NCT04023045

Assist-Knee: Energy-Harvesting Knee Prosthesis

Completed NA Results posted Last updated 18 October 2023

What this trial tests

NA trial testing Assist-Knee in Transfemoral Amputation in 3 participants. Completed in 26 February 2020.

Timeline

15 July 2019

Primary endpoint
26 February 2020

26 February 2020

Quick facts

Lead sponsor	Orthocare Innovations, LLC
Phase	NA
Status	Completed
Study type	INTERVENTIONAL
Allocation	non randomized
Design	crossover
Masking	none
Primary purpose	device feasibility
Enrollment	3
Start date	15 July 2019
Primary completion	26 February 2020
Estimated completion	26 February 2020
Sites	1 location across United States

Drugs / interventions tested

• Assist-Knee
• Habitual Prosthesis

Conditions studied

• Transfemoral Amputation — all drugs for Transfemoral Amputation →
• Artificial Limbs — all drugs for Artificial Limbs →

Sponsor

Orthocare Innovations, LLC

Who can join

Adults 21 to 80, any sex, with Transfemoral Amputation or Artificial Limbs. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Time to Complete Sit-to-Stand Primary · Collection at baseline

The amount of time, measured in seconds, needed by the subject to complete the sit-to-stand transition. At least four trials of the sit-to-stand maneuver were collected for each participant using a motion analysis system. Average and standard deviation of the time to complete the sit-to-stand transition were calculated for each participant (each participant served as their own control in this pilot study). The start of the transition was determined by participant initiation; the end of the transition was determined by the participant reaching full knee extension.

Participant A

Group	Value	95% CI
Habitual Prosthesis	1.6	± 0.1

Participant B

Group	Value	95% CI
Habitual Prosthesis	2.2	± 0.2

Participant C

Group	Value	95% CI
Habitual Prosthesis	1.4	± 0.2

Time to Complete Sit-to-Stand Primary · After acclimation to Assist-Knee (Participants are given at least 10 minutes and no more than 60 minutes to acclimate to each Assist-Knee condition for safety. After acclimating, participants will complete the maneuver to measure this outcome.)

The amount of time, measured in seconds, needed by the subject to complete the sit-to-stand transition. At least four trials of the sit-to-stand maneuver were collected for each participant using a motion analysis system. Average and standard deviation of the time to complete the sit-to-stand transition were calculated for each participant (each participant served as their own control in this pilot study). The start of the transition was determined by participant initiation; the end of the transition was determined by the participant reaching full knee extension.

Participant A

Group	Value	95% CI
Assist-Knee (Settings 1)	3.4	± 0.6
Assist-Knee (Settings 2)	2.7	± 0.2

Participant B

Group	Value	95% CI
Assist-Knee (Settings 1)	6.4	± 1.3
Assist-Knee (Settings 2)	3.8	± 0.5

Participant C

Group	Value	95% CI
Assist-Knee (Settings 1)	2.4	± 0.5
Assist-Knee (Settings 2)	2.9	± 0.5

Timed Up and Go (TUG) Test Secondary · Collection at baseline

The Timed Up and Go (TUG) test is a validated timed functional test that involves standing up from a chair, walking forward for 3 meters, turning around, walking back to the chair for 3 meter, and sitting down. Each participant completed the TUG test for three trials. Time was measured using a stopwatch. Average and standard deviation of the time to complete the TUG test were calculated for each participant (each participant served as their own control in this pilot study).

Participant A

Group	Value	95% CI
Habitual Prosthesis	7.1	± 0.5

Participant B

Group	Value	95% CI
Habitual Prosthesis	13.7	± 1.0

Participant C

Group	Value	95% CI
Habitual Prosthesis	12.3	± 0.8

Timed Up and Go (TUG) Test Secondary · After acclimation to Assist-Knee (Participants are given at least 10 minutes and no more than 60 minutes to acclimate to each Assist-Knee condition for safety. After acclimating, participants will complete the maneuver to measure this outcome.)

The Timed Up and Go (TUG) test is a validated timed functional test that involves standing up from a chair, walking forward for 3 meters, turning around, walking back to the chair for 3 meter, and sitting down. Each participant completed the TUG test for three trials. Time was measured using a stopwatch. Average and standard deviation of the time to complete the TUG test were calculated for each participant (each participant served as their own control in this pilot study).

Participant A

Group	Value	95% CI
Assist-Knee (Settings 1)	12.3	± 1.1
Assist-Knee (Settings 2)	12.8	± 0.8

Participant B

Group	Value	95% CI
Assist-Knee (Settings 1)	25.0	± 3.0
Assist-Knee (Settings 2)	22.0	± 1.4

Participant C

Group	Value	95% CI
Assist-Knee (Settings 1)	20.8	± 3.5
Assist-Knee (Settings 2)	18.8	± 1.5

Time to Complete Stand-to-Sit Secondary · Collection at baseline

The amount of time, measured in seconds, needed by the subject to complete the stand-to-sit transition. At least four trials of the stand-to-sit maneuver were collected for each participant using a motion analysis system. Average and standard deviation of the time to complete the stand-to-sit transition were calculated for each participant (each participant served as their own control in this pilot study). The start of the transition was determined by participant initiation; the end of the transition was determined by the participant being seated on a chair.

