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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 four individual socket comfort survey items. Socket comfort items were included in a self-report paper survey, which was administered to participants 2-3 days apart. Setting General community. Participants A minimum convenience sample of 63 participants was targeted for this study; 72 lower limb prosthesis users (>1-year post-amputation) 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 seven days. Results Best, worst, and average socket comfort items demonstrated better reliability, as indicated by higher intra-class 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 four 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. While administration of all four items may provide more comprehensive assessment of a lower limb prosthesis user's socket fit, administrators should expect variations in scores over time due to the variable nature of the underlying construct over time. Future research should examine whether a multi-item socket comfort scale provides an improved overall assessment of socket fit.

INTRODUCTION: Mobility tests are increasingly used in prosthetic rehabilitation to evaluate patient outcomes. Knowledge of the space, equipment, and time resources available to clinicians who work in different settings can guide recommendations for which tests are most clinically-feasible and promote coordination of mobility testing among members of the rehabilitation team. The primary aim of this study was to characterize the different resources available to clinicians for measuring mobility of people with lower limb amputation. A secondary aim was to identify performance tasks that clinicians use to evaluate prosthetic mobility. MATERIALS AND METHODS: Semi-structured interviews were conducted with prosthetists, physical therapists, and physiatrists who treat people with lower limb amputation. Researchers used convenience and snowball sampling to identify participants. Interviews included questions about the resources available for conducting mobility tests, as well as questions about which tasks clinicians deemed valuable to assessing mobility of patients with lower limb amputation. Interviews were audio-recorded and transcribed. Summary and frequency statistics were calculated for quantitative data; explanatory comments were summarized. RESULTS: Interviews were conducted with 25 clinicians (8 prosthetists, 9 physical therapists, and 8 physiatrists). Participants had access to multiple spaces and basic measurement equipment. The maximum time participants were willing to spend on performance tests varied. Physiatrists reported less time available (median=10 minutes, range 5-30 minutes) than prosthetists and physical therapists (median=30 minutes, range 5-60 minutes for both professions). Mobility tasks commonly used to evaluate patients with lower limb amputation included sit-to-stand, standing balance, walking, and varying speed. Participant comments suggested that mobility tests need to be quick, simple, and add value; existing mobility tests are beneficial but challenging to incorporate into practice; mobility tests should reflect real-world activities; and technological advancements could improve mobility testing. CONCLUSIONS: Clinicians generally had small-to-medium spaces, basic measurement equipment, and sufficient training to administer mobility tests in their clinics. A limiting factor was time, which can be addressed through selection of efficient measures and collaboration within the rehabilitation team.

Previous studies investigating limb volume change with elevated vacuum have shown inconsistent results and have been limited by out-of-socket volume measurements and short, single-activity protocols.To evaluate the effectiveness of elevated vacuum for managing limb fluid volume compared to suction suspension with an in-socket measurement modality during many hours of activity.Fixed-order crossover design with a standardized out-of-laboratory activity protocol.Transtibial electronic elevated vacuum users participated in two sessions. Elevated vacuum was used during the first session, and suction suspension in the second. Participants completed a 5.5-h protocol consisting of multiple intervals of activity. In-socket residual limb fluid volume was continuously measured using a custom portable bioimpedance analyzer.A total of 12 individuals participated. Overall rate of fluid volume change was not significantly different, though the rate of posterior fluid volume change during Cycle 3 was significantly lower with elevated vacuum. Although individual results varied, 11 participants experienced lower overall rates of fluid volume loss in at least one limb region using elevated vacuum.Elevated vacuum may be more effective as a volume management strategy after accumulation of activity. Individual variation suggests the potential to optimize the limb fluid volume benefits of elevated vacuum by reducing socket vacuum pressure for some users.A better understanding of how elevated vacuum (EV) affects residual limb fluid volume will allow prosthetists to make more informed clinical decisions regarding accommodation strategies designed to improve daily socket fit.

Objective A major barrier to reducing falls among users of lower limb prostheses (LLP) has been an absence of statistical indices required for clinicians to select and interpret scores from performance-based clinical tests. The study aimed to derive estimates of reliability, measurement error, and minimal detectable change values in performance-based clinical tests administered to unilateral LLP users. Methods A total of 60 unilateral LLP users were administered the Narrowing Beam Walking Test, Timed ``Up and Go'' (TUG), Four Square Step Test (FSST), and 10-Meter Walk Test on 2 occasions, 3 to 9 days apart. Intraclass correlation coefficients (ICCs) were calculated to assess interrater and test-retest reliability, while standard error of measurement (SEM) and minimal detectable change (MDC90) were derived to establish estimates of measurement error in individual scores or changes in score for each test. Results Interrater reliability ICCs (1,1) were high for all tests (ie, ≥0.98). Test-retest ICCs (2,1) varied by test, ranging from .88 for the TUG to .97 for the FSST. SEM and MDC90 varied between .39 and .96 and between .91 seconds and 2.2 seconds for the time-based tests (FSST, TUG, 10-Meter Walk Test). SEM and MDC90 for the Narrowing Beam Walking Test were .07 and .16, respectively. Conclusion With the exception of the TUG, studied tests had test-retest ICCs (2,1) that exceeded the minimum required threshold to be considered suitable for group- and individual-level applications (ie, ICC ≥ 0.70 and ≥ 0.90, respectively). Future research on individuals with dysvascular and transfemoral amputations or in specific age categories is required. Impact Along with published validity indices, these reliability, error, and change indices can help clinicians select balance tests suitable for LLP users. They can also help clinicians interpret test scores to make informed, evidence-based clinical decisions.

