A Pilot Clinical Trial to Assess the Effect of Transfemoral Socket Design on Hip Muscle Function
Overview
- Phase
- N/A
- Intervention
- Not specified
- Conditions
- Amputation
- Sponsor
- University of Illinois at Chicago
- Enrollment
- 5
- Locations
- 1
- Primary Endpoint
- Residual Limb Hip Muscle Peak Torque at Baseline
- Status
- Completed
- Last Updated
- last year
Overview
Brief Summary
The objective of this pilot research project is to evaluate the effect of prosthetic socket design on amputated limb hip muscle strength and endurance in Service members, Veterans, and civilians who use above-the-knee prostheses. Traditional above-the-knee socket designs provide pelvic support that interferes with hip motion. They may also reduce the effort required from amputated limb hip muscles to stabilize the hip and amputated limb, risking further loss of muscle mass and strength beyond that due to amputation. Long-standing use of above-the-knee sockets with pelvic support may therefore intensify amputated limb muscle loss and weakness, leading to challenges with walking and balance, increasing the effort required to walk, and contributing to degenerative changes in the hips and knees. Alternative socket designs that lessen the loss of muscle mass and strength are therefore required.
The investigators have developed a new socket without pelvic support for above-the-knee prosthesis users called the Northwestern University Flexible Sub-Ischial Suction (NU-FlexSIS) Socket. This new socket design increases user comfort and is often preferred by users over sockets with pelvic support. This new socket does not lessen the mechanical function of the socket, or walking and balance performance. Our recent research suggests that walking with this new socket may also increase amputated limb hip muscle size. However, more research is needed to demonstrate that this new socket design improves amputated limb hip muscle strength and endurance, leading to better function.
A socket design that increases amputated limb hip muscle strength and endurance would provide a simple way to restore amputated limb hip muscle weakness in above-the-knee prosthesis users. Despite a considerable decrease in hip muscle size and strength due to amputation surgery, amputated limb hip muscles are expected to compensate for the loss of knee and ankle function by providing stability and propulsion during walking. Walking in the new socket design without pelvic support is expected to increase amputated limb hip muscle strength and endurance, providing an appealing alternative to traditional resistance training in order to retain hip muscle strength. Unlike traditional resistance training, using this new socket design would not require additional time or equipment, and may be effective just by walking in the home, community, or workplace. Due to existing infrastructure (e.g., ongoing clinical adoption of the NU-FlexSIS Socket, existing instructional materials and courses for fabrication and fitting of the NU-FlexSIS Socket, as well as a continuing partnership with Chicago's largest provider of prosthetic clinical care), the investigators anticipate being able to translate our research results to clinical practice by the end of the project period.
The investigators expect the results of the proposed pilot research project to directly and positively benefit the health and well-being of Service members, Veterans, and civilians who are above-the-knee prosthesis users. Benefits of increasing amputated limb hip muscle strength and endurance may include: i) improved control over the prosthesis, ii) better balance, iii) reduced effort to walk, and iv) protection against joint degeneration. For Service members these benefits could improve their performance on challenging and/or uneven ground, and increase the distance and speed they can walk or run. For Veterans, these benefits could lead to greater independence during activities of daily living, and fewer falls, reducing the physical and emotional burden on family members and caregivers.
Investigators
Andrew Sawers
Assistant Professor
University of Illinois at Chicago
Eligibility Criteria
Inclusion Criteria
- •worn an ischial containment socket for ≥ 2 years, able to walk short distances (10 meters), ability to read, write, and speak English, ≥ 2 years using a liner-based suspension, and a residual limb length ≥ 5".
Exclusion Criteria
- •amputation of a second leg, contralateral complications (e.g., hip replacement), or other major neuromusculoskeletal or cardiovascular conditions (e.g., heart failure).
Outcomes
Primary Outcomes
Residual Limb Hip Muscle Peak Torque at Baseline
Time Frame: Baseline
Hip flexor, extensor, adductor and abductor muscle strength will be measured in transfemoral prosthesis users using a motor-driven isokinetic dynamometer. Muscular strength will be assessed via average peak torque (i.e., highest torque) across the first three repetitions of 12.
Residual Limb Hip Muscle Peak Torque at 8-weeks
Time Frame: 8 weeks after intervention
Hip flexor, extensor, adductor and abductor muscle strength will be measured in transfemoral prosthesis users using a motor-driven isokinetic dynamometer. Muscular strength will be assessed via average peak torque (i.e., highest torque) across the first three repetitions of 12. Comparison will be made to baseline measure.
