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The functional differences between persons with amputation who are classified as Medicare Functional Classification Level (MFCL)-2 and -3 include the abilities to walk at various cadences and to negotiate environmental barriers outside the home. This study compared the effect of active microprocessor control and passive mechanical control of the prosthetic knee on function and safety in 17 subjects with transfemoral amputation (8 MFCL-2 and 9 MFCL-3). Assessed functional tasks included hill and stair descent, an attentional demand task, and an obstacle course. Self-reported measures included concentration, multitasking ability, and numbers of stumbles and falls. Active knee control was associated with significant improvements (p < 0.05) in hill and stair gait, speed (hills, obstacle course, and attentional demand task), and ability to multitask while walking for both cohorts. MFCL-2 subjects also reported a significant reduction (p < 0.01) in uncontrolled falls. Over the study, 50% of MFCL-2 subjects and 33% of MFCL-3 subjects transitioned to a higher MFCL. Results suggest that active knee control improves function and reduces the frequency of adverse events in a population that is at risk for falls. Use of active knee control may allow persons with amputation to expand their functional domain, transition to a higher MFCL, and access additional prosthetic options. [ABSTRACT FROM AUTHOR]

Prosthetic devices that can store and return energy during gait enhance the mobility and functionality of lower-limb amputees. The process of selecting and fitting such devices is complicated, partly because of confusing literature on the topic. Gait analysis methods for measuring energy characteristics are often incomplete, leading to inconsistencies in the energy classifications of different products. These inconsistencies are part of the reason for the lack of universally accurate terminology in the field. Inaccurate terminology perpetuates misunderstanding. In this paper, important prosthetic energy concepts and methods for measuring energy characteristics are reviewed. Then a technically accurate nomenclature and a method of functional classification are proposed. This review and proposed classification scheme should help to alleviate confusion and should facilitate enhancement of the design, selection, and fitting of prosthetic limbs for amputee patients. [ABSTRACT FROM AUTHOR]

Purpose: To determine if falls perceived as significant by lower limb prosthesis (LLP) users were associated with fall circumstances and/or consequences., Materials and Methods: The circumstances and consequences of LLP users' most significant fall in the past 12-months were collected using the Lower Limb Prosthesis User Fall Event Survey. Participants rated fall significance from 0 (not significant) to 10 (extremely significant), which was then dichotomized into "low" and "high". Binary logistic regression was used to assess associations between fall significance and fall circumstances and consequences., Results: Ninety-eight participants were included in the analysis. Five fall consequences were associated with greater significance: major injury (OR = 26.7, 95% CI: 1.6-459.6, p  = 0.024), need to seek medical treatment (OR = 19.0, 95% CI: 1.1-329.8, p  = 0.043), or allied-health treatment (OR = 18.2, 95% CI: 2.3-142.4, p  = 0.006), decreased balance confidence (OR = 10.9, 95% CI: 2.4-49.3, p  = 0.002), and increased fear of falling (OR = 7.5, 95% CI: 2.4-23.8, p  = 0.001), compared to two fall circumstances: impact to the arm (OR = 5.0, 95% CI: 2.0-12.1, p  = 0.001), and impact to the face, head, or neck (OR = 9.7, 95% CI: 1.2-77.4, p  = 0.032)., Conclusions: Significant falls were generally more associated with fall consequence than fall circumstances.

Background: Outcome measures (OMs) are useful tools; however, clinicians may find implementing them into clinical practice challenging., Objectives: To characterize Canadian prosthetists' use of OMs for people with lower-limb amputation, including motivations for use, comfort selecting OMs, resources available for administration, and barriers to implementation., Methods: A cross-sectional study was conducted between March and July 2021. Orthotics Prosthetics Canada sent Canadian prosthetists an invitation to take the online survey., Results: Forty-nine Certified Prosthetists completed the survey. Only 16% of participants reported that they were expected to use OMs. Participants reported being more comfortable administering performance-based OMs than self-report surveys. More than two-thirds of participants agreed that OMs "can be administered with knowledge they have" and are "within their scope of practice." However, less than 25% agreed that OMs are "administered in a standardized way in the profession," and less than 40% indicated they are "easy to make part of my routine." Participants reported they generally have time and space to do OMs, but there was no agreed-on reason to use them., Conclusions: Use of OMs among Canadian prosthetists seems to be low relative to prosthetists in the United States. Education, financial incentives, or changes to professional expectations are likely needed to increase routine OM use. Efforts to improve the standardization of OM administration and ease the incorporation of OMs into routine practice may also increase use. Canadian prosthetists may elevate their standards of clinical practice and better understand the impact of prosthetic treatments on their patients by more routinely using OMs., (Copyright © 2024 International Society for Prosthetics and Orthotics.)

Background: Prosthetic treatment options for people with ankle disarticulation (i.e., Syme amputation) are limited. Prosthetic feet designed for people with Syme amputation are often low profile to accommodate build-height restrictions, resulting in decreased energy return during gait. High-profile crossover feet that attach to the posterior proximal aspect of the prosthetic socket can bypass these restrictions and may promote a more physiologic gait pattern., Objectives: To compare level-ground gait biomechanics and patient-reported outcomes between crossover and traditional energy-storing feet in people with Syme amputation., Study Design: Within-participant pilot study., Methods: Both participants were fit with energy-storing and crossover feet and were randomized to the order they used the feet. Participants used each foot for 2 weeks before assessment. Step length symmetry, prosthetic ankle range of motion, prosthetic-side energy return, and peak sound-side loading were determined from motion capture data obtained in a laboratory. Mobility and balance confidence were measured using standardized patient-reported outcome measures. Foot preference was assessed with an ad hoc survey., Results: Two participants with Syme amputations completed the study. Prosthetic ankle peak dorsiflexion and push-off power increased with the crossover foot compared with the energy-storing foot for both participants. Both participants reported an overall preference of the crossover foot. Changes in patient-reported outcomes did not exceed published minimum detectable change values., Conclusion: Crossover feet increased prosthetic ankle range of motion and energy return compared with traditional energy-storing feet in this pilot investigation of 2 participants. Crossover feet seem to promote physiologic gait and may be a promising alternative to traditional low-profile feet for people with Syme amputation., (Copyright © 2023 International Society for Prosthetics and Orthotics.)

Purpose: Use of a lower limb prosthesis generally requires increased cognitive effort to compensate for missing motor and sensory inputs. This study sought to examine how lower limb prosthesis users perceive paying attention to their prosthesis(es) in daily life., Materials and Methods: Focus groups with lower limb prosthesis users were conducted virtually using semi-structured questions. Verbatim transcripts were excerpted, coded, and reconciled. Inductive thematic analysis was undertaken to identify experiences shared by participants., Results: Five themes emerged from five focus groups conducted with thirty individuals: Paying attention to my prosthesis is just what I have to do; I pay attention to how my prosthetic socket fits and feels every day; I pay attention because I don't want to fall; I pay attention because I have to learn to do things in a new way; and If I can trust that my prosthesis will do what I want, I can pay less attention to it., Conclusions: Prosthetic attention, including both background and foreground attention, is a shared experience among lower limb prosthesis users. The amount and frequency of prosthetic attention fluctuates throughout the day and changes over time. Measuring attention could inform the evaluation and prescription of technology intended to reduce cognitive effort.

