monolimb were 416.8 kPa and 118.3 kPa, respectively. Conclusion: Compared with traditional prosthesis, monolimb is more economical, good-looking and portable, so that amputees prefer to monolimb. The monolimb appears very evident stress damping in the border section between the socket and the prosthetic shank; And the stresses of the stump in the monolimb are lower than those in the traditional prosthesis. Owing to the obvious biomechanical capability, monolimb will be the guide of prosthesis development.
|Number of pages||3|
|Journal||Chinese Journal of Clinical Rehabilitation|
|Publication status||Published - 10 Sep 2006|
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