Transfemoral Socket Design and Muscle Function

Amputation Clinical Trial

Official title:

A Pilot Clinical Trial to Assess the Effect of Transfemoral Socket Design on Hip Muscle Function

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04212299
• Other study ID #: 2019-0725
• Secondary ID: W81XWH1910507
• Status: Recruiting
• Phase: N/A
• Start date: September 24, 2019
• Est. completion date: September 23, 2022

Study information

• Verified date: March 2021
• Source: University of Illinois at Chicago
• Contact: Andrew B Sawers, PhD
• Phone: 312-996-1427
• Email: asawers[@]uic.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 8
• Est. completion date: September 23, 2022
• Est. primary completion date: June 23, 2022
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 21 Years to 85 Years

Eligibility

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).

Related Conditions & MeSH terms

• Amputation

Intervention

Device:
• Northwestern University Flexible Sub-Ischial Suction Socket (NU-FlexSIS)
The sub-ischial socket includes a firm, compressive, preferably cylindrical, fabric-covered silicone liner, a flexible inner socket, and a shorter rigid outer socket. The socket has proximal trim lines that do not impinge on the pelvis; they terminate distal to the ischial tuberosity and greater trochanter. For the NU-FlexSIS Socket, passive suction suspension is achieved using a one way valve and a liner with an internal seal. Since the prosthetic socket is a custom-made device, it is considered Class I exempt by the Food and Drug Administration (FDA).

Locations

Country	Name	City	State
United States	University of Illinois at Chicago	Chicago	Illinois

Sponsors (2)

Lead Sponsor	Collaborator
University of Illinois at Chicago	Northwestern University