Background: A limitation of tether lanyards is that fastening and unfastening the tether from the liner, which needs to be performed to clean or replace the liner, is difficult for some users., Objective: The purpose of this research was to create a quick connect that allows users to easily attach and detach the tether from the liner., Study Design: Mechanical testing and pilot study., Methods: A slide-and-lock mechanism was used. To operate the quick connect, the prosthesis user turns open the lock, slides it onto a short pin extending from the liner, and releases the mechanism, causing it to spring back to the locked position., Results: Mechanical tests demonstrated that the system well-tolerated tensile loads of 25,000 cycles at 100 N and single cycles at 350 N. Five transtibial users trialed the system and took between 2 and 30 s to fasten and unfasten the quick connect. They found the quick connect intuitive to use, secure, relatively quiet, and stable. However, they preferred their traditional pin lock over the quick connect system, mainly because the quick connect required a multistep procedure (twist-align-slide) that they considered more complex than operating the locking pin to which they were accustomed., Conclusions: In its current form, the quick connect is likely to be used by limited community ambulators who struggle with the pin lock donning procedure. It also has potential use with powered tethers that use a motor to adjust tether length., (Copyright © 2023 International Society for Prosthetics and Orthotics.)

Introduction: Lower limb orthoses (LLOs) and assistive devices (ADs) can be used together or separately to improve mobility when performing daily activities. The goal of this study was to examine utilization of LLOs and ADs in a national sample of adult LLO users., Methods: A survey was designed to ask participants whether they typically use their LLOs and/or ADs to perform 20 daily activities. LLO users from orthotic clinics across the United States were invited to complete the survey. Descriptive statistics were used to examine utilization trends., Results: Survey responses from 1036 LLO users were analyzed. Community-based activities were performed with LLOs by at least 80% of participants. Activities that involved walking short distances in the home were more often performed without LLOs or ADs. Among participants with the four most prevalent health conditions, LLO use in the community was greatest among participants with Charcot-Marie-Tooth disease., Conclusions: LLOs were frequently used for a wide range of community-based activities. Simultaneous use of ADs and LLOs may be most beneficial for LLO users when performing activities outside of the home. Clinicians can discuss LLO and AD use with patients to optimize their functional outcomes at home and in the community., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2024.)

Purpose: To develop and administer an assessment tool for facilitating patient-clinician discussions regarding amputation-related pain and sensation., Materials and Methods: An assessment tool was developed to measure the impact of different types of amputation-related pain and sensation on a patient's life. The tool first provides patients with written descriptions and images of three common types of amputation-related pain or sensations: residual limb pain, phantom limb sensation, and phantom limb pain. The tool then asks them to rate the frequency, intensity, and interference of each experience. Participants were also asked to provide qualitative descriptions of these experiences., Results: Fifty Veterans with lower limb amputation participated in the study. In the past month, 74% reported experiencing residual limb pain, 76% reported phantom limb sensation, and 84% reported phantom limb pain, with 52% reporting all three. Participants' descriptions of some experiences were distinct, while others (e.g., "tingling") were common between experiences. Phantom limb pain had the most varied descriptions., Conclusions: The amputation-related pain and sensation assessment tool can be used to identify and measure the effects of different experiences on patients' lives, thereby improving the specificity of diagnosis and informing clinical treatment recommendations. Further development of this tool should include evaluating its psychometric properties.

Purpose: Evaluate specific elements of previously proposed fall and near-fall definitions to determine whether they fully capture lower limb prosthesis (LLP) users' lived experiences., Methods: Semi-structured interviews were conducted with 24 LLP users. Interview transcripts were reviewed, coded, and analyzed using deductive thematic analysis to identify shared experiences and inform revisions to previously reported definitions., Results: Four major themes emerged: a fall can be initiated by more than just a loss of balance, loss of balance and losing balance are considered similar, falls are not limited to landing on the ground or floor, and catching yourself and recovering your balance are distinct responses to a loss of balance., Conclusions: Two revisions were made to previous definitions to better align with LLP users' experiences and historically overlooked fall circumstances. A fall is defined as a loss of balance or sudden loss of support where your body lands on the ground, floor, or another object. A near-fall was defined as a loss of balance where you caught yourself or recovered your balance without landing on the ground, floor, or another object. Implementation of these new definitions will aid the collection of accurate, consistent, and meaningful fall data, enhancing aggregation and comparison across studies.

As health care attempts to bridge the gap between evidence and practice, the concept of the learning health system (LHS) is becoming increasingly relevant. LHS integrates evidence with health systems data, driving health care quality and outcomes through updates in policy, practice, and care delivery. In addition, LHS research is becoming critically important as there are several initiatives underway to increase research capacity, expertise, and implementation, including attempts to stimulate increasing numbers of LHS researchers. Physical Medicine & Rehabilitation (PM&R) physicians (physiatrists), nurses, therapists (physical therapists, occupational therapists, speech therapists, clinical psychologists), and scientists are affiliated with LHSs. As LHS research expands in health care systems, better awareness and understanding of LHSs and LHS research competencies are key for rehabilitation professionals including physiatrists. To address this need, the Agency of Healthcare Research and Quality (AHRQ) identified 33 core competencies, grouped into eight domains, for training LHS researchers. The domains are: (1) Systems Science; (2) Research Questions and Standards of Scientific Evidence; (3) Research Methods; (4) Informatics; (5) Ethics of Research and Implementation in Health Systems; (6) Improvement and Implementation Science; (7) Engagement, Leadership, and Research Management; and the recently added (8) Health and Healthcare Equity and Justice. The purpose of this commentary is to define LHS and its relevance to physiatrists, present the role of implementation science (IS) in LHSs and application of IS principles to design LHSs, illustrate current LHS research in rehabilitation, and discuss potential solutions to improve awareness and to stimulate interest in LHS research and IS among physiatrists in LHSs., (© 2024 The Authors. PM&R published by Wiley Periodicals LLC on behalf of American Academy of Physical Medicine and Rehabilitation. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Purpose: In this study, we sought to examine how lower limb prosthesis users define success, what constructs they associate with success, and what barriers and facilitators contribute to achieving success., Materials and Methods: Purposively sampled lower limb prosthesis users were recruited to participate in a focus group study. Verbatim transcripts from focus groups were analyzed using inductive thematic analysis. Identified constructs were mapped to existing outcome measures, and a conceptual framework for success with a lower limb prosthesis was proposed., Results: Thirty-one lower limb prosthesis users participated in one of five focus groups. Five themes were developed: keep moving forward, despite ups and downs; being able to live MY normal life and do the things I want to do with ease; learning what works for me and how to manage my prosthesis; only I can define my success; and what about my mental health? Several constructs that do not align with existing measures were identified, including prosthetic attention, grief/loss after amputation, and trust in prosthesis. Facilitators for success described by participants included peer connection, finding the right prosthetist, and mental health support., Conclusions: According to lower limb prosthesis users, success must be patient-driven, individually defined, and continually reassessed.

It is essential that people with limb amputation maintain proper prosthetic socket fit to prevent injury. Monitoring and adjusting socket fit, for example by removing the prosthesis to add prosthetic socks, is burdensome and can adversely affect users' function and quality-of-life. This study presents results from take-home testing of a motor-driven adaptive socket that automatically adjusted socket size during walking. A socket fit metric was calculated from inductive sensor measurements of the distance between the elastomeric liner surrounding the residual limb and the socket's inner surface. A proportional-integral controller was implemented to adjust socket size. When tested on 12 participants with transtibial amputation, the controller was active a mean of 68% of the walking time. In general, participants who walked more than 20 min/day demonstrated greater activity, less doff time, and fewer manual socket size adjustments for the adaptive socket compared with a locked non-adjustable socket and a motor-driven socket that participants adjusted with a smartphone application. Nine of 12 participants reported that they would use a motor-driven adjustable socket if it were available as it would limit their socket fit issues. The size and weight of the adaptive socket were considered the most important variables to improve., (© 2024. The Author(s).)

