Prosthetic Socket Research Articles

Effect of the ischial support on muscle force estimation during transfemoral walking.

Transmission of loads between the prosthetic socket and the residual limb is critical for the comfort and walking ability of people with transfemoral amputation. This transmission is mainly determined by the socket tightening, muscle forces, and socket ischial support. However, numerical investigations of the amputated gait, using modeling approaches such as MusculoSkeletal (MSK) modeling, ignore the weight-bearing role of the ischial support. This simplification may lead to errors in the muscle force estimation. This study aims to propose a MSK model of the amputated gait that accounts for the interaction between the body and the ischial support for the estimation of the muscle forces of 13 subjects with unilateral transfemoral amputation. Contrary to previous studies on the amputated gait which ignored the interaction with the ischial support, here, the contact on the ischial support was included in the external loads acting on the pelvis in a MSK model of the amputated gait. Including the ischial support induced an increase in the activity of the main abductor muscles, while adductor muscles' activity was reduced. These results suggest that neglecting the interaction with the ischial support leads to erroneous muscle force distribution considering the gait of people with transfemoral amputation. Although subjects with various bone geometries, particularly femur lengths, were included in the study, similar results were obtained for all subjects. Eventually, the estimation of muscle forces from MSK models could be used in combination with finite element models to provide quantitative data for the design of prosthetic sockets.

Modifiable Prosthetic Socket Using Air Pump Method

A prosthesis backup for a part of the body that may have been missing at birth or lost in an accident or through amputation. Prostheses are used to restore the normal functions of the missing body part. Traumatic injuries and different conditions have been set up as common causes of amputation. The need for prostheses in being patterns requires individual measuring and manufacturing of prostheses inclusively for every case. Also, Amputees find it delicate to fit and carry out their routine with a prosthetic duly heavy for them making it considered a burden. Quality of life, phantom branch pain, and the psycho-social impact of prosthetics are duly taken into account for the development of malleable prosthetic sockets. thus, preventing the individual manufacturing of prosthetic legs and the treatment is done and fixing of prosthesis becomes easier. A collaborative observation demands the design of a bio-compatible, feathery, and provident prosthesis to track normal mortal gait by barring phantom limb pain. This will improve the amputee's confidence to live a quality life in society.

A smart demonstration unit for upper-limb myoelectric prostheses

Demonstration unit devices are designed and built for the CPO (Certified Prosthetist Orthotist) to illustrate the functionalities of robotic hands to patients without the need for a prosthetic socket. Demonstration units are also of invaluable importance during the calibration and learning stages, which are preparatory for the final adoption of a prosthesis. This paper presents a smart demo unit (SDU) developed for Adam’s Hand, a robotic underactuated prosthesis proposed by BionIT Labs. It serves as a prosthetic sleeve that powers the robotic hand and gathers the electromyographic commands from the user. The details of the SDU are presented in terms of hardware and firmware, devoting special attention to the electromechanical interface with the robotic hand and the patient or CPO. The advantages of the system over existing alternatives are discussed, showing that the proposed SDU can be a valuable tool in the field of extremity upper limb prosthetics.

Study of Abaca/Carbon/Epoxy Hybrid Composite Properties as an Alternative Prosthetic Socket Material

Composites of natural fiber-reinforced thermoplastic and thermoset polymers have been studied for developing prosthetic socket materials. This study investigated the abaca fiber (AF)/carbon fiber (CF)/epoxy (EP) hybrid composite properties: i.e., tensile, flexural, impact, thermal, and water absorption, by varying AF and CF ratios of 1: 0, 0: 1, 2: 1, 3: 1, and 4: 1 with 80 vol% epoxy resin. The cracks formed in bending test specimens were characterized with an optical microscope, whereas the tensile fracture surface was characterized by scanning electron microscopy (SEM). The results confirmed that the mechanical properties of the CF/EP composite are the highest. The higher the AF/CF ratio, the lower the hybrid composite's mechanical properties and the higher the water absorption. The hybrid composite with a 2:1 AF/CF ratio achieved the highest tensile and flexural strengths of 70 MPa and 103 MPa, respectively, and the lowest water absorption of 7.89%. Based on the experimental results, a simulation of the prosthetic socket was performed using Autodesk Inventor 2019 integrated with ANSYS Workbench 2019 R1, resulting in von Mises stress of 2.14 MPa and deformation of 0.015 mm. Besides, its thermal gravimetric analysis (TGA) resulted in good thermal stability.

