Trial Outcomes & Findings for Clinical Investigation (Beta) of Power Knee Mainstream - Dynamic (NCT NCT04787627)

NCT ID: NCT04787627

Last Updated: 2025-09-22

Results Overview

Mean difference in perceived exertion on the Borg rating scale of perceived exertion before and after 6 minute walk test (6MWT) (see outcome 2) with investigational device (Power Knee) compared to comparator (prescribed device). Subjects are asked how exerted they feel on a scale of 0-10 (0 indicating no exertion and 10 indicating the most exertion) at rest before they carry out the 6MWT, and after carrying out the 6MWT, the difference is recorded. The Borg Category Rating 10 scale (CR10) is a validated measure of perceived exertion.

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 17 participants
• Primary outcome timeframe: At baseline, after 2 weeks of either using the Power knee or their own prescription prosthesis, and at the fourth follow-up (at approximately weeks 22-16)
• Results posted on: 2025-09-22

Participant Flow

Participant milestones

Measure	Power Knee Before Prescribed Prosthesis Power Knee, the investigational device is fitted on subjects and they use it as their primary prosthesis for 2 weeks before coming in for data collection on the device. After being on the investigational device for 2 weeks subjects go back on their prescribed prosthesis for 2 weeks and comparator data is collected. Power Knee: Powered microprocessor controlled prosthetic knee	Power Knee After Prescribed Prosthesis Subjects start the study by using their prescribed prosthesis for 2 weeks, then they come in for data collection of comparator data, in that same visit they are fitted with the investigational device and wear that for 2 weeks before coming in for data collection on that device. Power Knee: Powered microprocessor controlled prosthetic knee
Overall Study STARTED	9	8
Overall Study COMPLETED	4	7
Overall Study NOT COMPLETED	5	1

Reasons for withdrawal

Measure	Power Knee Before Prescribed Prosthesis Power Knee, the investigational device is fitted on subjects and they use it as their primary prosthesis for 2 weeks before coming in for data collection on the device. After being on the investigational device for 2 weeks subjects go back on their prescribed prosthesis for 2 weeks and comparator data is collected. Power Knee: Powered microprocessor controlled prosthetic knee	Power Knee After Prescribed Prosthesis Subjects start the study by using their prescribed prosthesis for 2 weeks, then they come in for data collection of comparator data, in that same visit they are fitted with the investigational device and wear that for 2 weeks before coming in for data collection on that device. Power Knee: Powered microprocessor controlled prosthetic knee
Overall Study Withdrawal by Subject	3	0
Overall Study Physician Decision	2	0
Overall Study Excluded	0	1

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Measure	Combined Crossover Evaluation Group n=17 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.
Age, Continuous	52 years n=17 Participants
Sex: Female, Male Female	0 Participants n=17 Participants
Sex: Female, Male Male	17 Participants n=17 Participants
Region of Enrollment United States	17 Participants n=17 Participants
Amputation level Transfemoral	17 Participants n=17 Participants

PRIMARY outcome

Timeframe: At baseline, after 2 weeks of either using the Power knee or their own prescription prosthesis, and at the fourth follow-up (at approximately weeks 22-16)

Population: Only 6 out of the 11 subjects decided to do a prolonged follow up period.

Mean difference in perceived exertion on the Borg rating scale of perceived exertion before and after 6 minute walk test (6MWT) (see outcome 2) with investigational device (Power Knee) compared to comparator (prescribed device). Subjects are asked how exerted they feel on a scale of 0-10 (0 indicating no exertion and 10 indicating the most exertion) at rest before they carry out the 6MWT, and after carrying out the 6MWT, the difference is recorded.

The Borg Category Rating 10 scale (CR10) is a validated measure of perceived exertion.

