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.

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.

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.

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.

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.

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.

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.

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 Effectiveness of the DoD/VA Mobile Device Outcomes-Based Rehabilitation Program for High Functioning Service Members and Veterans with Lower Limb Amputation.

INTRODUCTION: The objective was to determine if the Mobile Device Outcomes-based Rehabilitation Program (MDORP) improved strength, mobility, and gait quality in service members (SMs) and Veterans with lower limb amputation (LLA). METHODS: Seven SMs and 10 Veterans with LLA enrolled and were trained to use a mobile sensor system, called Rehabilitative Lower Limb Orthopedic Analysis Device (ReLOAD). ReLOAD provided participants with real-time assessment of gait deviations, subsequent corrective audio feedback, and exercise prescription for normalizing gait at home and in the community. After baseline testing, prosthetic gait and exercise training, participants took ReLOAD home and completed an 8-week walking and home exercise program. Home visits were conducted every 2 weeks to review gait training and home exercises. RESULTS: Significant improvements in hip extensor strength, basic and high-level mobility, musculoskeletal endurance, and gait quality (P < 0.05) were found at the completion of the 8-week intervention. CONCLUSION: Preliminary MDORP results are promising in its ability to improve basic and high-level mobility, lower limb strength, and gait quality in a group of SMs and Veterans with LLA. In addition, "booster" prosthetic training may be justified in an effort helps maintain an active lifestyle, promotes prosthetic use, and mitigates secondary health effects.

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.

The development and internal consistency of the comprehensive lower limb amputee socket survey in active lower limb amputees.

BACKGROUND:: Prosthetic socket fit is an important element associated with successful ambulation and use of a prosthesis. Prosthetists and rehabilitation clinicians would benefit from an assessment tool that discriminates between and quantifies the multiple determinants that influence the lower limb amputee's performance and satisfaction of a prosthetic socket. OBJECTIVES:: To determine the internal consistency of the comprehensive lower limb amputee socket survey, a new self-report measure of prosthetic socket satisfaction that quantifies suspension, stability, comfort, and appearance. STUDY DESIGN:: Cross-sectional sample of active amputees. METHODS:: Interviews were conducted with prosthetists, physical therapists, and lower limb amputees to identify clinical concerns and common activities influencing socket fit. An expert panel of five clinicians reviewed the items and constructed the original version of the comprehensive lower limb amputee socket survey which was then administered to a convenience sample of 47 active lower limb amputees. Item analysis and Cronbach's alpha were used to determine the final version of the comprehensive lower limb amputee socket survey. RESULTS:: Following item raw score-to-total score correlation with Cronbach's alpha for comprehensive lower limb amputee socket survey determinants, internal consistency improved when nine questions were eliminated. CONCLUSION:: The comprehensive lower limb amputee socket survey is a self-report measure of prosthetic socket satisfaction with very good internal consistency. CLINICAL RELEVANCE: When socket problems occur, the ability to determine the specific cause can reduce modification time, enhance socket fit, and promote patient satisfaction. A standardized multi-dimensional assessment measure of socket satisfaction enables prosthetists to quantify the multiple determinants of socket satisfaction, improve patient communication, and demonstrate the value of socket interventions.

Outdoor dynamic subject-specific evaluation of internal stresses in the residual limb: hydraulic energy-stored prosthetic foot compared to conventional energy-stored prosthetic feet.

The prosthetic foot plays an important role in propelling, breaking, balancing and supporting body loads while the amputee ambulates on different grounds. It is therefore important to quantify the effect of the prosthetic foot mechanism on biomechanical parameters, in order to prevent pressure ulcers and deep tissue injury. Our aim was to monitor the internal stresses in the residuum of transtibial amputation (TTA) prosthetic-users ambulating on different terrains, which the amputees encounter during their daily activities, i.e. paved floor, grass, ascending and descending stairs and slope. We specifically aimed to compare between the internal stresses in the TTA residuum of amputees ambulating with a novel hydraulic prosthetic foot compared to conventional energy storage and return (ESR) prosthetic feet. Monitoring of internal stresses was accomplished using a portable subject-specific real-time internal stress monitor. We found significant decrease (p<0.01) in peak internal stresses and in the loading rate of the amputated limb, while walking with the hydraulic foot, compared to walking with ESR feet. The loading rate calculated while ambulating with the hydraulic foot was at least three times lower than the loading rate calculated while ambulating with the ESR foot. Although the average decrease in internal stresses was ≈ 2-fold larger when replacing single-toe ESR feet with the hydraulic foot than when replacing split-toed ESR feet with the hydraulic foot, the differences were statistically insignificant. Our findings suggest that using a hydraulic prosthetic foot may protect the distal tibial end of the TTA residuum from high stresses, therefore preventing pressure-related injury and pain.

Real-time subject-specific analyses of dynamic internal tissue loads in the residual limb of transtibial amputees.

Transtibial amputation (TTA) prosthetic-users may risk the integrity of their residuum while trying to maintain everyday activities. Compression of the muscle flap between the truncated bones and the prosthetic socket may cause pressure ulcers and deep tissue injury (DTI). We hypothesize that mechanical stresses in the muscle flap are higher when walking over complex terrains than during plane gait, and so, the residuum could be at risk for DTI when walking over these terrains. Accordingly, we evaluated internal soft tissue stresses in the residuum at the vicinity of the tibia in 18 prosthetic-users (7 vascular, 11 traumatic). For this purpose, we developed a portable monitor that calculated subject-specific internal stresses in the residuum in real-time. Each subject was studied while walking on plane floor, grass, stairs and slope. We found that internal stresses were the highest while subjects descended a slope, during which internal peak and root mean square (RMS) stresses were approximately 40% and 50% greater than in plane gait, respectively. Peak and RMS stresses calculated while descending a slope were approximately 2 times higher for the sub-group of vascular subjects compared to traumatic, but were similar between the two sub-groups for other ambulation tasks. Overall, the present internal stress monitor is a practical tool for real-time evaluation of internal stresses in the residuum of TTA prosthetic-users in the clinical setting or outdoors. Pending integration of appropriate dynamic tissue injury thresholds, the device can be utilized for alerting to the danger of DTI.