Investigation on three-dimensional printed prosthetics leg sockets coated with different reinforcement materials: analysis on mechanical strength and microstructural

Previous research has primarily focused on pre-processing parameters such as design, material selection, and printing techniques to improve the strength of 3D-printed prosthetic leg sockets. However, these methods fail to address the major challenges that arise post-printing, namely failures at the distal end of the socket and susceptibility to shear failure. Addressing this gap, the study aims to enhance the mechanical properties of 3D-printed prosthetic leg sockets through post-processing techniques. Fifteen PLA + prosthetic leg sockets are fabricated and reinforced with four materials: carbon fiber, carbon-Kevlar fiber, fiberglass, and cement. Mechanical and microstructural properties of the sockets are evaluated through axial compression testing and scanning electron microscopy (SEM). Results highlight superior attributes of cement-reinforced sockets, exhibiting significantly higher yield strength (up to 89.57% more than counterparts) and higher Young’s modulus (up to 76.15% greater). SEM reveals correlations between microstructural properties and socket strength. These findings deepen the comprehension of 3D-printed prosthetic leg socket post-processing, presenting optimization prospects. Future research can focus on refining fabrication techniques, exploring alternative reinforcement materials, and investigating the long-term durability and functionality of post-processed 3D-printed prosthetic leg sockets.

Preliminary characterization of rectification for transradial prosthetic sockets

Achieving proper socket fit is crucial for the effective use of a prosthesis. However, digital socket design lacks standardization and presents a steep learning curve for prosthetists. While research has focused on digital socket design for the lower-limb population, there is a research gap in upper-limb socket design. This study aimed to characterize the design (rectification) process for the transradial socket, specifically the three-quarter Northwestern-style design, towards the development of a more systematic, data-driven socket design approach. Fourteen (n = 14) pairs of unrectified and rectified plaster models were compared. Six common rectification zones were identified through shape analysis, with zones of plaster addition being the most prominent in terms of volume and surface area. A novel 3D vector mapping technique was employed, which revealed that most of the shape changes occurred in the anterior–posterior and proximal–distal directions. Overall, the interquartile range of each rectification zone demonstrated reasonable consistency in terms of volume, surface deviation, and 3D vector representation. The initial findings from this study support the potential for quantitively modelling the transradial socket design process. This opens the door for developing tools for categorizing and predicting socket designs across diverse populations through the application of techniques such as machine learning.

Structural integrity of custom-designed additive manufactured prosthetic sockets compared to traditional sockets

Over the past decades, the number of patients with lower extremity amputation increased world-wide. The increasing rate of patients, particularly in developing countries, has led to limited access to clinics and services for prosthetic and orthotic care. Additive manufacturing has rapidly evolved over the last decade and is opening new possibilities for prosthetics and orthotics. 3D printed prosthetic sockets are a promising solution to reduce access- or cost-related barriers to prosthesis use since 3D printed prosthetic sockets can be manufactured at an affordable cost and quickly delivered to patients. We sought to compare the ultimate strength of 3D printed sockets made of different filaments (polyethylene terephthalate glycol, polycarbonate, and co-polymer polypropylene) with that of traditionally fabricated sockets (laminated composite sockets and thermoplastic sockets) and to examine whether the strength of 3D printed sockets could be improved through iterative design changes focused on reinforcing the distal end of the socket. All sockets were mechanically tested in accordance with ISO 10328 standards. Although the strength of all of the 3D printed sockets was weaker than that of laminated composite sockets, design modifications to reinforce the distal end improved the strength of 3D printed sockets made of polycarbonate and polypropylene (but not polyethylene terephthalate glycol), resulting in ultimate strengths and stiffnesses that were comparable to the traditionally fabricated thermoplastic socket. In addition, our results demonstrated that socket failure occurred mainly at the distal end regardless of material type. The strength of some 3D printed sockets under limited testing conditions showed promise to be used for clinical purpose, especially when the socket was reinforced with distal struts.

