Amputation
Conditions
Keywords
Rehabilitation
Brief summary
Previous studies suggest that Veterans with below the knee amputation using passive-elastic or powered prostheses have impaired physical function, which could increase the risk of osteoarthritis, leg/back pain, and diabetes/obesity. Utilization of rehabilitation strategies/techniques such as real-time visual feedback training could restore physical function, increase physical activity, and reduce injury risk. The investigators will systematically determine the effects of using real-time visual feedback training of peak propulsive (push-off) force during walking while Veterans with below the knee amputations use a passive-elastic and battery-powered prosthesis. Similar to previous studies of non-amputee older (\>65 years) and post-stroke adults, use of real-time visual feedback training of propulsive force will likely improve walking function in Veterans with amputations. Such training presents a promising rehabilitation strategy that could reduce comorbidities, while improving quality of life, comfort, and physical function, and advancing rehabilitation research and prosthetic development.
Detailed description
Due to the functional impairments caused by a lower limb amputation, it is essential to determine the benefits of rehabilitation strategies such as real-time visual feedback training. Such training could allow Veterans with transtibial amputations (TTAs) to better utilize their prostheses and regain the greatest possible level of function. It is not clear how much the prosthetic device (passive-elastic prosthetic foot versus battery-powered ankle-foot prosthesis) and/or the user's response to the prosthesis contribute to the biomechanical and metabolic effects of using these prostheses during walking. Better use of a prosthesis due to targeted real-time visual feedback training could enhance rehabilitation, improve function and reduce asymmetric biomechanics, which in turn could reduce common comorbidities such as osteoarthritis, leg and back pain, and indirectly, diabetes in Veterans with TTAs. The purpose of the proposed project is to systematically establish the metabolic and biomechanical effects of targeted real-time visual feedback training of peak propulsive ground reaction force (GRF) on the biomechanics, metabolic costs, and muscle activity of Veterans with TTAs using their own passive-elastic prosthetic foot and a battery-powered ankle-foot prosthesis. The results of the investigators' research could enhance the use of prosthetic technology to improve the rehabilitation and function of Veterans with lower limb amputations. Previous studies suggest that use of passive-elastic and/or powered ankle-foot prostheses may not optimize the function of Veterans with TTAs during walking. Targeted, real-time visual feedback training of peak propulsive ground reaction forces increased propulsion and improved walking function in older (\>65 years) and post-stroke adults, who typically have impaired ankle power. To the investigators' knowledge, no research has addressed how visual feedback of peak propulsive force affects the use of passive-elastic or powered ankle-foot prostheses by people with TTAs. In the proposed research, the investigators will determine the underlying metabolic costs, biomechanics, stability, and muscle activity resulting from targeted real-time visual feedback training of peak propulsive force to identify how Veterans with a TTA benefit from more effective use of a passive-elastic prosthesis and/or a battery-powered ankle-foot prosthesis and to determine if the addition of mechanical power provided by a battery-powered ankle-foot prosthesis can further enhance the function of Veterans with unilateral TTAs during walking. 30 Veterans with unilateral TTAs will use their own passive-elastic prosthesis both with and without visual feedback training during level-ground walking, while the investigators measure their metabolic costs and biomechanics. Then, they will use a powered ankle-foot prosthesis (emPOWER, BiONX, Ottobock) both with and without visual feedback training during level-ground walking, while the investigators measure their metabolic costs and biomechanics. With each prosthesis, subjects will walk at 1.25 m/s on a dual-belt force-measuring treadmill 1) with no visual feedback, and then with real-time visual feedback of: 2) peak propulsive force from the no feedback condition, 3) +20% greater peak propulsive force, and 4) +40% greater peak propulsive force. During these visual feedback trials, the investigators will ask subjects to match the peak propulsive force displayed on a computer screen with their affected leg. The investigators will also ask subjects to: 5) match symmetric visual feedback of the peak propulsive force from both legs. The investigators will determine if Veterans with TTAs utilizing real-time visual feedback training of peak propulsive force can improve metabolic costs, biomechanical symmetry, and dynamic stability/balance, while using their own passive-elastic prosthesis or a powered ankle-foot prosthesis. The investigators will also establish if Veterans with TTAs can retain the metabolic and biomechanical benefits elicited by real-time visual feedback training once that feedback is removed. Results from the proposed project will be used to inform rehabilitation strategies and prosthetic design, which could ultimately improve health, maximize function, and improve quality of life for Veterans with TTAs.
