Clinical trial NCT06433648: Understanding How Powered Componentry Impacts K2-Level Transfemoral Amputee Gait
Official title: Understanding How Powered Componentry Impacts K2-Level Transfemoral Amputee Gait
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Amputation
Amputation, Traumatic
Amputation of Knee
Amputation; Traumatic, Limb
Lead sponsor: Shirley Ryan AbilityLab
Sponsor class: OTHER
First posted: 2024-05-30
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Maximum age (years): 95
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: The goal of this study is to understand how providing power at the knee or ankle individually, or providing power at both the knee and ankle, impacts ambulation for transfemoral amputees with limited community mobility.

Aim 1: measure functional performance of transfemoral ambulators when using a commercially available passive microprocessor knee prosthesis (Ottobock Cleg/Ottobock foot) or a powered knee and ankle prosthesis (SRALab Hybrid Knee and SRAlab Polycentric Powered Ankle.

Aim 2: Participants will be evaluated on the contribution of adding power at the knee only or the ankle only.

Aim 3: The investigators will evaluate the functional performance after intensive clinical gait training on the powered knee and ankle prosthesis (SRALab Hybrid Knee and SRALab Polycentric Powered Ankle).
Primary purpose: BASIC_SCIENCE

Brief summary: The goal of this study is to understand how providing power at the knee or ankle individually, or providing power at both the knee and ankle, impacts ambulation for K2 level transfemoral amputees.

Aim 1: measure functional performance of K2 level ambulators when using a commercially available passive microprocessor knee prosthesis (Ottobock Cleg/Ottobock foot) or a powered knee and ankle prosthesis (SRALab Hybrid Knee and SRAlab Polycentric Powered Ankle.

Aim 2: Participants will be evaluated on the contribution of adding power at the knee only or the ankle only.

Aim 3: The investigators will evaluate the functional performance after intensive clinical gait training on the powered knee and ankle prosthesis (SRALab Hybrid Knee and SRALab Polycentric Powered Ankle).

Our hypothesis is that providing powered componentry will improve function and that intensive training will magnify those improvements.

Detailed description: Amputation of the lower limb causes profound disability, significantly limiting mobility, independence, and the ability to pursue employment or leisure activities. Nearly 90% of all lower limb amputations in the United States occur in older persons, mostly due to vascular disease, and this population is expected to triple by 2050. After lower limb loss, individuals walk more slowly and more asymmetrically are less stable, and expend more metabolic energy during walking than persons with intact limbs. Even when using state-of-the-art microprocessor-controlled prostheses (typically a microprocessor knee with a passive ankle), persons with transfemoral amputations expend approximately 60% more energy than able-bodied individuals during ambulation. In addition to the physical limitations caused by the amputation, the increased energy requirements affect performance of everyday activities, including getting up out of a chair or off the toilet, or stepping up or down a curb.

Most commercially available prosthetic legs are passive. The movement of a passive prosthetic joint relies on the properties of its mechanical components, such as hydraulic or pneumatic valves or sliding joints, together with compensatory adjustments made by the user. Since these computerized prostheses are passive, the user cannot efficiently negotiate stairs, an incline, or the numerous other functions that require net knee and/or ankle power.

Powered prostheses can actively generate joint torque, allowing easy and efficient performance of more demanding activities, such as ascending stairs and hills. Powered knees and ankles, may allow for better outcomes in both older and younger individuals with transfemoral amputation; this powered componentry may enable more energy efficient walking, allow users to stand up from a seated position with ease, and enable them to walk across more challenging terrains-such as up and down hills, ramps, and stairs-safely and with more normal and symmetric gait kinematics and kinetics.

This study will demonstrate the functional benefits of adding power at an individual joint. This knowledge will be critical for prioritizing future device development and will provide valuable information for clinicians and individuals on selecting appropriate componentry for transfemoral K2 amputees.

Eligibility criteria: Inclusion Criteria:

* Ages 18-95
* A unilateral transfemoral amputation
* At least 6 months since definitive prosthesis fitting
* Able to walk 50 meters (55 yards) with a prosthesis without the assistance of another person.
* Medically cleared by physician to participate in study
* English speaking

Exclusion Criteria:

* Weight greater than 250 pounds
* Significant new injury that would prevent use of a prosthesis: The ability to consistently wear a prosthesis and perform activities of daily living and specific performance tasks is necessary to evaluate the relative benefits of the interventions.
* Cognitive impairment sufficient to adversely affect understanding of or compliance with study requirements, ability to communicate experiences, or ability to give informed consent: The ability to understand and comply with requirements of the study is essential in order for the study to generate useable, reliable data. The ability to obtain relevant user feedback through questionnaires and informal discussion adds significant value to this study.
* Significant other comorbidity: Any other medical issues or injuries that would preclude completion of the study, use of the prostheses, or that would otherwise prevent acquisition of useable data by researchers.

Primary outcomes:
measure: Amputee Mobility Predictor with Prosthesis (AMPRO) score
timeFrame: Completed at visit during week 5, week 10, week 11, week 14, week 15, week 18, week 35 and week 38.
Secondary outcomes:
measure: 6 Minute Walk Test (6MWT)
timeFrame: Completed at visit during week 5, week 10, week 11, week 14, week 15, week 18, week 35 and week 38.
measure: Timed Up and Go (TUG)
timeFrame: Completed at visit during week 5, week 10, week 11, week 14, week 15, week 18, week 35 and week 38.
measure: Four Square Step Test (FSST)
timeFrame: Completed at visit during week 5, week 10, week 11, week 14, week 15, week 18, week 35 and week 38.
measure: Metabolic Testing
timeFrame: Completed at visit during week 5, week 10, week 11, week 14, week 15, week 18, week 35 and week 38
Other outcomes:
Locations:
city: Chicago
country: United States
facility: Shirley Ryan AbilityLab
state: Illinois
Study officials:
References:
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citation: Hafner BJ, Sanders JE, Czerniecki J, Fergason J. Energy storage and return prostheses: does patient perception correlate with biomechanical analysis? Clin Biomech (Bristol). 2002 Jun;17(5):325-44. doi: 10.1016/s0268-0033(02)00020-7.
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citation: Fey NP, Simon AM, Young AJ, Hargrove LJ. Controlling Knee Swing Initiation and Ankle Plantarflexion With an Active Prosthesis on Level and Inclined Surfaces at Variable Walking Speeds. IEEE J Transl Eng Health Med. 2014 Jul 25;2:2100412. doi: 10.1109/JTEHM.2014.2343228. eCollection 2014.
citation: Adamczyk PG, Kuo AD. Mechanisms of Gait Asymmetry Due to Push-Off Deficiency in Unilateral Amputees. IEEE Trans Neural Syst Rehabil Eng. 2015 Sep;23(5):776-85. doi: 10.1109/TNSRE.2014.2356722. Epub 2014 Sep 12.