The development and reliability testing of the Functional Lower-Limb Amputee Gait Assessment.

OBJECTIVE: The study purpose was three-fold: (a) to describe the development of the Functional Lower-Limb Amputee Gait Assessment, (b) to determine its reliability with two groups of raters, physical therapists, and certified prosthetists, and (c) to determine the agreement on its results between the two groups. DESIGN: A reliability study. SETTING: Institution for higher education. PARTICIPANTS: Five physical therapists and five certified prosthetists. INTERVENTION: Not applicable. MAIN MEASURE: The gait of people with unilateral lower limb amputation was evaluated using the Functional Lower-Limb Amputee Gait Assessment. Kappa statistic was used to analyze reliability. RESULTS: The intra-rater reliability of nine gait deviations in the physical therapists' group and eight in the certified prosthetists' group was between moderate and almost perfect agreement (kappa = .41-1). In the physical therapists' group, the inter-rater reliability of four gait deviations was moderate (kappa = .41-.6). In the certified prosthetists' group, the inter-rater reliability of six gait deviations was moderate to substantial (kappa = .41-.8). Three gait deviations achieved moderate agreement in both groups of clinicians (kappa = .41-.6). CONCLUSIONS: Most gait deviations included in the Functional Lower-Limb Amputee Gait Assessment appear stable over time when used by the same clinician. Six gait deviations in the certified prosthetists' group and four in the physical therapists' group may be used by multiple clinicians, and three gait deviations may be used across both professions to assist in communication and collaboration on the best course of treatment for a patient with a unilateral lower limb amputation.

Use of Standardized Outcome Measures for People With Lower Limb Amputation: A Survey of Prosthetic Practitioners in the United States.

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.

A Comparison of the Two-Minute Walk Test (2MWT) and Comprehensive High-level Activity Mobility Predictor (CHAMP) in People with a Leg Prosthesis.

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.

Clinical Resources for Assessing Mobility of People with Lower-Limb Amputation: Interviews with Rehabilitation Clinicians.

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.

The Utility of the 2-Minute Walk Test as a Measure of Mobility in People With Lower Limb Amputation.

OBJECTIVES: To establish reference values for the 2-minute walk test (2-MWT) distance and gait speed in people with a lower limb amputation (LLA) who are prosthetic ambulators. Also, to describe the differences in distance and gait speed between sexes, causes of amputation, levels of amputation, health risk classification, functional levels, and age groups. DESIGN: Cross-sectional study. SETTING: National meeting for people with lower limb amputation. PARTICIPANTS: A convenience sample of unilateral people (N=101; 47 men, 54 women; mean age ± SD, 50.9±14.3 y) with an LLA; 48 had a transtibial amputation and 53 had a transfemoral amputation. Participants were classified as either limited community ambulators, community ambulators, or those who exceed basic ambulation skills (K2, n=7; K3, n=70; K4, n=24). INTERVENTION: Not applicable. MAIN OUTCOME MEASURE: 2-MWT performance (ie, distance and gait speed). RESULTS: The mean ± SD 2-MWT distance and gait speed for the entire sample was 143.8±37.5 meters (range, 49-259 m) and 72.1±18.8 meters per minute (range, 25-130 m/min), respectively. Men walked farther (distance: men, 154.2±34.2 m; women, 134.4±38.1 m) and faster (gait speed: men, 77.3±17.1 m/min; women, 67.4±19.1 m/min) than women (P<.05). The mean ± SD 2-MWT distance for K4, K3, and K2 level participants was 177.9±31.1 meters, 138.4±28.5 meters, and 81.7±26.9 meters, respectively. Functional level K4 participants performed better than K3 participants (P<.05), and K3 participants performed better than K2 participants (P<.05). People with transtibial amputation walked farther than those with transfemoral amputation (152.9±43.0 m vs 135.6±43.0 m) (P<.05). The distance and speed ambulated by those participants classified in the very high health risk group was worse than those categorized as being at an increased high health risk group (P<.05) and the no increase health risk group (P<.05). The performance of participants older than 70 years old was inferior to the performance of all younger age groups. CONCLUSIONS: Reference values for the 2-MWT distance and gait speed were established in people with LLA who are prosthetic ambulators. Significant differences in the 2-MWT performance were found between sexes, causes of amputation, levels of amputation, health risk classification, functional levels, and age groups.