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period n=6 Participants Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Mean Difference in Borg Category Rating Scale Before and After 6MWT at 2 Weeks After 2 weeks : Power Knee	3.4 score on a scale Standard Deviation 2.5	2.8 score on a scale Standard Deviation 1.7
Mean Difference in Borg Category Rating Scale Before and After 6MWT at 2 Weeks After 2 weeks : Prescribed knee	3.1 score on a scale Standard Deviation 1.5	2.5 score on a scale Standard Deviation 0.9
Mean Difference in Borg Category Rating Scale Before and After 6MWT at 2 Weeks At Baseline: Prescribed knee	3.4 score on a scale Standard Deviation 1.6	3.3 score on a scale Standard Deviation 1.4
Mean Difference in Borg Category Rating Scale Before and After 6MWT at 2 Weeks After a prolonged follow up period : Power Knee	—	3.2 score on a scale Standard Deviation 0.7

PRIMARY outcome

Timeframe: At baseline, after 2 weeks of either using the Power knee or their own prescription prosthesis, and at the fourth follow-up (at approximately weeks 22-16)

Population: Only 6 out of the 11 subjects decided to do a prolonged follow up period.

Average distance walked in 6MWT with investigational device (Power Knee) compared to comparator (prescribed device) User walk for 6 minutes in their self selected walking speed on a 30 meter track.

Shorter time indicates better mobility performance.

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period n=6 Participants Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Average Distance Walked in 6 Minute Walk Test After 2 weeks: Power Knee	381.7 meters Standard Deviation 137.1	402.5 meters Standard Deviation 151.5
Average Distance Walked in 6 Minute Walk Test After 2 weeks: Prescribed knee	377.2 meters Standard Deviation 108.6	390.7 meters Standard Deviation 136.0
Average Distance Walked in 6 Minute Walk Test At Baseline : Prescribed knee	369.2 meters Standard Deviation 113.4	381.5 meters Standard Deviation 140.3
Average Distance Walked in 6 Minute Walk Test After a prolonged follow up period: Power Knee	—	393.1 meters Standard Deviation 112.1

SECONDARY outcome

Timeframe: At baseline, after 2 weeks of either using the Power knee or their own prescription prosthesis, and at the fourth follow-up (at approximately weeks 22-16)

Population: Only 6 out of the 11 subjects decided to do a prolonged follow up period.

Support in sit to stand and stand to sit evaluation:

Total score (minimum score 0 - maximum score 8) of Prosthetic Mobility Questionnaire (PMQ) questions 9 and 10 with investigational device (Power Knee) compared to comparator (prescribed knee):

PMQ : Over the past 2 weeks, please rate your ability in the following activities when using your prosthesis (0=no ability, 4=fully able):

• Question 9. To sit down and get up from a chair with a high seat (e.g. a dining chair, an office chair)
• Question 10. To sit down and get up from a low, soft chair (e.g. a deep sofa) A higher total score on these PMQ items indicates a better outcome as it reflects greater functional ability, independence, and overall quality of life for individuals using a prosthesis.

The total score is obtained by summing the scores from questions 9 and 10.

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period n=6 Participants Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Total Score of Prosthesis Mobility Questionnaire (PMQ) Questions 9 and 10 After 2 weeks: Power Knee	6.8 score on a scale Standard Deviation 1.3	7.2 score on a scale Standard Deviation 1.0
Total Score of Prosthesis Mobility Questionnaire (PMQ) Questions 9 and 10 After 2 weeks: Prescribed knee	5.8 score on a scale Standard Deviation 1.9	5.7 score on a scale Standard Deviation 2.1
Total Score of Prosthesis Mobility Questionnaire (PMQ) Questions 9 and 10 At baseline: Prescribed knee	5.6 score on a scale Standard Deviation 2.2	6.0 score on a scale Standard Deviation 1.4
Total Score of Prosthesis Mobility Questionnaire (PMQ) Questions 9 and 10 After a prolonged follow up period: Power Knee	—	6.3 score on a scale Standard Deviation 1.2

SECONDARY outcome

Timeframe: At baseline, after 2 weeks of either using the Power knee or their own prescription prosthesis, and at the fourth follow-up (at approximately weeks 22-16)

Population: Only 6 out of the 11 subjects decided to do a prolonged follow up period.

Average score with investigational device (Power Knee) compared to comparator (prescribed device) of modified PEQ Question 14F

Modified PEQ question 14F :

Over the past 2 weeks, please rate your ability in the following activities when using your prosthesis :

• Question 14F. Your safety when walking down a steep hill using the prosthesis The scale used is a Likert Scale 1-10 (1 indicating low rating of safety and 10 indicating a high rating of safety).

