Diabetes Mellitus, Leg Injuries, Traumatic Amputation
Conditions
Keywords
Amputation, Amputee, Artificial limbs, Gait, Locomotion, Walking
Brief summary
The biomechanics of changing direction while walking has been largely neglected despite its relevancy to functional mobility. In addition, an increased risk of injury can be associated with turning due to a decrease in stability. The objective of this study is to understand the biomechanics of turning gait in sample populations of intact and trans-tibial amputees and the capacity of prosthetic components to facilitate transverse plane movement. The clinical impact of this investigation is the development of interventions that increase functional mobility, stability and safety while turning. The researchers propose to investigate three sets of hypotheses. The first set addresses the fundamental biomechanical mechanisms associated with walking along a circular trajectory, how intact subjects differ from amputees, and the effect of a rotation adaptor pylon. The second set of hypotheses addresses dynamic stability and the potential influence of prosthetic interventions. The third set of hypotheses addresses how the rotational properties of the prosthetic pylon can influence comfort and mobility during daily activities.
Detailed description
Most of what is known about how amputees walk and how the properties of prosthetic components affect their gait has been discovered through sagittal plane observations while amputees walk back and forth along a straight line. Abnormal limb loading, thought to be a principal factor in the occurrence of residual limb pain which in turn may cause instability and limit mobility, can certainly occur while walking in a straight line. However, the incidence of abnormal limb loading is likely amplified when performing more complex gait activities, such as turning or avoiding obstacles; activities that are so very common in everyday life. The specific aims of this investigation are to: 1. discover the biomechanical strategies used and the stability of both intact individuals and trans-tibial amputees walking along a circular trajectory and 2. explore the effects of a prosthetic intervention on turning biomechanics, stability, comfort, and mobility. We propose to investigate three sets of hypotheses: The first set of hypotheses addresses the fundamental biomechanical mechanisms associated with walking along a circular trajectory, how intact subjects differ from amputees, and the effect of a rotation adaptor pylon. We will conduct experiments to test three hypotheses related to achieving a change of heading, orientation, and balancing of centripetal forces necessary to walk along a circular trajectory. The second set of hypotheses seeks to identify whether trans-tibial amputees with a rigid pylon are more unstable during a turning task than non-amputees and whether or not the rotation adaptors enhance stability. We will conduct experiments to calculate an index of dynamic stability that measures the rate at which a person can respond to a perturbation and return to a stable gait pattern. The third set of hypotheses addresses how the rotational properties of the prosthetic pylon can influence comfort and mobility during daily activities. To measure comfort and mobility, we will solicit questionnaire responses and step count measures from amputees after a one-month period of wearing a rigid pylon and after a one-month period of wearing a transverse plane rotation adaptor (within-subject comparison). In addition to these field measurements, we will also compare the distance traveled during a six-minute walk. Patient opinions about their prosthesis and mobility measures over long periods of time can play a significant role in prosthesis evaluation. For veteran amputees who experience discomfort and increased risk for residual limb skin problems, it seems reasonable to suppose that these problems might occur when walking along a curved trajectory rather than just a straight line. The joint forces and moments of turning may differ significantly from those exhibited while walking in a straight line. The proposed research will create a new knowledge base with which to understand prosthetic intervention effectiveness. The immediate clinical impact for the trans-tibial amputee is the determination if transverse plane rotational adapter pylons can improve their comfort, mobility, and stability.
Interventions
DEVICETransverse plane rotation adaptor pylon
Potential future practice
DEVICERigid pylon
Current clinical practice
Sponsors
US Department of Veterans Affairs
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
* Amputee Subjects: * be a unilateral trans-tibial amputee between the ages of 18 and 70, * weigh 220 pounds or less, * have been fit with a prosthesis and using a prosthesis for at least two years, * wear the prosthesis for at least 8 hours per day, * walk without crutches or a walker, * able to walk outside the home and in the community, * have not fallin within the last six months, * Non-amputee subjects participating in this investigation will meet similar inclusion criteria except for those related to prosthesis use.