BACKGROUND Self-report survey instruments can be used to improve clinical care for lower-limb prosthesis users on a global scale by pooling comparable health outcomes data from multiple countries. The language translation process is critical to the quality and comparability of a translated survey instrument. OBJECTIVES The goals of this research were to translate the Prosthetic Limb Users Survey of Mobility (PLUS-M) item bank from English to Japanese using established guidelines, and linguistically validate the translated instrument by assessing its clarity, comprehension, and cultural applicability with Japanese prosthesis users. STUDY DESIGN Instrument translation and qualitative interviews. METHODS The translation process included two forward translations, reconciliation, backward translation, and review by clinical experts in Japan. Adult lower-limb prosthesis users participated in a linguistic validation study by responding to translated survey items and providing item-by-item feedback through cognitive interviews. RESULTS Following expert reviews, translated items were classified as grammatically and contextually unchanged (n = 21), minor revision required (n = 19), major revision required (n = 3), or removed (n = 1). Cognitive interviews with 10 participants indicated that additional revisions were required (n = 4). Items were revised and retested until it was determined that they were clear, well understood, and culturally applicable. CONCLUSIONS Use of a multistep translation and linguistic validation processes resulted in a linguistically comparable Japanese translation of the PLUS-M item bank. Japanese translations of the PLUS-M 7- and 12-item short forms were created for use in clinical practice and research. Availability of these linguistically comparable instruments is expected to facilitate opportunities for international comparison of prosthetic mobility data.

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, ppp

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.

BACKGROUND: Loss of residual limb volume degrades socket fit and may require accommodation. OBJECTIVES: To examine if either of two accommodation strategies executed during resting, socket release with full socket size return and socket release with partial socket size return, enhanced limb fluid volume retention during subsequent activity. STUDY DESIGN: Two repeated-measures experiments were conducted to assess the effects of socket release on limb fluid volume retention. METHODS: Limb fluid volume was monitored while participants wore a socket with a single adjustable panel. Participants performed eight activity cycles that each included 10 minutes of sitting and 2 minutes of walking. The socket’s posterior panel and pin lock were released during the 5(th) cycle while participants were sitting. In one experiment (Full Return), the socket was returned to its pre-release size; in a second experiment (Partial Return), it was returned to 102% of its pre-release size. Short-term and long-term limb fluid volume retention were calculated and compared to a projected, No Intervention condition. RESULTS: Partial Return and Full Return short-term retentions and Partial Return long-term retention were greater than those projected under the control condition (p

Introduction Prosthetists have limited knowledge of their patients' use of a prosthesis outside of the clinical environment. Prosthesis-mounted monitors can be used to directly measure patients' prosthesis use and activity. Prosthetists' opinions regarding potential clinical applications for sensor-based information may inform further development of this technology. A pilot study was conducted to assess prosthetists' perceptions of prosthesis use and activity information obtained by a monitoring system. Materials and methods Three local prosthetists were recruited to participate in the study. One patient with transtibial amputation from each prosthetist volunteered to wear limb presence and activity monitors for two weeks. Collected data were used to determine prosthesis use and activity. Each prosthetist completed a survey, examined clinical reports of their patient's prosthesis use and activity, and participated in a semi-structured interview. Survey results and interview transcripts were analyzed to identify and compare prosthetists' perceptions. Results Prosthesis use and activity varied among patients. Prosthetists over- and under-estimated patient activity, relative to measurements recorded by the monitors. All three prosthetists selected multiple clinical applications for the prosthesis use and activity information in the survey, and several additional applications were suggested during the interviews. When presented with multiple report formats, prosthetists found features of each to be clinically useful. Conclusions Prosthesis-mounted monitors may provide prosthetists with a better understanding of their patients' prosthesis use and activity. Information provided by the monitoring system may inform clinical decisions and promote evidence-based practices.