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period n=6 Participants Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Average Score of Modified Prosthesis Evaluation Questionnaire (PEQ) Question 14F After 2 weeks : Power Knee	7.9 score on a scale Standard Deviation 1.6	8.3 score on a scale Standard Deviation 1.2
Average Score of Modified Prosthesis Evaluation Questionnaire (PEQ) Question 14F After 2 weeks : Prescribed knee	7.1 score on a scale Standard Deviation 2.4	6.8 score on a scale Standard Deviation 2.0
Average Score of Modified Prosthesis Evaluation Questionnaire (PEQ) Question 14F At Baseline: Prescribed knee	7.3 score on a scale Standard Deviation 2.0	6.8 score on a scale Standard Deviation 1.8
Average Score of Modified Prosthesis Evaluation Questionnaire (PEQ) Question 14F After a prolonged follow up period: Power Knee	—	6.7 score on a scale Standard Deviation 3.4

SECONDARY outcome

Timeframe: At baseline, after 2 weeks of either using the Power knee or their own prescription prosthesis, and at the fourth follow-up (at approximately weeks 22-16)

Population: Only 6 out of the 11 subjects decided to do a prolonged follow up period.

Average score with investigational device (Power Knee) compared to comparator (prescribed device) of modified PEQ Question 13D

Over the past 2 weeks, please rate your ability in the following activities when using your prosthesis :

• Question 13D.Your safety when walking downstairs using the prosthesis The scale used is a Likert Scale 1-10 (1 indicating low rating of safety and 10 indicating a high rating of safety).

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period n=6 Participants Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Average Score of Modified Prosthesis Evaluation Questionnaire (PEQ) Question 13D After 2 weeks: Power Knee	9.2 score on a scale Standard Deviation 0.8	9.5 score on a scale Standard Deviation 0.6
Average Score of Modified Prosthesis Evaluation Questionnaire (PEQ) Question 13D After 2 weeks: Prescribed Knee	7.8 score on a scale Standard Deviation 2.0	7.2 score on a scale Standard Deviation 2.2
Average Score of Modified Prosthesis Evaluation Questionnaire (PEQ) Question 13D At baseline: Prescribed Knee	7.7 score on a scale Standard Deviation 1.9	7.7 score on a scale Standard Deviation 1.6
Average Score of Modified Prosthesis Evaluation Questionnaire (PEQ) Question 13D After a prolonged follow up period: Power Knee	—	8.2 score on a scale Standard Deviation 4.0

SECONDARY outcome

Timeframe: At baseline, after 2 weeks of either using the Power knee or their own prescription prosthesis, and at the fourth follow-up (at approximately weeks 22-16)

Population: Only 6 out of the 11 subjects decided to do a prolonged follow up period.

Proportion of subjects reporting satisfaction with walking speed on investigational device

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period n=6 Participants Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Satisfaction With Walking Speed	100 percentage of participants	100 percentage of participants

SECONDARY outcome

Timeframe: At baseline, after 2 weeks of either using the Power knee or their own prescription prosthesis, and at the fourth follow-up (at approximately weeks 22-16)

Population: Only 6 out of the 11 subjects decided to do a prolonged follow up period

Ability to ambulate over typical environmental obstacles measured by the Prosthetic Limb Users Survey of Mobility (PLUS-M), T-score with Power Knee compared to comparator (prescribed device).

The Prosthetic Limb Users Survey of Mobility™ is a self-report instrument for measuring mobility of adults with lower limb amputation.

Scoring a PLUS-M short form produces a T-score. To find the T-score, the scores must be summed for all responses on the short form (creating a raw score). Then the raw score needs to be used to determine the T-score in the conversation table provided with the PLUS-M questionnaire.

The T-score is a standardized score with a mean of 50 and a standard deviation of 10. A higher T-score indicates a higher level of mobility. The highest possible T-score is 71.4 and the lowest one is 21.8.