Purpose: Prostheses designed for daily use are often inappropriate for high-level activities and/or are susceptible to water damage and mechanical failure. Secondary prostheses, such as activity-specific or back-up prostheses, are typically required to facilitate uninterrupted participation in desired life pursuits. This study estimated the prevalence of secondary prosthesis use in a large, national sample of lower limb prosthesis users (LLPUs)., Methods: We conducted a secondary analysis of survey data from three cross-sectional studies that assessed mobility in LLPUs. Descriptive statistics were used to determine the percentage of secondary prosthesis users and percentages of LLPUs that used different type(s) of secondary prosthesis(es). Secondary prosthesis users and non-users were compared to identify differences in participant characteristics between groups., Results: Of participants in the analysis ( n  = 1566), most (65.8%) did not use a secondary prosthesis. The most common secondary prosthesis types were back-up (19.2%) and activity-specific prostheses (13.5%). Secondary prosthesis users differed significantly from non-users with respect to gender, race, and other characteristics., Conclusions: Results suggest that secondary prosthesis use for most LLPUs is limited and may differ based on users' demographic and clinical characteristics. Future research should determine how LLPUs' health-related quality-of-life outcomes are affected by access to and use of secondary prostheses.Implications for RehabilitationSecondary prostheses, including activity-specific, back-up, and shower prostheses, have the potential to improve function, mobility, and participation for people who use lower limb prostheses.Most lower limb prosthesis users do not use secondary prostheses, and access to these devices may be related to users' demographic and clinical characteristics.Rehabilitation professionals play a key role in facilitating prosthesis users' access to secondary prostheses and should advocate for those who need them.

Background: Selection of a foot is an important aspect of prosthetic prescription and vital to maximizing mobility and functional goals after lower limb amputation. Development of a standardized approach to soliciting user experiential preferences is needed to improve evaluation and comparison of prosthetic feet., Objective: To develop rating scales to assess prosthetic foot preference and to evaluate use of these scales in people with transtibial amputation after trialing different prosthetic feet., Design: Participant-blinded, repeated measures crossover trial., Setting: Veterans Affairs and Department of Defense Medical Centers, laboratory setting., Participants: Seventy-two male prosthesis users with unilateral transtibial amputation started, and 68 participants completed this study., Interventions: Participants trialed three mobility-level appropriate commercial prosthetic feet briefly in the laboratory., Main Outcome Measures: "Activity-specific" rating scales were developed to assess participants' ability with a given prosthetic foot to perform typical mobility activities (eg, walking at different speeds, on inclines, and stairs) and "global" scales to rate overall perceived energy required to walk, satisfaction, and willingness to regularly use the prosthetic foot. Foot preference was determined by comparing the rating scale scores, after laboratory testing., Results: The greatest within-participant differences in scores among feet were observed in the "incline" activity, where 57% ± 6% of participants reported 2+ point differences. There was a significant association (p < .05) between all "activity-specific" rating scores (except standing) and each "global" rating score., Conclusions: The standardized rating scales developed in this study could be used to assess prosthetic foot preference in both the research and clinical settings to guide prosthetic foot prescription for people with lower limb amputation capable of a range of mobility levels., (© 2023 American Academy of Physical Medicine and Rehabilitation.)

Background: Understanding the psychometric strengths and limitations of outcome measures for use with people with lower limb absence (LLA) is important for selecting measures suited to evaluating patient outcomes, answering clinical and research questions, and informing health care policy. The aim of this project was to review the current psychometric evidence on outcome measures in people with LLA to determine which measures should be included in a stakeholder consensus process., Methods: An expert panel was assembled, and a 3-stage review process was used to categorize outcome measures identified in a systematic literature review into 3 distinct categories (recommended for measures with better than adequate psychometric properties; recommended with qualification; and unable to recommend). Panelists were asked to individually categorize measures based on results of a systematic review of identified measures' psychometric properties. Each measure's final categorization was based on ≥70% agreement by all panelists., Results: No outcome measure attained the ≥70% consensus threshold needed to achieve a rating of "recommend." Hence, panelists suggested combining "recommend" and "recommend with qualifications" into a single category of "recommend with qualifications." Using this approach, consensus was reached for 59 of 60 measures. Consensus could not be reached on 1 outcome measure (socket comfort score). Thirty-six outcome measures were categorized as "unable to recommend" based on available evidence; however, 23 (12 patient-reported measures and 11 performance-based measures) demonstrated adequate psychometric properties in LLA samples and were thus rated as "recommend with qualification" by the expert panel. The panel of experts were able to recommend 23 measures for inclusion in the subsequent stakeholder review. A key strength of this process was bringing together international researchers with extensive experience in developing and/or using LLA outcome measures who could assist in identifying psychometrically sound measures to include in a subsequent stakeholder consensus process., Conclusion: The above categorizations represent the current state of psychometric evidence on outcome measures for people with LLA and hence may change over time as additional research becomes available. The results will be used to achieve wider consensus from clinicians, health policymakers, health clinic managers, researchers, and end users (i.e., individuals with LLA) on outcome measures for the International Society of Prosthetics and Orthotics lower limb Consensus Outcome Measures for Prosthetic and Amputation ServiceS., (Copyright © 2023 International Society for Prosthetics and Orthotics.)

Lower limb orthoses (LLOs) are externally-applied leg braces that are designed to improve or maintain mobility in people with a variety of health conditions that affect lower limb function. Clinicians and researchers are therefore often motivated to measure LLO users' mobility to select or assess the effectiveness of these devices. Patient-reported outcome measures (PROMs) can provide insights into important aspects of a LLO user's mobility for these purposes. However, few PROMs are available to measure mobility of LLO users. Those few that exist have issues that may limit their clinical or scientific utility. The objective of this study was to create a population-specific item bank for measuring mobility of LLO users. Previously-developed candidate items were administered in a cross-sectional study to a large national sample of LLO users. Responses from study participants (n = 1036) were calibrated to a graded response statistical model using Item Response Theory methods. A set of 39 items was found to be unidimensional, locally independent, and function without bias due to characteristics unrelated to mobility. The set of final calibrated items, termed the Orthotic Patient-Reported Outcomes-Mobility (OPRO-M) item bank, was evaluated for initial evidence of convergent, divergent, and known groups construct validity. OPRO-M was strongly correlated with existing PROMs designed to measure aspects of physical function. Conversely, OPRO-M was weakly correlated with PROMs that measured unrelated constructs, like sleep disturbance and depression. OPRO-M also showed an ability to differentiate groups with expected mobility differences. Two fixed-length short forms were created from the OPRO-M item bank. Items on the short forms were selected based on statistical and clinical criteria. Collectively, results from this study indicate that OPRO-M can effectively measure mobility of LLO users, and OPRO-M short forms can now be recommended for use in routine clinical practice and research studies., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Balkman et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Prostheses are a primary rehabilitative intervention for people after lower limb amputation. To appropriately measure the effectiveness of prosthetic interventions, valid and reliable measures of prosthetic mobility are required. The Prosthetic Limb Users Survey of Mobility (PLUS-M) is a promising instrument for measuring prosthesis users' mobility. However, German translations of the PLUS-M short forms have not yet been validated., Objectives: Rasch validation of the German translation of the PLUS-M short forms in people with lower limb amputation., Study Design: This study is based on a cross-sectional survey of prosthesis-using lower limb amputees from a nation-wide cohort., Methods: PLUS-M data (the 7-item and the 12-item shortforms; PLUS-M-7 and PLUS-M-12, respectively) from 194 lower limb prosthesis users were subjected to Rasch analysis, an advanced statistical method for assessing if the measurement properties of a questionnaire comply with a wide spectrum of psychometric requirements., Results: Analysis showed appropriate rating scale functioning, good internal construct validity (item fit), unidimensionality, and good targeting of the PLUS-M-7 and PLUS-M-12 short forms. Moreover, the greater conditional measurement precision of PLUS-M-12 (regarding higher test information and lower standard error of mobility estimates) was quantified., Conclusions: Rasch analysis of the German translation of both PLUS-M short forms showed good psychometric qualities. In addition, our study showed that test scores from the PLUS-M-12 are more accurate. Therefore, the PLUS-M-12 is recommended for individual-level clinical applications (e.g., classification or change assessment)., (Copyright © 2022 International Society for Prosthetics and Orthotics.)