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Hip muscle strength at 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) and rate of torque development (i.e., slope of the torque/time curve from onset to peak) across the first three repetitions of 12.	Baseline
Primary	Change in hip muscle strength at 8-weeks	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) and rate of torque development (i.e., slope of the torque/time curve from onset to peak) across the first three repetitions of 12. Comparison will be made to baseline measure.	8 weeks after intervention
Primary	Change in hip muscle strength at 42-weeks	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) and rate of torque development (i.e., slope of the torque/time curve from onset to peak) across the first three repetitions of 12. Comparison will be made to baseline measure.	42 weeks after intervention
Primary	Hip muscle endurance at 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.	Baseline
Primary	Change in hip muscle endurance at 8-weeks	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.	8 weeks after intervention
Primary	Change in hip muscle endurance at 42-weeks	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.	42 weeks after intervention
Primary	Hip muscle onset and offset times at baseline	The onset and offset times of residual limb hip muscles will be calculated from electromyographic signals recorded while walking using surface electrodes.	Baseline
Primary	Changes in hip muscle onset and offset times at 8-weeks	The onset and offset times of residual limb hip muscles will be calculated from electromyographic signals recorded while walking using surface electrodes. Comparison will be made to baseline measure.	8 weeks after intervention
Primary	Changes in hip muscle onset and offset times at 42-weeks	The onset and offset times of residual limb hip muscles will be calculated from electromyographic signals recorded while walking using surface electrodes. Comparison will be made to baseline measure.	42
Primary	Hip muscle integrated area at baseline	The integrated area of electromyographic signals will be calculated from residual limb hip muscles recorded using surface electrodes while walking.	Baseline
Primary	Change in hip muscle integrated area at 8-weeks	The integrated area of electromyographic signals will be calculated from residual limb hip muscles recorded using surface electrodes while walking. Comparison will be made to baseline measure.	8 weeks after intervention
Primary	Change in hip muscle integrated area at 42-weeks	The integrated area of electromyographic signals will be calculated from residual limb hip muscles recorded using surface electrodes while walking. Comparison will be made to baseline measure.	42 weeks after intervention
Primary	Peak hip muscle activity at baseline	The peak activity of residual limb hip muscles will be characterized from electromyographic signals recorded while walking using surface electrodes.	Baseline
Primary	Peak hip muscle activity at 8 weeks	The peak activity of residual limb hip muscles will be characterized from electromyographic signals recorded while walking using surface electrodes. Comparison will be made to baseline measure.	8 weeks after intervention
Primary	Peak hip muscle activity at 42 weeks	The peak activity of residual limb hip muscles will be characterized from electromyographic signals recorded while walking using surface electrodes. Comparison will be made to baseline measure.	42 weeks after intervention
Secondary	Four Square Step Test (dynamic balance) at baseline	Four Square Step Test (dynamic balance) will be administered and scored as the best time (i.e., fastest) of two trials.	Baseline
Secondary	Change in Four Square Step Test (dynamic balance) at 8 weeks	Four Square Step Test (dynamic balance) will be administered and scored as the best time (i.e., fastest) of two trials. Comparisons will be made to baseline.	8-weeks after intervention
Secondary	Change in Four Square Step Test (dynamic balance) at 42 weeks	Four Square Step Test (dynamic balance) will be administered and scored as the best time (i.e., fastest) of two trials. Comparisons will be made to baseline.	42-weeks after intervention
Secondary	One Leg Stance Test (static balance) at baseline	One Leg Stance Test (static balance) will be administered and scored as the best time (i.e., longest) of two trials.	Baseline
Secondary	One Leg Stance Test (static balance) at 8 weeks	One Leg Stance Test (static balance) will be administered and scored as the best time (i.e., longest) of two trials. Comparisons will be made to baseline.	8 weeks after intervention
Secondary	One Leg Stance Test (static balance) at 42 weeks	One Leg Stance Test (static balance) will be administered and scored as the best time (i.e., longest) of two trials. Comparisons will be made to baseline.	42 weeks after intervention
Secondary	10-Meter Walk Test (walking speed) at baseline	One Leg Stance Test (static balance) will be administered and scored as the best time (i.e., fastest time) of two trials.	Baseline
Secondary	Change in 10-Meter Walk Test (walking speed) at 8 weeks	One Leg Stance Test (static balance) will be administered and scored as the best time (i.e., fastest time) of two trials. Comparisons will be made to baseline.	8 weeks after intervention
Secondary	Change in 10-Meter Walk Test (walking speed) at 42 weeks	One Leg Stance Test (static balance) will be administered and scored as the best time (i.e., fastest time) of two trials.Comparisons will be made to baseline.	42 weeks after intervention
Secondary	2-Minute Walk Test (walking endurance) at baseline	2-Minute Walk Test (walking endurance) will be administered and scored as the distance walked in 2 minutes.	Baseline
Secondary	Change in 2-Minute Walk Test (walking endurance) at 8 weeks	2-Minute Walk Test (walking endurance) will be administered and scored as the distance walked in 2 minutes. Comparisons will be made to baseline.	8-weeks after intervention.
Secondary	Change in 2-Minute Walk Test (walking endurance) at 42 weeks	2-Minute Walk Test (walking endurance) will be administered and scored as the distance walked in 2 minutes. Comparisons will be made to baseline.	42-weeks after intervention.
Secondary	Volume of physical activity at baseline	To assess the volume of physical activity, transfemoral prosthesis users will wear a StepWatch4 activity monitor (Modus Health, Edmonds, WA) for three 2-week periods. Activity bouts, or periods of time in which steps occur in successive 10-second intervals, will be derived from step count data. The volume of physical activity will be quantified by the mean number of steps per activity bout.Higher values will be taken as evidence of greater physical activity.	2 weeks prior to intervention (baseline)
Secondary	Change in volume of physical activity at 8 weeks	To assess the volume of physical activity, transfemoral prosthesis users will wear a StepWatch4 activity monitor (Modus Health, Edmonds, WA) for three 2-week periods. Activity bouts, or periods of time in which steps occur in successive 10-second intervals, will be derived from step count data. The volume of physical activity will be quantified by the mean number of steps per activity bout.Higher values will be taken as evidence of greater physical activity. Comparisons will be made to baseline.	8-weeks after intervention
Secondary	Change in volume of physical activity at 42 weeks	To assess the volume of physical activity, transfemoral prosthesis users will wear a StepWatch4 activity monitor (Modus Health, Edmonds, WA) for three 2-week periods. Activity bouts, or periods of time in which steps occur in successive 10-second intervals, will be derived from step count data. The volume of physical activity will be quantified by the mean number of steps per activity bout. Higher values will be taken as evidence of greater physical activity. Comparisons will be made to baseline.	42-weeks after intervention
Secondary	Frequency of physical activity at baseline	To assess the frequency of physical activity, transfemoral prosthesis users will wear a StepWatch4 activity monitor (Modus Health, Edmonds, WA) for three 2-week periods. Activity bouts, or periods of time in which steps occur in successive 10-second intervals, will be derived from step count data. The frequency of physical activity will be quantified by the mean number of activity bouts per day. Higher values will be taken as evidence of greater physical activity.	2 weeks prior to intervention (baseline)
Secondary	Change in frequency of physical activity at 8 weeks	To assess the frequency of physical activity, transfemoral prosthesis users will wear a StepWatch4 activity monitor (Modus Health, Edmonds, WA) for three 2-week periods. Activity bouts, or periods of time in which steps occur in successive 10-second intervals, will be derived from step count data. The frequency of physical activity will be quantified by the mean number of activity bouts per day. Higher values will be taken as evidence of greater physical activity. Comparisons will be made to baseline.	8 weeks after intervention
Secondary	Change in frequency of physical activity at 42 weeks	To assess the frequency of physical activity, transfemoral prosthesis users will wear a StepWatch4 activity monitor (Modus Health, Edmonds, WA) for three 2-week periods. Activity bouts, or periods of time in which steps occur in successive 10-second intervals, will be derived from step count data. The frequency of physical activity will be quantified by the mean number of activity bouts per day. Higher values will be taken as evidence of greater physical activity. Comparisons will be made to baseline.	42 weeks after intervention
Secondary	Duration of physical activity at baseline	To assess the duration of physical activity, transfemoral prosthesis users will wear a StepWatch4 activity monitor (Modus Health, Edmonds, WA) for three 2-week periods. Activity bouts, or periods of time in which steps occur in successive 10-second intervals, will be derived from step count data. The duration of physical activity will be quantified by the mean time (in minutes) of activity bouts per day. Higher values will be taken as evidence of greater physical activity.	2 weeks prior to intervention (baseline)
Secondary	Duration of physical activity at 8 weeks	To assess the duration of physical activity, transfemoral prosthesis users will wear a StepWatch4 activity monitor (Modus Health, Edmonds, WA) for three 2-week periods. Activity bouts, or periods of time in which steps occur in successive 10-second intervals, will be derived from step count data. The duration of physical activity will be quantified by the mean time (in minutes) of activity bouts per day. Higher values will be taken as evidence of greater physical activity. Comparisons will be made to baseline.	8 weeks after intervention
Secondary	Duration of physical activity at 42 weeks	To assess the duration of physical activity, transfemoral prosthesis users will wear a StepWatch4 activity monitor (Modus Health, Edmonds, WA) for three 2-week periods. Activity bouts, or periods of time in which steps occur in successive 10-second intervals, will be derived from step count data. The duration of physical activity will be quantified by the mean time (in minutes) of activity bouts per day. Higher values will be taken as evidence of greater physical activity. Comparisons will be made to baseline.	42 weeks after intervention