Quantifying prosthetic gait deviation using simple outcome measures

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.

Clinimetrics of performance-based functional outcome measures for vascular amputees: A systematic review

BACKGROUND

Objective physical performance-based outcome measures (PerBOMs) are essential tools for the holistic management of people who have had an amputation due to vascular disease. These people are often non-ambulatory, however it is currently unclear which PerBOMs are high quality and appropriate for those who are either ambulatory or non-ambulatory.

RESEARCH QUESTION

Which PerBOMs have appropriate clinimetric properties to be recommended for those who have had amputations due to vascular disease ('vascular amputee')?

DATA SOURCES

MEDLINE, CINAHL, EMBASE, EMCARE, the Cochrane Library, Cochrane Central Register of Controlled Trials (CENTRAL) and Scopus databases were searched for the terms: "physical performance" or "function", "clinimetric properties", "reliability", "validity", "amputee" and "peripheral vascular disease" or "diabetes".

REVIEW METHODS

A systematic review of PerBOMs for vascular amputees was performed following COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology and PRISMA guidelines. The quality of studies and individual PerBOMs was assessed using COSMIN risk of bias and good measurement properties. Overall PerBOM quality was evaluated with a modified GRADE rating. Key clinimetric properties evaluated were reliability, validity, predictive validity and responsiveness.

RESULTS

A total of 15,259 records were screened. Forty-eight studies (2650 participants) were included: 7 exclusively included vascular amputees only, 35 investigated validity, 20 studied predictive validity, 23 investigated reliability or internal consistency and 7 assessed responsiveness. Meta-analysis was neither possible nor appropriate for this systematic review in accordance with COSMIN guidelines, due to heterogeneity of the data. Thirty-four different PerBOMs were identified of which only 4 are suitable for non-ambulatory vascular amputees. The Amputee Mobility Predictor no Prosthesis (AMPnoPro) and Transfemoral Fitting Predictor (TFP) predict prosthesis use only. PerBOMs available for assessing physical performance are the One-Leg Balance Test (OLBT) and Basic Amputee Mobility Score (BAMS).

CONCLUSION

At present, few PerBOMs can be recommended for vascular amputees. Only 4 are available for non-ambulatory individuals: AMPnoPro, TFP, OLBT and BAMS.

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.

Derivation of the Gait Deviation Index for Spinal Cord Injury

The Gait Deviation Index (GDI) is a dimensionless multivariate measure of overall gait pathology represented as a single score that indicates the gait deviation from a normal gait average. It is calculated using kinematic data recorded during a three-dimensional gait analysis and an orthonormal vectorial basis with 15 gait features that was originally obtained using singular value decomposition and feature analysis on a dataset of children with cerebral palsy. Ever since, it has been used as an outcome measure to study gait in several conditions, including spinal cord injury (SCI). Nevertheless, the validity of implementing the GDI in a population with SCI has not been studied yet. We investigate the application of these mathematical methods to derive a similar metric but with a dataset of adults with SCI (SCI-GDI). The new SCI-GDI is compared with the original GDI to evaluate their differences and assess the need for a specific GDI for SCI and with the WISCI II to evaluate its sensibility. Our findings show that a 21-feature basis is necessary to account for most of the variance in gait patterns in the SCI population and to provide high-quality reconstructions of the gait curves included in the dataset and in foreign data. Furthermore, using only the first 15 features of our SCI basis, the fidelity of the reconstructions obtained in our population is higher than that when using the basis of the original GDI. The results showed that the SCI-GDI discriminates most levels of the WISCI II scale, except for levels 12 and 18. Statistically significant differences were found between both indexes within each WISCI II level except for 12, 20, and the control group (p < 0.05). In all levels, the average GDI value was greater than the average SCI-GDI value, but the difference between both indexes is larger in data with greater impairment and it reduces progressively toward a normal gait pattern. In conclusion, the implementation of the original GDI in SCI may lead to overestimation of gait function, and our new SCI-GDI is more sensitive to larger gait impairment than the GDI. Further validation of the SCI-GDI with other scales validated in SCI is needed.