Background: A challenge often faced by people with lower extremity amputation is management of prosthetic socket fit due to changes in fluid volume within their residual limb. Prior research suggests that intermittently doffing the prosthetic socket may help stabilize daily residual limb fluid volume., Methods: To assess the effects of partial doff duration on residual limb fluid volume retention, participants with transtibial amputation were tested by walking on a treadmill in a controlled, laboratory setting under three conditions. An automated system to release the locking pin and enlarge the socket was used to produce the partial doffing. Percent limb fluid volume changes after partial doffing for 4 min (Short Rest) and for 10 min (Long Rest) were compared with no partial doffing (No Release). Limb fluid volume was monitored using bioimpedance analysis., Findings: Mean percent fluid volume changes in the posterior region were  -1.2% for No Release, 2.7% for Short Rest, and 1.0% for Long Rest. Short and Long Rests had larger increases than No Release (P = 0.005 and 0.03, respectively); Short and Long Rests were not statistically different (P = 0.10). Eight of the thirteen participants experienced a higher percent fluid volume gain for both release protocols while four experienced a higher percent fluid volume gain for only one release protocol., Interpretation: A partial doff duration as short as 4 min may be an effective strategy to stabilize limb fluid volume in prosthesis users with transtibial amputation. Trials in at-home settings should be pursued., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objective: The Learning Health Systems Rehabilitation Research Network (LeaRRn), an NIH-funded rehabilitation research resource center, aims to advance the research capacity of learning health systems (LHSs) within the rehabilitation community. A needs assessment survey was administered to inform development of educational resources., Methods: The online survey included 55 items addressing interest in and knowledge of 33 LHS research core competencies in 7 domains and additional items on respondent characteristics. Recruitment targeting rehabilitation researchers and health system collaborators was conducted by LeaRRn, LeaRRn health system partners, rehabilitation professional organizations, and research university program directors using email, listservs, and social media announcements., Results: Of the 650 people who initiated the survey, 410 respondents constituted the study sample. Respondents indicated interest in LHS research and responded to at least 1 competency item and/or demographic question. Two-thirds of the study sample had doctoral research degrees, and one-third reported research as their profession. The most common clinical disciplines were physical therapy (38%), communication sciences and disorders (22%), and occupational therapy (10%). Across all 55 competency items, 95% of respondents expressed "a lot" or "some" interest in learning more, but only 19% reported "a lot" of knowledge. Respondents reported "a lot" of interest in a range of topics, including selecting outcome measures that are meaningful to patients (78%) and implementing research evidence in health systems (75%). "None" or "some" knowledge was reported most often in Systems Science areas such as understanding the interrelationships between financing, organization, delivery, and rehabilitation outcomes (93%) and assessing the extent to which research activities will improve the equity of health systems (93%)., Conclusion: Results from this large survey of the rehabilitation research community indicate strong interest in LHS research competencies and opportunities to advance skills and training., Impact: Competencies where respondents indicated high interest and limited knowledge can inform development of LHS educational content that is most needed., (© The Author(s) 2023. Published by Oxford University Press on behalf of the American Physical Therapy Association. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Several personal characteristics have been associated with an increased risk of injurious falls by lower limb prosthesis (LLP) users. To date, however, none have been used to effectively predict the occurrence of injurious falls., Objective: To develop a model that could predict the number of injurious falls over the next 6 months and identify fall-related circumstances that may increase the odds of a fall being injurious in unilateral LLP users., Design: A secondary analysis of a prospective observational study., Setting: Research laboratory., Participants: Sixty unilateral LLP users with a transtibial or transfemoral amputation., Intervention: Not applicable., Main Outcome Measure(s): Participants' characteristics were recorded at baseline. Falls and their circumstances and consequences were collected prospectively over 6 months via monthly telephone calls. Multivariate negative binomial regression was used to predict the number of injurious falls over the next 6 months in LLP users. Incidence rate ratios (IRRs) were derived to determine the risk of an injurious fall. Bivariate logistic regression was used to identify the associations between injurious falls and fall-related circumstances. Odds ratios (ORs) were derived to characterize the odds that a fall would be injurious., Results: The final multivariate model, which included the number of falls recalled in the past year (IRR = 1.31, 95% confidence interval [CI]: 1.01-1.71, p = .045) and balance confidence (p = .120), predicted the number of injurious falls in the next 6 months (χ 2 (2) = 8.15, p = .017). Two fall-related circumstances were found to increase the odds that a fall would be injurious, fatigue due to activity (OR = 13.5, 95% CI: 3.50-52.3, p  = .001), and tiredness from a lack of sleep (OR = 5.36, 95% CI: 1.22-23.6, p = .026)., Conclusion: The results suggest that the number of falls recalled in the past year and balance confidence scores predict the number of injurious falls an LLP user will experience in the next 6 months., (© 2022 American Academy of Physical Medicine and Rehabilitation.)

Background: Achieving mobility with a prosthesis is a common post-amputation rehabilitation goal and primary outcome in prosthetic research studies. Patient-reported outcome measures (PROMs) available to measure prosthetic mobility have practical and psychometric limitations that inhibit their use in clinical care and research., Objective: To develop a brief, clinically meaningful, and psychometrically robust PROM to measure prosthetic mobility., Design: A cross-sectional study was conducted to administer previously developed candidate items to a national sample of lower limb prosthesis users. Items were calibrated to an item response theory model and two fixed-length short forms were created. Instruments were assessed for readability, effective range of measurement, agreement with the full item bank, ceiling and floor effects, convergent validity, and known groups validity., Setting: Participants were recruited using flyers posted in hospitals and prosthetics clinics across the United States, magazine advertisements, notices posted to consumer websites, and direct mailings., Participants: Adult prosthesis users (N = 1091) with unilateral lower limb amputation due to traumatic or dysvascular causes., Interventions: Not applicable., Main Outcome Measures: Candidate items (N = 105) were administered along with the Patient Reported Outcome Measurement Information System Brief Profile, Prosthesis Evaluation Questionnaire - Mobility Subscale, and Activities-Specific Balance Confidence Scale, and questions created to characterize respondents., Results: A bank of 44 calibrated self-report items, termed the Prosthetic Limb Users Survey of Mobility (PLUS-M), was produced. Clinical and statistical criteria were used to select items for 7- and 12-item short forms. PLUS-M instruments had an 8th grade reading level, measured with precision across a wide range of respondents, exhibited little-to-no ceiling or floor effects, correlated expectedly with scores from existing PROMs, and differentiated between groups of respondents expected to have different levels of mobility., Conclusion: The PLUS-M appears to be well suited to measuring prosthetic mobility in people with lower limb amputation. PLUS-M instruments are recommended for use in clinical and research settings., (© 2023 The Authors. PM&R published by Wiley Periodicals LLC on behalf of American Academy of Physical Medicine and Rehabilitation.)