Background More than 50% of lower limb prosthesis (LLP) users report falling at least once a year, placing them at high risk for adverse health outcomes such as decreased mobility and diminished quality of life. Efforts to decrease falls in LLP users have traditionally focused on developing clinical tests to assess fall risk, designing prosthetic components to improve patient safety, and identifying risk factors to recognize potential fallers. Little attention has been directed toward recording, reporting, and characterizing the circumstances of falls in LLP users. Identifying the most common types of falls could help guide and prioritize clinical and research needs. Objective To characterize the frequency and circumstances of falls reported by unilateral LLP users. Design Secondary analysis of data from 2 cross-sectional studies. Setting Outpatient clinic and research laboratory. Participants Ambulatory unilateral transtibial and transfemoral LLP users (N = 66). Intervention None. Outcome A fall-type classification framework was developed based on biomechanical theory and published falls terminology. Self-reported falls and accompanying narrative descriptions of LLP users’ falls in the previous 12 months were analyzed with the framework. Frequencies, estimated proportions, and estimated counts were compared across fall circumstances using 95% confidence intervals. Results Thirty-eight participants (57.6%) reported 90 falls during the previous year. All reported falls were successfully categorized using the proposed framework. Most falls occurred from disruptions to the base of support, intrinsic destabilizing factors, and a diverse set of fall patterns. Walking on level terrain was the most common activity at the time of a fall. Conclusion This secondary analysis showed that falls remain frequent in ambulatory LLP users and that clinicians and researchers might wish to prioritize falls owing to disruptions of the base of support that occur while walking. Additional research with a larger sample is required to confirm and expand these results. Level of Evidence III

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.

Objective Falls are a frequent and costly concern for lower limb prosthesis (LLP) users. At present, there are no models that clinicians can use to predict the incidence of future falls in LLP users. Assessing who is at risk for falls, therefore, remains a challenge. The purpose of this study was to test whether easily accessible clinical attributes and measurements predict the incidence of future falls in LLP users. Methods In this prospective observational study, a secondary analysis of data from 60 LLP users was conducted. LLP users reported the number of falls that they recalled over the past year before prospectively reporting falls over a 6-month observation period via monthly telephone calls. Additional candidate predictor variables were recorded at baseline. Negative binomial regression was used to develop a model intended to predict the incidence of future falls. Results The final model, which included the number of recalled falls (incidence rate ratio = 1.13; 95% CI = 1.01 to 1.28) and Prosthetic Limb Users Survey of Mobility T-scores (incidence rate ratio = 0.949; 95% CI = 0.90 to 1.01), was significantly better than a null model at predicting the number of falls over the next 6 months (χ22 = 9.76) and fit the observed prospective fall count data (χ256 = 54.78). Conclusion The number of recalled falls and Prosthetic Limb Users Survey of Mobility T-scores predicted the incidence of falls over the next 6 months in established, unilateral LLP users. The success and simplicity of the final model suggests that it may serve as a screening tool for clinicians to use for assessing risk of falls. Additional research to validate the proposed model in an independent sample of LLP users is needed. Impact Owing to its simplicity, the final model may serve as a suitable screening measure for clinicians to ascertain an initial evaluation of fall risk in established unilateral LLP users. Analyzing falls data as counts rather than as a categorical variable may be an important methodological consideration for falls prevention research.

Background Performance-based tests are viewed as a gold standard for measuring physical capability. Practice effects, however, may threaten their predictive, discriminative, and evaluative applications. Despite these potential consequences, practice effects have received limited attention in users of lower limb prostheses (LLP). Objective To perform an initial characterization of the occurrence, time-course, and magnitude of practice effects in three performance-based tests administered to users of LLP. Design Secondary analysis of data from a multisite repeated-measures study. Setting Outpatient clinic and research laboratory. Participants Convenience sample of established ambulatory users of unilateral transtibial and transfemoral prostheses (n = 60). Intervention Not applicable. Main outcome measures Practice effects were identified as significant changes in slope of participants' cumulative trial-by-trial records. The occurrence, time-course, and magnitude of practice effects were computed for the Timed Up and Go (TUG), Four Square Step Test (FSST), and the 10-m Walk Test (10mWT). Results Across tests, practice effects were observed in 45% to 76% of participants. The proportion of participants with practice effects (ie, occurrence) was significantly greater for the FSST than the 10mWT (P = .008). The median number of trials (ie, time-course) required for participants to reach a consistent level of performance was not significantly different between tests (FSST: 4 trials, TUG: 4 trials; 10mWT: 3.5 trials; P = .481). Practice effect magnitude (ie, difference between the mean of trials during the plateau and best performance over the first two trials) was significantly greater than zero for the FSST (1.6 s; 16%) and TUG (1.4 s; 13%) (P Conclusion Results indicate that the FSST, TUG, and 10mWT were susceptible to practice effects in this sample of users of LLP. Practice effects may obscure significant differences in walking and balance ability, and thereby, in the absence of modifications, limit the use of these tests for making individual patient clinical decisions and analyzing group-level data.

