Prosthetic Components and Stability in Amputee Gait

Diabetes Mellitus Clinical Trial

Official title:

Turning Corners: Prosthetic Components and Stability in Amputee Gait

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00167778
• Other study ID #: A3611-R
• Status: Completed
• Phase: N/A
• First received: July 1, 2005
• Last updated: July 28, 2014
• Start date: January 2005
• Est. completion date: September 2008

Study information

• Verified date: July 2014
• Source: VA Office of Research and Development
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Federal Government
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 12
• Est. completion date: September 2008
• Est. primary completion date: September 2008
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years to 70 Years

Eligibility

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 exclusion criteria except for those related to cause of amputation.

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Crossover Assignment, Masking: Single Blind (Subject), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Amputation, Traumatic
• Diabetes Mellitus
• Leg Injuries
• Traumatic Amputation

Intervention

Device:
• Transverse plane rotation adaptor pylon
Potential future practice
• Rigid pylon
Current clinical practice

Locations

Country	Name	City	State
United States	VA Puget Sound Health Care System, Seattle	Seattle	Washington

Sponsors (1)

Lead Sponsor	Collaborator
VA Office of Research and Development

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
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.	Measurements were taken after wearing the study prostheses for three weeks.	No
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.	Measurements were taken after wearing the study prostheses for three weeks.	No
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.	Measurements were taken after wearing the study prostheses for three weeks.	No
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.	Measurements were taken after wearing the study prostheses for three weeks.	No
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.	Measurements were taken after wearing the study prostheses for three weeks.	No
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.	Measurements were taken after wearing the study prostheses for three weeks.	No
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.	Measurements were taken after wearing the study prostheses for three weeks.	No
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.	Measurements were taken after wearing the study prostheses for three weeks.	No
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.	Measurements were taken after wearing the study prostheses for three weeks.	No
Secondary	Peak External Rotation Moment of the Outside Hip While Turning		Measurements were taken after wearing the study prostheses for three weeks.	No
Secondary	Peak External Rotation Moment of the Outside Knee While Turning		Measurements were taken after wearing the study prostheses for three weeks.	No
Secondary	Peak External Rotation Moment of the Outside Ankle While Turning		Measurements were taken after wearing the study prostheses for three weeks.	No
Secondary	Peak External Rotation Moment of the Inside Hip While Turning		Measurements were taken after wearing the study prostheses for three weeks.	No
Secondary	Peak External Rotation Moment of the Inside Knee While Turning		Measurements were taken after wearing the study prostheses for three weeks.	No
Secondary	Peak External Rotation Moment of the Inside Ankle While Turning		Measurements were taken after wearing the study prostheses for three weeks.	No
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)	One week	No
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.	Six minutes after wearing the study prostheses for four weeks.	No
Secondary	Residual Limb Pain at Present?	The residual limb pain grade scores ranged from 0 "No Pain/ Interference" to 10 "Severe Pain/Interference."	Measurements were taken after wearing the study prostheses for four weeks	No
Secondary	Average Residual Limb Pain?	The residual limb pain grade scores ranged from 0 "No Pain/ Interference" to 10 "Severe Pain/Interference."	Measurements were taken after wearing the study prostheses for four weeks.	No
Secondary	Worst Residual Limb Pain?	The residual limb pain grade scores ranged from 0 "No Pain/ Interference" to 10 "Severe Pain/Interference."	Measurements were taken after wearing the study prostheses for four weeks.	No
Secondary	Least Residual Limb Pain?	The residual limb pain grade scores ranged from 0 "No Pain/ Interference" to 10 "Severe Pain/Interference."	Measurements were taken after wearing the study prostheses for four weeks.	No
Secondary	Pain Interference With Activities?	The residual limb pain grade scores ranged from 0 "No Pain/ Interference" to 10 "Severe Pain/Interference."	Measurements were taken after wearing the study prostheses for four weeks.	No
Secondary	How Bothersome Was Your Pain?	The residual limb pain grade scores ranged from 0 "No Pain/ Interference" to 10 "Severe Pain/Interference."	Measurements were taken after wearing the study prostheses for four weeks.	No