Pattern recognition (PR)-based myoelectric control is a data-driven approach that allows a user to control multiple prosthetic functions using natural muscle activation patterns rather than discrete, isolated signals. Instead of mapping one muscle to one motion (as in conventional Direct Control), PR systems record the spatial and temporal pattern of EMG activity from multiple sites on the residual limb and use machine learning algorithms to classify which intended movement the user is trying to make.

NPRS is a pain screening tool that uses two 0 to 10 scales to measure pain intensity over the last seven days. The two scales interrogate different dimensions of pain: 1) residual limb pain; and 2) phantom limb pain. Both scales include descriptive anchors at the extremes (i.e., "no pain" is 0 and "the highest pain you can imagine" is 10). A higher score indicates a more intense pain experience. Full administration of the NPRS is estimated to take about 5 minutes.

PROMIS Pain Interference short form 4a is a validated, self-report questionnaire that assesses consequences of pain on relevant aspects of one's life, including the extent to which pain hinders engagement with social, cognitive, emotional, physical, and recreational activities. The assessment comprises of four, 5-point Likert-type questions, each querying the respondent on their experience of pain in the previous seven days. PROMIS instruments are scored on a T-score metric (0 - 100) in which 50 is the mean of the reference population and 10 is the standard deviation. In general, a higher score equals more of the concept being measured. For the PROMIS Pain Interference questionnaire, a higher score then indicates a greater degree to which individuals believe pain interferes with their daily lives. Full administration of the PROMIS Pain Interference short form 4a is estimated to take about 5 minutes.

PROMIS Satisfaction short form 8a is a validated, self-report questionnaire designed to query individuals on their satisfaction with their ability to participate in social roles and activities. The survey consists of eight, 5-point Likert-type questions covering several aspects of social engagement, including work, recreation, and maintaining interpersonal relationships. A higher score indicates a higher satisfaction with the respondent's ability to participate in work and home life. Full administration of the PROMIS Satisfaction short form 8a is estimated to take about 10 minutes.

OPUS UEFS is a validated, self-report questionnaire that asks respondents to score how easily they can complete several activities of daily living (e.g., drink from a paper cup, brush hair, etc.). It is a low burden measure that provides a subjective view of a participant's functionality with a prosthesis. OPUS UEFS includes a total of 28 questions, each regarding an activity of daily living. Responses are divided into two parts: 1) a 5-point, Likert-type scale with descriptive anchors for each Level of Ease (e.g., "Cannot perform activity" is 0, "Very easy" is 4); and 2) an indication on if the activity is usually performed with or without a prosthesis. Participants may also provide a null response (i.e., "Not applicable") if they believe that the activity does not apply to them. The total score of the OPUS UEFS is the sum of the 28 responses converted to a Rasch measure (0 - 100). Higher scores therefore indicate greater functionality. Full administration takes about 25 minutes.

MDPWD acts as a proxy for improved prosthesis acceptance. Prosthesis wear time is defined as the time from when participants don their prostheses to the time they doff their prostheses. Prosthesis wear duration is self-reported (in hours) by participants via a study diary.