Assist-Knee: Energy-Harvesting Knee Prosthesis

Conditions

Artificial Limbs, Transfemoral Amputation

Brief summary

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 .

Related papers

No related papers found yet.

Interventions

DEVICEAssist-Knee

Assist-Knee is an experimental lower limb knee prosthesis.

DEVICEHabitual Prosthesis

Habitual baseline prosthesis prescribed by participant's clinician.

Study design

Allocation

NON_RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

DEVICE_FEASIBILITY

Masking

NONE

Intervention model description

Crossover clinical trial

Eligibility

Sex/Gender

ALL

Age

21 Years to 80 Years

Healthy volunteers

No

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)

Design outcomes

Primary

Measure	Time frame	Description
Time to Complete Sit-to-Stand	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.

Secondary

Measure	Time frame	Description
Timed Up and Go (TUG) Test	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).
Time to Complete Stand-to-Sit	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.
Percentage of Body Weight on Contralateral Limb at 65 Degrees Knee Flexion	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.

Countries

United States

Participant flow

Recruitment details

Individuals were recruited from a sample of convenience in the local area between 07/15/2019 and 02/26/2020.

Participants by arm

Arm	Count
Study Participants Study participants completed both arms of the study: Habitual and Assist-Knee. Habitual Prosthesis: Habitual baseline prosthesis prescribed by participant's clinician. Assist-Knee Prosthesis: Assist-Knee is an experimental lower limb knee prosthesis.	3
Total	3

Baseline characteristics

Characteristic	Study Participants
Age, Categorical <=18 years	0 Participants
Age, Categorical >=65 years	2 Participants
Age, Categorical Between 18 and 65 years	1 Participants
Age, Continuous	69 years STANDARD_DEVIATION 5
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	3 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants
Race (NIH/OMB) Asian	0 Participants
Race (NIH/OMB) Black or African American	0 Participants
Race (NIH/OMB) More than one race	0 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants
Race (NIH/OMB) White	3 Participants
Region of Enrollment United States	3 participants
Sex: Female, Male Female	2 Participants
Sex: Female, Male Male	1 Participants

Adverse events

Event type	EG000 affected / at risk
deaths Total, all-cause mortality	0 / 3
other Total, other adverse events	0 / 3
serious Total, serious adverse events	0 / 3

Outcome results

Primary

Time to Complete Sit-to-Stand

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.

Time frame: Collection at baseline