Skip to main content
OpenTrials
Completed

NCT Number: NCT04023045

Assist-Knee: Energy-Harvesting Knee Prosthesis

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 .

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Transfemoral Amputation Artificial Limbs

Age range

21 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Orthocare Innovations, LLC

Edmonds, Washington, 98020, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Unilateral transfemoral limb loss
  • At least one year post-amputation and currently successfully using a prosthesis
  • Uses modular endoskeletal prosthetic components
  • Has bilateral normal range of motion
  • Ability to perform the following activities:
  • Walking ability or ability to take steps over 10 meters
  • Upright standing stability
  • Stand-to-sit stability (i.e. go from a standing position to a seated position independently)
  • Sit-to-stand stability (i.e. rise from a seated position independently)
  • Ability to communicate individual perceptions in the English language
  • Ability to provide informed consent

Exclusion criteria

  • Confounding injury or musculoskeletal problem
  • Pregnancy
  • Lower limb peripheral neuropathy
  • Symptomatic cardiovascular disease or chronic obstructive pulmonary disease
  • Not able to read and understand English
  • Use of assistive devices for sit-to-stand and stand-to-sit (e.g. canes, walkers)

Treatment and study plan

Assist-Knee

Device

Assist-Knee is an experimental lower limb knee prosthesis.

Habitual Prosthesis

Device

Habitual baseline prosthesis prescribed by participant's clinician.

Primary outcomes

  1. Time to Complete Sit-to-Stand

    Time frame: 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.

  2. Time to Complete Sit-to-Stand

    Time frame: 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.

Secondary outcomes

  1. Timed Up and Go (TUG) Test

    Time frame: 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).

  2. Timed Up and Go (TUG) Test

    Time frame: 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).

  3. Time to Complete Stand-to-Sit

    Time frame: 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.

  4. Time to Complete Stand-to-Sit

    Time frame: 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.

  5. Percentage of Body Weight on Contralateral Limb at 65 Degrees Knee Flexion

    Time frame: 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.

  6. Percentage of Body Weight on Contralateral Limb at 65 Degrees Knee Flexion

    Time frame: 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.

Sponsors and collaborators

Lead sponsor

Orthocare Innovations, LLC

Industry

Collaborators

  • Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

Registry information

Official study title

Evaluation of an Energy-Harvesting Knee Prosthesis in Transfemoral Prosthesis Users

Important dates

Study start
2019
Primary completion
2020
Study completion
2020
First posted
Jul 17, 2019
Registry last updated
Oct 18, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.