Participant A

Group	Value	95% CI
Habitual Prosthesis	2.7	± 0.1

Participant B

Group	Value	95% CI
Habitual Prosthesis	4.1	± 1.0

Participant C

Group	Value	95% CI
Habitual Prosthesis	1.6	± 0.2

Time to Complete Stand-to-Sit Secondary · After acclimation to Assist-Knee (Participants are given at least 10 minutes and no more than 60 minutes to acclimate to each Assist-Knee condition for safety. After acclimating, participants will complete the maneuver to measure this outcome.)

The amount of time, measured in seconds, needed by the subject to complete the stand-to-sit transition. At least four trials of the stand-to-sit maneuver were collected for each participant using a motion analysis system. Average and standard deviation of the time to complete the stand-to-sit transition were calculated for each participant (each participant served as their own control in this pilot study). The start of the transition was determined by participant initiation; the end of the transition was determined by the participant being seated on a chair.

Participant A

Group	Value	95% CI
Assist-Knee (Settings 1)	4.4	± 0.4
Assist-Knee (Settings 2)	3.3	± 0.4

Participant B

Group	Value	95% CI
Assist-Knee (Settings 1)	4.9	± 1.7
Assist-Knee (Settings 2)	4.5	± 0.9

Participant C

Group	Value	95% CI
Assist-Knee (Settings 1)	2.5	± 0.1
Assist-Knee (Settings 2)	2.7	± 0.7

Percentage of Body Weight on Contralateral Limb at 65 Degrees Knee Flexion Secondary · Collection at baseline

The percentage of body weight on the contralateral limb was determined for both stand-to-sit and sit-to-stand transitions at 65 degrees knee flexion. A force plate under the contralateral limb recorded the amount of loading on the limb during the stand-to-sit and sit-to-stand transitions. The amount of contralateral limb loading at 65 degrees knee flexion was determined and divided by the participant's total loading due to overall body weight. This value was then converted to a percentage.

Participant A

Group	Value	95% CI
SIT With Habitual Prosthesis	79.2	± 2.8
STAND With Habitual Prosthesis	85.9	± 2.5

Participant B

Group	Value	95% CI
SIT With Habitual Prosthesis	61.8	± 11.4
STAND With Habitual Prosthesis	49.0	± 2.3

Participant C

Group	Value	95% CI
SIT With Habitual Prosthesis	87.0	± 3.6
STAND With Habitual Prosthesis	95.8	± 2.6

Percentage of Body Weight on Contralateral Limb at 65 Degrees Knee Flexion Secondary · After acclimation to Assist-Knee (Participants are given at least 10 minutes and no more than 60 minutes to acclimate to each Assist-Knee condition for safety. After acclimating, participants will complete the maneuver to measure this outcome.)

The percentage of body weight on the contralateral limb was determined for both stand-to-sit and sit-to-stand transitions at 65 degrees knee flexion. A force plate under the contralateral limb recorded the amount of loading on the limb during the stand-to-sit and sit-to-stand transitions. The amount of contralateral limb loading at 65 degrees knee flexion was determined and divided by the participant's total loading due to overall body weight. This value was then converted to a percentage.

Participant A

Group	Value	95% CI
SIT With Assist-Knee (Settings 1)	67.7	± 7.5
STAND With Assist-Knee (Settings 1)	82.0	± 1.9
SIT With Assist-Knee (Settings 2)	48.0	± 9.4
STAND With Assist-Knee (Settings 2)	83.5	± 1.2

Participant B

Group	Value	95% CI
SIT With Assist-Knee (Settings 1)	23.5	± 13.7
STAND With Assist-Knee (Settings 1)	27.0	± 6.9
SIT With Assist-Knee (Settings 2)	19.4	± 10.4
STAND With Assist-Knee (Settings 2)	31.3	± 2.3

Participant C

Group	Value	95% CI
SIT With Assist-Knee (Settings 1)	67.0	± 1.6
STAND With Assist-Knee (Settings 1)	78.6	± 4.5
SIT With Assist-Knee (Settings 2)	63.4	± 9.9
STAND With Assist-Knee (Settings 2)	76.4	± 3.2

Sponsor's own description

The purpose of this research is to validate the Assist-Knee design and function by collecting pilot data during the stand-to-sit-to-stand transition in transfemoral prosthesis users when using the Assist-Knee to harvest energy and return energy .

Publications & conference data

1 peer-reviewed publication reference this trial (live from Europe PMC):

1. Through-knee versus above-knee amputation for vascular and non-vascular major lower limb amputations.
   Crane H, Boam G, Carradice D, Vanicek N, et al · · 2021 · cited 15× · PMID 34904714 · DOI 10.1002/14651858.cd013839.pub2