Elevated vacuum (EV) is suggested to improve suspension and limb volume management for lower limb prosthesis users. However, few guidelines have been established to facilitate configuration of EV sockets to ensure their safe and proper function. A benchtop model of an EV socket was created to study how prosthetic liner tensile elasticity, socket fit, and socket vacuum pressure affect liner displacement and subsequent pressure on the residual limb. A domed carbon fiber layup was used to represent an EV socket. Inserts were used to simulate various air gaps between the socket and liner. Various prosthetic liner samples were placed under the carbon fiber layup. Liner displacement and the corresponding pressure change underneath the liner were measured as vacuum was applied between the liner sample and socket wall. Tissue vacuum pressure increased linearly with socket vacuum pressure until the liner contacted the socket wall. Predicted tissue vacuum pressure matched well with experimental results. Findings suggest that the effect of vacuum pressure on the residual limb is primarily determined by air gap distance. The developed model may be used to assess effects of EV on residual limb tissues based on an individual's socket fit, liner characteristics, and applied vacuum. Understanding the physiological effects of EV on the residual limb could help practitioners avoid blister formation and improve EV implementation.

IntroductionA 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.MethodsAdjustable 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.ResultsIn 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.ConclusionsStable operation of the control system suggests that the auto-adjusting socket is ready for testing in users’ at-home settings.

Use of elastomeric or “gel” liners in prosthetics practice has become increasingly common, with recent data suggesting that practitioners select gel liners for about 85% of their prosthetic patients.1 To accommodate the clinical needs of a broad range of prosthetic limb users, liner manufacturers have created an array of different liner products. Although elastomeric liners are derived primarily from the same base materials (i.e., urethane, silicone, and thermoplastic elastomer (TPE]), differences in a liner’s chemical composition, shape, geometry, and manufacturing determine a liner’s overall performance. Presence of fabric backing, antibacterial additives, or features such as sealing sleeves, distal pads, or reinforcement can additionally affect mechanical performance of a liner. Given the number of variables that contribute to a liner’s design, it is not surprising that a large number of liner products are commercially available – a recent study identified more than 70 liner products on the market.2 Despite the availability of so many different liner products, a recent survey indicated that a typical practitioner choses among only two or three products when selecting liners for his or her prosthetic patients.2 An explanation for such limited selection among many available options may be a lack of comparable, objective information about the similarities and differences among liner products.3 Without information about how a new liner compares to the two or three familiar products, practitioners are hesitant to change. The same study found that only 33% of practitioners surveyed obtained information from scientific journals, while the majority sought information directly from manufacturers (94%) or clinical magazines (65%). These results suggest there is a need to distinguish liners and provide practitioners with practical information to help them identify products that best match individual patient needs. The purpose of this research study was to characterize mechanical properties of commonly used prosthetic liner products and to compare findings with previous liners characterized in the literature. We also evaluated the influence of design variables fabric backing and liner thickness on testing results. Selecting a liner for an individual patient may require the practitioner optimize the most preferred property or identify a liner that exhibits a balance among several preferred properties.

Residual limb volume loss over the day is a source of socket fit problems for people using transtibial prostheses.1. Research studies have shown that prosthesis users may gain fluid volume during walking, but lose fluid volume during sitting.2 Pin suspension systems may accentuate limb fluid volume loss during sitting. With the distal end of the residual limb held in place by the pin, the posterior proximal residual limb tissues in the popliteal area are stretched tightly over the posterior brim of the socket, focusing stress that may reduce limb fluid volume and cause soft-tissue damage. If the foot is flat on the floor, anterior distal pressures may increase. Intermittent doffing may reduce fluid volume loss and mitigate socket fit problems.3 In a study on 16 people with transtibial amputation, a 30-minute doff performed after activity significantly increased limb fluid volume compared with not doffing. While doffing a prosthesis with locking-pin suspension during sitting either partially or completely may reduce socket fit problems caused by fluid volume loss, re-donning the prosthesis can often be difficult. Typically, donning requires the user has access to the socket (i.e., the user must remove pants or other lower-limb garments). Further, the user may have difficulty aligning the locking pin with the shuttle lock since it is not visible during donning. A mechanism that conveniently allows partial doffing and facilitates easy re-donning may help prosthesis users to implement intermittent doffing practices and overcome discomfort and fluid volume loss during sitting. Several systems have been designed to facilitate re-donning, with most of them using a fabric pull cord that passes through a hole in the distal end of the socket.4 The user draws the cord to pull in and seat the liner. One system (Lanyard Plunger Pin, Bulldog Tools Incorporated, Lewisburg, Ohio) is simply a cord affixed to a locking pin. Other systems eliminate the locking pin and shuttle lock and instead attach the cord to the liner using a threaded fastener5 (Icelock 300, Ossur, Reykjavik, Iceland; Keep It Simple Suspension,6 KISS Technologies, Baltimore, Maryland; Hook and Loop System,7 HOLO). The cord is pulled proximally by the user and held against the socket to maintain tension in the cord. One system uses a ratcheting mechanism that allows tension to be incrementally applied to the cord.5 The primary limitations of all of these systems are that users must have direct access to the socket to operate them, and users must have sufficient dexterity, balance, and strength to pull the cord taut. Further, systems without locking mechanisms would be expected to have weaker socket connections and thus be less secure during active gait than systems that include them. The purpose of this research was to develop and test a suspension system that allowed partial or complete doffing but did not require access to the socket, nor require the user to pull a cord taught during donning. A retractable tethered pin system was developed to operate with a normal shuttle lock suspension. Initial tests with prosthesis users were conducted.

