Lower extremity prosthetic mobility: a comparison of 3 self-report scales

Convergent construct validity of the Brazilian version of the Houghton scale

BACKGROUND

After lower limb amputations, a decrease in gait capacity, even with prostheses, is common and persistent. Functional ability involves multiple constructs; therefore, several outcome measures, such as performance tests or self-report questionnaires, should be used to evaluate people with amputation who use prostheses.

OBJECTIVE

To analyze the convergent construct validity of the Brazilian version of the Houghton scale in a sample of lower limb prosthesis users.

METHODS

Volunteers selected were older than 18 years with any level of lower limb amputation and prosthesis use for at least 6 months. In this study, evidence of construct validity of the Houghton scale was established by the Spearman rho correlation with the Brazilian translation of the Prosthetic Limb Users Survey of Mobility and with the Physical Function (PF) and Emotional Well-being subdomains of the Medical Outcomes Study 36-Short Form Health Survey.

RESULTS

Seventy-one volunteers were recruited for the study. The sample consisted mainly of men (70.4%) with a mean age of 50 ± 12 years. The primary cause of amputation was traumatic (53.5%), and most participants (54.9%) had a transtibial amputation. The Houghton questionnaire correlated strongly with the Brazilian translation of the Prosthetic Limb Users Survey of Mobility questionnaire (rho: 0.74, p < 0.01) and weakly with the PF and Emotional Well-being of the 36-Short Form Health Survey (rho: 0.06 and rho: 0.22, respectively, p > 0.05).

CONCLUSION

This study showed evidence of convergent construct validity of the Houghton questionnaire to measure and classify functional use of lower limb prostheses, with great value to clinical practice. Additional work is needed to assess other measurement properties in different samples.

Quantitative methods used to evaluate balance, postural control, and the fear of falling in lower limb prosthesis users: A systematic review

Problems with balance, postural control, and fear of falling are highly prevalent in lower limb prosthesis users, with much research conducted to understand these issues. The variety of tools used to assess these concepts presents a challenge when interpreting research outcomes. This systematic review aimed to provide a synthesis of quantifiable methods used in the evaluation of balance, postural control, and fear of falling in lower limb prosthesis users with an amputation level at or proximal to the ankle joint. A systematic search was conducted in CINAHL, Medline, AMED, Cochrane, AgeLine, Scopus, Web of Science, Proquest, PsycINFO, PsycArticles, and PubPsych databases followed by additional manual searching via reference lists in the reviewed articles databases. Included articles used quantitative measure of balance or postural control as one of the dependent variables, lower limb prosthesis users as a sample group, and were published in a peer-reviewed journal in English. Relevant assessment questions were created by the investigators to rate the assessment methods used in the individual studies. Descriptive and summary statistics are used to synthesize the results. The search yielded (n = 187) articles assessing balance or postural control (n = 5487 persons in total) and (n = 66) articles assessing fear of falling or balance confidence (n = 7325 persons in total). The most used test to measure balance was the Berg Balance Scale and the most used test to measure fear of falling was the Activities-specific Balance Confidence scale. A large number of studies did not present if the chosen methods were valid and reliable for the lower limb prosthesis users. Among study limitations, small sample size was common.

Measuring residual limb health in persons with upper limb amputation: Modifications of the Prosthetic Evaluation Questionnaire residual limb health scale

BACKGROUND

Assessing the user perspective on residual limb health problems is particularly important for amputation care, given the relationship between residual limb health and prosthetic satisfaction. Only 1 measure, the Residual Limb Health scale of the Prosthetic Evaluation Questionnaire (PEQ) has been validated for use in lower limb amputation, but not examined in persons with upper limb amputation (ULA).

OBJECTIVES

The objective of this study was to examine the psychometric properties of a modified PEQ Residual Limb Health scale in a sample of persons with ULA.

STUDY DESIGN

The study involved a telephone survey of 392 prosthesis users with ULA, with a 40-person retest sample.

METHODS

The PEQ item response scale was modified to a Likert scale. The item set and instructions were refined in cognitive and pilot testing. Descriptive analyses characterized the prevalence of residual limb issues. Factor analyses and Rasch analyses evaluated unidimensionality, monotonicity, item fit, differential item functioning, and reliability. Test-retest reliability was assessed by an intraclass correlation coefficient.

RESULTS

Sweating and prosthesis odor were prevalent at 90.7% and 72.5%, respectively; blisters/sores (12.1%) and ingrown hairs (7.7%) were the least prevalent problems. Response categories were dichotomized for 3 items and trichotomized for 3 items to improve monotonicity. After adjusting for residual correlations, confirmatory factor analyses showed acceptable fit (comparative fit index = 0.984, Tucker-Lewis index = 0.970, and root mean square error approximation = 0.032). Person reliability was 0.65. No items had moderate-to-severe differential item functioning by age or sex. Intraclass correlation coefficient for test-retest reliability was 0.87 (95% CI, 0.76-0.93).

CONCLUSIONS

The modified scale had excellent structural validity, fair person reliability, very good test-retest reliability, and no floor or ceiling effects. The scale is recommended for use with persons with wrist disarticulation, transradial amputation, elbow disarticulation, and above-elbow amputation.

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.

Validity and Reliability of the German Version of the Locomotor Capabilities Index-5 (LCI-5)

BACKGROUND

Before foreign language questionnaires, such as patient reported outcome measures (PROMs), can be scientifically used in the national language, guideline-based translation, cultural adaptation and comprehensive verification of their validity and reliability are needed. The aim of this study was to assess the psychometric properties of the German version of the LCI-5 (LCI-5-D) on a sample of people with lower limb amputation (LLA).

METHODS

The LCI-5 was translated into German (LCI-5-D) based on the ISPOR guidelines for cross-cultural adaptation following pilot testing. The final LCI-5-D was administered to n = 52 lower limb amputees in order to determine the validity and reliability of both the total score and the subscores ("basic items" and "advanced items"). Internal consistency (Cronbach's alpha), test-retest reliability (ICC2,1), standard error of the mean (SEM), minimal detectable change (MDC), item-to-total correlation, and item-to-subscale correlation were calculated. Floor and ceiling effects were checked. For construct validity, the Rivermead Mobility Index (RMI) and timed up and go (TUG) test were correlated, and differences of defined subgroups (amputation height and prosthesis user type) were calculated.

RESULTS

On average, the score of the LCI-5-D was 40.13 ± 16.64 points. High ceiling effects were present for the subscale "basic items" (57.7% maximum score). Internal consistency showed excellent results (Cronbach's α = 0.97). A strong correlation to the RMI (r = 0.863; p < 0.001) and to the TUG (r = - 0.714; p < 0.001) demonstrated construct validity. Test-rest reliability was measured after an averaged time span of 5.3 ± 2.47 days and resulted in very high reliability [ICC (2,1) = 0.97; p < 0.001]. MDC was 7.57 points for the total score.

CONCLUSION

The LCI-5-D is a valid and reliable PROM for measuring mobility with prostheses in German-speaking lower limb amputees, which is rather suitable for people with low to moderate mobility abilities. It can be used in a German-speaking population.

Recommendations from the ISPO lower-limb COMPASS: Patient-reported and performance-based outcome measures

BACKGROUND

Outcome measures (patient-reported and performance-based) are used widely but not uniformly within the clinical setting for individuals with lower-limb absence (LLA). The need for more detailed information by funding bodies, service planners and providers, and researchers requires the systematic and routine use of outcome measures. Currently, there is no consensus on which outcome measure(s) should be used for individuals with LLA. The aim of the International Society of Prosthetics and Orthotics (ISPO) lower-limb Consensus Outcome Measures for Prosthetic and Amputation Services (COMPASS) was to produce a recommended list of outcome measures to be actively promoted for routine use within clinical practice before and after an episode of care.

METHODS

Between May and June 2021, 46 users, clinicians, researchers, managers, and policymakers working in the field of LLA and prosthetic users met virtually. Consensus participants were first asked to complete an online survey with questions based on the results from a systematic review and the outcomes from an expert panel. A modified Delphi technique was used to determine outcome measures for use in routine clinical practice. This paper discusses the ISPO lower-limb COMPASS process from which recommendations were made.