Exclusion criteria
* Amputee Subjects: * amputation due to tumor, have an active tumor, or are undergoing treatment of a tumor, * have pain in legs or any condition that interferes with walking. * Non-amputee subjects participating in this investigation will meet similar
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Local Dynamic Stability (Hip During Straight Walking) | Measurements were taken after wearing the study prostheses for three weeks. | Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system. |
| Local Dynamic Stability (Knee During Straight Walking) | Measurements were taken after wearing the study prostheses for three weeks. | Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system. |
| Local Dynamic Stability (Ankle During Straight Walking) | Measurements were taken after wearing the study prostheses for three weeks. | Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system. |
| Local Dynamic Stability (Hip During Turning With the Prosthesis on the Inside of the Turn) | Measurements were taken after wearing the study prostheses for three weeks. | Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system. |
| Local Dynamic Stability (Knee During Turning With the Prosthesis on the Inside of the Turn) | Measurements were taken after wearing the study prostheses for three weeks. | Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system. |
| Local Dynamic Stability (Ankle During Turning With the Prosthesis on the Inside of the Turn) | Measurements were taken after wearing the study prostheses for three weeks. | Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system. |
| Local Dynamic Stability (Hip During Turning With the Prosthesis on the Outside of the Turn) | Measurements were taken after wearing the study prostheses for three weeks. | Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system. |
| Local Dynamic Stability (Knee During Turning With the Prosthesis on the Outside of the Turn) | Measurements were taken after wearing the study prostheses for three weeks. | Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system. |
| Local Dynamic Stability (Ankle During Turning With the Prosthesis on the Outside of the Turn) | Measurements were taken after wearing the study prostheses for three weeks. | Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Average Residual Limb Pain? | Measurements were taken after wearing the study prostheses for four weeks. | The residual limb pain grade scores ranged from 0 No Pain/ Interference to 10 Severe Pain/Interference. |
| Worst Residual Limb Pain? | Measurements were taken after wearing the study prostheses for four weeks. | The residual limb pain grade scores ranged from 0 No Pain/ Interference to 10 Severe Pain/Interference. |
| Peak External Rotation Moment of the Outside Hip While Turning | Measurements were taken after wearing the study prostheses for three weeks. | — |
| Pain Interference With Activities? | Measurements were taken after wearing the study prostheses for four weeks. | The residual limb pain grade scores ranged from 0 No Pain/ Interference to 10 Severe Pain/Interference. |
| How Bothersome Was Your Pain? | Measurements were taken after wearing the study prostheses for four weeks. | The residual limb pain grade scores ranged from 0 No Pain/ Interference to 10 Severe Pain/Interference. |
| Least Residual Limb Pain? | Measurements were taken after wearing the study prostheses for four weeks. | The residual limb pain grade scores ranged from 0 No Pain/ Interference to 10 Severe Pain/Interference. |
| Peak External Rotation Moment of the Outside Knee While Turning | Measurements were taken after wearing the study prostheses for three weeks. | — |
| Peak External Rotation Moment of the Outside Ankle While Turning | Measurements were taken after wearing the study prostheses for three weeks. | — |
| Peak External Rotation Moment of the Inside Hip While Turning | Measurements were taken after wearing the study prostheses for three weeks. | — |
| Peak External Rotation Moment of the Inside Knee While Turning | Measurements were taken after wearing the study prostheses for three weeks. | — |
| Peak External Rotation Moment of the Inside Ankle While Turning | Measurements were taken after wearing the study prostheses for three weeks. | — |
| Activity Level | One week | Average number of steps per day over a 1 week period ending in the fourth week of each study prosthesis (Rigid and Torsion adapter) |
| Six-minute Walk Distance | Six minutes after wearing the study prostheses for four weeks. | Participants are asked to walk alone as far as possible without running for six minutes. This test is performed indoors along a long, flat straight hallway of approximately 30 meters in length with two orange cones marking the 180 degree turnaround points at each end of the corridor. Approximately 40 straight steps were taken for every four turning steps. |
| Residual Limb Pain at Present? | Measurements were taken after wearing the study prostheses for four weeks | The residual limb pain grade scores ranged from 0 No Pain/ Interference to 10 Severe Pain/Interference. |
Countries
United States
Participant flow
Recruitment details
Recruitment for this study was conducted at the VA Puget Sound Health Care System (Seattle VA hospital). Recruitment began on May 18, 2006. The study was closed to enrollment on April 24, 2008. Data was not collected on the order in which participants received each study intervention.
Pre-assignment details
The prostheses used in this study were built and aligned by a certified and licensed prosthetist prior to beginning starting the protocol. 12 individuals provided informed consent. 1 withdrew prior to starting for personal reasons. 1 withdrew due to unrelated back pain after being fit with both study prostheses and starting with the rigid pylon.