The Component Timed-Up-and-Go test: the utility and psychometric properties of using a mobile application to determine prosthetic mobility in people with lower limb amputations.

OBJECTIVE: Using a custom mobile application to evaluate the reliability and validity of the Component Timed-Up-and-Go test to assess prosthetic mobility in people with lower limb amputation. DESIGN: Cross-sectional design. SETTING: National conference for people with limb loss. SUBJECTS: A total of 118 people with non-vascular cause of lower limb amputation participated. Subjects had a mean age of 48 (±13.7) years and were an average of 10 years post amputation. Of them, 54% ( n = 64) of subjects were male. INTERVENTION: None. MAIN MEASURE: The Component Timed-Up-and-Go was administered using a mobile iPad application, generating a total time to complete the test and five component times capturing each subtask (sit to stand transitions, linear gait, turning) of the standard timed-up-and-go test. The outcome underwent test-retest reliability using intraclass correlation coefficients (ICCs) and convergent validity analyses through correlation with self-report measures of balance and mobility. RESULTS: The Component Timed-Up-and-Go exhibited excellent test-retest reliability with ICCs ranging from .98 to .86 for total and component times. Evidence of discriminative validity resulted from significant differences in mean total times between people with transtibial (10.1 (SD: ±2.3)) and transfemoral (12.76 (SD: ±5.1) amputation, as well as significant differences in all five component times ( P < .05). Convergent validity of the Component Timed-Up-and-Go was demonstrated through moderate correlations with the PLUS-M ( rs = -.56). CONCLUSION: The Component Timed-Up-and-Go is a reliable and valid clinical tool for detailed assessment of prosthetic mobility in people with non-vascular lower limb amputation. The iPad application provided a means to easily record data, contributing to clinical utility.

A Novel Method for Estimating Knee Angle Using Two Leg-Mounted Gyroscopes for Continuous Monitoring with Mobile Health Devices.

Tele-rehabilitation of patients with gait abnormalities could benefit from continuous monitoring of knee joint angle in the home and community. Continuous monitoring with mobile devices can be restricted by the number of body-worn sensors, signal bandwidth, and the complexity of operating algorithms. Therefore, this paper proposes a novel algorithm for estimating knee joint angle using lower limb angular velocity, obtained with only two leg-mounted gyroscopes. This gyroscope only (GO) algorithm calculates knee angle by integrating gyroscope-derived knee angular velocity signal, and thus avoids reliance on noisy accelerometer data. To eliminate drift in gyroscope data, a zero-angle update derived from a characteristic point in the knee angular velocity is applied to every stride. The concurrent validity and construct convergent validity of the GO algorithm was determined with two existing IMU-based algorithms, complementary and Kalman filters, and an optical motion capture system, respectively. Bland⁻Altman analysis indicated a high-level of agreement between the GO algorithm and other measures of knee angle.

Construct Validity of the Prosthetic Limb Users Survey of Mobility (PLUS-M) in Adults With Lower Limb Amputation.

OBJECTIVE: 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). DESIGN: Cross-sectional study. SETTING: Private prosthetic clinics (n=37). PARTICIPANTS: 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. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: 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). RESULTS: 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. CONCLUSIONS: 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.

Analysis of weight distribution strategies in unilateral transtibial amputees during the stand-to-sit activity.