Residual Limb Hip Muscle Peak Torque at 42-weeks
Time Frame: 42 weeks after intervention
Hip flexor, extensor, adductor and abductor muscle strength will be measured in transfemoral prosthesis users using a motor-driven isokinetic dynamometer. Muscular strength will be assessed via average peak torque (i.e., highest torque) across the first three repetitions of 12. Comparison will be made to baseline measure.
Residual Limb Hip Muscle Endurance at Baseline
Time Frame: Baseline
Hip flexor, extensor, adductor and abductor muscle endurance will be measured in transfemoral prosthesis users using a motor-driven isokinetic dynamometer. Muscular endurance will be assessed via a fatigue index, calculated as a percentage of the difference between total work performed during the first and last 3 repetitions divided by total work over the first 3 repetitions. A higher fatigue index will be taken as evidence of reduced muscular endurance.
Residual Limb Hip Muscle Endurance at 8-weeks
Time Frame: 8 weeks after intervention
Hip flexor, extensor, adductor and abductor muscle endurance will be measured in transfemoral prosthesis users using a motor-driven isokinetic dynamometer. Muscular endurance will be assessed via a fatigue index, calculated as a percentage of the difference between total work performed during the first and last 3 repetitions divided by total work over the first 3 repetitions. A higher fatigue index will be taken as evidence of reduced muscular endurance. Comparison will be made to baseline measure.
Residual Limb Hip Muscle Endurance at 42-weeks
Time Frame: 42 weeks after intervention
Hip flexor, extensor, adductor and abductor muscle endurance will be measured in transfemoral prosthesis users using a motor-driven isokinetic dynamometer. Muscular endurance will be assessed via a fatigue index, calculated as a percentage of the difference between total work performed during the first and last 3 repetitions divided by total work over the first 3 repetitions. A higher fatigue index will be taken as evidence of reduced muscular endurance. Comparison will be made to baseline measure.
Residual Limb Hip Muscle Duration at Baseline
Time Frame: Baseline
Electromyographic (EMG) signals were recorded from transfemoral prosthesis users' residual limb muscles while walking. The duration of time each hip muscle was active during a stride was calculated as the percentage of the gait cycle (i.e., heel-strike to heel-strike) for which that EMG signal was above a baseline value (min: 0%, max: 100%). The larger the percentage of the gait cycle that a muscle was deemed to be active, the greater its duration.
Residual Limb Hip Muscle Duration at 8-weeks
Time Frame: 8 weeks after intervention
Electromyographic (EMG) signals were recorded from transfemoral prosthesis users' residual limb muscles while walking. The duration of time each hip muscle was active during a stride was calculated as the percentage of the gait cycle (i.e., heel-strike to heel-strike) for which that EMG signal was above a baseline value (min: 0%, max: 100%). The larger the percentage of the gait cycle that a muscle was deemed to be active, the greater its duration.
Residual Limb Hip Muscle Duration at at 42-weeks
Time Frame: 42 weeks
Electromyographic (EMG) signals were recorded from transfemoral prosthesis users' residual limb muscles while walking. The duration of time each hip muscle was active during a stride was calculated as the percentage of the gait cycle (i.e., heel-strike to heel-strike) for which that EMG signal was above a baseline value (min: 0%, max: 100%). The larger the percentage of the gait cycle that a muscle was deemed to be active, the greater its duration.
Residual Limb Hip Muscle Integrated Area at Baseline
Time Frame: Baseline
Electromyographic (EMG) signals were recorded from transfemoral prosthesis users' residual limb muscles while walking. The total amount of hip muscle activity was calculated as the integrated area under the EMG signal during a gait cycle (i.e., heel-strike to heel-strike). Each EMG signal was normalized (i.e., divided by its maximum value across all the gait cycles and multiple by 100. The integrated areas is therefore reported as a percentage of that maximum (min: 0%, max: 100%). The larger the integrated area the more the muscle was deemed to be active.
Residual Limb Hip Muscle Integrated Area at 8-weeks
Time Frame: 8 weeks after intervention
Electromyographic (EMG) signals were recorded from transfemoral prosthesis users' residual limb muscles while walking. The total amount of hip muscle activity was calculated as the integrated area under the EMG signal during a gait cycle (i.e., heel-strike to heel-strike). Each EMG signal was normalized (i.e., divided by its maximum value across all the gait cycles and multiple by 100. The integrated areas is therefore reported as a percentage of that maximum (min: 0%, max: 100%). The larger the integrated area the more the muscle was deemed to be active.