Background: Orthoses are often prescribed to improve mobility of people with chronic health conditions that affect lower limb function. Patient-reported survey instruments can be used to measure aspects of mobility that cannot be easily assessed in clinical or research settings. A population-specific item bank could be designed to measure aspects of mobility that are most important to lower limb orthosis users and used to evaluate the effects of orthoses., Objective: To develop items for a new survey instrument to measure mobility of lower limb orthosis users., Design: Survey items were developed using a qualitative item review process., Setting: Focus groups were held by video conferencing. Cognitive interviews were conducted by telephone., Participants: Focus group and cognitive interview participants were adults with at least 6 months of experience using a lower limb orthosis that extended from the foot to a level above the ankle., Methods: Research methods included focus groups with lower limb orthosis users, an item generation and reduction process that involved a stakeholder advisory panel, and cognitive interviews with target respondents., Results: A total of 1180 extant items were identified in a literature review. Focus group participants (n = 29) provided feedback that informed the suitability of a construct definition and conceptual model. An advisory panel contributed to the selection of 118 candidate items for measuring orthotic mobility. Feedback from cognitive interview participants (n = 30) informed removal or revision of problematic items, resulting in a candidate bank of 100 mobility items., Conclusions: The rigorous qualitative methods applied here resulted in a large set of candidate items that spanned a range of situations relevant to moving with a lower limb orthosis. Next steps include administration of the candidate items to a large sample of lower limb orthosis users and calibration of the item bank., (© 2022 American Academy of Physical Medicine and Rehabilitation.)

Introduction: The purpose of this study was to test a novel activity monitor that tracks the time a prosthesis is worn, and the nature of the ambulatory activity conducted with the prosthesis. These capabilities allow prosthesis users' wear and accommodation practices (e.g., temporary doffing) to be monitored, and the intensity of their activities to be assessed., Methods: A portable limb-socket motion sensing system was used to monitor doffs, walk bouts (≥5 steps), low locomotion (2-4 steps), stationary positions, and weight shifts in a group of transtibial prosthesis users. The relationship between doff time and active motion time was investigated, and durations of low and high intensity active motions were compared., Results: For the 14 participants tested, the median prosthesis day duration ranged from 12.8-18.8 h. Eleven participants typically doffed five or fewer times per day, and three participants typically doffed 10 or more times per day. Nine participants demonstrated a positive correlation between daily doff duration and active motion duration. Six participants spent more time in weight shifts than walk bouts, while eight participants spent more time in walk bouts than weight shifts., Conclusion: Capturing don time and temporary doffs and distinguishing weight shifts from walks may provide insight relevant to patient care. Longer-term monitoring studies should be conducted, and the clinical utility of the data evaluated., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2023.)

The Five-time Sit-to-Stand (5xSTS) Test is a performance-based measure used by clinicians and researchers to assess the body functions needed to accomplish sit-to-stand transitions (e.g., lower limb strength, balance, and trunk control). The current requirements for performance of the 5xSTS Test (i.e., crossing arms over the chest) may not be appropriate for many, if not most lower limb prosthesis (LLP) users. The study aims were to (1) develop a modified five-time sit-to-stand (m5xSTS) Test protocol; (2) to examine initial evidence of known-groups construct validity among LLP users by comparing differences in performance by amputation level, amputation etiology, and functional level; and (3) to assess initial evidence of convergent construct validity by examining the correlations between m5xSTS performance with self-reported mobility (Prosthetic Limb Users Survey of Mobility (PLUS-M)), self-reported balance confidence (Activities-balance Confidence Scale (ABC)) and functional capability (comfortable walking speed). Three-hundred sixty-one LLP users participated in this cross-sectional study. The investigators developed a m5xSTS Test protocol that allows tested individuals to use different assistance strategies (i.e., use of upper limbs to push off thighs, push up from the armrests, or use a walker) when needed to perform the test. The investigators recorded m5xSTS Test times and assistance strategies. Significant differences in m5xSTS Test times were found between those who did and did not use an assistance strategy, as well as between participants grouped by different amputation level, etiology, and functional level. Significant moderate negative correlations were found between m5xSTS Test times and PLUS-M T-score (ρ = -0.42, p<0.001), ABC score (ρ = -0.42, p<0.001), and comfortable walking speed (ρ = -0.64, p<0.001), respectively. The m5xSTS Test allows LLP users to perform sit-to-stand transitions in a manner that accounts for their functional impairments, is consistent with post-amputation training, and is safe for the tested individual. Results from this study provide preliminary evidence of known groups and convergent construct validity for the m5xSTS Test with a large national sample of LLP users., Competing Interests: The authors have declared that no competing interests exist., (Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.)

Purpose: People with lower limb impairments are often prescribed orthoses to preserve or enhance their mobility. Exploration of mobility experiences common among orthosis users may provide insights into how orthoses, and other mobility aids, are utilized and regarded. The objective of this study was to broadly explore how lower limb orthosis users describe their mobility., Materials and Methods: Four focus groups were held online with participants who lived in the U.S. or Canada. Participants had at least six months of experience using an ankle-foot- and/or a knee-ankle-foot-orthosis for one or both legs. All discussions were transcribed and coded. Thematic analysis was used to identify cross-cutting themes., Results: Participants included 29 orthosis users with a variety of health conditions. Inter-related themes, including personal factors, situational contexts, and assistance were identified as elements that influenced participants' mobility. Participants described a process of modifying their mobility through the use and non-use of one or more mobility aids., Conclusions: The current study findings may assist clinicians in developing strategies to optimize orthosis users' mobility in different situations. Experiences described by participants in this study may also help researchers identify aspects of mobility most pertinent to orthosis users and inform the development of new outcome measures.Implications for RehabilitationPeople who use lower-limb orthoses share common mobility experiences, despite differences in health diagnoses.Orthosis users often have opportunities to modify their mobility by choosing to use or not use their brace(s) and/or handheld mobility aids.When providing mobility aid interventions, clinicians should consider how each patient's individual characteristics, including physical characteristics (e.g., the health condition and how it presents, pain, fatigue) and psychosocial characteristics (e.g., fear and confidence, self-motivation, emotional responses), can affect mobility.Clinicians may be able to help patients optimize their mobility by asking about environmental obstacles they regularly encounter and recommending strategies for utilization of mobility aids, including simultaneous use of multiple aids, use of one aid, or choosing not to use any aids, depending on the activity and situation.Clinicians should inquire about all mobility aids available to a patient at home and in the community, including fixed objects, and consider how new mobility aid interventions might affect the patient's mobility when used alone and in combination with other forms of assistance.

Prosthetic foot selection for individuals with lower limb amputation relies primarily on clinician judgment. The prosthesis user rarely has an opportunity to provide experiential input into the decision by trying different feet. A prosthetic foot emulator (PFE) is a robotic prosthetic foot that could facilitate prosthesis users' ability to trial feet with different mechanical characteristics. Here, we introduce a procedure by which a robotic PFE is configured to emulate the sagittal plane effective ankle stiffness of a range of commercial prosthetic forefeet. Mechanical testing was used to collect data on five types of commercial prosthetic feet across a range of foot sizes and intended user body weights. Emulated forefoot profiles were parameterized using Bezier curve fitting on ankle torque-angle data. Mechanical testing was repeated with the PFE, across a subset of emulated foot conditions, to assess the accuracy of the emulation. Linear mixed-effects regression and Bland-Altman Limits of Agreement analyses were used to compare emulated and commercial ankle torque-angle data. Effective ankle stiffness of the emulated feet was significantly associated with the corresponding commercial prosthetic feet (p <0.001). On average, the emulated forefeet reproduced the effective ankle stiffness of corresponding commercial feet within 1%. Furthermore, differences were independent of prosthetic foot type, foot size, or user body weight. These findings suggest that commercial prosthetic foot properties can be effectively mimicked by a PFE, which is the important first step toward enabling prosthesis users to quickly trial different feet using a PFE as part of prosthetic foot prescription., (Copyright © 2022 by ASME.)