Current methods of quantifying the stand-to-sit activity (StTS) are resource intensive and have not been applied to unilateral transtibial amputees (TTAs). The purpose of this study is to define five phases of arm-rest assisted and unassisted StTS using simple instrumentation and implement this method for assessing TTA movement patterns. Twelve TTAs and 12 age-matched non-amputees performed StTS with and without arm-rest support. Symmetry of weight distribution between lower limbs was calculated for five StTS phases: Descent Initiation; Descent Deceleration; Seat-Contact; Stabilisation and Sitting. TTAs demonstrated an asymmetrical weight distribution pattern and a tendency to transfer weight to the intact limb during the course of the activity. Non-amputees had relatively higher symmetry and did not exhibit substantial weight shifts during the activity. Symmetry indices were similar for assisted and unassisted sitting in both subject groups. These results highlight a need for therapeutic interventions in TTAs for reducing loading asymmetries and associated co-morbidities. PRACTITIONER SUMMARY: This study defines a novel method for quantifying stand-to-sit movements using clinically friendly equipment and is the first to investigate the stand-to-sit activity of unilateral transtibial amputees. The observed differences in inter-limb weight distribution strategies between amputees and non-amputees could provide insights for clinical assessment and intervention.

Exercise limitation in IPF patients: a randomized trial of pulmonary rehabilitation.

BACKGROUND: Patients with idiopathic pulmonary fibrosis (IPF) have severely limited exercise capacity due to dyspnea, hypoxemia, and abnormal lung mechanics. This pilot study was designed to determine whether pulmonary rehabilitation were efficacious in improving the 6-min walk test (6-MWT) distance, exercise oxygen uptake, respiratory muscle strength [maximum inspiratory pressure (MIP)], and dyspnea in patients with IPF. Underlying physiological mechanisms and effects of the intervention were investigated. METHODS: Subjects were randomly assigned to a 3-month pulmonary rehabilitation program (n = 11) or to a control group (n = 10). All subjects initially underwent the 6-MWT and constant load exercise gas exchange studies. RESULTS: Subjects in the rehabilitation group increased treadmill exercise [metabolic equivalent of task-minutes] over the first 14 sessions. Beneficial effects on physical function resulted in those who completed rehabilitation. Subjects who completed the program increased cycle ergometer time and maintained exercise oxygen consumption (exercise VO(2)) at the baseline level over 3 months, while the control group suffered a significant decrease in exercise VO(2). Rehabilitation subjects also increased their MIP. Plasma lactate doubled and brain natriuretic peptide levels increased significantly after exercise, as did the plasma amino acids glutamic acid, arginine, histidine, and methionine. These changes were associated with significant decreases in arterial oxygen saturation and increases in 15-F(2t)-isoprostanes after exercise. CONCLUSIONS: Pulmonary rehabilitation effectively maintained exercise oxygen uptake over 3 months and lengthened constant load exercise time in patients with moderately severe IPF. Exercise endurance on cycle ergometry testing was limited by dyspnea and severe hypoxemia associated with systemic oxidant stress.

Current State, Needs, and Opportunities for Wearable Robots in Military Medical Rehabilitation and Force Protection.

Despite advances in wearable robots across various fields, there is no consensus definition or design framework for the application of this technology in rehabilitation or musculoskeletal (MSK) injury prevention. This paper aims to define wearable robots and explore their applications and challenges for military rehabilitation and force protection for MSK injury prevention. We conducted a modified Delphi method, including a steering group and 14 panelists with 10+ years of expertise in wearable robots. Panelists presented current wearable robots currently in use or in development for rehabilitation or assistance use in the military workforce and healthcare. The steering group and panelists met to obtain a consensus on the wearable robot definition applicable for rehabilitation or primary injury prevention. Panelists unanimously agreed that wearable robots can be grouped into three main applications, as follows: (1) primary and secondary MSK injury prevention, (2) enhancement of military activities and tasks, and (3) rehabilitation and reintegration. Each application was presented within the context of its target population and state-of-the-art technology currently in use or under development. Capturing expert opinions, this study defines wearable robots for military rehabilitation and MSK injury prevention, identifies health outcomes and assessment tools, and outlines design requirements for future advancements.

Modifying the five-time sit-to-stand test to allow use of the upper limbs: Assessing initial evidence of construct validity among lower limb prosthesis users.