Interventions
DEVICEPassive-elastic prosthetic foot
The investigators will measure the biomechanics (motion, forces, and muscle activity) and metabolic rates while subjects walk using their own passive-elastic prosthesis with and without visual feedback of peak propulsive force targets.
The investigators will measure the biomechanics (motion, forces, and muscle activity) and metabolic rates while subjects walk using a battery-powered ankle-foot prosthesis with and without visual feedback of peak propulsive force targets.
Sponsors
VA Office of Research and Development
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to 67 Years
Healthy volunteers
Yes
Inclusion criteria
* One amputation below the knee * At least 1 year of experience using a prosthesis * No current problems with the prosthesis or residual limb * At or above a K3 Medicare Functional Classification Level
Exclusion criteria
* Poor general health * Difficulty with mobility * Problems with balance or dizziness * Current serious musculoskeletal injury besides that associated with an amputation * Cardiovascular, pulmonary, or neurological disease or disorder
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 18 trials that are 5 minutes in length | The investigators measured peak propulsive horizontal ground reaction force (hGRFpeak) from the affected leg while participants with a transtibial amputation walked at 1.25 m/s for 18 trials that were 5 minutes each over 3 separate days using an elastic energy storage and return (ESAR) and stance-phase powered ankle-foot (BiOM) prosthesis. During the first trial we measured their baseline hGRFpeak and then for the subsequent trials we provided a trial with visual feedback (FB) targets of hGRFpeak relative to their baseline (BL) trial using a monitor placed at eye level as well as VF of symmetric (Sym) targets of hGRFpeak from both legs and then removed the visual feedback during a retention (RT) trial that immediately followed the VF trial. The order of trials was randomized and included targets of 0, +20, and +40% of baseline hGRFpeak as well as a Sym target of hGRFpeak. Thus, participants performed 9 trials per prosthesis. |
| Net Metabolic Power | 18 trials that are 5 minutes in length | The investigators measured net metabolic power while participants with a transtibial amputation walked at 1.25 m/s for 18 trials that were 5 minutes each over 3 separate days using an elastic energy storage and return (ESAR) and stance-phase powered ankle-foot (BiOM) prosthesis. During the first trial we measured their baseline peak propulsive horizontal ground reaction force (hGRFpeak) from the affected leg and then for the subsequent trials we provided a trial with visual feedback (FB) targets of hGRFpeak relative to their baseline (BL) trial using a monitor placed at eye level as well as VF of symmetric (Sym) targets of hGRFpeak from both legs and then removed the visual feedback during a retention (RT) trial that immediately followed the VF trial. The order of trials was randomized and included targets of 0, +20, and +40% of baseline hGRFpeak as well as a Sym target of hGRFpeak. Thus, participants performed 9 trials per prosthesis. |
| Trailing Affected Leg Positive Work | 18 trials that are 5 minutes in length | The investigators measured ground reaction forces and calculated individual leg work during step to step transitions while participants with a transtibial amputation walked at 1.25 m/s for 18 trials that were 5 minutes each over 3 separate days using an elastic energy storage and return (ESAR) and stance-phase powered ankle-foot (BiOM) prosthesis. During the first trial we measured their baseline peak propulsive horizontal ground reaction force (hGRFpeak) from the affected leg and then for the subsequent trials we provided a trial with visual feedback (FB) targets of hGRFpeak relative to their baseline (BL) trial using a monitor placed at eye level as well as VF of symmetric (Sym) targets of hGRFpeak from both legs and then removed the visual feedback during a retention (RT) trial that immediately followed the VF trial. The order of trials was randomized and included targets of 0, +20, and +40% of baseline hGRFpeak as well as a Sym target of hGRFpeak. |
| Leading Unaffected Leg Negative Work | 18 trials that are 5 minutes in length | The investigators measured ground reaction forces and calculated individual leg work during step to step transitions while participants with a transtibial amputation walked at 1.25 m/s for 18 trials that were 5 minutes each over 3 separate days using an elastic energy storage and return (ESAR) and stance-phase powered ankle-foot (BiOM) prosthesis. During the first trial we measured their baseline peak propulsive horizontal ground reaction force (hGRFpeak) from the affected leg and then for the subsequent trials we provided a trial with visual feedback (FB) targets of hGRFpeak relative to their baseline (BL) trial using a monitor placed at eye level as well as VF of symmetric (Sym) targets of hGRFpeak from both legs and then removed the visual feedback during a retention (RT) trial that immediately followed the VF trial. The order of trials was randomized and included targets of 0, +20, and +40% of baseline hGRFpeak as well as a Sym target of hGRFpeak. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Participants With Transtibial Amputation The investigators will recruit participants with unilateral transtibial amputations who are at or above a K3 Medicare functional classification level (MFCL), and 18-60 years old. A K3 MFCL means that a person has the ability or potential for ambulation with variable cadence. A person at K3 MFCL is a typical community ambulator who has the ability to traverse most environmental barriers and may have vocational, therapeutic or exercise activity that demands prosthetic use beyond simple locomotion.
