Clinical Research Directory

Effect of a Microprocessor-controlled Prosthetic Knee Joint on K2 Level Ambulators

Microprocessor-controlled knees (MPKs) automatically adjust resistance or damping in the joint to improve swing- and/or stance-phase control as appropriate for the prosthesis user during gait. The purpose of this proposed investigation is to determine if there are substantial physical and psychological benefits to fitting lower functioning Veteran ambulators having transfemoral amputations with an MPK compared with a nonmicroprocessor-controlled knee (NMPK). Using a repeated-measures, cross-sectional experimental design, approximately 20 Veterans with unilateral, transfemoral amputations will be evaluated on two separate occasions at the Jesse Brown VA Medical Center or the Edward Hines, Jr. VA Hospital, first with their conventional NMPK and then again after a 2-month accommodation period with the College Park Icon MPK.

Metabolic Cost of Walking With Passive vs. Powered Prosthetic Knees Among Persons With Limb Loss

The purpose of this industry-initiated research study is to test that a powered microprocessor controlled knee improves metabolic function during walking in level and sloped conditions as compared to the subject's physician prescribed prosthesis.

Transfemoral Osseointegrated Prosthesis Limb-Load Symmetry Training

This randomized controlled trial (n=25 enrolled, n=15 expected to complete) will 1) determine the feasibility of a 40-week limb-load biofeedback training intervention, 2) determine if there is an intervention signal of efficacy, and 3) identify functional movement priorities for people with transfemoral osseointegrated (OI) prostheses. A limb-load biofeedback training group (EXP (n=10)) will be compared to a standard of care attention-control group without limb-load biofeedback training (CTL (n=5)). Outcomes will be assessed at standard of care pre-habilitation end (Week 5), standard of care rehabilitation end (Week 24), and one year after OI Stage 2 surgery (Week 64).

Active Knee Prosthesis Study

The purpose of the study is to investigate the clinical and functional outcomes of a powered knee prosthesis for people with a transfemoral amputation in the domain of gait, free space control, and embodiment

Towards Efficient Personalization of Computerized Lower Limb Prostheses Via Reinforcement Learning in a Clinical Setup - Group 1

The goal of this clinical trial is to understand the feasibility and effectiveness of using reinforcement learning to personalize robotic prosthetic legs (an experimental prototype) for unilateral transfemoral amputees. The main questions it aims to answer are: * With the developed RL-based Recommendation Interfacing System (RISE), clinicians are able to personalize prosthetic legs faster compared with existing manual personalization procedures. * With the developed RL-based Recommendation Interfacing System (RISE), clinicians are able to personalize prosthetic legs without detailed knowledge about how the prosthetic legs are controlled. * Patients perform better when the prosthetic legs are personalized with RISE system compared with the ones personalized manually Researchers will compare two arms (RISE guided personalization and manual personalization) to see if the tuning speed will increase and if patients can perform better. Participants will go through the standard prosthetic fitting procedures, such as alignment adjustment, then they will experience repeated prosthesis personalization procedures conducted by tuning specialists without RISE, tuning specialists with RISE, and prosthetists (without tuning expertise) with RISE on different types of terrains. In the end, the participants will go through a testing trial, in which they will experience the prototype personalized through the three different approaches without knowing how the control parameters are decided. Their walking performance will be recorded. It is expected that the participants will visit the testing site 8 times, which including alignment (1 visit), three personalization procedures (twice for each), and one testing trial (1-2 visits).

Evaluation of a Neural-Controlled Powered Prosthesis Across Diverse Real-World Tasks

The purpose of this study is to evaluate the performance and adaptability of a neural-controlled powered knee or ankle prosthesis across diverse real-world mobility tasks. This research aims to assess how compare the sense of embodiment with the device, symmetry, and stability of a person with an lower-extremity amputation walking with a bionic prosthesis and their prescribed prosthesis. Findings from this study will inform future developments in bionic prosthesis design with optimal integration with the human body, with the goal of improving prosthetic integration into daily life.

A Biomechanical Evaluation of the Ossur Power Knee in Persons With Transfemoral Amputation

Microprocessor-controlled knees (MPKs) do not typically utilize motors to power joint rotation, but they automatically adjust resistance or damping in the joint to improve swing- and/or stance-phase control as appropriate for the prosthesis user during gait. The Ossur Power Knee is the only commercially-available MPK that uses a motor to provide active power generation during walking and other activities. The purpose of this proposed investigation is to perform and compare biomechanical evaluations of the Power Knee and Ossur Rheo XC, a passive MPK, during walking and other activities by prosthesis users. Furthermore, mobility between male and female subjects will be compared to determine if there are differences in prosthetic knee usage on the basis of sex.

Assessment of Strength, Balance, and Function in Above-Knee Amputees in Relation to Residual Limb Length

The goal of this observational study is to learn how muscle strength, balance, and functional ability are affected in people with above-knee (transfemoral) amputations. The main questions it aims to answer are: How does the length of the lost part of the leg, compared to the intact leg, affect muscle strength, balance, and functional capacity? Is muscle strength at specific lower limb joints related to balance and performance ? Participants will: Have muscle strength measured at all intact lower limb joints using an isokinetic dynamometer Complete balance assessments using force platform technology that measures weight distribution and evaluates both static and dynamic balance Perform a six-minute walk test to evaluate endurance and functional capacity The study will help improve understanding of how limb length and joint-specific muscle strength impact mobility, supporting the development of better rehabilitation programs for amputees.

Improving Socket Fit in Female and Male Veterans With Transtibial and Transfemoral Amputation

The investigators do not yet know how a prosthetic socket with adjustable panels affects the performance of people with a lower limb amputation compared to a conventional prosthetic socket. The primary objective of this study is to compare an adjustable and conventional prosthetic socket and use this information to determine the optimal socket that would improve rehabilitation and function in people with lower limb amputation.

Osseointegrated Prostheses for the Rehabilitation of Amputees

Patients with transfemoral amputations (TFA) frequently experience problems related to the use of socket-suspended prostheses 1-3. These problems increase with short or deformed stumps 4. The potential for improvement is substantial. Based on the very good long-term results with osseointegrated titanium implants for edentulous patients 5, osseointegrated hearing aids 6, cranio-facial prostheses 7 and prostheses for thumb-amputated patients 8, the clinical development of osseointegrated prostheses for TFA started in 1990, in Gothenburg, Sweden. The concept has gradually been modified and improved. In 1999, a prospective clinical trial began. The hypothesis is that the treatment will improve quality of life.