Path planning of complicated hierarchical thin-wall structures using multi-material additive manufacturing technology

Multilayer thin-wall structures have demonstrated significant application potential in wearable devices, pressure vessels, and aerospace industries, with additive manufacturing (AM) poised to further unlock their capabilities. Although path planning, a crucial aspect of AM, has been extensively studied for homogeneous structures, research on path planning for heterogeneous structures remains limited. This study introduces a novel path planning algorithm, termed CPCNHTS, for generating continuous paths in complex non-rotating bodies with hierarchical thin-walled structures. CPCNHTS encompasses adaptive slicing, path offset, and robotic postprocessing techniques. The adaptive slicing method is employed to enhance the slicing model’s accuracy through volume error control. Moreover, the path offset method is designed to derive the printing path using a parallel curve of the inner contour. Identification of the inner contour is based on the curvatures and areas of single and double contours, respectively. The robotic postprocessing method is employed to convert the printing path into executable codes for multimaterial additive equipment. As a compelling application of the CPCNHTS algorithm, a limb prosthetic socket was successfully fabricated, highlighting the remarkable potential of this approach within the wearable devices domain.

Characterization of flexural and compressive behavior in polylactic acid composites for low‐cost transtibial prosthetic applications: Influence of reinforcements

AbstractLoss of a lower limb leads to immobility, necessitating the use of prosthetic foot and socket as substitutes for lost limbs. However, the production of these prosthetic devices poses challenges due to the wide array of printing settings, materials, and post‐processing techniques involved. The objectives of this study were to examine the compression and flexural behavior of polylactic acid reinforced with carbon fiber fabricated via fused filament fabrication (FFF) and to investigate the effects of process constraints, namely nozzle hole diameter (0.20, 0.40, and 0.60 mm) and internal filling pattern (rectilinear, honeycomb, and triangle). The study employed compression and flexural tests, along with the analysis of failure morphology, on build samples. The resulting data were analyzed using Taguchi ANOVA and response surface methodology (RSM) to determine how compression and flexural behavior vary with the specified process constraints. The research findings demonstrate that the prosthetic socket and foot prosthesis created using FFF exhibit superior flexural and compressive behavior and strength, respectively. These results signify the potential for cost reduction in the production of prosthetic devices. The significance of these results lies in the improvement of prosthetic device production, enabling enhanced mobility and independence for amputees.

Magnetorheological fluid in prostheses: A state-of-the-art review

Magnetorheological fluids (MRF) are intelligent materials that can vary their yield stress in response to an applied magnetic field. This characteristic, combined with active and multifunctional control, allows the development of actuators with fast response time, low energy consumption, long service life, and reduced dimensions and weights. Various studies have been conducted to improve MR dampers in prosthetic applications, including knees, ankle-foot, hands, and sockets. Here, we present a critical review of the progress of MRFs in the prosthetic field. In addition, research in prostheses’ design, optimization, and control of magnetorheological actuators is investigated, along with MRF modeling, mode of operation, type of MR actuator, classification, and working principle of MRF-based devices. Although MRFs are considered promising materials for designing novel prosthetic devices, this review shows that applications have been predominantly focused on lower limb prostheses. We conclude by discussing possible future applications and challenges that must be faced to enable and improve commercial applications based on MRF technology.

Adaptive Locomotion Transition Recognition With Wearable Sensors for Lower Limb Robotic Prosthesis

Locomotion transition recognition with external disturbances is a key issue in lower limb robotic prostheses. Redonning the prosthetic socket and individual differences are encountered frequently in daily life. They change the feature distribution and further fail the previously trained recognition model. To bridge the technical gap between laboratory validation and practical demands, researchers need to construct an adaptive recognition method with high accuracy, quick response, time-efficient calibration, and minimal interference to the human body. Our study developed an adaptive recognition algorithm based on two miniaturized inertial sensors (anterior thigh and forefoot) and a foot pressure sensor, which can easily be integrated into the prosthesis. The algorithm fused probability-based fuzzy classifiers, which took heuristic-based features as inputs with a dynamic-time-warping-based automatic template generation block. It enables the recognition model to quickly fit the parameters for an untrained mode after external disturbances. We validated the proposed adaptive recognition method on 13 healthy subjects, performing 18 motion transitions with random interday intervals and across user evaluation, both offline and online. Even with the data of one subject as the prior knowledge, the other subjects produced an average accuracy of 98.04% and an average transition time latency of −180.99 ms without manual training in interday and intersubject uses. We also tested the method on two subjects using robotic prostheses, one person with a transfemoral amputation and the other person with a transtibial amputation. The average accuracy was still as high as 98.06% (transfemoral) and 100% (transtibial) without manual calibration after seven days of intervals. The results proved that the adaptive recognition method is robust to sensor redonning and user changes. Compared with the state-of-the-art methods, our study makes a further step toward the practical use of robotic prostheses. Future studies will be conducted to implement the algorithm on the robotic prosthesis for more extensive tests.