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period n=6 Participants Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Prosthetic Limb Users Survey of Mobility (PLUS-M) T-score After 2 weeks: Power Knee	57.2 score on a scale Standard Deviation 7.9	57.9 score on a scale Standard Deviation 6.2
Prosthetic Limb Users Survey of Mobility (PLUS-M) T-score After 2 weeks: Prescribed Knee	51.7 score on a scale Standard Deviation 10.2	51.9 score on a scale Standard Deviation 10.1
Prosthetic Limb Users Survey of Mobility (PLUS-M) T-score At Baseline: Prescribed Knee	53.1 score on a scale Standard Deviation 9.1	54.1 score on a scale Standard Deviation 8.3
Prosthetic Limb Users Survey of Mobility (PLUS-M) T-score After a prolonged follow up period: Power Knee	—	56.3 score on a scale Standard Deviation 6.3

SECONDARY outcome

Timeframe: At baseline, after 2 weeks of either using the Power knee or their own prescription prosthesis, and at the fourth follow-up (at approximately weeks 22-16)

Population: Only 6 out of the 11 subjects decided to do a prolonged follow up period.

Average score with investigational device (Power Knee) compared to comparator (prescribed device) of modified PEQ Question 13A

Over the past 2 weeks, please rate your ability in the following activities when using your prosthesis :

• Question 13A. Your safety (during stance phase) when walking with your prosthesis (prescribed device) /test prosthesis (Power Knee)? The scale used is a Likert Scale 1-10 (1 indicating low rating of safety and 10 indicating a high rating of safety).

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period n=6 Participants Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Average Score of Modified Prosthesis Evaluation Questionnaire (PEQ) Question 13A After 2 weeks: Power Knee	8.4 score on a scale Standard Deviation 2.1	9.0 score on a scale Standard Deviation 1.6
Average Score of Modified Prosthesis Evaluation Questionnaire (PEQ) Question 13A After 2 weeks: Prescribed Knee	8.5 score on a scale Standard Deviation 1.7	8.3 score on a scale Standard Deviation 1.9
Average Score of Modified Prosthesis Evaluation Questionnaire (PEQ) Question 13A At Baseline: Prescribed Knee	8.6 score on a scale Standard Deviation 1.4	8.7 score on a scale Standard Deviation 1.2
Average Score of Modified Prosthesis Evaluation Questionnaire (PEQ) Question 13A After a prolonged follow up period: Power Knee	—	8.0 score on a scale Standard Deviation 4.0

SECONDARY outcome

Timeframe: At baseline, after 2 weeks of either using the Power knee or their own prescription prosthesis, and at the fourth follow-up (at approximately weeks 22-16)

Population: Only 6 out of the 11 subjects decided to do a prolonged follow up period.

Average score with investigational device (Power Knee) compared to comparator (prescribed device) of modified PEQ Question 1D

Over the past 2 weeks, please rate your ability in the following activities when using your prosthesis :

• Question 1D. Your comfort while standing when using your prosthesis/test prosthesis? The scale used is a Likert Scale 1-10 (1 indicating low rating of safety and 10 indicating a high rating of safety).

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period n=6 Participants Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Average Score of Prosthesis Evaluation Questionnaire (PEQ) Question 1D After 2 weeks: Power Knee	9.0 score on a scale Standard Deviation 2.1	9.5 score on a scale Standard Deviation 0.8
Average Score of Prosthesis Evaluation Questionnaire (PEQ) Question 1D After 2 weeks: Prescribed Knee	8.5 score on a scale Standard Deviation 1.2	8.0 score on a scale Standard Deviation 1.4
Average Score of Prosthesis Evaluation Questionnaire (PEQ) Question 1D At Baseline: Prescribed Knee	8.6 score on a scale Standard Deviation 1.1	8.3 score on a scale Standard Deviation 1.4
Average Score of Prosthesis Evaluation Questionnaire (PEQ) Question 1D After a prolonged follow up period: Power Knee	—	7.7 score on a scale Standard Deviation 3.4

SECONDARY outcome

Timeframe: Immediately after the intervention (fitting of the investigational device)

Self reported ease of setup of investigational device compared to state of the art microprocessor knees (SOTA MPKs) and previous version of the investigational device.