RESULTS

The ISPO lower-limb COMPASS resulted in the following 6 recommendations: (1) Amputee Mobility Predictor, Timed Up and Go, Two-Minute Walk Test, Prosthetic Evaluation Questionnaire-Residual Limb Health, Prosthetic Evaluation Questionnaire-Utility, and Trinity Amputation and Prosthesis Experience Scales-Revised, which make up the ISPO lower-limb COMPASS ; (2) Comprehensive High-Level Activity Mobility Predictor and Six-Minute Walk Test are 2 additional outcome measures recommended for higher-activity-level individuals with LLA, which make up the COMPASS+ ; (3) Patient-Specific Function Scale makes up the COMPASS Adjunct ; (4) a generic health-related quality of life outcome measure such as the European Quality of Life-5D-5L or Patient-Reported Outcomes Measurement Information System-29 item can be used to supplement the COMPASS; (5) outcome measures suited to low- and middle-income countries need to be developed with a focus on activities such as sitting cross-legged, kneeling, squatting, and other culturally important mobility-related activities; and (6) translation, validation, and open sharing of translated outcome measures included in the COMPASS, COMPASS+, and COMPASS Adjunct occurs.

CONCLUSION

The above recommendations represent the current status of knowledge on outcome measures for LLA based on research and international consensus and hence, will change over time. This work has been developed for clinicians and researchers to improve knowledge on outcome measures to guide clinical decision-making and future research initiatives.

Walking asymmetry and its relation to patient-reported and performance-based outcome measures in individuals with unilateral lower limb loss

Gait asymmetry persists for most people after lower limb amputation and is associated with slower walking speeds. However, the relationship between gait asymmetry and patient-reported function remains unclear because they are not commonly assessed together. The purpose of this study was to determine relationships between gait asymmetries in people with lower limb loss and (1) patient-reported outcomes and (2) performance-based prosthetic functional measures. This cross-sectional analysis included nine people with unilateral limb loss aged 48.2 ± 13.1 years of mixed amputation etiology. Patient-reported outcomes included the Prosthetic Evaluation Questionnaire mobility subscale and Activities-specific Balance Confidence scale. Performance outcomes included the Berg Balance Scale and the 30-second sit-to-stand test. Walking performance measures included the 2-Minute Walk Test, during which APDM Opal sensors recorded spatiotemporal gait parameters, and daily step-counts from StepWatch4 activity monitors. The study found that the most asymmetric gait symmetry ratios (prosthetic-limb divided by intact-limb) could be attributed to prosthetic foot dorsiflexion-plantarflexion and rotation motion limitations: prosthetic-limb trailing double support (0.789 ± 0.052), toe-off (0.760 ± 0.068) and toe-out angle (0.653 ± 0.256). Single limb stance, and stance and swing phase durations were most strongly associated with balance and walking performance measures. Notably, no symmetry ratio was significantly associated with patient-reported prosthetic function (unadjusted Pearson correlation coefficients r < 0.50, P > 0.05). More gait symmetry was associated with better balance and walking performance but had no significant relationship with patient-reported function. Although achieving gait symmetry after lower limb loss is a common walking goal, symmetry was unrelated to the perception of functional mobility for people with lower limb loss.

Preliminary analysis of reliability and validity of the Life Space Questionnaire as a real-world mobility measure for people with lower limb loss: A technical note

People with lower-limb loss (PLL) often have reduced mobility that translates into limited community access. The Life Space Questionnaire (LSQ) measures a person's real-world mobility within their home environment and community but has not been used among PLL. This study assessed preliminary LSQ test-retest reliability and discriminant validity from subjective and objective balance and walking measures in PLL. In addition, LSQ was hypothesized to have an inverse association with overall health status. Nine subjects were analyzed with mean age 48.2 ± 13.1 years and 4.8 ± 3.9 years' time since amputation. Six had transtibial and three had transfemoral amputations due to diabetes (4), vascular disease (3), and trauma (2). The primary outcome was the LSQ, a 9-level scale quantifying the extent to which people accessed their life space including home, yard, and community. Test-retest reliability for the LSQ was moderate (intraclass coefficient = 0.61 with 90% confidence interval: 0.19-0.87). Discriminant validity from balance and walking function was demonstrated by lack of correlation between LSQ score and the Activities-specific Balance Confidence and Berg Balance Scale and the Prosthetic Evaluation Questionnaire mobility subscale and walking speed (r < 0.50, P > .05). LSQ correlated with health status assessed with the Charlson Comorbidity Index (r = -0.84, P = .005). In this sample of PLL, the LSQ demonstrated moderate test-retest reliability as a measure of real-world mobility distinct as a construct from subjective and objective balance or walking measures. People may access their communities using various levels of assistance and methods of transportation. For this sample of PLL, health status was most strongly associated with LSQ score.

Quantifying the risk of falls and injuries for amputees beyond annual fall rates-A longitudinal cohort analysis based on person-step exposure over time

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People with lower-limb loss even with community walking ability have high annual fall and injury rates.

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True fall and injury risk may be obscured if exposure to risk measured by person-steps over time is not considered.

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Risk was higher for amputees with limited walking ability per person-step exposure over time.

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Incorporating person-step exposure over time clarifies fall and injury risk level.

People with lower-limb loss (PLL) have high annual fall and injury rates. People with transtibial amputations have better walking function than those with transfemoral amputations but paradoxically incur more fall-related injuries. Risk exposure, however, has not been previously considered. This study examined whether all-cause fall and injury incidence per person-step exposure over time varied in PLL of different walking abilities. The prospective cohort design, conducted at a major medical center, included five assessments 1-month apart. Walking ability level was categorized by Houghton Scale scores: ≥9 indicating community walking and ≤ 8 indicating limited community-household walking. Accelerometer-measured daily step counts were collected via StepWatch4 monitors. The main outcome measures, self-reported all-cause falls and injuries were assessed using the standard National Health Injury Survey. Generalized estimating equations, using Poisson distributions and log of step count as an offset, determined fall and injury incidence rate ratio [IRR] according to walking ability level. Ten people, aged 33–63 years with amputations of different causes and levels, were assessed monthly over five months. The community walking group (n = 6) had six falls and seven injuries; the limited community walking group (n = 4) had four falls and three injuries. For PLL, limited community walking ability was associated with higher incidence of falls (IRR = 6.10, 95%CI = 1.12–33.33, p = 0.037) and injuries (IRR = 8.56, 95%CI = 1.73–42.40, p = 0.009) when accounting for person-steps. Considering per person-step exposure over time added precision to fall and injury risk assessment that clarified the risks: PLL with limited community walking ability have higher fall and injury risks.

Time Since Lower-Limb Amputation: An Important Consideration in Mobility Outcomes

OBJECTIVE

The aim of this study was to evaluate associations between time since amputation (TSAmp) and mobility outcomes of adults with lower-limb amputation.

DESIGN

A secondary analysis of a cross-sectional dataset, including 109 community-dwelling adults, 1 yr or more after unilateral transfemoral (n = 39; mean age, 54 ± 15 yrs) or transtibial (n = 70; mean age = 58 ± 14 yrs) amputation, was conducted. Participants attended standardized clinical evaluations and completed mobility-related outcome measures: Prosthesis Evaluation Questionnaire-Mobility Subscale, timed up and go, 10-m walk test, and 6-min walk test.

RESULTS

After controlling for age, sex, amputation level, and etiology, TSAmp was significantly associated with each mobility outcome. Prosthesis Evaluation Questionnaire-Mobility Subscale and TSAmp were linearly associated, with TSAmp explaining 10.6% of the overall variance. Timed up and go test time and TSAmp were linearly associated, with TSAmp and an interaction term (LevelxTSAmp) explaining 8.4% of the overall variance; 10-m walk test speed and 6-min walk test distance had nonlinear associations with TSAmp, with TSAmp and nonlinear terms (TSAmp2) explaining 12.1% and 13.2% of the overall variance, respectively.

CONCLUSIONS

Based on the findings, longer TSAmp may be associated with better Prosthesis Evaluation Questionnaire-Mobility Subscale score and timed up and go test time, whereas longer TSAmp may be associated with better or worse 10-m walk test speed and 6-min walk test distance depending upon time elapsed since lower-limb amputation. Estimations of postamputation mobility among adults with lower-limb amputation should consider TSAmp.

Do chronic pain syndromes in lower limb amputees have an effect on the use of prostheses?

BACKGROUND

The use of a prosthesis is critical to regain the ability to walk in lower limb amputees but the relationship between the use of a prosthesis and chronic pain syndromes (PLS, PLP, RLP), common in amputees patients, is still poorly understood.

OBJECTIVE

This long-term follow-up study investigates the possible correlation between prosthesis use and the presence of PLP, PLS and RLP in lower limb amputees.

METHODS

Patients undergoing transtibial, transfemoral or hemipelvectomy amputation of any aetiology at the Rizzoli Orthopaedic Institute from 2008 to 2018 were included. The Houghton scale was used to assess functional use of the prosthesis.

RESULTS

The results show that, in lower limb amputees, prosthesis use is greater in individuals with below-the-knee amputation and in those who were younger at the time of amputation. No significant correlation between the presence of pain syndromes (PLS, PLP, RLP) and the various items on the Houghton scale was found.