A Study on the Fabrication of Pressure Measurement Sensors and Intention Verification in a Personalized Socket of Intelligent Above-Knee Prostheses: A Guideline for Fabricating Flexible Sensors Using Velostat Film

Intelligent transfemoral prostheses, which have recently been studied, are equipped with a microcontroller, providing appropriate motion functions for their walking environments. Thus, studies have been conducted to estimate user intentions in locomotion movements by applying biomechanical sensors inside the socket. Among them, a pressure sensor is used to determine the intentions of locomotion movements through changes in the internal pressure of the prosthetic socket. However, existing studies have a problem in that the reproducibility of pressure change data is degraded due to the non-detection and saturation of the pressure measurement value. Accordingly, this study proposes a fabrication method for a wide and flexible pressure sensor that can solve this problem and a method for the identification of user intentions in locomotion movements using it. The proposed system was fabricated with Velostat film, which has a smaller noise impact and can be fabricated in various sizes and shapes. The fabricated sensor was attached to four points inside the socket, confirming the possibility of detecting the intention of six movements according to the multi-critical detection method. The proposed pressure-sensor-based intention detection system can be applied individually by prosthetic users through simple tasks. Moreover, it will be universally applicable for commercialization.

Developing a Mechatronics-Twin Framework for Effective Exploration of Operational Behaviors of Prosthetic Sockets

A Stewart platform is a six-degree-of-freedom parallel manipulator widely used as the motion base for flight simulators and antenna positioning systems, among others. This work presents a novel mechatronics-twin framework that integrates such a manipulator with advanced biomechanical models and simulations for effective exploration of operational behaviors of prosthetic sockets with amputees. By means of the biomechanical models and simulations, the framework allows the users to first analyze the fundamental operational characteristics of individual amputees according to their specific body geometries, pelvis-femur structures, and sizes of transfemoral sockets. Such operational characteristics are then fed to one Stewart platform as the reference control signals for the generation of dynamic loads and behaviors of prosthetic sockets that are otherwise difficult to observe or realize with the real amputees. Experiments in form of integration testing show that the proposed control strategy is capable of generating expected dynamic operational conditions. Currently, the mechatronics-twin framework supports a wide range of biomechanical configurations and the quantification of the respective intra-socket load conditions for socket design optimization and anomaly detection.

Numerical simulation and experimental testing for static failure prediction in additively manufactured below-knee prosthetic sockets.

The socket of a transtibial prosthesis is a structural part customized to a patient's amputated residual lower limb. The free-form geometry of the socket can be suitable for additive manufacturing (AM) to save time and cost. However, the mechanical fracture of additively manufactured lower limb prostheses is not yet fully understood. A novel experimental method and numerical approach by finite element method (FEM) to test the strength and fracture behavior of a lower limb prosthetic socket of acrylonitrile butadiene styrene (ABS), reverse-engineered using computer-aided design (CAD) from the actual amputee's residual limb and manufactured using fused filament fabrication (FFF) are proposed in the present work. The mechanical behavior, von Mises stress distribution, and the damage status of layered AM sockets of different thicknesses were simulated by FEM using Hashin's transversely isotropic mechanical damage model, initially developed for composite materials. The experimental work showed that the fracture failure initiated at the corner of the lobe in the 4 mm thickness socket at a failure load of 918.5 N. The FEM results predicted this failure load to be 896.6 N, with only a 2.45% error as compared to the experiment. The failure loads predicted by FEM in the sockets with thicknesses of 3, 5, and 6 mm were 618.1, 1008.6, and 1105.2 N, respectively. The present work provides a dependable method for testing a below-knee prosthetic socket against static failure and arriving at a factor-of-safety (FoS) based socket thickness selection for any amputee.

A pneumatic reconfigurable socket for transtibial amputees.