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People with transtibial amputation often experience skin breakdown due to the pressures and shear stresses that occur at the limb-socket interface. The purpose of this research was to create a transtibial finite element model (FEM) of a contemporary prosthesis that included complete socket geometry, two frictional interactions (limb-liner and liner-socket), and an elastomeric liner. Magnetic resonance imaging scans from three people with characteristic transtibial limb shapes (i.e., short-conical, long-conical, and cylindrical) were acquired and used to develop the models. Each model was evaluated with two loading profiles to identify locations of focused stresses during stance phase. The models identified five locations on the participants' residual limbs where peak stresses matched locations of mechanically induced skin issues they experienced in the 9 months prior to being scanned. The peak contact pressure across all simulations was 98 kPa and the maximum resultant shear stress was 50 kPa, showing reasonable agreement with interface stress measurements reported in the literature. Future research could take advantage of the developed FEM to assess the influence of changes in limb volume or liner material properties on interface stress distributions. Graphical abstract Residual limb finite element model. Left: model components. Right: interface pressures during stance phase.

Continuing education is intended to facilitate clinicians' skills and knowledge in areas of practice, such as administration and interpretation of outcome measures.To evaluate the long-term effect of continuing education on prosthetists' confidence in administering outcome measures and their perceptions of outcomes measurement in clinical practice.Pretest-posttest survey methods.A total of 66 prosthetists were surveyed before, immediately after, and 2 years after outcomes measurement education and training. Prosthetists were grouped as routine or non-routine outcome measures users, based on experience reported prior to training.On average, prosthetists were just as confident administering measures 1-2 years after continuing education as they were immediately after continuing education. In all, 20% of prosthetists, initially classified as non-routine users, were subsequently classified as routine users at follow-up. Routine and non-routine users' opinions differed on whether outcome measures contributed to efficient patient evaluations (79.3% and 32.4%, respectively). Both routine and non-routine users reported challenges integrating outcome measures into normal clinical routines (20.7% and 45.9%, respectively).Continuing education had a long-term impact on prosthetists' confidence in administering outcome measures and may influence their clinical practices. However, remaining barriers to using standardized measures need to be addressed to keep practitioners current with evolving practice expectations. Clinical relevance Continuing education (CE) had a significant long-term impact on prosthetists' confidence in administering outcome measures and influenced their clinical practices. In all, approximately 20% of prosthetists, who previously were non-routine outcome measure users, became routine users after CE. There remains a need to develop strategies to integrate outcome measurement into routine clinical practice.

To assess construct validity of the Prosthetic Limb Users Survey of Mobility (PLUS-M), a self-report mobility measure for people with lower limb amputation (LLA).Cross-sectional study.Private prosthetic clinics (n=37).Current lower limb prosthesis users (N=199; mean age ± SD, 55.4±14.3y; 71.4% men) were assessed before receiving a replacement prosthesis, prosthetic socket, and/or prosthetic knee.Not applicable.Convergent construct validity was examined using correlations between participants' PLUS-M T-scores and measures of physical function, mobility, and balance, including the Amputee Mobility Predictor (AMP), timed Up and Go (TUG), Patient-Reported Outcomes Measurement Information System-Physical Function (PROMIS-PF), Prosthesis Evaluation Questionnaire-Mobility Subscale (PEQ-MS), and Activities-specific Balance Confidence (ABC) Scale. Known-groups construct validity was evaluated by comparing differences in PLUS-M T-scores among participants grouped by Medicare Functional Classification Level (MFCL).PLUS-M T-scores demonstrated a moderate positive relationship with AMP scores (ρ=.54, P.001) and a moderate negative relationship with TUG times (ρ=-.56, P.001). The PLUS-M also showed a strong positive relationship with PEQ-MS scores (ρ=.78, P.001), ABC Scale scores (ρ=.81, P.001), and PROMIS-PF T-scores (ρ=.81, P.001). Significant differences (P.05) in PLUS-M T-scores were found among groups of people classified by different MFCLs.Study results support the validity of the PLUS-M as a self-report measure of prosthetic mobility. Correlations between PLUS-M and measures of physical function, mobility, and balance indicate convergent construct validity. Similarly, significant differences in PLUS-M T-scores across MFCL groups provide evidence of known-groups construct validity. In summary, evidence indicates that PLUS-M has good construct validity among people with LLA.