Application of the Gait Deviation Index to Study Gait Impairment in Adult Population With Spinal Cord Injury: Comparison With the Walking Index for Spinal Cord Injury Levels

The Gait Deviation Index (GDI) is a multivariate measure of overall gait pathology based on 15 gait features derived from three-dimensional (3D) kinematic data. GDI aims at providing a comprehensive, easy to interpret, and clinically meaningful metric of overall gait function. It has been used as an outcome measure to study gait in several conditions: cerebral palsy (CP), post-stroke hemiparetic gait, Duchenne muscular dystrophy, and Parkinson’s disease, among others. Nevertheless, its use in population with Spinal Cord Injury (SCI) has not been studied yet. The aim of the present study was to investigate the applicability of the GDI to SCI through the assessment of the relationship of the GDI with the Walking Index for Spinal Cord Injury (WISCI) II. 3D gait kinematics of 34 patients with incomplete SCI (iSCI) was obtained. Besides, 3D gait kinematics of a sample of 50 healthy volunteers (HV) was also gathered with Codamotion motion capture system. A total of 302 (iSCI) and 446 (HV) strides were collected. GDI was calculated for each stride and grouped for each WISCI II level. HV data were analyzed as an additional set. Normal distribution for each group was assessed with Kolmogorov-Smirnov tests. Afterward, ANOVA tests were performed between each pair of WISCI II levels to identify differences among groups (p < 0.05). The results showed that the GDI was normally distributed across all WISCI II levels in both iSCI and HV groups. Furthermore, our results showed an increasing relationship between the GDI values and WISCI II levels in subjects with iSCI, but only discriminative in WISCI II levels 13, 19, and 20. The index successfully distinguished HV group from all the individuals with iSCI. Findings of this study indicated that the GDI is not an appropriate multivariate walking metric to represent the deviation of gait pattern in adult population with iSCI from a normal gait profile when it is compared with the levels of walking impairment described by the WISCI II. Future work should aim at defining and validating an overall gait index derived from 3D kinematic gait variables appropriate for SCI, additionally taking into account other walking ability outcome measures.

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.

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.

Reproducibility and discriminant validity of two clinically feasible measurement methods to obtain coronal plane gait kinematics in participants with a lower extremity amputation

Introduction

Measuring coronal plane gait kinematics of the pelvis and trunk during rehabilitation of participants with a lower extremity amputation is important to detect asymmetries in gait which are hypothesised as associated with secondary complaints. The aim of this study was to test the reproducibility and discriminant validity of a three-dimensional (3-D; inertial measurement units) and a two-dimensional (2-D; video-based) system.

Methods

We tested the test-retest and inter-rater reproducibility of both systems and the 2-D system, respectively, in participants with a lower extremity amputation (group 1) and healthy subjects (group 2). The discriminant validity was determined with a within-group comparison for the 3-D system and with a between-group comparison for both systems.

Results

Both system showed to be test-retest reliable, both in group 1 (2-D system: ICC3.1_agreement 0.52–0.83; 3-D system: ICC3.1_agreement 0.81–0.95) and in group 2 (3-D system: ICC3.1_agreement 0.33–0.92; 2-D system: ICC3.1_agreement 0.54–0.95). The 2-D system was also inter-rater reliable (group 1: ICC2.1_agreement 0.80–0.92; group 2: ICC2.1_agreement 0.39–0.90). The within-group comparison of the 3-D system revealed a statistically significant asymmetry of 0.4°-0.5° in group 1 and no statistically significant asymmetry in group 2. The between-group comparison revealed that the maximum amplitude towards the residual limb (MARL) in the low back (3-D system) and the (residual) limb—trunk angle (2-D system) were significantly larger with a mean difference of 1.2° and 6.4°, respectively, than the maximum amplitude of healthy subjects. However, these average differences were smaller than the smallest detectable change (SDC) of group 1 for both the MARL (SDC_agreement: 1.5°) and the residual limb—trunk angle (SDC_agreement: 6.7°-7.6°).

Conclusion

The 3-D and 2-D systems tested in this study were not sensitive enough to detect real differences within and between participants with a lower extremity amputation and healthy subjects although promising reproducibility parameters for some of the outcome measures.