Many transtibial amputees rate the fit between their residual limb and prosthetic socket as the most critical factor in satisfaction with using their prosthesis. This study aims to address the issue of prosthetic socket fit by reconfiguring the socket shape at the interface of the residual limb and socket. The proposed reconfigurable socket shifts pressure from sensitive areas and compensates for residual limb volume fluctuations, the most important factors in determining a good socket fit. Computed tomography scan images are employed to create the phantom limb of an amputee and to manufacture the reconfigurable socket. The performance of the reconfigurable socket was evaluated both experimentally and numerically using finite element modelling. The study showed that the reconfigurable socket can reduce interface pressure at targeted areas by up to 61%.

Mechanical load applied by Intraosseous Transcutaneous Amputation Prosthesis (ITAP) during walking on level and sloped treadmill: A case study

This proof of concept study presents a method to collect and analyse kinetic data from one participant with a transfemoral amputation fitted with a percutaneous osseointegrated implant walking on a level and sloped treadmill. We describe the construction of and results from a bespoke wireless six axis load cell built into one participant's prosthetic assembly. The load cell does not clinically compromise the participant in any way and is an initial milestone in the development of a light-weight wireless load cell for use with percutaneous osseointegrated implants. In this case, it is the first time that kinetic data from a participant fitted with an Intraosseous Transcutaneous Amputation Prosthesis has been published. We propose that the data can be used to model the load transfer to the host bone, with several clinically significant applications. The raw dynamic data are made available and quasi-static load cases for each functional phase of gait are presented. Peak forces obtained in the medio-lateral (X), cranio-caudal (Y) and antero-posterior (Z) axes over level ground respectively were -243.8 N (0.24 BW), 1321.5 N (1.31 BW) and -421.8 N (0.42 BW); uphill were -141.0 N (0.14 BW), 1604.2 N (1.59 BW), -498.1 N (0.49 BW); downhill were -206.0 N (0.20 BW), 1103.9 N (1.09 BW), -547.2 N (0.54 BW). The kinetics broadly followed able bodied gait patterns with some gait strategies consistent in participants with other implant designs or prosthetic socket connections, for example offloading the artificial limb downhill.

A Systematic Review of Natural Fiber-Reinforced Polymer Composites in Prosthetic Socket Fabrication

This review systematically examines the burgeoning field of natural fiber-reinforced polymer (NFRP) composites in prosthetic socket fabrication. The review begins by exploring the historical context and recent shift towards sustainable and biocompatible materials in prosthetics, with a specific focus on NFRP. It delves into the composition and properties of NFRP, detailing the types of natural fibers used and the characteristics of these innovative composites. The review highlights the advantages of NFRP in prosthetics, notably their biocompatibility, sustainability, and mechanical properties that are pertinent to prosthetic applications. The technical aspects of fabricating prosthetic sockets with NFRP are examined, discussing both traditional and advanced manufacturing techniques and design considerations that take into account anatomical and biomechanical factors, as well as the need for customization. The clinical outcomes and user experiences with NFRP prosthetic sockets are evaluated, focusing on their durability, functionality, and comparison with traditional materials. User-centric perspectives, including comfort, satisfaction, and adaptation challenges, are also considered. Crucial challenges and limitations in the field are identified, such as technical and fabrication complexities, consistency and quality control issues, as well as clinical and practical barriers like accessibility, cost, and the necessity for specialized training. The review outlines future directions and research needs, emphasizing potential innovations in NFRP, integration with emerging technologies, and the importance of translational research and interdisciplinary collaboration. The review underscores the significant role NFRP could play in advancing prosthetic technology, envisioning a future where prosthetic design is not only user-friendly and functional but also sustainable

A Pneumatically Controlled Prosthetic Socket for Transfemoral Amputees.