Residual Limb Hip Muscle Integrated Area at 42-weeks
Time Frame: 42 weeks after intervention
Electromyographic (EMG) signals were recorded from transfemoral prosthesis users' residual limb muscles while walking. The total amount of hip muscle activity was calculated as the integrated area under the EMG signal during a gait cycle (i.e., heel-strike to heel-strike). Each EMG signal was normalized (i.e., divided by its maximum value across all the gait cycles and multiple by 100. The integrated areas is therefore reported as a percentage of that maximum (min: 0%, max: 100%). The larger the integrated area the more the muscle was deemed to be active.
Peak Residual Limb Hip Muscle Activity at Baseline
Time Frame: Baseline
Electromyographic (EMG) signals were recorded from transfemoral prosthesis users' residual limb muscles while walking. The highest level of hip muscle activity was calculated as the peak of the EMG signal during a gait cycle (i.e., heel-strike to heel-strike). Each EMG signal was normalized (i.e., divided by its maximum value across all the gait cycles recorded during baseline). The peak EMG is therefore typically reported as a value between 0 and 1. However, if the peak value during assessments increases relative to baseline, the value of the peak activity will exceed 1. The larger the peak value the greater the activation of that muscle.
Peak Residual Limb Hip Muscle Activity at 8 Weeks
Time Frame: 8 weeks after intervention
Electromyographic (EMG) signals were recorded from transfemoral prosthesis users' residual limb muscles while walking. The highest level of hip muscle activity was calculated as the peak of the EMG signal during a gait cycle (i.e., heel-strike to heel-strike). Each EMG signal was normalized (i.e., divided by its maximum value across all the gait cycles recorded during baseline). The peak EMG is therefore typically reported as a value between 0 and 1. However, if the peak value during assessments increases relative to baseline, the value of the peak activity will exceed 1. The larger the peak value the greater the activation of that muscle.
Peak Residual Limb Hip Muscle Activity at 42 Weeks
Time Frame: 42 weeks after intervention
Electromyographic (EMG) signals were recorded from transfemoral prosthesis users' residual limb muscles while walking. The highest level of hip muscle activity was calculated as the peak of the EMG signal during a gait cycle (i.e., heel-strike to heel-strike). Each EMG signal was normalized (i.e., divided by its maximum value across all the gait cycles recorded during baseline). The peak EMG is therefore typically reported as a value between 0 and 1. However, if the peak value during assessments increases relative to baseline, the value of the peak activity will exceed 1. The larger the peak value the greater the activation of that muscle.
Secondary Outcomes
- Volume of Physical Activity at 8 Weeks(8-weeks after intervention)
- Four Square Step Test at Baseline(Baseline)
- Four Square Step Test at 8 Weeks(8-weeks after intervention)
- Four Square Step Test at 42 Weeks(42-weeks after intervention)
- One Leg Stance Test at Baseline(Baseline)
- One Leg Stance Test at 8 Weeks(8 weeks after intervention)
- One Leg Stance Test at 42 Weeks(42 weeks after intervention)
- 10-Meter Walk Test at Baseline(Baseline)
- 10-Meter Walk Test at 8 Weeks(8 weeks after intervention)
- 10-Meter Walk Test at 42 Weeks(42 weeks after intervention)
- 2-Minute Walk Test at Baseline(Baseline)
- 2-Minute Walk Test at 8 Weeks(8-weeks after intervention.)
- 2-Minute Walk Test at 42 Weeks(42-weeks after intervention.)
- Volume of Physical Activity at Baseline(2 weeks prior to intervention (baseline))
- Volume of Physical Activity at 42 Weeks(42-weeks after intervention)
- Frequency of Physical Activity at Baseline(2 weeks prior to intervention (baseline))
- Frequency of Physical Activity at 8 Weeks(8 weeks after intervention)
- Frequency of Physical Activity at 42 Weeks(42 weeks after intervention)
- Duration of Physical Activity at Baseline(2 weeks prior to intervention (baseline))
- Duration of Physical Activity at 8 Weeks(8 weeks after intervention)
- Duration of Physical Activity at 42 Weeks(42 weeks after intervention)