CONCLUSIONS

The study found no significant correlation indicating that phantom limb pain syndromes affect amputee use of a prosthesis.

Validade de construto do teste de caminhada de 2 minutos para pacientes com amputação de membro inferior protetizados

RESUMO Aliados da avaliação funcional, os testes de caminhada têm sido considerados confiáveis e válidos para várias populações, quantificando a capacidade funcional do indivíduo e respondendo a mudanças durante o processo de reabilitação. O objetivo deste artigo foi analisar a validade de construto do teste de caminhada de 2 minutos para pacientes com amputação de membro inferior protetizados, submetidos à reabilitação. Foi aplicado o teste de caminhada de 2 minutos em 51 pacientes maiores de 18 anos com diagnóstico clínico de amputação de membro inferior em qualquer nível e que tivessem sido submetidos à reabilitação há pelo menos seis meses no momento da avaliação, que foi correlacionada com os questionários Medida Funcional para Amputados (MFA) e os aspectos do Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), a fim de obter o coeficiente de correlação de Pearson com o nível de significância de p<0,05. Entre os participantes do estudo, 64,7% eram do sexo masculino, com média de idade de 53,4 anos; 59,92% tinham amputação de nível transtibial e a principal causa foi trauma, com 54,9%. O escore médio para os questionários foi de 63,58 pontos para a capacidade física do SF-36, e 37,14 pontos para a segunda questão do MFA. A correlação da distância percorrida no teste de caminhada de 2 minutos mostrou moderada correlação com a capacidade física do SF-36 e com a segunda questão do MFA. Os achados mostram moderada correlação entre o teste de caminhada de 2 minutos e as ferramentas subjetivas de avaliação de função utilizadas, mostrando que é um instrumento válido como medida objetiva para a população estudada.

A new valid Walking Aid Scale better predicts distance walked by prosthesis users than Prosthetic Mobility Questionnaire 2.0 and Activities-Specific Balance Confidence Scale

The availability of psychometrically-sound and parsimonious outcome measures is key for optimizing decision-making about prosthetic fitting and rehabilitation in lower limb prosthesis users. Despite the increasing clinical use of observational and self-reported scales for assessing mobility and balance, there is currently no scale that accounts for the use of assistive devices while walking under conditions of increasing difficulty. Therefore, the purpose of this study was to develop and validate a Walking Aid Scale (WAS) in a cross-sectional sample of 144 prosthesis users. Specifically, we examined internal consistency and concurrent validity of WAS against two commonly used self-report measures of prosthetic mobility and balance confidence - the Prosthetic Mobility Questionnaire 2.0 (PMQ 2.0) and Activities-Specific Balance Confidence Scale (ABC-5). The predictive value of WAS, in comparison to PMQ 2.0 and ABC-5, was assessed using a 6-Minute Walk Test (6MWT) and participants' characteristics. The WAS showed significant moderate-to-good correlations with PMQ 2.0 and ABC-5, and all scales correlated well with age and 6MWT. Participants who relied less on walking aids reported higher mobility levels, greater balance confidence, and walked longer distances. Age was associated with greater use of walking aids and lower mobility and balance confidence. In the stepwise linear regression analysis, age, amputation level, time since amputation, and WAS predicted about two-thirds of the variability in 6MWT with no significant contribution of PMQ 2.0 and ABC-5. These findings indicate that WAS is a valid instrument and a better predictor of walking distance than PMQ 2.0 and ABC-5 in the lower limb prosthesis users.

[Correlation among tests and functional assessment scales in the follow-up of prosthetic adaptation in people with lower limb amputation]

INTRODUCTION

There is a wide variety of functional tests and scales for the assessment of different aspects in the adaptation of amputees, but there is still no consensus on which are the most appropriate.

OBJECTIVES

To describe the measures of correlation and association among three functional tests for lower-limb amputees and to define the most appropriate for this assessment. To assess general satisfaction in lower-limb prostheses users and its association with the functional tests.

METHODS

We included 83 unilateral lower-limb amputees who were users of low-cost exoskeletal prostheses. The instruments employed were the Houghton scale, the Prosthesis Evaluation Questionnaire - Mobility Scale (PEQ-MS) and the 2-minute walk test (2MWT). The statistical analysis was performed using the chi-square test and Spearman's correlation coefficient.

RESULTS

The functional tests evaluated had an acceptable correlation and association with each other, but the Spearman correlation between the Houghton scale and the 2MWT was of greater significance (whole sample: r=0.56; below-knee amputees: r=0.53). The association measures did not achieve statistically significant results for above-knee amputees or for general satisfaction.

CONCLUSIONS

The Houghton Scale and the 2MWT showed a good correlation and association with each other, becoming possible first-line instruments for the follow-up of exoskeletal lower limb prosthesis users. No significant association was identified between satisfaction and the instruments measured.

Psychometric Assessment of the Connor-Davidson Resilience Scale for People With Lower-Limb Amputation

OBJECTIVE

The purpose of this study was to (1) determine the psychometric properties of the 25- and 10-item Connor-Davidson Resilience Scales (CD-RISC25, CD-RISC10) for people with lower-limb amputation (LLA) in middle age or later, and (2) describe relationships of the CD-RISC with biopsychosocial, sociodemographic, and health variables.

METHODS

Participants were included if their most recent LLA was 1 or more years prior, if they were independently walking with a prosthesis, and if they were between 45 and 88 years of age (N = 122; mean = 62.5 years of age [SD = 8]; 59.5 [mean = 58] months since LLA; 88.5% male; 82.0% with dysvascular etiology; 68.0% with unilateral transtibial LLA). Psychometric analyses included assessment of skewness, floor and ceiling effects, internal consistency, and agreement between versions. Correlation analyses were used to determine associations between the CD-RISC with disability, perceived functional capacity, falls efficacy, life-space, anxiety, depression, self-efficacy, social support, sociodemographic, and health variables. Additionally, quartiles of participants were identified using CD-RISC25 and CD-RISC10 scores and compared using ANOVA and post-hoc comparisons for disability, perceived functional capacity, falls efficacy, and life-space.

RESULTS

Skewness, floor, and ceiling effects of both CD-RISC versions were acceptable. Both versions of the CD-RISC were internally consistent (CD-RISC25: α = .92; CD-RISC10: α = .89). The CD-RISC25 and CD-RISC10 were highly correlated with disability, perceived functional capacity, falls efficacy, anxiety, depression, and self-efficacy (r = 0.52-0.67). CD-RISC25 and CD-RISC10 quartile differences, especially the lowest quartile, were identified for disability, perceived functional capacity, falls efficacy, and life-space.

CONCLUSION

The CD-RISC25 and CD-RISC10 have acceptable psychometric properties for use with people who have LLA. CD-RISC scores are associated with clinically relevant biopsychosocial measures targeted by physical therapist intervention following LLA.

IMPACT

The CD-RISC may be an appropriate tool to measure resilience following LLA.

Focusing research efforts on the unique needs of women prosthesis users

Introduction

Women with lower limb loss represent a relevant and growing patient cohort with unique rehabilitation needs. These needs are emphasized in a growing body of literature and the most recent Veteran Affairs/Department of Defense clinical practice guidelines.

Prosthetics Challenges

Women with limb loss experience greater dissatisfaction with prosthetic fit, appearance, and types of footwear they can use. There is a lack of prosthetics solutions to accommodate the desire of women to wear different footwear varieties, including high heels. The choice to wear a variety of footwear is important to attire and hence community participation. Despite these recognized challenges, women are still underserved in prosthetics research, which limits available information to guide the rehabilitation process.

Research Initiatives

This narrative review describes considerations of lower limb prosthesis prescription and use by women, and examples of current research to address these topics. Research efforts are beginning to explore factors that contribute to prosthetics prescription for women, and design creative prosthetics solutions to expand the range of available footwear options. Research is still needed to characterize the types of footwear women with limb loss prefer to use, and the effects of prosthesis designs, footwear, and lower limb loss on women mobility outcomes and community participation.

Conclusions

Through targeted research initiatives, scientists and clinicians can be responsive to the specific needs of women to provide evidence-based guidelines for prosthetics prescription and improve the patient-centered care after limb loss.

A Semi-Powered Ankle Prosthesis and Unified Controller for Level and Sloped Walking

This paper describes a semi-powered ankle prosthesis and corresponding unified controller that provides biomimetic behavior for level and sloped walking without requiring identification of ground slope or modulation of control parameters. The controller is based on the observation that healthy individuals maintain an invariant external quasi-stiffness (spring like behavior between the shank and ground) when walking on level and sloped terrain. Emulating an invariant external quasi-stiffness requires an ankle that can vary the set-point (i.e., equilibrium angle) of the ankle stiffness. A semi-powered ankle prosthesis that incorporates a novel constant-volume power-asymmetric actuator was developed to provide this behavior, and the unified controller was implemented on it. The device and unified controller were assessed on three subjects with transtibial amputations while walking on inclines, level ground, and declines. Experimental results suggest that the prosthesis and accompanying controller can provide a consistent external quasi-stiffness similar to healthy subjects across all tested ground slopes.