Amputees typically experience changes in residual limb volume in their daily lives. It causes an uncomfortable fit of the socket by applying high pressure on the sensitive area of the residual limb or by loosening the socket. In this study, we developed a transfemoral prosthetic socket for above-the-knee amputees that ensures a good socket fit by maintaining uniform and constant contact pressure despite volume changes in the residual limb. The socket has two air bladders in the posterior femoral region, and the pneumatic controller is located on the tibia of the prosthesis. The pneumatic system aims to minimize unstable fitting of the socket and improve walking performance by inflating or deflating the air bladder. The developed socket autonomously maintains the air pressure inside the prosthetic socket at a steady-state error of 3 mmHg or less by adjusting the amount of air in the air bladder via closed-loop control. In the clinical trial, amputee participants walked on flat and inclined surfaces. The displacement between the residual limb and socket during the gait cycle was reduced by up to 33.4% after air injection into the socket. The inflatable bladder increased the knee flexion angle on the affected side, resulting in increased stride length and gait velocity. The pneumatic socket provides a stable and comfortable walking experience not only when walking on flat ground but also on slopes.

EVALUATING FEASIBILITY AND DURABILITY OF THE AERO PROSTHETIC LINER IN TRANSTIBIAL PROSTHETIC USERS

BACKGROUND: The choice of prosthetic socket interface material significantly affects user comfort and satisfaction. The Affordable Ethylene-Vinyl Acetate Roll-On (AERO) liner was created with the aim of improving functionality and streamlining the wearing process for users. OBJECTIVE: The purpose of this study was to comprehensively assess user satisfaction, comfort, and durability of the AERO liner and compare it with the common soft Pe-Lite liner. METHODOLOGY: Fourteen individuals with transtibial amputation participated in this three-month randomized crossover trial study. The Prosthesis Evaluation Questionnaire (PEQ), Expanded Socket Comfort Score (ESCS), and liner thickness measurements were used to comprehensively compare the AERO and Pe-Lite liner. FINDINGS: The AERO liner demonstrated notable improvements in prosthetic comfort and functionality over Pe-Lite liner. After three months use, there was a significant reduction in reported frustration with the AERO liner (p=0.023, r=0.604) in the PEQ subscale. Specific aspects, such as walking with the prosthesis (p=0.030, r=0.601) and odor perception (p=0.024, d=0.579), favored the use of the AERO liner. The expanded socket comfort score (ESCS) revealed significant superiority for the AERO liner “at best” (p=0.04) and “on average” (p=0.02) after one and three months, respectively. Liner thickness analysis showed significant reductions at the mid-patellar tendon location for the AERO liner at one (0.57±0.48) and three months (0.90±0.69, p=0.01) and in the posterior region after three months (0.63±0.64, p=0.05). CONCLUSION: Our study highlights the potential advantages of the AERO liner in enhancing comfort and satisfaction. Yet, durability and thinning of the liner when compared to Pe-Lite may be a concern which may eventually affect socket fit. These findings contribute to ongoing efforts to optimize prosthetic interventions and improve the quality of life of individuals with lower limb prosthesis in resource-limited environments. Layman's Abstract Comfort and satisfaction are essential for people using prosthetics. The socket interface material, which encompasses the limb, is crucial for comfort and suspension of the prosthesis on the limb. In resource-limited environments, people mainly use an interface material called Pe-Lite in their prosthetic sockets. However, there is an ongoing debate regarding its comfort and suitability for the residual limb. We aimed to evaluate an alternative material to determine if it was more comfortable and functional than Pe-Lite for these individuals. We invited fourteen people with transtibial amputations to participate in this study. They used a traditional prosthetic design and were provided both Pe-Lite and AERO liners. We asked them about their experiences and measured the various aspects of their treatment. The results were promising. People who used the AERO liner reported much less frustration after three months. They felt an improvement in walking, and they didn't have odor problems expressed when using Pe-Lite. The AERO liner was more comfortable when using the prosthesis. Although the AERO liner compressed more in certain areas compared to the Pe-Lite liner, it remained usable after three months. However, reduce the liner thickness compared to Pe-Lite may be a concern and could affect the socket fit. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/41865/32282 How To Cite: Miyata Y, Sasaki K, Guerra G, Dacharux W, Chaiwan P. Evaluating feasibility and durability of the AERO prosthetic liner in transtibial prosthetic users. Canadian Prosthetics & Orthotics Journal. 2023; Volume 6, Issue 1, No.5. https://doi.org/10.33137/cpoj.v6i1.41865 Corresponding Author: Kazuhiko Sasaki,  Sirindhorn School of Prosthetics and Orthotics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.E-Mail: kazuhiko.sas@mahidol.eduORCID ID: https://orcid.org/0000-0002-1778-6308

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

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.