Background: Step activity monitors provide insight into the amount of physical activity prosthesis users conduct but not how they use their prosthesis. The purpose of this research was to help fill this void by developing and testing a technology to monitor bodily position and type of activity., Methods: Thin inductive distance sensors were adhered to the insides of sockets of a small group of transtibial prosthesis users, two at proximal locations and two at distal locations. An in-lab structured protocol and a semi-structured out-of-lab protocol were video recorded, and then participants wore the sensing system for up to 7 days. A data processing algorithm was developed to identify sit, seated shift, stand, standing weight-shift, walk, partial doff, and non-use. Sensed distance data from the structured and semi-structured protocols were compared against the video data to characterize accuracy. Bodily positions and activities during take-home testing were tabulated to characterize participants' use of the prosthesis., Findings: Sit and walk detection accuracies were above 95% for all four participants tested. Stand detection accuracy was above 90% for three participants and 62.5% for one participant. The reduced accuracy may have been due to limited stand data from that participant. Step count was not proportional to active use time (sum of stand, walk, and standing weight-shift times)., Interpretation: Step count may provide an incomplete picture of prosthesis use. Larger studies should be pursued to investigate how bodily position and type of activity may facilitate clinical decision-making and improve the lives of people with lower limb amputation., Competing Interests: Declaration of Competing Interest None, (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Despite the effects of prosthetic foot mechanical properties on gait of people with lower limb amputation, scant forefoot and heel stiffness data exist to help guide prosthetic foot prescription., Objective: To measure forefoot and heel linear stiffness properties across commonly prescribed commercial prosthetic foot models and to describe variations in stiffness across feet targeted for users with different body weights and foot sizes., Study Design: Mechanical testing of five types of commercial prosthetic feet across nine user body weight and foot size combinations., Methods: Linear forefoot and heel stiffness (force vs. displacement) data were collected for 41 prosthetic feet. Quasistatic testing was conducted at -15 and +20 degrees to isolate loading of the heel and forefoot, respectively., Results: Overall, there was a significant relationship between user body weight and both forefoot and heel stiffness, when adjusted for foot size and type ( P < 0.001). However, there were a substantial number of inconsistencies across foot type within example user body weight and foot sizes combination. Furthermore, the relative order of forefoot stiffness across foot type differed from the relative order of heel stiffness across foot type., Conclusions: The inconsistencies and differences in relative order of forefoot and heel stiffness across commercial foot type suggest the importance of publishing objective stiffness and other mechanical properties of prosthetic feet. These data can aid clinicians in better matching mechanical properties of prosthetic feet with the functional goals and abilities of prosthesis users., (Copyright © 2022 International Society for Prosthetics and Orthotics.)

Introduction: The most suitable elevated vacuum (EV) pressure may differ for each individual prosthesis user depending on suspension needs, socket fit, prosthetic components, and health. Mechanical and physiological effects of EV were evaluated in an effort to determine the optimal vacuum pressure for three individuals., Methods: Instrumented EV sockets were created based on the participants' regular EV sockets. Inductive distance sensors were embedded into the wall of the socket at select locations to measure limb movement relative to the socket. Each participant conducted an activity protocol while limb movement, limb fluid volume, and user-reported comfort were measured at various socket vacuum pressure settings., Results: Increased socket vacuum pressure resulted in reduced limb-socket displacement for each participant; however, 81-93% of limb movement was eliminated by a vacuum pressure setting of 12 (approximately -9 inHg). Relative limb-socket displacement by sensor location varied for each participant, suggesting distinct differences related to socket fit or residual limb tissue content. The rate of limb fluid volume change and the change in socket comfort did not consistently differ with socket vacuum pressure, suggesting a more complex relationship unique to each individual., Conclusions: Practitioners may use individual responses to optimize socket vacuum pressure settings, balancing mechanical and physiological effects of EV for improved clinical outcomes., Competing Interests: Conflict of Interest: Authors state no conflicts of interest.

Objective: To assess the effects of different prosthetic feet on energy costs associated with walking and running in people with transtibial amputation., Literature Survey: The Pubmed, CINAHL, and Web-of-Science bibliographic databases were searched for original research published through June 30, 2018. References from identified articles were also reviewed., Methodology: Two reviewers screened titles, abstracts, and articles for pertinent studies. Details were extracted with a standardized template. Risk of bias was assessed using domain-based methods. Prosthetic feet were grouped into categories and compared according to energy costs associated with walking or running over various terrain conditions. Meta-analyses were conducted when data quantity and homogeneity permitted. Evidence statements were formed when results were consistent or undisputed., Synthesis: Fifteen studies were included. Participants (n = 141) were predominantly male (87.9%), had unilateral amputation (95.7%) from non-dysvascular causes (87.9%), and were classified as unlimited community ambulators or active adults (56.0%). Participants were often young but varied in age (mean age 24.8-66.6 years). Available evidence indicates that feet with powered dorsiflexion reduce energy costs relative to dynamic response feet in unlimited community ambulators or active adults when walking on level or declined surfaces. Dynamic response feet do not significantly reduce energy costs compared to energy storing, flexible keel, or solid ankle feet when walking on level terrain. Running feet do not reduce energy costs relative to dynamic response in active adults when running. Select feet may reduce energy costs under specific conditions, but additional research is needed to confirm preliminary results., Conclusions: The overall body of evidence is based on small samples, comprised mostly of participants who may not well represent the population of prosthesis users and test conditions that may not well reflect how prostheses are used in daily life. However, evidence suggests energy costs are affected by prosthetic foot type only under select conditions., (© 2021 American Academy of Physical Medicine and Rehabilitation.)

Objective: To assess the clinical resources available for the assessment of health outcomes in people with lower limb amputation and to understand barriers and facilitators associated with use of standardized outcome measures in clinical practice., Design: Cross-sectional survey., Setting: General community (online)., Participants: A volunteer sample of prosthetic practitioners was recruited through national professional organizations. Eligible participants were practitioners certified by a professional prosthetics organization and currently practicing as a prosthetist, prosthetist-orthotist, or prosthetic assistant., Interventions: Not applicable., Main Outcome Measures: A custom-designed online survey on clinical use of patient-reported and performance-based standardized outcome measures to assess patients with lower limb amputation., Results: A total of 375 participants completed the survey. Most participants (79%) reported that they are encouraged or required to administer standardized outcome measures in their clinic or facility. Most participants reported that use of patient-reported and performance-based outcome measures are within their scope of practice (88%) and that they have the knowledge required for outcomes measurement (84%). Few participants agreed that outcomes measurement is standardized across the profession (30%). Most participants had access to small spaces and equipment for outcomes measurement, such as short hallways (65%-94%), stairs (69%), and tablets with wireless internet connection (83%). Most participants reported that they would be willing to spend between 5 (36% of participants) and 10 (43% of participants) minutes on self-reported surveys, and between 10 (41% of participants) and 20 (28% of participants) minutes on performance-based tests., Conclusions: Outcomes measurement is encouraged or expected in contemporary prosthetic practice. Strategies to improve standardization and efficiency of administration are needed to facilitate routine use of outcome measures in clinical care., (Copyright © 2022 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Despite their importance to fall prevention research, little is known about the details of real-world fall events experienced by lower limb prosthesis users. This gap can be attributed to the lack of a structured, population-specific fall survey to document these adverse health events. The objective of this project was to develop a survey capable of characterizing the circumstances and consequences of fall events in lower limb prosthesis users. Best practices in survey development, including focus groups and cognitive interviews with diverse samples of lower limb prosthesis users, were used to solicit input and feedback from target respondents, so survey content would be meaningful, clear, and applicable to lower limb prosthesis users. Focus group data were used to develop fall event definitions and construct a conceptual fall framework that guided the creation of potential survey questions and response options. Survey questions focused on the activity, surroundings, situation, mechanics, and consequences of fall events. Cognitive interviews revealed that with minor revisions, survey definitions, questions, and response options were clear, comprehensive, and applicable to the experiences of lower limb prosthesis users. Administration of the fall survey to a national sample of 235 lower limb prosthesis users in a cross-sectional preliminary validation study, found survey questions to function as intended. Revisions to the survey were made at each stage of development based on analysis of participant feedback and data. The structured, 37-question lower limb prosthesis user fall event survey developed in this study offers clinicians and researchers the means to document, monitor, and compare fall details that are meaningful and relevant to lower limb prosthesis users in a standardized and consistent manner. Data that can be collected with the developed survey are essential to establishing specific goals for fall prevention initiatives in lower limb prosthesis users., Competing Interests: The authors have declared that no competing interests exist.