Passive-elastic prosthetic foot: The investigators will measure the biomechanics (motion, forces, and muscle activity) and metabolic rates while subjects walk using their own passive-elastic prosthesis with and without visual feedback of peak propulsive force targets.
Powered ankle-foot prosthesis: The investigators will measure the biomechanics (motion, forces, and muscle activity) and metabolic rates while subjects walk using a battery-powered ankle-foot prosthesis with and without visual feedback of peak propulsive force targets. | 12 |
| Total | 12 |
Baseline characteristics
| Characteristic | Participants With Transtibial Amputation |
|---|---|
| Age, Continuous | 40.4 years STANDARD_DEVIATION 8.2 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants |
| Race (NIH/OMB) Black or African American | 1 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 10 Participants |
| Region of Enrollment United States | 12 Participants |
| Sex: Female, Male Female | 4 Participants |
| Sex: Female, Male Male | 8 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 12 |
| other Total, other adverse events | 0 / 12 |
| serious Total, serious adverse events | 0 / 12 |
Outcome results
Primary
Affected Leg Peak Propulsive Horizontal Ground Reaction Force
The investigators measured peak propulsive horizontal ground reaction force (hGRFpeak) from the affected leg while participants with a transtibial amputation walked at 1.25 m/s for 18 trials that were 5 minutes each over 3 separate days using an elastic energy storage and return (ESAR) and stance-phase powered ankle-foot (BiOM) prosthesis. During the first trial we measured their baseline hGRFpeak and then for the subsequent trials we provided a trial with visual feedback (FB) targets of hGRFpeak relative to their baseline (BL) trial using a monitor placed at eye level as well as VF of symmetric (Sym) targets of hGRFpeak from both legs and then removed the visual feedback during a retention (RT) trial that immediately followed the VF trial. The order of trials was randomized and included targets of 0, +20, and +40% of baseline hGRFpeak as well as a Sym target of hGRFpeak. Thus, participants performed 9 trials per prosthesis.
Time frame: 18 trials that are 5 minutes in length
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| ESAR - BL | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.151 proportion of body weight | Standard Deviation 0.022 |
| ESAR - 0FB | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.145 proportion of body weight | Standard Deviation 0.019 |
| ESAR - 0RT | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.166 proportion of body weight | Standard Deviation 0.021 |
| ESAR - 20FB | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.150 proportion of body weight | Standard Deviation 0.022 |
| ESAR - 20RT | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.175 proportion of body weight | Standard Deviation 0.02 |
| ESAR - 40FB | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.147 proportion of body weight | Standard Deviation 0.018 |
| ESAR - 40RT | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.145 proportion of body weight | Standard Deviation 0.022 |
| ESAR - SymFB | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.171 proportion of body weight | Standard Deviation 0.031 |
| ESAR - SymRT | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.146 proportion of body weight | Standard Deviation 0.022 |
| BiOM - BL | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.169 proportion of body weight | Standard Deviation 0.011 |
| BiOM - 0FB | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.160 proportion of body weight | Standard Deviation 0.011 |
| BiOM - 0RT | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.178 proportion of body weight | Standard Deviation 0.021 |
| BiOM - 20FB | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.161 proportion of body weight | Standard Deviation 0.011 |
| BiOM - 20RT | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.186 proportion of body weight | Standard Deviation 0.02 |
| BiOM - 40FB | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.166 proportion of body weight | Standard Deviation 0.014 |
| BiOM - 40RT | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.157 proportion of body weight | Standard Deviation 0.018 |
| BiOM - SymFB | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.174 proportion of body weight | Standard Deviation 0.019 |
| BiOM - SymRT | Affected Leg Peak Propulsive Horizontal Ground Reaction Force | 0.172 proportion of body weight | Standard Deviation 0.024 |
Primary
Leading Unaffected Leg Negative Work
The investigators measured ground reaction forces and calculated individual leg work during step to step transitions while participants with a transtibial amputation walked at 1.25 m/s for 18 trials that were 5 minutes each over 3 separate days using an elastic energy storage and return (ESAR) and stance-phase powered ankle-foot (BiOM) prosthesis. During the first trial we measured their baseline peak propulsive horizontal ground reaction force (hGRFpeak) from the affected leg and then for the subsequent trials we provided a trial with visual feedback (FB) targets of hGRFpeak relative to their baseline (BL) trial using a monitor placed at eye level as well as VF of symmetric (Sym) targets of hGRFpeak from both legs and then removed the visual feedback during a retention (RT) trial that immediately followed the VF trial. The order of trials was randomized and included targets of 0, +20, and +40% of baseline hGRFpeak as well as a Sym target of hGRFpeak.