Participants by arm
| Arm | Count |
|---|---|
| Amputee Lower limb amputees who wore both rigid and torsion adapter pylons in random order and completed the study protocol. | 10 |
| Total | 10 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Withdrawal by Subject | 1 |
Baseline characteristics
| Characteristic | Amputee |
|---|---|
| Age, Categorical <=18 years | 0 Participants |
| Age, Categorical >=65 years | 1 Participants |
| Age, Categorical Between 18 and 65 years | 9 Participants |
| Age, Continuous | 56 years STANDARD_DEVIATION 12 |
| Amputation Etiology Diabetic/Dysvascular | 4 participants |
| Amputation Etiology Trauma | 5 participants |
| Amputation Etiology Tumor | 1 participants |
| Height | 1.79 m STANDARD_DEVIATION 0.08 |
| Sex: Female, Male Female | 1 Participants |
| Sex: Female, Male Male | 9 Participants |
| Torsion adapter stiffness | 4 units on a scale STANDARD_DEVIATION 2 |
| Weight | 88 kg STANDARD_DEVIATION 11 |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 0 / 12 |
| serious Total, serious adverse events | 0 / 12 |
Outcome results
Primary
Local Dynamic Stability (Ankle During Straight Walking)
Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system.
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Local Dynamic Stability (Ankle During Straight Walking) | .81 dimensionless | Standard Deviation 0.23 |
| Torsion Adapter Pylon | Local Dynamic Stability (Ankle During Straight Walking) | .96 dimensionless | Standard Deviation 0.28 |
p-value: =0.09Mixed Models Analysis
Primary
Local Dynamic Stability (Ankle During Turning With the Prosthesis on the Inside of the Turn)
Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system.
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Local Dynamic Stability (Ankle During Turning With the Prosthesis on the Inside of the Turn) | .96 dimensionless | Standard Deviation 0.22 |
| Torsion Adapter Pylon | Local Dynamic Stability (Ankle During Turning With the Prosthesis on the Inside of the Turn) | .87 dimensionless | Standard Deviation 0.27 |
Primary
Local Dynamic Stability (Ankle During Turning With the Prosthesis on the Outside of the Turn)
Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system.
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Local Dynamic Stability (Ankle During Turning With the Prosthesis on the Outside of the Turn) | .84 dimensionless | Standard Deviation 0.33 |
| Torsion Adapter Pylon | Local Dynamic Stability (Ankle During Turning With the Prosthesis on the Outside of the Turn) | .96 dimensionless | Standard Deviation 0.21 |
p-value: =0.4Mixed Models Analysis
Primary
Local Dynamic Stability (Hip During Straight Walking)
Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system.
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Local Dynamic Stability (Hip During Straight Walking) | .74 dimensionless | Standard Deviation 0.12 |
| Torsion Adapter Pylon | Local Dynamic Stability (Hip During Straight Walking) | .74 dimensionless | Standard Deviation 0.13 |
p-value: >0.99Mixed Models Analysis
Primary
Local Dynamic Stability (Hip During Turning With the Prosthesis on the Inside of the Turn)
Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system.
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Local Dynamic Stability (Hip During Turning With the Prosthesis on the Inside of the Turn) | .85 dimensionless | Standard Deviation 0.11 |
| Torsion Adapter Pylon | Local Dynamic Stability (Hip During Turning With the Prosthesis on the Inside of the Turn) | .83 dimensionless | Standard Deviation 0.14 |
p-value: =0.7Mixed Models Analysis
Primary
Local Dynamic Stability (Hip During Turning With the Prosthesis on the Outside of the Turn)
Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system.
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Local Dynamic Stability (Hip During Turning With the Prosthesis on the Outside of the Turn) | .75 dimensionless | Standard Deviation 0.1 |
| Torsion Adapter Pylon | Local Dynamic Stability (Hip During Turning With the Prosthesis on the Outside of the Turn) | .74 dimensionless | Standard Deviation 0.11 |
p-value: =0.8Mixed Models Analysis
Primary
Local Dynamic Stability (Knee During Straight Walking)
Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system.
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Local Dynamic Stability (Knee During Straight Walking) | 1.00 dimensionless | Standard Deviation 0.21 |
| Torsion Adapter Pylon | Local Dynamic Stability (Knee During Straight Walking) | 1.16 dimensionless | Standard Deviation 0.3 |
p-value: =0.09Mixed Models Analysis
Primary
Local Dynamic Stability (Knee During Turning With the Prosthesis on the Inside of the Turn)
Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system.