Background Clinicians are routinely required to make decisions about fall risk among lower limb prosthesis (LLP) users. These decisions can be guided by standardized clinical balance tests but require population- and test-specific cutoff scores and validity indices to categorize individuals as probable fallers or nonfallers on the basis of test performance. Despite the importance of cutoff scores and validity indices to clinical interpretation of clinical balance test scores, they are rarely reported for LLP users. In their absence, clinicians cannot use results from clinical balance tests to assess the likelihood of a fall by any one patient. Objective Derive cutoff scores, and associated validity indices, for clinical balance tests administered to established unilateral LLP users. Design Cross-sectional study. Setting Outpatient clinic and research laboratory. Participants Established ambulatory unilateral transtibial and transfemoral prosthesis users (n = 40). Intervention Not applicable. Main outcome measure(s) Optimal cutoff scores and related validity indices (ie, area under the curve, sensitivity, specificity, likelihood ratios) were computed for five balance tests, the activities-specific balance confidence scale (ABC), timed up and go (TUG), four square step test (FSST), Berg balance scale (BBS), and narrowing-beam walking test (NBWT). Results Cutoff scores were identified for the NBWT (≤.43/1.0), TUG (≥8.17 seconds], FSST (≥8.49 seconds), BBS (≤50.5/56), and ABC (≤80.2/100). Validity indices (ie, area under the curve, sensitivity, specificity, and likelihood ratios) for the NBWT, TUG, and FSST had greater diagnostic accuracy and provided more information about the probability of a fall than those for the BBS or ABC. Conclusion Performance above or below identified cutoff scores for the NBWT, FSST, and TUG provides information about potentially important shifts in the probability of falling among established unilateral LLP users. These results can serve as initial benchmarks to reduce uncertainty surrounding fall risk assessment in established unilateral LLP users but require future prospective evaluation. Level of evidence III.

Keeping pace with the ever-growing orthotic and prosthetic profession : New faces and changes at Prosthetics and Orthotics International

This study tested the hypothesis that greater perceived cognitive concerns are associated with worse mobility in a cohort of prosthesis users with lower limb loss (LLL).We performed a secondary analysis of cross-sectional self-report data from a volunteer sample of people with LLL due to dysvascular and non-dysvacular causes. Perceived cognitive difficulties were assessed using the Quality of Life in Neurological Disorders Applied Cognition - General Concerns (Neuro-QoL ACGC). Mobility was measured with the Activities-Specific Balance Confidence Scale (ABC) and the Prosthetic Limb Users Survey of Mobility (PLUS-M). Simple linear regressions examined univariate relationships between cognitive concerns and mobility. Multiple linear regression analyses included demographic and amputation-related variables that could influence this relationship.Analysis of data from 1291 people with LLL demonstrated that greater cognitive concerns, measured by the Neuro-QoL ACGC, were associated with poorer perceived mobility, measured by both ABC and PLUS-M instruments. This relationship remained statistically significant after adjusting for demographic and amputation-related factors.These results suggest that greater cognitive concerns are associated with worse mobility among a broad range of people with LLL. An improved understanding of this relationship is critical for optimizing rehabilitation outcomes for this population. Implications for rehabilitation Rehabilitation for people with lower limb loss (LLL) typically focuses on physical impairments and mobility limitations, but cognition is increasingly recognized to have an impact on functional outcomes. Greater perceived cognitive concerns are associated with poorer mobility among a broad range of people with LLL, even when adjusting for demographic and amputation-related factors. Cognitive status can impact relevant rehabilitative outcomes, including mobility, and should be considered when planning prosthetic and therapeutic interventions.

To investigate differences between self-reported cognitive concerns in people with lower limb loss (LLL) and normative data derived from the U.S. general population, and secondarily to determine whether there were cognitive differences based on amputation etiology or age.Survey.General community.A volunteer sample of persons with LLL (N=1086) resulting from trauma or dysvascular complications who regularly use a prosthetic limb.Not applicable.The Quality of Life in Neurological Disorders Applied Cognition-General Concerns Short Form version 1.0 (Neuro-QoL ACGC), an 8-item self-report measure of general cognitive concerns.People with LLL reported significantly more cognitive concerns than the Quality of Life in Neurological Disorders normative sample. Mean Neuro-QoL ACGC scores were significantly lower than normative values (P.001) across subgroups defined by age (ie,40, 40-49, 50-59, 60-69, and 70+ years) and subgroups defined by etiology (ie, traumatic and dysvascular LLL). However, there were no significant differences in cognitive concerns among age subgroups (P=.84) or between the etiology subgroups (P=.58).When compared with the Quality of Life in Neurological Disorders normative sample, individuals with LLL report greater concerns with cognitive health. Cognitive concerns were not differentially affected by age or cause of amputation. The presence of cognitive concerns in people with LLL suggests a need to assess perceived cognitive function in order to tailor education and training in prosthetic use and care.

It has long been reported that a range of prosthesis alignments is acceptable in trans-tibial prosthetics. This range was shown to be smaller when walking on uneven surfaces. It has also been argued that findings on gait with prostheses that were obtained under laboratory conditions are limited in their applicability to real-life environments.This study investigated the hypothesis that efforts to compensate for suboptimal alignments by active users of trans-tibial prostheses become less effective when levels of physical exertion increase.A 2 × 2 repeated-measures analysis of variance was conducted to compare the effects of physical exertion and subtle alignment perturbations on gait with trans-tibial prostheses.The gait of eight subjects with trans-tibial amputation was analyzed when walking with two different prosthesis alignments and two different physical exertion levels. The main and interaction effects were statistically evaluated.Bilateral step length symmetry and measures of step variability within the same leg were found to be affected by the intervention. There was no significant effect on index variables that combined kinematic or kinetic measures.Findings showed that persons with trans-tibial prostheses responded heterogeneously to the interventions. For most variables, the research hypothesis could not be confirmed.Findings support the practice of allotting several sessions to the alignment of trans-tibial prostheses, as users' gait responds differently to perturbations when external factors (e.g. exertion) change. Furthermore, the found inhomogeneity in the population of persons with trans-tibial amputation supports the use of technical gait assessment methods in clinical practice.

