Preliminary assessment of balance with the Berg Balance Scale in adults who have a leg amputation and dwell in the community: Rasch rating scale analysis

Quality of Life in People with Diabetes Mellitus and Unilateral Transtibial Amputation - Aspects of Using the Berg Balance Scale

Approximately 40%-60% of all amputations are lower limb amputations (LLAs) related to diabetes mellitus (DM). The importance of quality of life (QoL) is increasingly recognized as after amputation. The objective of this cross-sectional study was to compare QoL (evaluated by Berg Balance Scale, BBS) in DM patients with unilateral transtibial amputation (TTA) using prosthesis (group A) with that of patients amputated due to other causes (group B). Overall, 32 patients completed two questionnaires: the 36-Item Health Survey (SF - 36) for QoL assessment and the Trinity Amputation and Prosthesis Experience Scale-Revised (TAPES-R). In group A, patients were significantly older (P < .05) with shorter periods of prosthesis use (P < .05) and had significantly lower (P = .008) adjustment to limitation (TAPES-R). Correlations were found between BBS score and SF-36, including physical functioning (P < .001, r = 0.682), energy and fatigue (P < .001, r = 0.643) and emotional well-being (P < .001, r = 0.644). In the TAPES-R, a large negative correlation was found between BBS and activity restriction (P = .001, r = -0.595). Poorer balance ability, greater activity limitation, and worse psychosocial adjustment to the prosthesis were found in patients with unilateral TTA and DM compared to TTA prosthesis users without DM.

Computerized Adaptive Testing for the Berg Balance Scale Improves Measurement Efficiency Without Compromising Precision in People With Stroke

OBJECTIVE

The objectives of this study were to confirm the Berg Balance Scale's (BBS) measurement properties and unidimensionality with an item response theory analysis in persons with subacute and chronic stroke and to examine the precision and efficiency of computerized adaptive testing (CAT).

METHODS

Data were obtained from 519 ambulatory persons with subacute and chronic stroke in 2 retrospective databases. A principal component analysis (PCA) of residuals was used to evaluate unidimensionality. BBS fit to a rating scale model versus a partial credit model was examined, and item parameters were generated for CAT calibration. Person measures from all 14 items were defined as actual balance ability. BBS CAT simulations were used to examine changes in measurement precision with increasing number of items administered and a precision-based stopping rule (0.5 logit standard error [SE] threshold).

RESULTS

A PCA of residuals supports the BBS unidimensionality and Rasch analysis supports using the rating scale model for measurement. Maximum precision for BBS CAT was SE = 0.40 logits when administering all items. BBS CAT estimated balance ability was highly correlated with actual ability when 4 or more items were administered (r > 0.9). Precision was within 0.5 logits when 5 or more items were administered (SE < 0.48 logits). BBS CAT estimated balance ability was highly correlated with actual ability (r = 0.952) using a precision-based stopping rule. The average number of items administered with the precision-based stopping rule was 5.43.

CONCLUSION

The BBS is sufficiently unidimensional, and the rating scale model can be used for measurement. BBS CAT is efficient and replicates the full instrument's reliability when measuring balance ability in ambulatory persons with subacute and chronic stroke. Future work should aim to enhance the interpretability of measures to facilitate clinical decision-making.

IMPACT

BBS CAT provides an efficient way of measuring balance ability for individuals in stroke rehabilitation giving clinicians more time with patients.

A scoping review of postoperative early rehabilitation programs after dysvascular-related amputations

BACKGROUND

After amputation, people face challenges including wound healing and decreased functional mobility. Early mobilization in acute hospital care has proved safe, improved function, and sped discharge. Still, loss of a leg complicates standing and early mobilization after amputation. Approaches to early mobilization and rehabilitation after amputation surgery have not been widely studied.

OBJECTIVES

To map the evidence regarding early postoperative mobilization after dysvascular amputation. Specific aims included identifying research designs and populations, describing rehabilitation approaches, and identifying gaps within the literature.

STUDY DESIGN

Scoping review following PRISMA-Sc guidelines.

METHODS

The a priori scoping review methodology conducted in June 2022 with English language and 20-year limits used the OVID Medline, OVID Allied and Complementary Medicine Database, Cumulative Index to Nursing and Allied Health Literature, Cochrane databases, and Journal of Prosthetics and Orthotics archive. Reviewer pairs used Covidence software to screen for inclusion (subjects with major lower limb dysvascular amputations, seen immediately postoperatively for hospital-based rehabilitation) with decisions by concurrence. Data for best practice scoping reviews were synthesized for analysis.