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.

Comparison of prosthetic mobility and balance in transfemoral amputees with bone-anchored prosthesis vs. socket prosthesis.

BACKGROUND: The literature comparing bone-anchored prosthesis (BAP) with socket prosthesis (SP) consistently reports improvement in physical health and quality of life using primarily patient-reported outcome measures (PROMs). OBJECTIVE: To determine the differences in mobility and balance using performance-based outcome measures and PROMs in people with transfemoral amputations (TFAs) fitted with BAP vs. SP. STUDY DESIGN: Causal comparative. METHODS: Two groups of people with TFAs were recruited: one using a BAP (N = 11; mean age ± standard deviation, 44 ± 14.9 years; mean residual limb length as a percentage of the intact femur, 68% ± 15.9) and another group using a SP (N = 11; mean age ± standard deviation, 49.6 ± 16.0 years; mean residual limb length as a percentage of the intact femur, 81% ± 13.9), and completed the 10-meter walk test, component timed-up-and-go, Prosthetic Limb Users Survey of Mobility™ 12-item, and Activities-specific Balance Confidence Scale. RESULTS: There were no statistically significant differences between the BAP and SP groups in temporal spatial gait parameters and prosthetic mobility as measured by the 10-meter walk test and component timed-up-and-go, yet large effect sizes were found for several variables. In addition, Activities-specific Balance Confidence Scale and Prosthetic Limb Users Survey of Mobility™ scores were not statistically different between the BAP and SP groups, yet a large effect sizes were found for both variables. CONCLUSIONS: This study found that people with TFA who use a BAP can demonstrate similar temporal spatial gait parameters and prosthetic mobility, as well as self-perceived balance confidence and prosthetic mobility as SP users. Therefore, suggesting that the osseointegration reconstruction surgical procedure provides an alternative option for a specific population with TFA who cannot wear nor have limitations with a SP. Future research with a larger sample and other performance-based outcome measures and PROMs of prosthetic mobility and balance would further determine the differences between the prosthetic options.

Development of an item bank for measuring prosthetic mobility in people with lower limb amputation: The Prosthetic Limb Users Survey of Mobility (PLUS-M).

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.

Using theoretical frameworks to examine fall history and associated prosthetic mobility in people with nondysvascular lower limb amputation.

BACKGROUND: Over a million people live with lower limb amputation (LLA) in the United States, and many of them will experience a fall in the next year. The aim of this study was to use existing theoretical frameworks in an attempt to organize the complex interactions of reported fall history and prosthetic mobility in community-ambulating people with LLA. METHODS: Self-reported fall rate and fall circumstances were recorded in a cross-section of people with unilateral LLA due to nondysvascular causes. Self-report and performance-based standardized outcome measures assessed prosthetic mobility and balance confidence. All variables were considered and appropriately placed within a proposed International Classification of Functioning, Disability, and Health framework while using a fall-type classification framework to classify fall circumstances. RESULTS: Information from 69 participants was analyzed. The reported fall rate was at 46%, with those with transfemoral amputation reporting significantly more falls than those with transtibial amputation ( P = 0.001). Tripping over an object was the most common cause (62.5%), and fallers reported significantly lower perceived prosthetic mobility than nonfallers ( P = 0.001). Despite reporting high levels of balance confidence, results indicate that all groups of fallers and nonfallers are at increased fall risk according to performance-based prosthetic mobility score cutoffs. CONCLUSIONS: Community-dwelling people with nondysvascular LLA are at increased fall risk. Classifying fall-related variables using theoretical frameworks provides a means to structure more informative fall risk surveys for people with LLA in an attempt to identify those at greater risk for falling and its potential detrimental effects.

Variations in 2-Minute Walk Test outcomes for people with lower limb amputation in the outpatient clinic and research settings.