Patient Reported Outcome Measures for Major Lower Limb Amputation Caused by Peripheral Artery Disease or Diabetes: A Systematic Review

OBJECTIVE

Most major lower limb amputations are related to peripheral artery disease (PAD) or diabetes. Just 40% of patients who undergo major lower limb amputation will use a prosthesis yet measures of surgical success commonly focus on prosthesis use. Patient reported outcome measures (PROMs) are valuable to comprehensively evaluate health related quality of life (HRQL) after surgery. This systematic review aimed to identify and describe PROMs available to assess HRQL in patients after amputation for PAD or diabetes.

METHODS

A search was conducted based on the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) for systematic reviews of PROMs. Ovid MEDLINE, Ovid EMBASE, PsycINFO, CINAHL, and Cochrane CENTRAL were also searched from inception until August 2019. Included were articles describing the development, measurement properties, or evaluation of HRQL via a PROM in adult patients after amputation for PAD or diabetes. Studies of amputation exclusively for trauma or malignancy were excluded. Data were collected on study characteristics, PROM characteristics (generic/disease specific), and properties of amputation specific PROMs.

RESULTS

Of 3 317 abstracts screened, 111 full text articles were assessed for eligibility and 64 included. Fifty-six studies evaluated HRQL, with 23 (46%) of these using an amputation specific PROM to do so. Eleven different amputation specific PROMs were identified, 10 (91%) of which were developed only for prosthesis users. One measure was suitable for use in all patients after amputation. This "Amputee single item mobility measure" includes a single item evaluating mobility. Nine studies reported some psychometric testing of an amputation specific PROM.

CONCLUSION

A well tested, multidimensional PROM applicable to wheelchair and prosthetic users after amputation is lacking and urgently needed for studies in this field. Future work to develop an appropriate measure is required.

Patterns of Sitting, Standing, and Stepping After Lower Limb Amputation

OBJECTIVE

The objectives of this study were to describe sitting, standing, and stepping patterns for people with lower limb amputation (LLA) and to compare sitting, standing, and stepping between people with dysvascular LLA and people with traumatic LLA.

METHODS

Participants with dysvascular or traumatic LLA were included if their most recent LLA was at least 1 year earlier, they were ambulating independently with a prosthesis, and they were between 45 and 88 years old. Sitting, standing, and stepping were measured using accelerometry. Daily sitting, standing, and stepping times were expressed as percentages of waking time. Time spent in bouts of specified durations of sitting (<30, 30-60, 60-90, and >90 minutes), standing (0-1, 1-5, and >5 minutes), and stepping (0-1, 1-5, and >5 minutes) was also calculated.

RESULTS

Participants (N = 32; mean age = 62.6 [SD = 7.8] years; 84% men; 53% with dysvascular LLA) spent most of the day sitting (median = 77% [quartile 1 {Q1}-quartile 3 {Q3} = 67%-84%]), followed by standing (median = 16% [Q1-Q3 = 12%-27%]) and stepping (median = 6% [Q1-Q3 = 4%-9%]). One-quarter (median = 25% [Q1-Q3 = 16%-38%]) of sitting was accumulated in bouts of >90 minutes, and most standing and stepping was accrued in bouts of <1 minute (standing: median = 42% [Q1-Q3 = 34%-54%]; stepping: median = 98% [Q1-Q3 = 95%-99%]). Between-etiology differences included proportion of time sitting (traumatic: median = 70% [Q1-Q3 = 59%-78%]; dysvascular: median = 79% [Q1-Q3 = 73%-86%]) and standing (traumatic: median = 23% [Q1-Q3 = 16%-32%]; dysvascular: median = 15% [Q1-Q3 = 11%-20%]).

CONCLUSION

Participants had high daily volumes of long durations of sitting. Further, these individuals accumulated most physical activity in bouts of <1 minute.

IMPACT

High levels of sedentary behavior and physical inactivity patterns may place people with LLA at greater mortality risk relative to the general population. Interventions to minimize sedentary behaviors and increase physical activity are potential strategies for improving poor outcomes of physical therapy after LLA.

Maximal Walking Distance in Persons with a Lower Limb Amputation

The distance one can walk at a time could be considered an important functional outcome in people with a lower limb amputation. In clinical practice, walking distance in daily life is based on self-report (SIGAM mobility grade (Special Interest Group in Amputee Medicine)), which is known to overestimate physical activity. The aim of this study was to assess the number of consecutive steps and walking bouts in persons with a lower limb amputation, using an accelerometer sensor. The number of consecutive steps was related to their SIGAM mobility grade and to the consecutive steps of age-matched controls in daily life. Twenty subjects with a lower limb amputation and ten age-matched controls participated in the experiment for two consecutive days, in their own environment. Maximal number of consecutive steps and walking bouts were obtained by two accelerometers in the left and right trouser pocket, and one accelerometer on the sternum. In addition, the SIGAM mobility grade was determined and the 10 m walking test (10 MWT) was performed. The maximal number of consecutive steps and walking bouts were significantly smaller in persons with a lower limb amputation, compared to the control group (p < 0.001). Only 4 of the 20 persons with a lower limb amputation had a maximal number of consecutive steps in the range of the control group. Although the maximal covered distance was moderately correlated with the SIGAM mobility grade in participants with an amputation (r = 0.61), for 6 of them, the SIGAM mobility grade did not match with the maximal covered distance. The current study indicated that mobility was highly affected in most persons with an amputation and that the SIGAM mobility grade did not reflect what persons with a lower limb amputation actually do in daily life. Therefore, objective assessment of the maximal number of consecutive steps of maximal covered distance is recommended for clinical treatment.

Self-Efficacy and Social Support are Associated with Disability for Ambulatory Prosthesis Users After Lower-Limb Amputation

BACKGROUND

Interventions targeting psychosocial factors may improve rehabilitation outcomes for prosthesis users after lower-limb amputation (LLA), but there is a need to identify targeted factors for minimizing disability.

OBJECTIVE

To identify psychosocial factors related to disability for prosthesis users after LLA in middle age or later.

DESIGN

Cross-sectional study.

SETTING

General community.

PARTICIPANTS

Participants with LLA (N = 122) were included in this cross-sectional study if their most recent LLA was at least 1 year prior, they were ambulating independently with a prosthesis, and they were between 45 and 88 years old.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Disability, the primary outcome, was measured using the World Health Organization Disability Assessment Schedule 2.0 (WHODAS). Candidate psychosocial variables included self-efficacy, social support, and motivation, measured using the Self-Efficacy of Managing Chronic Disease questionnaire (SEMCD), Multidimensional Scale of Perceived Social Support questionnaire (MSPSS), and modified contemplation ladder (mCL), respectively. The hypothesis was that greater self-efficacy, social support, and motivation would be associated with lower disability when controlling for covariates.

RESULTS

The covariate model, including etiology, age, sex, U.S. military veteran status, LLA characteristics, time since LLA, medical complexity, and perceived functional capacity, explained 66.1% of disability variability (WHODAS 2.0). Backward elimination of candidate psychosocial variables stopped after removal of motivation (P = .10), with self-efficacy (P < .001) and social support (P = .002) variables remaining in the final model. The final model fit was statistically improved (P < .001) and explained an additional 6.1% of disability variability when compared to the covariate model.

CONCLUSIONS

Greater self-efficacy and social support are related to lower disability after LLA. Findings suggest there may be a role for interventions targeting increased physical function, self-efficacy, and social support for ambulatory prosthesis users after LLA in middle age or later, especially when complicated by multiple chronic conditions.

Effects of microprocessor-controlled prosthetic knees on self-reported mobility, quality of life, and psychological states in patients with transfemoral amputations

OBJECTIVE

This study aimed to determine the effects of the microprocessor-controlled prosthetic knee (MPK) joint on self-mobility, body perceptions, depression, and quality of life in patients with unilateral transfemoral amputations (TFAs).

METHODS

Thirty consecutive patients (28 males, mean age=38.5 years, age range=22-57) who had previously used non-MPKs and who were approved to use swing and stance phase-control MPKs were included in this 12-week clinical study. Before the MPK use and after the three-month follow-up, prosthetic use and locomotor capabilities were evaluated using the Houghton Scale and the Locomotor Capabilities Index (LCI-5), respectively. Body perception was assessed using the Amputee Body Image Scale (ABIS). The depressive symptoms and quality of life were evaluated using the Beck Depression Inventory (BDI) score and the 36-Item Short- Form Health Survey (SF-36), respectively.