Participation in valued interpersonal and community activities is a key component of rehabilitation for Veterans with amputation. The purpose of this study was to identify specific factors that promote or inhibit participation to inform development of interventions that may facilitate participation in desired life activities. A convenience sample of 408 Veterans with at least one lower limb amputation and who had received outpatient care from the Regional Amputation Center (RAC) completed a mailed survey. Participation was measured using the Community Participation Indicators (CPI) Importance, Control, and Frequency scales and the Patient Reported Outcome Measurement Information System (PROMIS) Ability to Participate in Social Roles and Satisfaction with Social Participation scales. Multiple imputation procedures were used to address missing data. Correlates of participation were examined through multiple linear regression. A total of 235 participants completed the survey, a response rate of 58%. Levels of participation, measured with the PROMIS instruments, were 43.2 (SD = 8.1) for Ability and 46.4 (SD = 8.6) for Satisfaction. Regression analyses found robust amputation-specific correlates for participation, including body image and balance confidence. Generic (non-amputation specific) correlates for participation included depression and pain interference. Development of treatment approaches and devices that can address body image, balance confidence, pain, and mental health concerns such as depression have the potential to enhance the participation and rehabilitation of Veterans with lower limb amputation., Competing Interests: The authors have declared that no competing interests exist.

Purpose: To explore lived experiences, and identify common themes as well as vocabulary associated with fall-related events in lower limb prosthesis (LLP) users., Materials and Methods: Five focus groups of LLP users from across the United States were conducted remotely via video or tele-conferencing. Focus group transcripts were coded and analyzed using methods adapted from a grounded theory approach to identify themes., Results: Focus group participants (n = 25) described experiences associated with fall-related events that resulted in the identification of six themes: (1) memories of fall-related events are shaped by time and context, (2) location and ground conditions influence whether falls occur, (3) some activities come with more risk, (4) fall-related situations are multi-faceted, and often involve the prosthesis, (5) how LLP users land, but not the way they go down, tends to vary, and (6) not all falls affect LLP users, but some near-falls do., Conclusion: Consideration for where LLP users fall, what they are doing when they fall, how they fall, what occurs as a result of a fall, and how well memory of a fall persists may enhance recording and reporting of falls, contribute to development of improved fall risk assessment tools, and inspire the design and function of prosthetic componentry for patient safety.Implications for rehabilitationFalls are a common problem in lower limb prosthesis (LLP) users that can lead to adverse health outcomes.Concerns over near falls, not just falls, may merit greater attention from rehabilitation professionals.Elements of the lived experience that appear unique to LLP users include the role of prosthetic fit, function, and comfort in losing and/or recovering balance; as well as the tendency of LLP users to modify rather than stop or avoid activities associated with falls.

Purpose: The Prosthetic Limb Users Survey of Mobility (PLUS-M) is a self-report item bank designed to measure the abilities with which people with lower limb amputation perform physical activities. Although PLUS-M includes items that span a range of mobility, additional items are needed to accurately measure mobility of highly active prosthesis users, such as athletes and service members with lower limb amputation. The aim of this study was to understand mobility in highly active lower limb prosthesis users to inform the development of new items for the PLUS-M item bank., Methods: Focus groups were conducted with active, lower limb prosthesis users from across the USA. In-person and online focus groups were conducted by a trained facilitator using a semi-structured guide. Focus group transcripts were reviewed and coded by two researchers. Thematic analysis was used to identify important experiences across participants., Results: Twenty-nine participants took part in four focus groups. Three resultant themes were identified: mobility after amputation, mobility characteristics, and healthcare providers and systems., Conclusions: Identified themes inform clinician and researcher understanding of mobility in highly active lower limb prosthesis users. The results of this study will be used to inform development of high-activity items for the PLUS-M item bank.Implications for rehabilitationParticipants described engagement in high-level activities as a learning process that included elements such as equipment challenges and modifications, pain and injury, and the need to trust the prosthetic limb.Participants with lower limb amputation who use prostheses identified mobility characteristics, such as postural changes, terrain, and obstacles, that influenced their ability to perform high-level activities.High-level mobility characteristics identified in these focus groups can be integrated into a revised version of the Prosthetic Limb Users Survey of Mobility to assess mobility in active adults and athletes with amputation.Rehabilitation professionals play an important role in facilitating access to specialized prosthetic components and training that can help patients achieve their mobility goals and potential.

Objective: To evaluate test-retest reliability and related measurement properties of items developed to assess best, worst, and average prosthetic socket comfort., Design: Methodological research to assess test-retest reliability of 4 individual socket comfort survey items. Socket comfort items were included in a self-report paper survey, which was administered to participants 2 to 3 days apart., Setting: General community., Participants: A minimum convenience sample of participants (N=63) was targeted for this study; 72 lower limb prosthesis users (>1y postamputation) completed the survey and were included in the final dataset., Interventions: Not applicable., Main Outcome Measure: The expanded socket comfort score (ESCS) was adapted from the original socket comfort score (SCS). The original SCS is a single-item self-report instrument developed to assess a lower limb prosthesis user's current socket comfort. Three additional items were designed to assess the user's best, worst, and average socket comfort over the previous 7 days., Results: Best, worst, and average socket comfort items demonstrated better reliability, as indicated by higher intraclass correlation coefficients. As such, these items also exhibited lower measurement error and smaller minimal detectable change values than the item that measured current socket comfort. However, test-retest coefficients for all 4 ESCS items were below the level desired for evaluation of within-individual changes of socket comfort., Conclusions: Items that assess best, worst, and average comfort provide a more stable measurement of socket fit than the existing SCS instrument. Although administration of all 4 ESCS items may provide more comprehensive assessment of a lower limb prosthesis user's socket fit, administrators should expect variations in scores over time owing to the variable nature of the underlying construct over time. Future research should examine whether the ESCS provides an improved overall assessment of socket fit., (Copyright © 2021 The American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Prosthetic foot stiffness plays a key role in the functional mobility of lower limb prosthesis users. However, limited objective data exists to guide selection of the optimal prosthetic foot stiffness category for a given individual. Clinicians often must rely solely on manufacturer recommendations, which are typically based on the intended user's weight and general activity level. Availability of comparable forefoot and heel stiffness data would allow for a better understanding of differences between different commercial prosthetic feet, and also between feet of different stiffness categories and foot sizes. Therefore, this study compared forefoot and heel linear stiffness properties across manufacturer-designated stiffness categories and foot sizes. Mechanical testing was completed for five types of commercial prosthetic feet across a range of stiffness categories and three foot-sizes. Data were collected for 56 prosthetic feet, in total. Testing at two discrete angles was conducted to isolate loading of the heel and forefoot components, respectively. Each prosthetic foot was loaded for six cycles while force and displacement data were collected. Forefoot and heel measured stiffness were both significantly associated with stiffness category (p = .001). There was no evidence that the relationships between stiffness category and measured stiffness differed by foot size (stiffness category by size interaction p = .80). However, there were inconsistencies between the expected and measured stiffness changes across stiffness categories (i.e., magnitude of stiffness changes varied substantially between consecutive stiffness categories of the same feet). While statistical results support that, on average, measured stiffness is positively correlated with stiffness category, force-displacement data suggest substantial variation in measured stiffness across consecutive categories. Published objective mechanical property data for commercial prosthetic feet would likely therefore be helpful to clinicians during prescription., Competing Interests: Co-authors J.M.C. and C.S.C. are employed by Human Motion Technologies LLC d/b/a Humotech, but Humotech was not a funder for this study and the company has no competing interests that would be relevant to the work done on this manuscript. Therefore, this does not alter our adherence to PLOS ONE policies on sharing data and materials. No authors on this manuscript have any competing interests.