Time frame: 18 trials that are 5 minutes in length
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| ESAR - BL | Leading Unaffected Leg Negative Work | -15.373 Joules | Standard Deviation 4.191 |
| ESAR - 0FB | Leading Unaffected Leg Negative Work | -14.438 Joules | Standard Deviation 4.394 |
| ESAR - 0RT | Leading Unaffected Leg Negative Work | -15.981 Joules | Standard Deviation 6.225 |
| ESAR - 20FB | Leading Unaffected Leg Negative Work | -14.363 Joules | Standard Deviation 4.59 |
| ESAR - 20RT | Leading Unaffected Leg Negative Work | -17.781 Joules | Standard Deviation 7.167 |
| ESAR - 40FB | Leading Unaffected Leg Negative Work | -14.018 Joules | Standard Deviation 5.195 |
| ESAR - 40RT | Leading Unaffected Leg Negative Work | -14.389 Joules | Standard Deviation 4.451 |
| ESAR - SymFB | Leading Unaffected Leg Negative Work | -15.350 Joules | Standard Deviation 6.056 |
| ESAR - SymRT | Leading Unaffected Leg Negative Work | -14.223 Joules | Standard Deviation 5.517 |
| BiOM - BL | Leading Unaffected Leg Negative Work | -15.781 Joules | Standard Deviation 6.674 |
| BiOM - 0FB | Leading Unaffected Leg Negative Work | -15.011 Joules | Standard Deviation 6.284 |
| BiOM - 0RT | Leading Unaffected Leg Negative Work | -17.975 Joules | Standard Deviation 5.403 |
| BiOM - 20FB | Leading Unaffected Leg Negative Work | -14.713 Joules | Standard Deviation 5.84 |
| BiOM - 20RT | Leading Unaffected Leg Negative Work | -18.475 Joules | Standard Deviation 7.963 |
| BiOM - 40FB | Leading Unaffected Leg Negative Work | -16.032 Joules | Standard Deviation 6.839 |
| BiOM - 40RT | Leading Unaffected Leg Negative Work | -15.507 Joules | Standard Deviation 5.169 |
| BiOM - SymFB | Leading Unaffected Leg Negative Work | -15.755 Joules | Standard Deviation 6.95 |
| BiOM - SymRT | Leading Unaffected Leg Negative Work | -14.918 Joules | Standard Deviation 5.957 |
Primary
Net Metabolic Power
The investigators measured net metabolic power while participants with a transtibial amputation walked at 1.25 m/s for 18 trials that were 5 minutes each over 3 separate days using an elastic energy storage and return (ESAR) and stance-phase powered ankle-foot (BiOM) prosthesis. During the first trial we measured their baseline peak propulsive horizontal ground reaction force (hGRFpeak) from the affected leg and then for the subsequent trials we provided a trial with visual feedback (FB) targets of hGRFpeak relative to their baseline (BL) trial using a monitor placed at eye level as well as VF of symmetric (Sym) targets of hGRFpeak from both legs and then removed the visual feedback during a retention (RT) trial that immediately followed the VF trial. The order of trials was randomized and included targets of 0, +20, and +40% of baseline hGRFpeak as well as a Sym target of hGRFpeak. Thus, participants performed 9 trials per prosthesis.