RESULTS

After MPK use, statistically significant ameliorations were observed in all outcome measures. The basic and advanced LCI-5 increased from 26.7±2.2 and 24.8±5.2 to 27.6±1.2 (p=0.007) and 27±2.1 (p=0.004), respectively. Houghton scores improved from 9±1 to 10.3±0.8 (p=0.000). The ABIS and BDI scores decreased from 43.2±10.9 and 5.7±6.6 to 37.1±8.9 (p=0.000) and 3.8±4.5 (p=0.015), respectively. Also, the SF-36 physical function and vitality subscales increased from 71.2±24.0 and 75.5±14.6 to 85.6±16.6 (p=0.001) and 81.7±14.1 (p=0.015), respectively.

CONCLUSION

MPK use provides significant improvements in the locomotor capabilities, quality of life, and activities of daily living to patients with TFAs as well as improves their body image perceptions and depressive symptoms.

LEVEL OF EVIDENCE

Level III, Self controlled study.

Syme Amputation: Function, Satisfaction, and Prostheses

BACKGROUND

Syme amputation (SA) is a term used to describe an amputation at the level of the ankle joint in which the heel pad is preserved. It is performed for a number of indications in a pediatric population. SA is purported to hold the advantage of allowing weight bearing without a prosthesis. A limb length discrepancy (LLD) is useful for ambulation without a prosthesis but can be restrictive with regards to the fitting of modern prostheses.

METHODS

A voluntary survey was distributed to persons living with SA. Recruitment occurred through hospital electronic database and electronic advertising. Data collected included baseline demographic information, data pertaining to weight bearing in different environments, as well as 2 validated outcome measures: the Trinity Amputation and Prosthesis Experience Scales-Revised (TAPES-R activity restriction scale) and the Locomotor Capabilities Index-5 (LCI-5). An illustration was designed to allow participants to classify their LLD by zone in relation to their nonamputated limb.

RESULTS

At total of 47 persons living with SA participated. The average age at amputation was 3.7 years (range, 0.5 to 14.1 y), and at survey completion 15.8 years (1.7 to 60.3). Five of the described "zones" of LLD were represented. Average LCI-5 score was 52.6. Mean TAPES-R activity restriction scale was 0.59, the lowest mean being achieved by zone E participants, indicating the least restriction. Ability to walk without a prosthesis was lower in those participants over 11 years, when compared with those under, as well as being dependent on the walking environment.

CONCLUSIONS

Our study found no trend indicating that a very low LLD was functionally optimal, and indeed found participants with a moderate LLD (zone E) to have the least mean restriction with regard to their prosthesis. Our study demonstrates that ambulation without a prosthesis depends on the environment (ie, flooring), and rates decrease significantly into adulthood. Optimal care should not focus simply "preserving length," but rather functional optimization and length modulation in parallel with a nuanced understanding of actual daily activities and prosthetic options.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Cell Phone Application to Monitor Pain and Quality of Life in Neurogenic Pain Patients

Supplemental Digital Content is available in the text.

Management of postoperative pain is a challenge for healthcare providers in all surgical fields, especially in the context of the current opioid epidemic. We developed a cell phone application to monitor pain, medication use, and relevant quality of life domains (eg, mood, mobility, return to work, and sleep) in patients with neurogenic pain, including those with limb loss. A literature review was conducted to define application length and design parameters. The final application includes 12 questions for patients with limb loss and 8 for patients with neurogenic pain without limb loss. Pilot testing with 21 participants demonstrates acceptable time to complete the application (mean = 158 seconds, SD = 81 seconds) and usability, based on the mHealth App Usability Questionnaire. We aim for our application to serve as an outcome measure for evaluation of an evolving group of peripheral nerve procedures, including targeted muscle reinnervation. In addition, the application could be adapted for clinical use in patients undergoing these procedures for neurogenic pain and thus serve as a tool to monitor and manage pain medication use.

Design of a Semi-Powered Stance-Control Swing-Assist Transfemoral Prosthesis

This paper describes the design of a new type of knee prosthesis called a stance-control, swing-assist (SCSA) knee prosthesis. The device is motivated by the recognition that energetically-passive stance-controlled microprocessor-controlled knees (SCMPKs) offer many desirable characteristics, such as quiet operation, low weight, high-impedance stance support, and an inertially-driven swing-phase motion. Due to the latter, however, SCMPKs are also highly susceptible to swing-phase perturbations, which can increase the likelihood of falling. The SCSA prosthesis supplements the behavior of an SCMPK with a small motor that maintains the low output impedance of the SCMPK swing state, while adding a supplemental closed-loop controller around it. This paper elaborates upon the motivation for the SCSA prosthesis, describes the design of a prosthesis prototype, and provides human-subject testing data that demonstrates potential device benefits relative to an SCMPK during both non-perturbed and perturbed walking.

Relevance of medical comorbidities for functional mobility in people with limb loss: retrospective explanatory models for a clinical walking measure and a patient-reported functional outcome

OBJECTIVES

Various modifiable and non-modifiable factors affect functional mobility, but subjective patient-reported and objective performance-based measures are rarely combined in explanatory analyses of functional mobility in people with limb loss. This study determined separate explanatory models for patient-reported function using the Prosthetic Evaluation Questionnaire Mobility Subscale (PEQ-MS), and performance-based 2-Minute Walk Test (2MWT).

DESIGN

Retrospective cross-sectional observational analysis.

SETTING

Wellness-walking program.

PARTICIPANTS

Three hundred five volunteers with lower limb loss participated. Sixty nine percent were men, mean age 56 (15) years. Fifty two percent had vascular amputation causes, 42% had surgical levels above the knee, and 82% had medical comorbidities. Walking levels included limited-household (21%), limited-community (30%), and independent-community (49%). Outcome measures included patient-reported PEQ-MS, Activities-specific Balance Confidence (ABC) and Houghton scales; and performance-based balance and walking.

MAIN OUTCOMES

Separate PEQ-MS and 2MWT multiple regression models fit using backward deletion.

RESULTS

Modifiable (balance ability, ABC, Houghton score; P<0.05) and non-modifiable factors (sex, amputation cause, surgical level; P<0.05) explained the variance in 2MWT (adjusted R²=0.685). Patient-reported and performance-based modifiable factors (Houghton score, 2MWT; P<0.001) explained PEQ-MS variance (adjusted R²=0.660). Integumentary (P=0.022) and cardiopulmonary (P<0.001) comorbidities explained an additional 4% of PEQ-MS variance, while surgical level was insignificant.

CONCLUSIONS

Both modifiable and non-modifiable factors explained prosthetic functional mobility. Performance-based walking was explained by modifiable factors including balance ability and confidence, prosthesis and walking aid use. Patient-reported function was also explained by prosthesis and walking aid use, walking speed and medical comorbidities. Modifiable factors for objective and subjective prosthetic mobility may provide a clinical roadmap for rehabilitation.

Self-aligning prosthetic device for older patients with vascular-related amputations: protocol for a randomised feasibility study (the STEPFORWARD study)

INTRODUCTION

The majority of older patients with a transtibial amputation are prescribed a standard (more rigid, not self-aligning) prosthesis. These are mostly suitable for level walking, and cannot adjust to different sloped surfaces. This makes walking more difficult and less energy efficient, possibly leading to longer term disuse. A Cochrane Review concluded that there was insufficient evidence to recommend any individual type of prosthetic ankle-foot mechanism. This trial will establish the feasibility of conducting a large-scale trial to assess the effectiveness and cost-effectiveness of a self-aligning prosthesis for older patients with vascular-related amputations and other health issues compared with a standard prosthesis.

METHODS AND ANALYSIS

This feasibility trial is a pragmatic, parallel group, randomised controlled trial (RCT) comparing standard treatment with a more rigid prosthesis versus a self-aligning prosthesis. The target sample size is 90 patients, who are aged 50 years and over, and have a transtibial amputation, where amputation aetiology is mostly vascular-related or non-traumatic. Feasibility will be measured by consent and retention rates, a plausible future sample size over a 24-month recruitment period and completeness of outcome measures. Qualitative interviews will be carried out with trial participants to explore issues around study processes and acceptability of the intervention. Focus groups with staff at prosthetics centres will explore barriers to successful delivery of the trial. Findings from the qualitative work will be integrated with the feasibility trial outcomes in order to inform the design of a full-scale RCT.

ETHICS AND DISSEMINATION

Ethical approval was granted by Yorkshire and the Humber-Leeds West Research Ethics Committee on 4 May 2018. The findings will be disseminated via peer-reviewed research publications, articles in relevant newsletters, presentations at relevant conferences and the patient advisory group.