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Local Dynamic Stability (Knee During Turning With the Prosthesis on the Inside of the Turn) | 1.20 dimensionless | Standard Deviation 0.3 |
| Torsion Adapter Pylon | Local Dynamic Stability (Knee During Turning With the Prosthesis on the Inside of the Turn) | 1.20 dimensionless | Standard Deviation 0.25 |
p-value: >0.99Mixed Models Analysis
Primary
Local Dynamic Stability (Knee During Turning With the Prosthesis on the Outside of the Turn)
Maximum finite-time Lyapunov exponents were used to estimate the local dynamic stability of the amputee's sagittal plane hip, knee and ankle angles for their prosthetic limb with and without the torsion adapter while walking straight, while turning with the prosthesis on the inside of the turn, and while turning with the prosthesis on the outside of the turn. Maximum finite-time Lyapunov exponents measure the rate of kinematic separation of a gait cycle trajectory perturbed by naturally occurring disturbances and neuromuscular control errors. A positive exponent indicates divergence of a system, with increasing values indicating a les stable system.
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Local Dynamic Stability (Knee During Turning With the Prosthesis on the Outside of the Turn) | 1.16 dimensionless | Standard Deviation 0.18 |
| Torsion Adapter Pylon | Local Dynamic Stability (Knee During Turning With the Prosthesis on the Outside of the Turn) | 1.12 dimensionless | Standard Deviation 0.29 |
p-value: =0.7Mixed Models Analysis
Secondary
Activity Level
Average number of steps per day over a 1 week period ending in the fourth week of each study prosthesis (Rigid and Torsion adapter)
Time frame: One week
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Activity Level | 6269 Steps/day | Standard Error 1080 |
| Torsion Adapter Pylon | Activity Level | 6728 Steps/day | Standard Error 1121 |
p-value: =0.13Wilcoxon (Mann-Whitney)
Secondary
Average Residual Limb Pain?
The residual limb pain grade scores ranged from 0 No Pain/ Interference to 10 Severe Pain/Interference.
Time frame: Measurements were taken after wearing the study prostheses for four weeks.
Population: 10 participants wore both study prostheses but only 7 participants presented with pain.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Average Residual Limb Pain? | 2.9 units on a scale | Standard Error 0.5 |
| Torsion Adapter Pylon | Average Residual Limb Pain? | 2.3 units on a scale | Standard Error 0.6 |
p-value: =0.27Wilcoxon (Mann-Whitney)
Secondary
How Bothersome Was Your Pain?
The residual limb pain grade scores ranged from 0 No Pain/ Interference to 10 Severe Pain/Interference.
Time frame: Measurements were taken after wearing the study prostheses for four weeks.
Population: 10 participants wore both study prostheses but only 7 participants presented with pain.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | How Bothersome Was Your Pain? | 3.1 units on a scale | Standard Error 1.1 |
| Torsion Adapter Pylon | How Bothersome Was Your Pain? | 2.9 units on a scale | Standard Error 1.1 |
p-value: =0.78Wilcoxon (Mann-Whitney)
Secondary
Least Residual Limb Pain?
The residual limb pain grade scores ranged from 0 No Pain/ Interference to 10 Severe Pain/Interference.
Time frame: Measurements were taken after wearing the study prostheses for four weeks.
Population: 10 participants wore both study prostheses but only 7 participants presented with pain.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Least Residual Limb Pain? | 1.9 units on a scale | Standard Error 0.6 |
| Torsion Adapter Pylon | Least Residual Limb Pain? | 1.6 units on a scale | Standard Error 0.6 |
p-value: =0.59Wilcoxon (Mann-Whitney)
Secondary
Pain Interference With Activities?
The residual limb pain grade scores ranged from 0 No Pain/ Interference to 10 Severe Pain/Interference.
Time frame: Measurements were taken after wearing the study prostheses for four weeks.