Documentation of clinical outcomes is increasingly expected in delivery of prosthetic services and devices. However, many outcome measures suitable for use in clinical care and research have not been psychometrically tested with prosthesis users. The aim of this study was to determine test-retest reliability, mode-of-administration (MoA) equivalence, standard error of measurement (SEM), and minimal detectable change (MDC) of standardized, self-report instruments that assess constructs of importance to people with lower limb loss. Prosthesis users (n = 201) were randomly assigned to groups based on MoA (i.e., paper, electronic, or mixed-mode). Participants completed two surveys 2 to 3 d apart. Instruments included the Prosthetic Limb Users Survey of Mobility, Prosthesis Evaluation Questionnaire-Mobility Subscale, Activities-Specific Balance Confidence Scale, Quality of Life in Neurological Conditions-Applied Cognition/General Concerns, Patient-Reported Outcomes Measurement Information System Profile, and Socket Comfort Score. Intraclass correlation coefficients indicated all instruments are appropriate for group-level comparisons and select instruments are suitable for individual-level applications. Several instruments showed evidence of possible floor and ceiling effects. All were equivalent across MoAs. SEM and MDC were quantified to facilitate interpretation of outcomes and change scores. These results can enhance clinicians' and researchers' ability to select, apply, and interpret scores from instruments administered to prosthesis users.

For people who wear a prosthetic limb, residual-limb fluid volume loss during the day may be problematic and detrimentally affect socket fit. The purpose of this research was to test the capability of a novel liner with adjustable bladders positioned within its wall to mitigate volume loss and facilitate limb fluid volume recovery and retention. Bioimpedance analysis was used to monitor fluid volume changes in the anterior and posterior residual limb of participants with transtibial amputation. Participants underwent six cycles of sitting for 90 s, standing for 90 s, and walking for 5 min with liquid within the bladder-liners. Between the third and fourth cycles, participants sat for 10 min with liquid left within the bladders (Liquid-In) or removed (Liquid-Out). Results showed that participants recovered more fluid volume during the 10 min of sitting with Liquid-Out than Liquid-In (p = 0.09 for anterior and p = 0.04 for posterior). However, those fluid volume recoveries were not well retained in the short term (after the fourth cycle) or the long term (after the sixth cycle). Physiologic differences between sessions, reflected in the rates of fluid volume change at the outset of the session, and excessive stiffness of the bladder-liners may have affected fluid volume retentions.

INTRODUCTION A variety of prosthetic feet are available to meet the diverse needs of people with lower limb amputation. Outcome measures selected to assess comparative effectiveness of prosthetic feet are most often chosen by clinicians and researchers.1 Therefore, these measures may not reflect the outcomes that are most important to lower limb prosthesis users. Qualitative research can give voice to prosthesis users and promote the consideration of user priorities when selecting outcome measures for clinical assessment and research studies. This study explored the lived experience and outcomes of importance to individuals who have worn both traditional energy storing feet and crossover feet. Abstract PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/32042/24456 How to cite:McDonald C.L, Cheever S.M , Morgan S.J., Hafner B.J. PROSTHETIC LIMB USER EXPERIENCES WITH CROSSOVER FEET: A FOCUS GROUP STUDY TO EXPLORE OUTCOMES THAT MATTER. CANADIAN PROSTHETICS & ORTHOTICS JOURNAL, VOLUME 1, ISSUE 2, 2018; ABSTRACT, ORAL PRESENTATION AT THE AOPA’S 101ST NATIONAL ASSEMBLY, SEPT. 26-29, VANCOUVER, CANADA, 2018. DOI: https://doi.org/10.33137/cpoj.v1i2.32042

INTRODUCTION A variety of performance-based tests are available to assess mobility in people with lower limb amputation (LLA)1. Selection of a specific test is likely to be guided by the clinical value of tasks patients perform; the space and equipment available to administrator the test; and/or the time required to set up, administer, score, and interpret the test results. The aim of this study was to collect information about the clinical value of performance tests, and the space, equipment, and time available to rehabilitation specialists who provide care to people with LLA (i.e., prosthetists, physical therapists (PTs), and physical medicine and rehabilitation (PM&R) physicians). Abstract PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/32018/24437 How to cite: Balkman G, Morgan S, Gaunaurd I, Kristal A, Amtmann D, Gailey R, Hafner B.J. PERFORMANCE TESTING IN PEOPLE WITH LOWER LIMB AMPUTATION: INTERVIEWS WITH PROSTHETISTS, PHYSICAL THERAPISTS, AND PHYSICIANS. CANADIAN PROSTHETICS & ORTHOTICS JOURNAL, VOLUME 1, ISSUE 2, 2018; ABSTRACT, POSTER PRESENTATION AT THE AOPA’S 101ST NATIONAL ASSEMBLY, SEPT. 26-29, VANCOUVER, CANADA, 2018. DOI: https://doi.org/10.33137/cpoj.v1i2.32018 Abstracts were Peer-reviewed by the American Orthotic Prosthetic Association (AOPA) 101st National Assembly Scientific Committee. http://www.aopanet.org/

