Clinical Investigation (Beta) of Power Knee Mainstream - Dynamic

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.

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.

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.

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).

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).

Proportion of subjects reporting satisfaction with walking speed on investigational device

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.

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).

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).

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).

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?"

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).

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).

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.

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.