TRIAL REGISTRATION NUMBER

ISRCTN15043643.

The minimal clinically-important difference of the Prosthesis Evaluation Questionnaire - Mobility Scale in subjects undergoing lower limb prosthetic rehabilitation training

BACKGROUND

There is increasing interest in psychometrically sound outcome measures of mobility for people with lower limb amputation (LLA), in order to accurately monitor the impact of the prosthetic training during and after rehabilitation.

AIM

To determine the minimum detectable change (MDC) and minimal clinically important difference (MCID) for the Prosthesis Evaluation Questionnaire-Mobility Scale (PEQ-MS) in people with LLA.

DESIGN

Prospective single-group observational study.

SETTING

Two free-standing Rehabilitation Hospitals.

POPULATION

Eighty-seven adult inpatients with LLA undergoing prosthetic rehabilitation.

METHODS

Patients completed the self-report PEQ-MS twice, immediately before and after prosthetic rehabilitation training. We administered a 7-point Global Rating of Change scale at the end of training as external anchor, to quantify the effect (improvement/deterioration) of the intervention.

RESULTS

Test-retest reliability of the PEQ-MS (N.=24) was high (ICC2,1=0.90). The MDC at the 95% confidence level was 5.5 points. This value, together with those of the mean-change approach and receiver-operating characteristic-curve analysis (AUC>0.89), suggested the selection of a MCID for PEQ-MS of eight points of change, i.e. 16.7% of the maximum possible score (95% CI: 6.5-9.5).

CONCLUSIONS

The PEQ-MS showed a high ability to detect change over time (responsiveness).The above MCID value - derived from a triangulation of distribution (MDC) and anchor-based methods - represents a minimal level of change (perceived as important by the patient) in mobility of people with LLA undergoing prosthetic rehabilitation training.

CLINICAL REHABILITATION IMPACT

The PEQ-MS is a widely used and analyzed outcome measure. The present study calculated - in a sample of people with LLA undergoing prosthetic training - both the MDC and MCID of the PEQ-MS, showing the high responsiveness of this tool. These values increase confidence in interpreting change in PEQ-MS values, and can help in clinical decision making.

Physical Function and Pre-Amputation Characteristics Explain Daily Step Count after Dysvascular Amputation

BACKGROUND

People with dysvascular lower limb amputation (LLA) achieve one-third of the recommended steps per day and experience severe disability. Although physical function improves with rehabilitation after dysvascular LLA, physical activity remains largely unchanged, and factors contributing to limited daily step count are unknown.

OBJECTIVES

To identify factors that contribute to daily step count after dysvascular LLA.

DESIGN

Cross-sectional, secondary data analysis.

SETTING

Outpatient rehabilitation facilities.

PARTICIPANTS

Fifty-eight patients with dysvascular major LLA (age: 64 ± 9 years, body mass index: 30 ± 8 kg/m² , male: 95%, transtibial LLA: 95%).

METHODS

Data were collected by a blinded assessor after dysvascular LLA. Candidate explanatory variables included (1) demographics, (2) LLA characteristics, (3) comorbidities and health behaviors, and (4) physical function. Variables with univariate associations with log steps/day (transformed due to non-normality) were included in a multiple linear regression model using backward elimination to identify factors that explained significant variability in log steps/day.

PRIMARY OUTCOME MEASURE

The primary outcome, daily step count, was measured with accelerometer-based activity monitors worn by participants for 10 days.

RESULTS

Participants took an average (± SD) of 1450 ± 1309 steps/day. After backward elimination, the final model included four variables explaining 62% of the overall daily step count (P < .0001): 2-minute walk distance (32%), assistive device use (11%), cardiovascular disease (10%), and pre-amputation walking time (11%).

CONCLUSIONS

Average daily step count of 1450 steps/day reflects the lowest category of sedentary behavior. Physical function, cardiovascular disease, and pre-amputation walking time explain 62% of daily step count after dysvascular LLA. Although physical rehabilitation commonly focuses on improving physical function, interventions to increase daily step count after dysvascular LLA should also consider chronic disease and health behaviors that predate LLA.

LEVEL OF EVIDENCE

III.

Psychometric Properties of Functional, Ambulatory, and Quality of Life Instruments in Lower Limb Amputees: A Systematic Review

OBJECTIVE

Summarize the psychometric properties of functional, ambulatory, and quality of life instruments among adult lower limb amputees, highlighting evidence deemed generalizable to the United States Medicare population.

DATA SOURCES

Six databases and existing systematic reviews through October 30, 2017. Searches included terms for lower limb amputation or prostheses and outcome measures in humans, without language restriction.

STUDY SELECTION

We included peer-reviewed studies of at least 20 adults (≥18 years) with lower limb amputation. Eligible studies reported on psychometric properties of functional, ambulatory, or quality of life instruments. Fifty-three of 425 retrieved articles (12%) met criteria.

DATA EXTRACTION

Study characteristics and psychometric property data (validity, reliability, responsiveness, minimum detectable change, minimal important difference, or floor or ceiling effect) were extracted into a customized form based on standardized criteria. All extracted data were confirmed by 2 experts in systematic review and rehabilitation outcome measurement. Instruments were categorized regarding having been validated and found reliable. Other reported psychometric properties were recorded. Studies were also assessed for applicability to the Medicare population based on age and amputation etiology (dysvascular).

DATA SYNTHESIS

Fifty-six studies (in 53 articles) reported psychometric properties of 50 instruments. There is evidence for both validity and reliability for 30 instruments, 17 of which have evidence that was deemed generalizable to the Medicare population. Most of the remaining instruments have evidence of either validity or reliability, but not both. Twelve instruments have been assessed specifically among lower limb amputees prior to prosthesis prescription. Thirteen instruments have been assessed regarding their predictive properties for future outcomes.

CONCLUSIONS

Numerous instruments assessing ambulation, function, quality of life, and other patient-centered outcomes have evidence of validity and reliability for adults with lower limb amputations. Researchers and clinicians should use validated, reliable instruments when feasible. Many existing and new instruments require validation for use with lower limb amputees.

Factors associated with committed participation in a wellness-walking program for people with lower limb loss: A prospective cohort study

BACKGROUND:

Wellness activities can benefit health, yet committed adherence is challenging.

OBJECTIVES:

Identify factors associated with committed participation in an amputee wellness-walking program and determine benefits of committed participation.

STUDY DESIGN:

Prospective longitudinal cohort.

METHODS:

Two former Paralympians led the wellness-walking sessions. Participants provided medical history and self-reported balance confidence and prosthetic functional measures. Physiotherapy professionals/paraprofessionals assessed balance and gait. Committed participants-those attending three sessions within 3 years-were compared to one-time-only participants using Fisher's exact and independent t-tests. First and third sessions for committed participants were compared with t-tests. A bootstrapped multivariable logistic regression model was developed using significant univariate predictors.

RESULTS:

A total of 305 volunteers averaged 55.7 ± 15.2 years, including 68.4% men, 78.4% White race; 51.8% with dysvascular amputations, 40.5% with ⩾1 prosthetic knee; and 49.1% independent community walkers. Committed participants were initially similar to one-time-only participants ( p > 0.05) except for fewer years since amputation ( p = 0.007), better balance ability ( p = 0.001), and greater likelihood of dieting ( p = 0.030). The final model-balance ability (odds ratio = 2.4), dieting (odds ratio = 3.3), and years since amputation (odds ratio = 0.94)-identified 88.0% of committed participants ( p = 0.007). Balance confidence and functional improvements after three sessions were not significant ( p > 0.07).

CONCLUSION:

Committed participants were more likely to diet, have better balance ability, and have more recent amputations than one-time-only participants.

CLINICAL RELEVANCE

Knowing which characteristics identify people most likely to become committed participants-such as people with recent amputations, an interest in dieting, and better balance ability-may help health practitioners from different professions promote consistent participation in wellness activities that may benefit self-reported function.

Test-retest reliability of the special interest group on amputation medicine/Dutch working group on amputations and prosthetics mobility scale, in persons wearing a prosthesis after a lower-limb amputation

Purpose: To assess the test-retest reliability of the Special Interest Group on Amputation Medicine Mobility Scale/Dutch Working Group on Amputations and Prosthetics, better known as SIGAM/WAP mobility scale, in persons with a lower-limb amputation.Method: Longitudinal study at the outpatient departments of a rehabilitation center and a university medical center. Persons with a lower-limb amputation, wearing a prosthesis, were assessed at the end of their multidisciplinary rehabilitation treatment twice, with a 3-week interval, by the same practitioner. Test-retest reliability was quantified using the intraclass correlation coefficient for agreement.Results: Eighty persons participated (mean age ± SD, 61 ± 15 years; 61% men; 76% vascular cause of amputation; 70% able to walk >50m). Fifty-one of them rated themselves to be stable with respect to their mobility and their intraclass correlation coefficient was 0.90 (95% confidence intervals 0.84-0.94).Conclusions: The Special Interest Group on Amputation Medicine Mobility Scale/Dutch Working Group on Amputations and Prosthetics had, at the outpatient departments of a rehabilitation center and a university medical center, excellent test-retest reliability in persons wearing a prosthesis after a lower-limb amputation.Implications for rehabilitationThe Special Interest Group on Amputation Medicine/Dutch Working Group on Amputations and Prosthetics Mobility Scale was developed to classify mobility after a lower-limb amputation and wearing a prosthesis.The Dutch translation of this mobility scale has excellent test-retest reliability.