Time frame: 18 trials that are 5 minutes in length
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| ESAR - BL | Net Metabolic Power | 2.967 Watts per kg | Standard Deviation 0.345 |
| ESAR - 0FB | Net Metabolic Power | 3.141 Watts per kg | Standard Deviation 0.275 |
| ESAR - 0RT | Net Metabolic Power | 3.020 Watts per kg | Standard Deviation 0.23 |
| ESAR - 20FB | Net Metabolic Power | 3.338 Watts per kg | Standard Deviation 0.422 |
| ESAR - 20RT | Net Metabolic Power | 3.124 Watts per kg | Standard Deviation 0.316 |
| ESAR - 40FB | Net Metabolic Power | 3.478 Watts per kg | Standard Deviation 0.488 |
| ESAR - 40RT | Net Metabolic Power | 3.168 Watts per kg | Standard Deviation 0.409 |
| ESAR - SymFB | Net Metabolic Power | 3.330 Watts per kg | Standard Deviation 0.554 |
| ESAR - SymRT | Net Metabolic Power | 3.062 Watts per kg | Standard Deviation 0.317 |
| BiOM - BL | Net Metabolic Power | 2.852 Watts per kg | Standard Deviation 0.413 |
| BiOM - 0FB | Net Metabolic Power | 2.979 Watts per kg | Standard Deviation 0.436 |
| BiOM - 0RT | Net Metabolic Power | 2.938 Watts per kg | Standard Deviation 0.425 |
| BiOM - 20FB | Net Metabolic Power | 3.268 Watts per kg | Standard Deviation 0.561 |
| BiOM - 20RT | Net Metabolic Power | 3.022 Watts per kg | Standard Deviation 0.473 |
| BiOM - 40FB | Net Metabolic Power | 3.314 Watts per kg | Standard Deviation 0.54 |
| BiOM - 40RT | Net Metabolic Power | 3.013 Watts per kg | Standard Deviation 0.418 |
| BiOM - SymFB | Net Metabolic Power | 2.974 Watts per kg | Standard Deviation 0.539 |
| BiOM - SymRT | Net Metabolic Power | 2.862 Watts per kg | Standard Deviation 0.399 |
Primary
Trailing Affected Leg Positive Work
The investigators measured ground reaction forces and calculated individual leg work during step to step transitions while participants with a transtibial amputation walked at 1.25 m/s for 18 trials that were 5 minutes each over 3 separate days using an elastic energy storage and return (ESAR) and stance-phase powered ankle-foot (BiOM) prosthesis. During the first trial we measured their baseline peak propulsive horizontal ground reaction force (hGRFpeak) from the affected leg and then for the subsequent trials we provided a trial with visual feedback (FB) targets of hGRFpeak relative to their baseline (BL) trial using a monitor placed at eye level as well as VF of symmetric (Sym) targets of hGRFpeak from both legs and then removed the visual feedback during a retention (RT) trial that immediately followed the VF trial. The order of trials was randomized and included targets of 0, +20, and +40% of baseline hGRFpeak as well as a Sym target of hGRFpeak.
Time frame: 18 trials that are 5 minutes in length
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| ESAR - BL | Trailing Affected Leg Positive Work | 9.859 Joules | Standard Deviation 3.392 |
| ESAR - 0FB | Trailing Affected Leg Positive Work | 10.321 Joules | Standard Deviation 4.325 |
| ESAR - 0RT | Trailing Affected Leg Positive Work | 10.773 Joules | Standard Deviation 4.326 |
| ESAR - 20FB | Trailing Affected Leg Positive Work | 10.212 Joules | Standard Deviation 4.419 |
| ESAR - 20RT | Trailing Affected Leg Positive Work | 11.203 Joules | Standard Deviation 4.652 |
| ESAR - 40FB | Trailing Affected Leg Positive Work | 10.319 Joules | Standard Deviation 4.463 |
| ESAR - 40RT | Trailing Affected Leg Positive Work | 9.592 Joules | Standard Deviation 4.212 |
| ESAR - SymFB | Trailing Affected Leg Positive Work | 11.384 Joules | Standard Deviation 3.941 |
| ESAR - SymRT | Trailing Affected Leg Positive Work | 10.410 Joules | Standard Deviation 4.642 |
| BiOM - BL | Trailing Affected Leg Positive Work | 14.624 Joules | Standard Deviation 5.8 |
| BiOM - 0FB | Trailing Affected Leg Positive Work | 14.108 Joules | Standard Deviation 4.835 |
| BiOM - 0RT | Trailing Affected Leg Positive Work | 15.211 Joules | Standard Deviation 6.363 |
| BiOM - 20FB | Trailing Affected Leg Positive Work | 13.597 Joules | Standard Deviation 5.413 |
| BiOM - 20RT | Trailing Affected Leg Positive Work | 15.274 Joules | Standard Deviation 6.466 |
| BiOM - 40FB | Trailing Affected Leg Positive Work | 14.071 Joules | Standard Deviation 4.45 |
| BiOM - 40RT | Trailing Affected Leg Positive Work | 12.818 Joules | Standard Deviation 4.203 |
| BiOM - SymFB | Trailing Affected Leg Positive Work | 14.730 Joules | Standard Deviation 6.242 |
| BiOM - SymRT | Trailing Affected Leg Positive Work | 15.078 Joules | Standard Deviation 5.575 |