Reliability, Validity, and Responsiveness of Clinical Performance-Based Outcome Measures of Walking for Individuals With Lower Limb Amputations: A Systematic Review

BACKGROUND

Clinical outcome measures are important to use for individuals with lower limb amputations (LLA) because such individuals require intensive functional gait training before and after being fitted with prostheses. Using standardized instruments throughout the episode of care allows clinicians to objectively monitor patient progress, make evidence-based decisions regarding the plan of care, and communicate results in meaningful ways to patients, payers, and other clinicians. Many clinical outcome measures exist, but not all have been validated and shown to be reliable within this population of interest.

PURPOSE

The aim of this review was to provide a comprehensive overview of the psychometric properties of all current performance-based outcome measures applicable to individuals with lower limb amputations.

DATA SOURCES

Reviewers searched for articles using the online databases PubMed/MEDLINE and CINAHL. Reviewers also conducted a manual search of the reference list of 1 of the previously published systematic reviews to identify any additional studies not detected with the online database search.

STUDY SELECTION

The 2 reviewers screened titles and abstracts for relevance. The same reviewers obtained and read full-text articles of the potentially relevant studies. Reviewers resolved any discrepancies of the inclusion assessment by further discussion.

DATA EXTRACTION

The reviewers created tables to extract psychometric properties of interest from the included articles. Both reviewers extracted the data from the articles and placed relevant values into a table for each primary outcome measure identified.

DATA SYNTHESIS

The rigor of study reporting was guided by use of the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Checklist. Each reviewer independently read and appraised the included articles, assigning a score to each checklist item. The sum of scores for each item was calculated to appraise the overall quality of reporting of the included articles.

LIMITATIONS

Review-level limitations included the absence of a third reviewer to settle any disagreements on article inclusion and article appraisal. Additionally, the percentage of reviewer agreement on article appraisal was not determined before disagreements about checklist item satisfaction were resolved. Furthermore, reviewers only extracted data on reliability, validity, and responsiveness; instrument characteristics, such as floor and ceiling effects, are also important.

CONCLUSIONS

Valid and reliable performance-based clinical measures of ambulation in individuals with LLA were identified. Further research should investigate the minimally clinical, important difference of these clinical measures and address trends in unmet reporting guidelines.

Mobility Analysis of AmpuTees (MAAT I): Quality of life and satisfaction are strongly related to mobility for patients with a lower limb prosthesis

BACKGROUND

While rehabilitation professionals are historically trained to place emphasis on the restoration of mobility following lower limb amputation, changes in healthcare dynamics are placing an increased emphasis on the limb loss patient's quality of life and general satisfaction. Thus, the relationship between these constructs and mobility in the patient with lower limb loss warrants further investigation.

OBJECTIVES

To determine the relationship between mobility of the patient with lower limb loss and both (1) general satisfaction and (2) quality of life.

STUDY DESIGN

Retrospective chart analysis.

METHODS

A retrospective chart review of the Prosthetic Limb Users Survey of Mobility and the Prosthesis Evaluation Questionnaire-Well-Being subsection. Pearson correlations were used to test relationships.

RESULTS

Data from 509 patients with a lower limb prosthesis were included. Mobility was found to be positively correlated with quality of life ( r = 0.511, p < 0.001, 95% confidence interval (0.443, 0.569)) and general satisfaction ( r = 0.475, p < 0.001, 95% confidence interval (0.403, 0.542)), as well as their arithmetic mean (i.e. Prosthesis Evaluation Questionnaire-Well-Being) ( r = 0.533, p < 0.001, 95% confidence interval (0.466, 0.592)).

CONCLUSION

This study provides evidence of a strong positive correlation between mobility and both quality of life and general satisfaction. Thus, in the holistic care of a patient with lower limb loss, maximizing mobility would correlate with greater quality of life and general satisfaction. Clinical relevance There is growing emphasis on the quality of life and general satisfaction experienced by patients undergoing prosthetic rehabilitation. The results of this study underscore the importance of providing prosthetic rehabilitation that maximizes the patient's mobility, noting that these individuals also report greater quality of life and general satisfaction.