2011

Objective: To investigate the effect of a vacuum-assisted socket suspension system as compared with pin suspension on lower extremity amputees. Design: Randomized crossover with 3-week acclimation. Setting: Household, community, and laboratory environments. Participants: Unilateral, transtibial amputees (Nϭ20 enrolled, Nϭ5 completed). Interventions: (1) Total surface-bearing socket with a vacuumassisted suspension system (VASS), and (2) modified patellar tendon-bearing socket with a pin lock suspension system. Main Outcome Measures: Activity level, residual limb volume before and after a 30-minute treadmill walk, residual limb pistoning, and Prosthesis Evaluation Questionnaire. Results: Activity levels were significantly lower while wearing the vacuum-assisted socket suspension system than the pin suspension (Pϭ.0056; 38,000Ϯ9,000 steps per 2wk vs 73,000Ϯ18,000 steps per 2wk, respectively). Residual limb pistoning was significantly less while wearing the vacuumassisted socket suspension system than the pin suspension (Pϭ.0021; 1Ϯ3mm vs 6Ϯ4mm, respectively). Treadmill walking had no effect on residual limb volume. In general, participants ranked their residual limb health higher, were less frustrated, and claimed it was easier to ambulate while wearing a pin suspension compared with the VASS. Conclusions: The VASS resulted in a better fitting socket as measured by limb movement relative to the prosthetic socket (pistoning), although the clinical relevance of the small but statistically significant difference is difficult to discern. Treadmill walking had no effect, suggesting that a skilled prosthetist can control for daily limb volume fluctuations by using conventional, nonvacuum systems. Participants took approximately half as many steps while wearing the VASS which, when coupled with their subjective responses, suggests a preference for the pin suspension system.

BioMedical Engineering OnLine, 2014

Background: Prosthesis suspension systems can alter the distribution of pressure within the prosthetic socket. This study evaluates a new suspension system for lower limb prostheses, and aims to compare the interface pressure and amputees' satisfaction with the new system compared with a common prosthetic suspension system (pin/lock).

Background: An optimal suspension system can improve comfort and quality of life in people with limb loss. To guide practice on prosthetic vacuum suspension systems, assessment of the current evidence and professional opinion are required. Methods: PubMed, Web of Science, and Google Scholar databases were explored to find related articles. Search terms were amputees, artificial limb, prosthetic suspension, prosthetic liner, vacuum, and prosthesis. The results were refined by vacuum socket or vacuum assisted suspension or sub-atmospheric suspension. Study design, research instrument, sample size, and outcome measures were reviewed. An online questionnaire was also designed and distributed worldwide among professionals and prosthetists (www.ispoint.org, OANDP-L, LinkedIn, personal email). Findings: 26 articles were published from 2001 to March 2016. The number of participants averaged 7 (SD = 4) for transtibial and 6 (SD = 6) for transfemoral amputees. Most studies evaluated the short-term effects of vacuum systems by measuring stump volume changes, gait parameters, pistoning, interface pressures, satisfaction, balance, and wound healing. 155 professionals replied to the questionnaire and supported results from the literature. Elevated vacuum systems may have some advantages over the other suspension systems, but may not be appropriate for all people with limb loss. Interpretation: Elevated vacuum suspension could improve comfort and quality of life for people with limb loss. However, future investigations with larger sample sizes are needed to provide strong statistical conclusions and to evaluate long-term effects of these systems.

Journal of Rehabilitation Research and Development, 2013

The objective of this study was to investigate the effect of brimless compared with ischial ramus containment (IRC) prosthetic sockets when using vacuum-assisted suspension (VAS) on persons with a unilateral transfemoral amputation (TFA). A randomized crossover design with a 2 d accommodation was used. People with unilateral TFA (n = 9 analyzed) were enrolled. Interventions were IRC VAS and brimless VAS sockets. Main outcome measures included coronal hip angle and vertical and lateral socket movement as measured by X-ray, skin pressure measured by Tekscan, and preference measured subjectively. The brimless design was statistically equivalent to IRC in all measured coronal hip angles and vertical and lateral socket displacement. The peak/stance mean pressure in the medial proximal aspect of the socket was 322 mmHg in the IRC compared with 190 mmHg in the brimless condition. Except for medial proximal pressure, no other measures reached statistical significance. All subjects reported the brimless design to be more comfortable than the IRC in short-term preference. Brimless VAS socket design may be a clinically viable choice for people with TFA.

Function and Disability Journal, 2023

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.

The Journal of Rehabilitation Research and Development, 2012

Technology & Innovation, 2014

Enhanced suspension can be a contributory factor to optimizing stability (2,20,26). A more solid connection to the interface would potentially create less motion during swing, likely resulting in greater stability for the amputee. Contemporary suspension strategies have evolved to include gel liners with locking systems, sealing gaskets, fabric, and matrixes. Although offering the patient alternatives to these methods, enhanced suspensions are not dynamic, and most have not been compared under the rigors of a clinical trial. Traditional forms of suspension are mechanically static. The user dons the prosthesis and a mechanism that holds it onto the RL prevents detachment. Once the user is fully

2000

Daily volume loss of the stump leads to a poor fit of the prosthetic socket. A method of preventing this volume loss and maintaining a good fit was developed. A vacuum (-78 kPa) was drawn on the expulsion port of a total surface-bearing suction socket to hold the liner tightly against the socket. Stump volume of 10 trans-tibial amputees was measured prior to and immediately after a 30 minute walk with normal and vacuum socket conditions. Under the nonnal condition, the limb lost an average of 6.5% of its volume during the walk. In contrast, with the liner held tightly by vacuum, the limb gained an average of 3.7% in volume. It is believed that the difference observed between conditions resulted from a greater negative pressure developed during the swing phase of gait with the vacuum condition. X-rays revealed that the limb and tibia pis toned 4mm and 7mm less, respectively, under the vacuum condition. The combination of reduced pis toning and maintenance of volume is thought to account for the more symmetrical gait observed with the vacuum.

BMC, 2014

Background: Good prosthetic suspension system secures the residual limb inside the prosthetic socket and enables easy donning and doffing. This study aimed to introduce, evaluate and compare a newly designed prosthetic suspension system (HOLO) with the current suspension systems (suction, pin/lock and magnetic systems).