INTRODUCTION Patient-reported outcome measures (PROMs) are used by prosthetists to assess and communicate effectiveness of prosthetic interventions. The Prosthetic Limb Users Survey of Mobility (PLUS-M) is a PROM developed to evaluate lower limb prosthetic mobility.1 Valid and reliable translations of prosthetics-specific PROMs, like PLUS-M, do not exist for Japanese-speaking patients. The purpose of this research was to translate PLUS-M to Japanese using rigorous translation guidelines in order to maintain the meaning and applicability of items across both languages. Abstract PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/32017/24436 How to cite: Balkman G, Samejima S, Aoki D, Hafner B.J. JAPANESE TRANSLATION OF THE PROSTHETIC LIMB USERS SURVEY OF MOBILITY. CANADIAN PROSTHETICS & ORTHOTICS JOURNAL, VOLUME 1, ISSUE 2, 2018; ABSTRACT, POSTER PRESENTATION AT THE AOPA’S 101ST NATIONAL ASSEMBLY, SEPT. 26-29, VANCOUVER, CANADA, 2018. DOI: https://doi.org/10.33137/cpoj.v1i2.32017 Abstracts were Peer-reviewed by the American Orthotic Prosthetic Association (AOPA) 101st National Assembly Scientific Committee. http://www.aopanet.org/

BACKGROUND: The volume of a prosthesis user’s residual limb changes during the day, and may affect the fit of the prosthesis. These changes must be managed by the user to prevent discomfort, skin breakdown, and falls. OBJECTIVES: The objectives were to test how activity, time of day, and intermittent doffing affected residual limb fluid volume in people with transtibial amputation. STUDY DESIGN: Standardized, repeated measure (A-B-A) out-of-laboratory protocol. METHODS: Participants with transtibial amputation completed three 6-hour test sessions. Two sessions served as controls (A protocol) during which participants left their prosthesis donned, and one session was an intervention (B protocol) where participants doffed their prosthesis twice for 20 minutes during the 6 hours of testing. Within-socket fluid volume was measured using a custom portable bioimpedance analysis system. RESULTS: Thirteen participants completed the study. The rate of limb fluid volume loss was higher early in the session compared with late in the session. Participants experienced less fluid volume loss during high-activity than low-activity. Socket users with pin suspension experienced less posterior fluid volume loss when they intermittently doffed their prosthesis. Intermittent doffing did not benefit limb fluid volume of mechanical vacuum and suction suspension users. CONCLUSIONS: High-activity may reduce fluid volume loss compared with low-activity. Intermittent doffing may provide volume accommodation for transtibial prosthesis users with pin suspension. CLINICAL RELEVANCE: Prosthetists should query their patients about the intensity of activity they conduct when advising them on limb volume management. Patients using sockets with pin suspension may be able to offset limb fluid volume loss by periodically doffing the prosthesis.

Fluctuations in limb volume degrade prosthesis fit and require users to accommodate changes using management strategies, such as donning and doffing prosthetic socks.To examine how activities and self-report outcomes relate to daily changes in residual limb fluid volume and volume accommodation.Standardized, two-part laboratory protocol with an interim observational period.Participants were classified as "accommodators" or "non-accommodators," based on self-report prosthetic sock use. Participants' residual limb fluid volume change was measured using a custom bioimpedance analyzer and a standardized in-laboratory activity protocol. Self-report health outcomes were assessed with the Socket Comfort Score and Prosthesis Evaluation Questionnaire. Activity was monitored while participants left the laboratory for at least 3 h. They then returned to repeat the bioimpedance test protocol.Twenty-nine people were enrolled. Morning-to-afternoon percent limb fluid volume change per hour was not strongly correlated to percent time weight-bearing or to self-report outcomes. As a group, non-accommodators ( n = 15) spent more time with their prosthesis doffed and reported better outcomes than accommodators.Factors other than time weight-bearing may contribute to morning-to-afternoon limb fluid volume changes and reported satisfaction with the prosthesis among trans-tibial prosthesis users. Temporary doffing may be a more effective and satisfying accommodation method than sock addition. Clinical relevance Practitioners should be mindful that daily limb fluid volume change and prosthesis satisfaction are not dictated exclusively by activity. Temporarily doffing the prosthesis may slow daily limb fluid volume loss and should be investigated as an alternative strategy to sock addition.