Clinical Trial: Prosthetic Components and Stability in Amputee Gait
Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: Turning Corners: Prosthetic Components and Stability in Amputee Gait
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 Summary:
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:
- discover the biomechanical strategies used and the stability of both intact individuals and trans-tibial amputees walking along a circular trajectory and
- 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
Sponsor: VA Office of Research and Development
Current Primary Outcome:
- Local Dynamic Stability (Hip During Straight Walking) [ Time Frame: 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) [ Time Frame: 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) [ Time Frame: Measurements w
Original Primary Outcome: Dynamic stability index at 3 weeks
Current Secondary Outcome:
- Peak External Rotation Moment of the Outside Hip While Turning [ Time Frame: Measurements were taken after wearing the study prostheses for three weeks. ]
- Peak External Rotation Moment of the Outside Knee While Turning [ Time Frame: Measurements were taken after wearing the study prostheses for three weeks. ]
- Peak External Rotation Moment of the Outside Ankle While Turning [ Time Frame: Measurements were taken after wearing the study prostheses for three weeks. ]
- Peak External Rotation Moment of the Inside Hip While Turning [ Time Frame: Measurements were taken after wearing the study prostheses for three weeks. ]
- Peak External Rotation Moment of the Inside Knee While Turning [ Time Frame: Measurements were taken after wearing the study prostheses for three weeks. ]
- Peak External Rotation Moment of the Inside Ankle While Turning [ Time Frame: Measurements were taken after wearing the study prostheses for three weeks. ]
- Activity Level [ Time Frame: 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 [ Time Frame: 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? [ Time Frame: 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."
- Average Residual Limb Pain? [ Time Frame: 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? [ Time Frame: 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? [ Time Frame: 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."
- Pain Interference With Activities? [ Time Frame: 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? [ Time Frame: 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."
Original Secondary Outcome:
- A 3 weeks:
- Lateral impulse
- Outside limb external moment
- Inside limb external moment
- Outside stride length
- Inside stride length
- Outside effective limb length
- Inside effective limb length
- Step counts between weeks 3 & 4
- At 4 weeks:
- Pain questinnaire at 4 week
- Distance during six-minute walk
Information By: VA Office of Research and Development
Dates:
Date Received: July 1, 2005
Date Started: January 2005
Date Completion:
Last Updated: July 28, 2014
Last Verified: July 2014