Population: 10 participants wore both study prostheses but only 7 participants presented with pain.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Pain Interference With Activities? | 3.4 units on a scale | Standard Error 0.8 |
| Torsion Adapter Pylon | Pain Interference With Activities? | 1.6 units on a scale | Standard Error 0.6 |
p-value: =0.057Wilcoxon (Mann-Whitney)
Secondary
Peak External Rotation Moment of the Inside Ankle While Turning
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Peak External Rotation Moment of the Inside Ankle While Turning | -36 N*mm/kg | Standard Deviation 48 |
| Torsion Adapter Pylon | Peak External Rotation Moment of the Inside Ankle While Turning | -25 N*mm/kg | Standard Deviation 16 |
p-value: >0.15Mixed Models Analysis
Secondary
Peak External Rotation Moment of the Inside Hip While Turning
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Peak External Rotation Moment of the Inside Hip While Turning | -54 N*mm/kg | Standard Deviation 47 |
| Torsion Adapter Pylon | Peak External Rotation Moment of the Inside Hip While Turning | -57 N*mm/kg | Standard Deviation 45 |
p-value: >0.15Mixed Models Analysis
Secondary
Peak External Rotation Moment of the Inside Knee While Turning
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Peak External Rotation Moment of the Inside Knee While Turning | -26 N*mm/kg | Standard Deviation 27 |
| Torsion Adapter Pylon | Peak External Rotation Moment of the Inside Knee While Turning | -24 N*mm/kg | Standard Deviation 15 |
p-value: >0.15Mixed Models Analysis
Secondary
Peak External Rotation Moment of the Outside Ankle While Turning
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Peak External Rotation Moment of the Outside Ankle While Turning | -28 N*mm/kg | Standard Deviation 31 |
| Torsion Adapter Pylon | Peak External Rotation Moment of the Outside Ankle While Turning | -42 N*mm/kg | Standard Deviation 33 |
p-value: >0.15Mixed Models Analysis
Secondary
Peak External Rotation Moment of the Outside Hip While Turning
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Peak External Rotation Moment of the Outside Hip While Turning | -70 N*mm/kg | Standard Deviation 54 |
| Torsion Adapter Pylon | Peak External Rotation Moment of the Outside Hip While Turning | -88 N*mm/kg | Standard Deviation 45 |
p-value: >0.15Mixed Models Analysis
Secondary
Peak External Rotation Moment of the Outside Knee While Turning
Time frame: Measurements were taken after wearing the study prostheses for three weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Peak External Rotation Moment of the Outside Knee While Turning | -7 N*mm/kg | Standard Deviation 21 |
| Torsion Adapter Pylon | Peak External Rotation Moment of the Outside Knee While Turning | -15 N*mm/kg | Standard Deviation 15 |
p-value: >0.15Mixed Models Analysis
Secondary
Residual Limb Pain at Present?
The residual limb pain grade scores ranged from 0 No Pain/ Interference to 10 Severe Pain/Interference.
Time frame: Measurements were taken after wearing the study prostheses for four weeks
Population: 10 participants wore both study prostheses but only 7 participants presented with pain.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Residual Limb Pain at Present? | 2.0 units on a scale | Standard Error 0.7 |
| Torsion Adapter Pylon | Residual Limb Pain at Present? | 1.6 units on a scale | Standard Error 0.7 |
p-value: =0.37Wilcoxon (Mann-Whitney)
Secondary
Six-minute Walk Distance
Participants are asked to walk alone as far as possible without running for six minutes. This test is performed indoors along a long, flat straight hallway of approximately 30 meters in length with two orange cones marking the 180 degree turnaround points at each end of the corridor. Approximately 40 straight steps were taken for every four turning steps.
Time frame: Six minutes after wearing the study prostheses for four weeks.
Population: Each participant wore both study prostheses.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Six-minute Walk Distance | 463 m | Standard Error 24 |
| Torsion Adapter Pylon | Six-minute Walk Distance | 464 m | Standard Error 26 |
p-value: =0.92Wilcoxon (Mann-Whitney)
Secondary
Worst Residual Limb Pain?
The residual limb pain grade scores ranged from 0 No Pain/ Interference to 10 Severe Pain/Interference.
Time frame: Measurements were taken after wearing the study prostheses for four weeks.
Population: 10 participants wore both study prostheses but only 7 participants presented with pain.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Rigid Pylon | Worst Residual Limb Pain? | 4.7 units on a scale | Standard Error 1 |
| Torsion Adapter Pylon | Worst Residual Limb Pain? | 3.6 units on a scale | Standard Error 0.7 |
p-value: =0.2Wilcoxon (Mann-Whitney)