Average score with investigational device (Power Knee) compared to comparator (previous version of Power Knee) and compared to state of the art microprocessor knees (SOTA MPKs) The scale used is a Likert Scale 1-10 (1 indicating low rating and 10 indicating a high rating).

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=6 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Average Score Regarding the Ease of Setup Power Knee	9.0 score on a scale Standard Deviation 1.3	—
Average Score Regarding the Ease of Setup Previous version of Power Knee	6.5 score on a scale Standard Deviation 3.3	—
Average Score Regarding the Ease of Setup SOTA MPKs	8.6 score on a scale Standard Deviation 1.2	—

SECONDARY outcome

Timeframe: After 2 weeks of either using the Power Knee or their own prescribed knee

Proportion of participants with Average score with investigational device of PEQ questions 3K and 3L over 5

PEQ- Questions 3K, 3L:

• Question 3K: Over the past two weeks, rate how often the test prosthesis made squeaking, clicking, or belching sounds The scale used is a Likert Scale 1-10 (1 indicating low frequency of prosthesis making sounds and 10 indicating a high frequency of the prosthesis making sounds).
• Question 3L: 3L: If it made any sounds in the past four weeks, rate how bothersome these sounds were to you. - Or check It made no sounds The scale used is a Likert Scale 1-10 (1 indicating low frequency of prosthesis making sounds and 10 indicating a high frequency of the prosthesis making sounds).

Support question (yes/no) "Would the noise from the test device prevent you from preferring it as your usual prosthesis?"

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Proportion of Participants With Average Score Over 5 on Questions 3K and 3L of the Prosthesis Evaluation Questionnaire (PEQ) With the Investigational Device	72 percentage of participants	—

SECONDARY outcome

Timeframe: At baseline, after 2 weeks of either using the Power knee or their own prescription prosthesis, and at the fourth follow-up (at approximately weeks 22-16)

Population: Only 6 out of the 11 subjects decided to do a prolonged follow up period.

Total score of PMQ questions 1,3-6 (minimum score 0 - maximum score 20):

PMQ (Questions 1 and 3-6):

Over the past 2 weeks, please rate your ability in the following activities when using your prosthesis:

• Question 1: To walk indoors
• Question 3: To walk upstairs
• Question 4: To walk downstairs
• Question 5: To walk up a steep hill
• Question 6: To walk down a steep hill The scale used is a Likert scale 0-4 (0= Unable or hardly able at all, 1= High difficulty, 2= Moderate Difficulty, 3= Little difficulty, 4= No problems or almost fully able).

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period n=6 Participants Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Total Score of Prosthesis Mobility Questionnaire (PMQ) Questions 1 and 3-6: After 2 weeks: Power Knee	15.6 score on a scale Standard Deviation 3.4	16.7 score on a scale Standard Deviation 2.4
Total Score of Prosthesis Mobility Questionnaire (PMQ) Questions 1 and 3-6: After 2 weeks: Prescribed Knee	14.2 score on a scale Standard Deviation 4.3	13.3 score on a scale Standard Deviation 4.2
Total Score of Prosthesis Mobility Questionnaire (PMQ) Questions 1 and 3-6: At Baseline: Prescribed Knee	13.8 score on a scale Standard Deviation 4.2	13.2 score on a scale Standard Deviation 3.4
Total Score of Prosthesis Mobility Questionnaire (PMQ) Questions 1 and 3-6: After a prolonged follow up period: Power Knee	—	15.8 score on a scale Standard Deviation 2.9

SECONDARY outcome

Timeframe: At baseline, after 2 weeks of either using the Power knee or their own prescription prosthesis, and at the fourth follow-up (at approximately weeks 22-16)

Population: Only 6 out of the 11 subjects decided to do a prolonged follow up period.

The L-Test of Functional Mobility consists of a series of movements designed to assess an individual's physical function and dynamic balance. The test involves the participant starting from a seated position, standing up, walking a short distance, turning, walking back, and returning to the seated position. The course typically forms an "L" shape, which includes two turns, and the total distance covered is longer than that of similar tests like the Timed Up and Go (TUG) test. The outcome measure is the time taken to complete these movements, providing an objective evaluation of the participant's functional mobility. There is no fixed minimum or maximum; lower times indicate better performance (i.e., faster completion reflects greater mobility).