Predicting ambulatory energy expenditure in lower limb amputees using multi-sensor methods

Purpose

To assess the validity of a derived algorithm, combining tri-axial accelerometry and heart rate (HR) data, compared to a research-grade multi-sensor physical activity device, for the estimation of ambulatory physical activity energy expenditure (PAEE) in individuals with traumatic lower-limb amputation.

Methods

Twenty-eight participants [unilateral (n = 9), bilateral (n = 10) with lower-limb amputations, and non-injured controls (n = 9)] completed eight activities; rest, ambulating at 5 progressive treadmill velocities (0.48, 0.67, 0.89, 1.12, 1.34m.s^-1) and 2 gradients (3 and 5%) at 0.89m.s^-1. During each task, expired gases were collected for the determination of V˙O2 and subsequent calculation of PAEE. An Actigraph GT3X+ accelerometer was worn on the hip of the shortest residual limb and, a HR monitor and an Actiheart (AHR) device were worn on the chest. Multiple linear regressions were employed to derive population-specific PAEE estimated algorithms using Actigraph GT3X+ outputs and HR signals (GT3X+HR). Mean bias±95% Limits of Agreement (LoA) and error statistics were calculated between criterion PAEE (indirect calorimetry) and PAEE predicted using GT3X+HR and AHR.

Results

Both measurement approaches used to predict PAEE were significantly related (P<0.01) with criterion PAEE. GT3X+HR revealed the strongest association, smallest LoA and least error. Predicted PAEE (GT3X+HR; unilateral; r = 0.92, bilateral; r = 0.93, and control; r = 0.91, and AHR; unilateral; r = 0.86, bilateral; r = 0.81, and control; r = 0.67). Mean±SD percent error across all activities were 18±14%, 15±12% and 15±14% for the GT3X+HR and 45±20%, 39±23% and 34±28% in the AHR model, for unilateral, bilateral and control groups, respectively.

Conclusions

Statistically derived algorithms (GT3X+HR) provide a more valid estimate of PAEE in individuals with traumatic lower-limb amputation, compared to a proprietary group calibration algorithm (AHR). Outputs from AHR displayed considerable random error when tested in a laboratory setting in individuals with lower-limb amputation.

FUNCTIONAL DIFFERENCES OF BILATERAL TRANSFEMORAL AMPUTEES USING FULL-LENGTH AND STUBBY-LENGTH PROSTHESES

Many unilateral amputations are followed by a contralateral amputation within three years, sometimes presenting as bilateral transfemoral amputations. Bilateral transfemoral amputees that successfully use prostheses are an understudied patient population. This study establishes reference values for this population in users of short non-articulating (stubby) or full-length articulating prostheses. Anthropometric and demographic information was collected from participants. Additionally, participants completed a self-reported Prosthesis Evaluation Questionnaire-Mobility Subscale 12/5 (PEQ-MS) and performed multiple physical mobility tests, including walking tests and the multi-directional Four Square Step Test (FSST). Full-length users rated their abilities to complete the PEQ-MS tasks as less difficult than stubby users in eight of the 12 items. Gait analysis revealed a greater amount of time is spent in stance phase with a greater portion in double limb support for both user groups, and a greater percentage in stance phase for the subject-reported dominant limb. Stubby users' gait velocity had a significant reduction from that of their full-length peers; however, cadence was similar between groups. Both user groups completed the FSST at comparable times. These outcomes may be of benefit for identifying tasks bilateral transfemoral prosthetic users may find to be most difficult as well as for identifying normal ambulation patterns within this population. Future studies with a greater number of subjects would enable these results to be further generalized.

Factors associated with the likelihood of fall-related injury among people with lower limb loss

Background

People with lower limb loss that live in the community fall at a rate that exceeds that of other vulnerable populations such as hospitalized elderly people. Past research in a small single state study has identified factors associated with fall-related injury. The purpose of this study was to use a larger multistate sample of people with lower limb loss living in community settings to evaluate factors associated with fall-related injury in a multivariable model.

Method

This retrospective cohort study included community-dwelling people with lower limb loss participating in wellness-walking programs in 6 states within the United States. Fall-related injury was considered injury sustained during a fall to the ground that required medical care. Pearson’s Chi-squared test and student’s t-test were used for descriptive statistics. Odds ratios and 95% confidence intervals from multivariable logistic regression modelling were used to estimate the likelihood of fall-related injuries.

Results

Of the 303 subjects recruited, 257 (84.8%) were included in the analyses. Overall, 45 subjects (17.5%) reported at least a single fall-related injury. Most subjects reported two or more falls within the previous 12 months (N = 161, 63.1%), were male (N = 177, 68.9%), and were White (N = 212, 83.8%). Most falls were associated with gait (44.5%), activities of daily living (ADL, 15.7%), or ramps and/or stairs (12%). The likelihood of fall-related injury was elevated among females versus males (OR = 2.90, 95% CI 1.35, 6.24), people of non-White versus White race (OR = 4.79, 95% CI 1.06, 21.76), people with vascular amputations due to peripheral artery disease or diabetes versus non-vascular amputations (OR = 2.22, 95% CI 1.04, 4.73) and people with transtibial versus transfemoral amputations (OR = 2.32, 95% CI 1.01, 4.89).

Discussion

Results of this study show that the likelihood of fall-related injury was significantly higher among women, non-White race, people with vascular and transtibial amputations. The results from this study were largely consistent with results from the prior multivariable fall-related injury model.

Conclusion

The results highlight the association of female sex, non-White race, vascular and transtibial amputations with the likelihood of fall-related injury. Future studies may use the study findings to develop educational fall prevention programs for women, minorities, and people with vascular etiology and transtibial amputations.

Test-Retest Reliability of Dynamic Balance Performance-Based Measures Among Adults With a Unilateral Lower-Limb Amputation

BACKGROUND

There is large variation in administration of performance-based, dynamic balance measures among adults with lower-limb amputation (LLA). Further, there has been limited exploration of test-retest reliability of these measures in adults with lower-limb loss, including whether there is a difference in reliability if one records "best" vs "average" performance across trials.

OBJECTIVE

To determine test-retest reliability of several balance tests for both "best" and "average" score performance in community-dwelling adults with a unilateral LLA, including quantification of the precision of individual scores (SE of the measurement, SEM) and estimates of minimal detectable change (MDC₉₀ ).

DESIGN

Cross-sectional study.

SETTING

Mobile research laboratory.

PARTICIPANTS

27 participants (55.5% female) with an average age of 51 (SD = 12.2) years, who were predominantly community-ambulators (92.5%), after a unilateral transtibial (n = 20), transfemoral (n = 5), or other major lower-extremity (n = 2) amputation, were included. Median time since amputation was 6.3 (2.3, 19 [25th, 75th interquartile range]) years.

METHODS

Reliability was evaluated using intraclass correlation coefficient (ICC) models (3,1 or 3,k). SEMs and MDC₉₀ values with 95% confidence intervals (CIs) were calculated.

MAIN OUTCOME MEASURES

360^o Turn Test, 5 Times Sit-To-Stand, Functional Reach Test, Figure-of-8 Walk Test, and Four Square Step Test (FSST).

RESULTS

The ICCs (3,1 or 3,k) for all tests (for both "best" and "average" performance) were considered good-to-excellent and CIs varied from 0.69 (95% CI = 0.40-0.85) to 0.97 (95% CI = 0.95-0.99). For most tests, "best" and "average" performance demonstrated similar ICC values. MDC₉₀ values did not surpass 10% of test means for any of the measures.

CONCLUSIONS

The dynamic balance measures evaluated for use among community-dwelling adults with a unilateral LLA demonstrated excellent reliability, along with high precision of scores and MDC values that did not exceed 10% of testing means. Either best or average scoring may be used when administering the majority of these tests, as long as the assessment method is appropriately documented and replicated at follow-up to allow direct comparisons. With the FSST, clinicians should consider taking the average of two FSST trials.

LEVEL OF EVIDENCE

III.

