Comparing New Plunger-cylinder and Conventional Pin-luck Suspension Methods on Piston Movement and Satisfaction of Patients With Transtibial Prosthesis

Abstract

Background and Objectives: One of the factors affecting the time of using the prosthesis is the level of satisfaction of the amputee with the quality of the prosthesis. Choosing the right suspension system based on the functional needs and expectations of the amputee is a crucial step in the process of making the prosthesis and as a result, prosthetic rehabilitation. The critical side effects caused by “a weak suspension system” are pain and skin sores due to piston movement between the socket and stump and as a result, abnormal walking, reducing the amputee’s satisfaction and comfort. Methods: This study was conducted using a simple quasi-experimental method on six unilateral below-the-knee amputees. For each person, two prosthetic sockets were made with different suspension systems, one socket with a conventional pin-lock suspension system and the other socket with an innovative suspension system with a plunger cylinder. In this study, the level of satisfaction with the suspension system with a questionnaire and the amount of piston movement between the remaining limb and the prosthetic socket with the method of photography and the use of an indicator during 5 stages of a constant loading test, including full weight bearing, half weight bearing, no weight bearing, 30 N and 50 N were measured. Results: The photography method did not show a significant difference in the amount of piston movement between the socket and the stump. However, the satisfaction level of the participants with the pin-lock suspension system was higher than with the plunge cylinder. Conclusion: The use of a plunger-cylinder suspension system can be useful for below-the-knee amputations with a low activity level.