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period n=6 Participants Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Time Required to Complete the L-test After 2 weeks: Power Knee	26.3 seconds Standard Deviation 11.9	25.2 seconds Standard Deviation 12.6
Time Required to Complete the L-test After 2 weeks: Prescribed Knee	24.2 seconds Standard Deviation 9.4	23.8 seconds Standard Deviation 11.7
Time Required to Complete the L-test At Baseline: Prescribed Knee	23.7 seconds Standard Deviation 8.2	23.0 seconds Standard Deviation 10.0
Time Required to Complete the L-test After a prolonged follow up period: Power Knee	—	24.1 seconds Standard Deviation 10.8

SECONDARY outcome

Timeframe: At baseline, after 2 weeks of either using the Power knee or their own prescription prosthesis, and at the fourth follow-up (at approximately weeks 22-16)

Population: Only 6 out of the 11 subjects decided to do a prolonged follow up period.

Average Prosthetic Mobility Questionnaire (PMQ) total score (minimum score 0 - maximum score 48) with investigational device (Power Knee) compared to comparator (prescribed device).

The Prosthetic Mobility Questionnaire is a tool for assessing mobility in people with lower-limb amputation, higher score indicates better mobility performance.

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period n=6 Participants Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Average Prosthetic Mobility Questionnaire (PMQ) Total Score After 2 weeks: Power Knee	35.5 score on a scale Standard Deviation 7.4	37.3 score on a scale Standard Deviation 4.5
Average Prosthetic Mobility Questionnaire (PMQ) Total Score After 2 weeks: Prescribed Knee	31.2 score on a scale Standard Deviation 10.3	29.8 score on a scale Standard Deviation 9.8
Average Prosthetic Mobility Questionnaire (PMQ) Total Score At Baseline: Prescribed Knee	31.5 score on a scale Standard Deviation 9.8	31.5 score on a scale Standard Deviation 7.2
Average Prosthetic Mobility Questionnaire (PMQ) Total Score After a prolonged follow up period: Power Knee	—	35.2 score on a scale Standard Deviation 5.6

SECONDARY outcome

Timeframe: After 2 weeks of using the Power Knee

Population: For this outcome measure, side effects were assessed only after 2 weeks of Power Knee use. Although the study followed a crossover design, the timing or order in which participants used each device did not affect the evaluation of side effects. No side effect data were collected for the prescribed prosthesis; therefore, results are reported solely for the Power Knee group, reflecting all participants who completed the 2-week evaluation. Reporting by arm is not applicable for this outcome.

Evaluating the occurrence of side effects associated with the Power Knee entails systematically documenting and analyzing any adverse effects experienced by users throughout the 2 weeks of use.

Outcome measures

Measure	Combined Crossover Evaluation Group "Combined Crossover Evaluation Group" n=11 Participants For the analysis, data from both arms were combined. In Group 1, participants initially used the investigational device, with the second visit corresponding to its evaluation after two weeks of use, and evaluated their prescribed device during the third visit, also after two weeks of use. In Group 2, participants started with the prescribed device, evaluating it during the second visit after two weeks of use, and switched to the investigational device for the evaluation during the third visit, again after two weeks of use.	Subset of 6 Subjects Who Opted for a Prolonged Follow up Period Out of the eleven subjects who completed the trial, six of them opted in for an optional extended follow up period on the investigational device, and fourth visit. No subjects were lost to follow up.
Occurrence of Side Effects That Could be Directly Related to Using the Power Knee	0 side effect	—

Adverse Events

Power Knee Group

Serious events: 0 serious events

Other events: 3 other events

Deaths: 0 deaths

Prescribed Prosthesis Group

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Measure	Power Knee Group n=17 participants at risk Participants during periods of Power Knee use	Prescribed Prosthesis Group n=17 participants at risk Participants during periods of prescribed prosthesis use
Musculoskeletal and connective tissue disorders Fall	17.6% 3/17 • Number of events 3 • 8 months	0.00% 0/17 • 8 months

Additional Information

Laurine Roussillon

Össur Iceland ehf.

Phone: +354 822 1812

Email: lroussillon@ossur.com

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place