Amputation
Conditions
Brief summary
The investigators have developed a novel layered low-profile prosthetic foot that is able to provide enhanced compliance without sacrificing strength for individuals with transtibial amputation who have long residual limbs. It is hypothesized that the proposed prosthesis will offer similar benefits to these individuals as comparable higher profile prostheses offer users with shorter residual limbs. The primary goal of this Phase I proposal is to assess the degree to which the proposed prosthesis can provide benefits to prosthesis users in this population, along with characterizing the degree to which the novel prosthesis emulates its taller counterparts.
Interventions
DEVICELayered Low Profile Foot
The layered LPF is a novel low-profile prosthetic foot that provides compliant behavior while simultaneously exhibiting high mechanical strength.
DEVICEPrescribed Ankle
The prescribed ankle is the prosthetic ankle that the subject wears for daily use.
Sponsors
Kennesaw State University
Little Room Innovations, LLC
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Masking description
The control prosthesis and the experimental prosthesis are covered by a sock to prevent the participant from knowing which has been fit.
Eligibility
Sex/Gender
ALL
Age
18 Years to 89 Years
Healthy volunteers
No
Inclusion criteria
1. 18-89 years old 2. unilateral transtibial amputation 3. daily use of a low profile foot 4. cognitive ability to understand and willingness to provide informed consent and follow the study protocol
Exclusion criteria
1. unable to perform walking for 2 minutes without an assistive device 2. other health conditions which may prevent them from participating in the study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Total Energy Stored (TES) | through study completion, an average of 1 day | TES is the amount of energy absorbed by the ankle joint during early and middle stance. It is the integral of the product of joint torque and angular velocity, as determined through inverse dynamics. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Ankle Quasi-Stiffness (AQS) | through study completion, an average of 1 day | AQS is a measure of joint deformation under an applied load. It is extracted from the torque-angle relationship during walking determined through inverse dynamics. The ideal AQS varies from person to person, but in this study we were interested in seeing if the prostheses could achiever lower AQS. |
| Walking Speed | through study completion, an average of 1 day | This is the linear rate of change of position when a person walks, typically given in m/s. |
| Likert Scale Rating of Device Satisfaction | through study completion, an average of 1 day | A 1 to 10 rating of device satisfaction where the pre-trial perceived device satisfaction of the participant's prescribed ankle is defined as a 5 out of 10. 1 is defined as completely unacceptable, and 10 is defined as ideal performance. |
Countries
United States
Participant flow
Recruitment details
6 subjects were enrolled between 3/21/2024 and 7/16/2024 at Kennesaw State University.
Pre-assignment details
6 of 6 patients completed this crossover study.
Participants by arm
| Arm | Count |
|---|---|
| Layered Low Profile Foot (LPF) vs. Prescribed Ankle In this arm, subjects will first test the LPF and then complete the tests with their prescribed ankle.
Layered Low Profile Foot: The layered LPF is a novel low-profile prosthetic foot that provides compliant behavior while simultaneously exhibiting high mechanical strength.
Prescribed Ankle: The prescribed ankle is the prosthetic ankle that the subject wears for daily use. | 3 |
| Prescribed Ankle vs. Layered Low Profile Foot (LPF) In this arm, subjects will first complete the tests with their prescribed ankle and then test the LPF.
Layered Low Profile Foot: The layered LPF is a novel low-profile prosthetic foot that provides compliant behavior while simultaneously exhibiting high mechanical strength.
Prescribed Ankle: The prescribed ankle is the prosthetic ankle that the subject wears for daily use. | 3 |
| Total | 6 |
Baseline characteristics
| Characteristic | Layered Low Profile Foot (LPF) vs. Prescribed Ankle | Prescribed Ankle vs. Layered Low Profile Foot (LPF) | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 3 Participants | 3 Participants | 6 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 3 Participants | 2 Participants | 5 Participants |
| Region of Enrollment United States | 3 participants | 3 participants | 6 participants |
| Sex: Female, Male Female | 0 Participants | 1 Participants | 1 Participants |
| Sex: Female, Male Male | 3 Participants | 2 Participants | 5 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 6 | 0 / 6 |
| other Total, other adverse events | 0 / 6 | 0 / 6 |
| serious Total, serious adverse events | 0 / 6 | 0 / 6 |
Outcome results
Primary
Total Energy Stored (TES)
TES is the amount of energy absorbed by the ankle joint during early and middle stance. It is the integral of the product of joint torque and angular velocity, as determined through inverse dynamics.
Time frame: through study completion, an average of 1 day
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prescribed Ankle | Total Energy Stored (TES) | 20.1 Joules | Standard Deviation 11.2 |
| Layered Low Profile Foot (LPF) | Total Energy Stored (TES) | 13.3 Joules | Standard Deviation 6.9 |
Secondary
Ankle Quasi-Stiffness (AQS)
AQS is a measure of joint deformation under an applied load. It is extracted from the torque-angle relationship during walking determined through inverse dynamics. The ideal AQS varies from person to person, but in this study we were interested in seeing if the prostheses could achiever lower AQS.
Time frame: through study completion, an average of 1 day
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prescribed Ankle | Ankle Quasi-Stiffness (AQS) | 9.8 Newton meters per degree | Standard Deviation 2.7 |
| Layered Low Profile Foot (LPF) | Ankle Quasi-Stiffness (AQS) | 9.3 Newton meters per degree | Standard Deviation 3.9 |
Secondary
Likert Scale Rating of Device Satisfaction
A 1 to 10 rating of device satisfaction where the pre-trial perceived device satisfaction of the participant's prescribed ankle is defined as a 5 out of 10. 1 is defined as completely unacceptable, and 10 is defined as ideal performance.
Time frame: through study completion, an average of 1 day
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prescribed Ankle | Likert Scale Rating of Device Satisfaction | 4.3 units on a scale | Standard Deviation 1.5 |
| Layered Low Profile Foot (LPF) | Likert Scale Rating of Device Satisfaction | 5.2 units on a scale | Standard Deviation 1.5 |
Secondary
Walking Speed
This is the linear rate of change of position when a person walks, typically given in m/s.
Time frame: through study completion, an average of 1 day
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Prescribed Ankle | Walking Speed | 1.27 Meters per second | Standard Deviation 0.2 |
| Layered Low Profile Foot (LPF) | Walking Speed | 1.28 Meters per second | Standard Deviation 0.2 |