BACKGROUND: This study determined the differences in 2-Minute Walk Test (2MWT) distances between people with lower limb amputations in clinical and research settings and described variations in test administration in various clinical settings. STUDY DESIGN: Retrospective Cross-sectional design. METHODS: The 2MWT for 290 patients with lower limb amputations were obtained from a medium-sized prosthetic company with locations within the central United States. Data on 12 prosthetists' 2MWT administration decisions were obtained from the results of an administrative questionnaire. Patient 2MWT distances were compared with published distances. Multiple regression was used to examine the impact of test settings on 2MWT outcomes. Descriptive statistics were used to present prosthetists' variations in test administration. RESULTS: Clinical 2MWT distances were significantly less than distances obtained in a research setting. Clinical facilities reported inconsistent path dimensions and potential obstacles in proximity to the test area. Variations in test administration by prosthetists with respect to path length, instructions, turn marker, and overage measurement may contribute to the differences. CONCLUSIONS: Prosthetists should be aware that comparisons of patients' 2MWT distance in a clinical environment may differ from published results. Although variations in clinical environments are usually nonmodifiable characteristics of the clinical facility, test administration and scoring could be modified.

Weight distribution symmetry during the sit-to-stand movement of unilateral transtibial amputees.

This study characterises weight distribution symmetry between the intact and amputated limbs of unilateral transtibial amputees during a sit-to-stand movement. A total of 12 amputees and 12 age-matched, non-amputees performed the activity for two conditions - rising with and without chair arm-rest assistance. The sit-to-stand movement was divided into five events: Pre-Ascent; Ascent Initiation; Seat-Off; Deceleration; Standing. Symmetry in ground reaction forces between limbs was calculated at each event together with the rise time. Results indicate that during the course of the movement, amputees increased loading of the intact limb by approximately 27%, resulting in a significant asymmetry at seat-off and deceleration events. Non-amputees loaded the dominant limb more than the non-dominant limb throughout the activity but did not exhibit substantial weight shifts. Weight distribution symmetry was not significantly different between the two rising conditions in either population. Amputees had significantly longer rise times than non-amputees only while rising without arm-rest assistance. STATEMENT OF RELEVANCE: Sit-to-stand movements are performed frequently every day. Incorrect movement biomechanics caused by musculoskeletal impairments can lead to reduced functional independence and secondary co-morbidities. This study defines five events of a sit-to-stand cycle and is the first to address asymmetries of transtibial amputees, providing ergonomic insights for clinical assessment and intervention.

Usability Assessment of the Rehabilitation Lower-limb Orthopedic Assistive Device by Service Members and Veterans With Lower Limb Loss.

INTRODUCTION: Telehealth is an increasingly common approach to improve healthcare delivery, especially within the Veterans Health Administration and Department of Defense (DoD). Telehealth has diminished many challenges to direct access for clinical follow-up; however, the use of mobile telehealth for specialty rehabilitative care is emerging and is referred to as telerehabilitation. As early adopters of telehealth, the Veterans Affairs and DoD have supported collaborated efforts for programs designed to increase the access and quality of rehabilitative care while improving the functional ability of our service members (SMs) and veterans with lower limb amputation (LLA). The DoD and Veterans Health Administration collaborated on a Mobile Device Outcomes-based Rehabilitation Program (MDORP) to help injured SMs and veterans with LLA. The MDORP project utilized a mobile health system called the Rehabilitative Lower Limb Orthopedic Accommodating Device (ReLOAD) to assess walking quality. The ReLOAD system includes real-time auditory biofeedback to notify the user of their most prominent gait deviation and then recommends exercises that address specific balance and strength impairments. The purpose of this study was to describe the responses to a postintervention survey evaluating the feasibility and usability of ReLOAD completed by SMs and veterans with LLA who used the system for 5 months. MATERIALS AND METHODS: A link to an anonymous usability survey was emailed to all participants who completed MDORP. The survey was modeled after the System Usability Scale, with agreeableness to items rated on a 5-point Likert-style questionnaire in addition to open feedback. Data visualization of Likert-style questionnaires was conducted using ggplot2 and reshape2 statistical packages and was analyzed using R. We obtained institutional review board approval through both Miami Veterans Affairs Healthcare System and Walter Reed National Military Medical Center. RESULTS: The majority of participants reported that they would use the system again for home rehabilitation (65%) and that auditory biofeedback helped them walk better (59%). Participants also suggested that future work should include a greater variety of exercise options and the use of smart phones for the ReLOAD application in addition to the iPad tablet. CONCLUSIONS: The participants provided positive and constructive feedback that will enhance the value and usability of telerehabilitation interventions like the ReLOAD system for future users.