Differences in Physical Performance Measures Among Patients With Unilateral Lower-Limb Amputations Classified as Functional Level K3 Versus K4

OBJECTIVE

To determine whether differences in physical function, assessed via self-report questionnaires and physical performance tests, exist between individuals with lower-limb loss using a prosthetic device classified as a K3 versus a K4 functional level.

DESIGN

Cross-sectional study.

SETTING

A university physical therapy amputee clinic.

PARTICIPANTS

Participants (N=55) were included if they (1) were aged ≥18 years with a unilateral transfemoral or transtibial amputation; (2) were classified as K3 or K4 functional level; (3) completed all relevant outcome measures; and (4) were currently using a prosthesis.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Locomotor Capabilities Index (LCI), Prosthetic Evaluation Questionnaire-Mobility Section (PEQ-MS), Timed Up and Go (TUG), 10-Meter Walk Test (10MWT), Amputee Mobility Predictor (AMPPRO), and 6-Minute Walk Test (6MWT). K level was determined by group consensus based on a standardized clinical evaluation.

RESULTS

After controlling for covariates, patients classified as K3 had slower TUG times (P=.002) and self-selected and fast gait speeds (P<.001), lower AMPPRO scores (P<.001), and walked shorter distances during the 6MWT (P=.003) when compared with patients classified as K4. No significant between-group differences for the LCI or PEQ-MS were found.

CONCLUSIONS

Clinicians involved in prosthetic prescription may consider including the TUG, 10MWT, AMPPRO, and 6MWT during their clinical evaluations to help differentiate between individuals of higher functional mobility. The LCI and PEQ-MS may be less useful in classifying individuals as K3 versus K4 because of a ceiling effect.

Balance-confidence is associated with community participation, perceived physical mobility, and performance-based function among individuals with a unilateral amputation

OBJECTIVE

To explore relationships between balance-confidence and: 1) community participation; 2) self-perceived mobility; and 3) performance-based physical function among individuals with a lower-limb amputation using a prosthetic. Design: Retrospective, cross-sectional study. Setting: Outpatient, multidisciplinary amputee clinic. Participants: Patients (n = 45) using a prosthesis, aged ≥ 18 years, with a unilateral transfemoral or transtibial amputation of ≥1 year, were included. Methods: Participants completed the following self-report measures: Activities-Specific Balance Confidence Scale (ABC); Community Integration Questionnaire (CIQ); Locomotor Capabilities Index (LCI); and two performance-based measures (i.e. Timed Up and Go and 6 Minute Walk Test). Linear regression modeling was used to explore relationships between balance-confidence (i.e. ABC) and self-report (i.e. CIQ and LCI) and performance-based measures (p ≤ 0.0125). Results: After controlling for potential covariates (i.e. age, sex, and body mass index), balance-confidence explained 47.4% of the variance in CIQ (p = 0.000), 53.0% of the variance in LCI (p = 0.000), 20.3% of the variance in Timed Up and Go (p = 0.001), and 18.2% of the variance in 6 Minute Walk Test (p = 0.001). Conclusion: Lower balance-confidence is associated with less community participation, lower self-perceived mobility, and poorer performance among patients with a unilateral lower-limb amputation.

Impact of anatomical placement of an accelerometer on prediction of physical activity energy expenditure in lower-limb amputees

Purpose

To assess the influence of the anatomical placement of a tri-axial accelerometer on the prediction of physical activity energy expenditure (PAEE) in traumatic lower-limb amputees during walking and to develop valid population-specific prediction algorithms.

Methods

Thirty participants, consisting of unilateral (n = 10), and bilateral (n = 10) amputees, and non-injured controls (n = 10) volunteered to complete eight activities; resting in a supine position, walking on a flat (0.48, 0.67, 0.89, 1.12, 1.34 m.s^-1) and an inclined (3 and 5% gradient at 0.89 m.s^-1) treadmill. During each task, expired gases were collected and an Actigraph GT3X+ accelerometer was worn on the right hip, left hip and lumbar spine. Linear regression analyses were conducted between outputs from each accelerometer site and criterion PAEE (indirect calorimetry). Mean bias ± 95% limits of agreement were calculated. Additional covariates were incorporated to assess whether they improved the prediction accuracy of regression models. Subsequent mean absolute error statistics were calculated for the derived models at all sites using a leave-one out cross-validation analysis.

Results

Predicted PAEE at each anatomical location was significantly (P< 0.01) correlated with criterion PAEE (P<0.01). Wearing the GT3X+ on the shortest residual limb demonstrates the strongest correlation (unilateral; r = 0.86, bilateral; r = 0.94), smallest ±95% limits of agreement (unilateral; ±2.15, bilateral ±1.99 kcal·min^-1) and least absolute percentage error (unilateral; 22±17%, bilateral 17±14%) to criterion PAEE.

Conclusions

We have developed accurate PAEE population specific prediction models in lower-limb amputees using an ActiGraph GT3X+ accelerometer. Of the 3 anatomical locations considered, wearing the accelerometer on the side of the shortest residual limb provides the most accurate prediction of PAEE with the least error in unilateral and bilateral traumatic lower-limb amputees.

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 ( r_s = -.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.

Standard and Amputation-Adjusted Body Mass Index Measures: Comparison and Relevance to Functional Measures, Weight-Related Comorbidities, and Dieting

People with limb loss may misjudge weight-related health when not adjusting body mass index (BMI) for amputation level. This cross-sectional, community-based study compared BMI and amputation-adjusted BMI (A-BMI) and evaluated relationships among BMI categories, function, and dieting. Subjects provided self-reported demographic, functional, and medical/prosthetic data including height and weight and completed performance-based balance and gait measures. A Web-based A-BMI calculator adjusted for amputation levels. Results for 294 subjects from 11 states (68.4% men; 76.5% white; average age, 55.6 [15.1] y) were reported, with vascular (49.7%) and unilateral transtibial (40.8%) amputations as the most common. Body mass index and A-BMI were closely correlated (Pearson r = 0.99), but a BMI of 28.6 (6.7) was less than an A-BMI of 30.3 (6.2) (t test, P < 0.001). Agreement among Centers for Disease Control BMI categories was moderate (κ = 0.48); 39.7% of BMI categories were underestimated without adjusting for amputations. Functional measures did not differ among BMI/A-BMI categories (P > 0.05). A larger than random proportion categorized as overweight by BMI dieted (χ, P < 0.05), and people categorized as overweight by A-BMI did not (38.3% classified as normal BMI). Functional abilities did not differ among BMI categories (Kruskal-Wallis and analysis of variance, P > 0.05). People with limb loss using BMI may underestimate weight-related health; a Web-based A-BMI calculator may help monitor weight to make dieting decisions.

The development and validation of a novel outcome measure to quantify mobility in the dysvascular lower extremity amputee: the amputee single item mobility measure

OBJECTIVE

This study describes the development and psychometric evaluation of a novel patient-reported single-item mobility measure.

DESIGN

Prospective cohort study.

SETTING

Four Veteran's Administration Medical Centers.

SUBJECTS

Individuals undergoing their first major unilateral lower extremity amputation; 198 met inclusion criteria; of these, 113 (57%) enrolled.

INTERVENTIONS

None.

MAIN MEASURES

The Amputee Single Item Mobility Measure, a single item measure with scores ranging from 0 to 6, was developed by an expert panel, and concurrently administered with the Locomotor Capabilities Index-5 (LCI-5) and other outcome measures at six weeks, four months, and 12 months post-amputation. Criterion and construct validity, responsiveness, and floor/ceiling effects were evaluated. Responsiveness was assessed using the standardized response mean.

RESULTS

The overall mean 12-month Amputee Single Item Mobility Measure score was 3.39 ±1.4. Scores for transmetatarsal, transtibial, and transfemoral amputees were 4.2 (±1.3), 3.2 (±1.5), and 2.9 (±1.1), respectively. Amputee Single Item Mobility Measure scores demonstrated "large" and statistically significant correlations with the LCI-5 scores at six weeks (r = 0.72), four months (r = 0.81), and 12 months (r = 0.86). At four months and 12 months, the correlation between Amputee Single Item Mobility Measure scores and hours of prosthetic use were r = 0.69 and r = 0.66, respectively, and between Amputee Single Item Mobility Measure scores and Trinity Amputation and Prosthesis Experience Scales functional restriction scores were r = 0.45 and r = 0.67, respectively. Amputee Single Item Mobility Measure scores increased significantly from six weeks to 12 months post-amputation. Minimal floor/ceiling effects were demonstrated.

CONCLUSIONS

In the unilateral dysvascular amputee, the Amputee Single Item Mobility Measure has strong criterion and construct validity, excellent responsiveness, and does not exhibit floor/ceiling effects.