The purpose of this research was to pursue an innovative cyclic panel-pull strategy during ambulation to minimize limb fluid volume loss in transtibial prosthesis users. Participants' traditional socket shapes were duplicated, and test sockets prepared with three adjustable motor-driven panels that were controlled by a microprocessor. After donning the prosthesis, participants' liners were fastened to the panels. During a 40 min test session, participants conducted three cycles of sitting (5 min) and walking (8 min). During the 5th and 6th min of each cycle of walking, the panels were cyclically pulled outward in late stance phase, decreasing pressure on the residual limb. Panels were returned to their original position in swing phase. Eight of twelve participants gained more fluid volume while walking when panel-pull was added than when it was removed. When the liner was uncoupled from the panels and panel-pull was executed, eight of twelve participants gained less fluid volume compared to when the liner was fastened to the panels. Panel-pull may facilitate limb fluid volume retention in transtibial prosthesis users. Efforts to simplify the design so that it can be implemented in long-term testing during at-home use should be considered., (Copyright © 2022 IPEM. Published by Elsevier Ltd. All rights reserved.)

Objective: To determine if the two-minute walk test (2MWT) could serve as an alternative measure of high-level mobility in lower limb prosthesis users when circumstances preclude administration of the Comprehensive High-level Activity Mobility Predictor (CHAMP)., Design: Cross-sectional study., Setting: Indoor recreational athletic field and gymnasium., Subjects: Fifty-eight adult lower limb prosthesis users with unilateral or bilateral lower limb amputation who participate in recreational athletic activities., Intervention: N/A., Main Measures: The 2MWT and CHAMP while using their preferred prosthesis(es) on an indoor artificial athletic field or hardwood gymnasium floor., Results: Thirty-nine men and nineteen women with a median age of 38.3 years participated in the study. Most participants experienced amputation(s) due to trauma (62%) or tumor (10%) and were generally higher functioning (K4 (91.4%) and K3 (8.6%)). The median (range) score for the CHAMP was 23.0 points (1.5-33.5) and the mean ± standard deviation (range) 2MWT distance walked was 188.6 ± 33.9 m (100.2-254.3 m). The CHAMP demonstrated a strong positive relationship with 2MWT (r = 0.83, p < 0.001). The 2MWT distance predicted 70% of the variance in CHAMP score., Conclusions: Although the 2MWT does not test multi-directional agility like the CHAMP, they were found to be highly correlated. If space is limited, the two-minute walk test can serve as an alternative measure for assessing high-level mobility capabilities in lower limb prosthesis users.

Introduction: A challenge in the engineering of auto-adjusting prosthetic sockets is to maintain stable operation of the control system while users change their bodily position and activity. The purpose of this study was to test the stability of a socket that automatically adjusted socket size to maintain fit. Socket release during sitting was conducted between bouts of walking., Methods: Adjustable sockets with sensors that monitored distance between the liner and socket were fabricated. Motor-driven panels and a microprocessor-based control system adjusted socket size during walking to maintain a target sensed distance. Limb fluid volume was recorded continuously. During eight sit/walk cycles, the socket panels were released upon sitting and then returned to position for walking, either the size at the end of the prior bout or a size 1.0% larger in volume., Results: In six transtibial prosthesis users, the control system maintained stable operation and did not saturate (move to and remain at the end of the actuator's range) during 98% of the walking bouts. Limb fluid volume changes generally matched the panel position changes executed by the control system., Conclusions: Stable operation of the control system suggests that the auto-adjusting socket is ready for testing in users' at-home settings., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2022.)

Background: Falls are common and consequential events for lower limb prosthesis (LLP) users. Currently, there are no models based on prospective falls data that clinicians can use to predict the incidence of future falls in LLP users. Assessing who is at risk for falls, and thus most likely to need and benefit from intervention, remains a challenge., Objective: To determine whether select performance-based balance tests predict future falls in established, unilateral transtibial prosthesis users (TTPU)., Design: Multisite prospective observational study., Setting: Research laboratory and prosthetics clinic., Participants: Forty-five established, unilateral TTPU., Intervention: Not applicable., Main Outcome Measures: The number of falls reported over a prospective 6-month period. Timed Up-and-Go (TUG) and Four-Square Step Test (FSST) times, as well as Narrowing Beam Walking Test scores were recorded at baseline, along with the number of falls recalled over the past 12 months and additional potential fall-risk factors., Results: The final negative binomial regression model, which included TUG (P = .044) and FSST (P = .159) times, as well as the number of recalled falls (P = .009), was significantly better than a null model at predicting the number of falls over the next 6 months (X 2 [3] = 11.6, P = .009) and fit the observed fall count data (X 2 [41] = 36.12, P = .20). The final model provided a significant improvement in fit to the prospective fall count data over a model with fall recall alone X 2 (1) = 4.342, P < .05., Conclusion: No combination of performance-based balance tests alone predicted the incidence of future falls in our sample of established, unilateral TTPU. Rather, a combination of the number of falls recalled over the past 12 months, along with TUG and FSST times, but not NBWT scores, was required to predict the number of "all-cause" falls over the next 6 months. The resulting predictive model may serve as a suitable method for clinicians to predict the incidence of falls in established, unilateral TTPU., (© 2021 American Academy of Physical Medicine and Rehabilitation.)

Background: Mechanical testing is the principal method used to quantify properties of commercial prosthetic feet in a controlled and standardized manner. To test feet in a mechanical testing machine without overconstraining the system, tangential shear forces must be minimized. However, there is scant published information comparing techniques for reducing shear forces during mechanical testing. Furthermore, there are no data on variability in linear stiffness across testing sessions., Objectives: To compare techniques for reducing shear forces during mechanical testing of prosthetic feet and to evaluate variation in linear stiffness across testing sessions., Study Design: Repeated measures., Technique: Force-displacement data were collected at two pylon progression angles, one for the forefoot and one for the heel, and compared across three conditions: roller plate (RoPl), low-friction interface on the shoe (SB), and no method for reducing shear forces (NoSB). Data were collected for a range of commercial prosthetic foot models and sizes. Select data were collected over multiple days to assess variation over test sessions., Results: Differences in stiffness between RoPl and SB test conditions ranged from -0.9% to +2.6% across foot models. By contrast, differences between RoPl and no method for reducing shear conditions ranged from -2.9% to +14.6%. Differences in linear stiffness between test sessions ranged from -2.2% to +3.6%., Conclusions: Methods for reducing shear force in this study demonstrated roughly equivalent effects. Thus, a low-friction interface may be used as a less expensive and less complex method for reducing shear force in prosthetic foot testing. In addition, mechanical testing results were relatively consistent across multiple test sessions, lending confidence to test consistency., (Copyright © 2021 International Society for Prosthetics and Orthotics.)