Inertial sensor-based measures of gait symmetry and repeatability in people with unilateral lower limb amputation.

BACKGROUND: People with lower limb amputation often walk with asymmetrical gait patterns potentially leading to long-term health problems, ultimately affecting their quality of life. The ability to discreetly detect and quantify the movement of bilateral thighs and shanks using wearable sensor technology can provide additional insight into how a person walks with a lower limb prosthesis. This study investigated segmental symmetry and segmental repeatability of people with unilateral lower limb amputation, examining performance of the prosthetic and intact limbs. METHODS: Gyroscope signals were recorded from four inertial measurement units worn on bilateral lower limb segments of subjects with unilateral lower limb amputation during the 10-m walk test. Raw angular velocity signals were processed using dynamic time warping and application of algorithms resulting in symmetry measures comparing similarity of prosthetic to intact limb strides, and repeatability measures comparing movement of one limb to its consecutive strides. FINDINGS: Biomechanical differences in performance of the prosthetic and intact limb segments were detected with the segmental symmetry and segmental repeatability measures in 128 subjects. More asymmetries and less consistent movements of the lower limbs were exhibited by subjects with transfemoral amputation versus transtibial amputation (p < .004, Cohen's d = 0.65-1.1). INTERPRETATION: Sensor-based measures of segmental symmetry and segmental repeatability were found to be reliable in detecting discreet differences in movement of the prosthetic versus intact lower limbs in amputee subjects. These measures provide a convenient tool for enhanced prosthetic gait analysis with the potential to focus rehabilitative and prosthetic interventions.

Variables that Influence Basic Prosthetic Mobility in People With Non-Vascular Lower Limb Amputation.

BACKGROUND: There exists a dearth of evidence on rehabilitation factors that influence prosthetic mobility in people with lower limb amputation (LLA). Examining variables that contribute to prosthetic mobility can inform rehabilitation interventions, providing guidance in developing more comprehensive care for these individuals. OBJECTIVE: To determine the influence of modifiable and non-modifiable variables related to LLA and their impact on prosthetic mobility, using the International Classification of Functioning, Disability and Health (ICF) model. Secondarily, to determine if personal factors and self-reported balance and mobility are predictive of Component timed-up-and-go (cTUG) performance. DESIGN: Cross-sectional study of a convenience sample. SETTING: National conference. PARTICIPANTS: People (N=68) with non-vascular causes of unilateral LLA. METHODS: Assessment of anthropometrics, mobility, bilateral hip extensor strength, hip range of motion, single limb balance, and self report measures. Lasso linear regression and extreme gradient boosting analyses were used to determine influence of variables on prosthetic mobility. MAIN OUTCOME MEASURE: Timed performance of the cTUG. RESULTS: The following five variables were found to influence basic prosthetic mobility (P ≤ .05) in people with transtibial amputation: hip extensor strength, hip range of motion, single limb balance, waist circumference, and age. In the transfemoral cohort, number of comorbidities and waist circumference primarily influenced prosthetic mobility. Additionally, 66% of the variance in cTUG total time for the entire sample could be explained by simply regressing on level of amputation, number of comorbidities, age and Activities-specific Balance Confidence scale score, all variables easily collected in a waiting room. CONCLUSION: Variables that are modifiable with physical therapy intervention including hip extensor strength, hip range of motion, single limb balance, and waist circumference significantly influenced basic prosthetic mobility. These variables can be affected by targeted rehabilitation interventions and lifestyle changes. LEVEL OF EVIDENCE: II.