RESULTS

Two hundred ninety-six citations were screened, 13 full texts reviewed, and 8 articles included: 2 cohort studies, 3 case-control studies, 2 single-group interventional studies, and 1 case study. There were no randomized control trials or prospective comparison group trials.

CONCLUSIONS

Few studies were identified regarding acute rehabilitation after major lower extremity amputation. The limited evidence in this review suggested that early mobilization in the days after amputation was safe with or without use of temporary prostheses, although further research is certainly warranted.

Item distribution of the Berg Balance Scale in older adults with Hip fracture: a Rasch analysis

INTRODUCTION

Balance impairment occurs after a hip fracture, but the characteristics of the impairment are not clear.

OBJECTIVE

To investigate the uni-dimensionality, fit statistics, and item difficulty of the Berg Balance Scale (BBS) in older adults with hip fracture by conducting a Rasch analysis.

METHODS

This was an observational cross-sectional study. The 254 participants were all ≥ 65 years old and had been hospitalized for rehabilitation after a unilateral hip fracture incurred during a fall. We collected their BBS scores at the time of hospital discharge and conducted a Rasch analysis to examine the uni-dimensionality, fit statistics, and item difficulty.

RESULTS

The principal component analysis (PCA) of the Rasch model demonstrated that the BBS is uni-dimensional. The information-weighted mean square (MnSq) fit statistic was within the range of fit criteria for all items. The underfit item of the outlier-sensitive MnSq fit statistics was "Standing unsupported eyes closed" with the MnSq of 2.06. The difficult items were in order of logits: "Standing on one leg" (logits = 4.01); "Step tool" (logits = 2.74); and "Turn 360°" (logits = 2.61).

CONCLUSION

The BBS is uni-dimensional and conforms with the Rasch model. The BBS most difficult items for older adults with a hip fracture required one-legged support and dynamic balance.

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.

Beyond exercise. Can application of manual therapy before exercise benefit a low functioning person with limb loss? A case study

BACKGROUND

Most people with lower-limb loss (PLL) have musculoskeletal conditions and range-of-motion and muscle performance impairments. Such impairments limit potential for functional movement but can be reduced with manual therapy. Manual therapy, however, is rarely used for PLL. This case demonstrated how integrating manual therapy, exercise, and functional training led to lasting benefits for one low functioning PLL.

CASE DESCRIPTION

A 54-year-old woman more than 1 year after transtibial amputation due to peripheral artery disease presented with multiple comorbidities and yellow flags. Her function remained limited to the Medicare K-1 household walking level with slow gait speed <0.25 m/s. Treatment included four weekly sessions each beginning with manual therapy, followed by exercise and functional training.

OUTCOMES

After 1 month, performance-based strength, balance, walking speed, and physical activity increased. She advanced to the K-2 limited community walking level and maintained her functional level without further treatment after 3 months.

DISCUSSION

Improvements maintained without treatment expanded upon research that lacked follow-up and excluded K-1 level walkers. Marked improvement after only four sessions was noteworthy since exercise protocols require ≥4 sessions.

CONCLUSION

Manual therapy followed by exercise and functional training may optimize movement potential and contribute to improving strength, balance, gait, and physical activity among PLL.

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.

When 'good' is not good enough: a retrospective Rasch analysis study of the Berg Balance Scale for persons with Multiple Sclerosis

Background

The Berg Balance Scale (BBS) is one of the most used tools to quantify balance in Persons with Multiple Sclerosis, a population at high risk of falling.

Aim

To evaluate the measurement characteristics of the BBS in Multiple Sclerosis through Rasch analysis.

Design

Retrospective study.

Setting

Outpatients in three Italian Rehabilitation centers.

Population

Eight hundred and fourteen persons with Multiple Sclerosis able to stand independently for more than 3 s.

Methods

The sample (N = 1,220) was split into one validating (B1) and three confirmatory subsamples. Following the Rasch analysis performed on B1, the item estimates were exported and anchored to the three confirmatory subsamples. After obtaining the same final solution across all samples, we studied the convergent and discriminant validity of the final BBS-MS using the EDSS, the ABC scale, and the number of falls.

Results

The base analysis on the B1 subsample failed the monotonicity, local independence, and unidimensionality requirements and did not fit the Rasch model. After grouping locally dependent items, the BBS-MS fitted the model (χ²₈ = 23.8; p = 0.003) and satisfied all requirements for adequate internal construct validity (ICV). However, it was mistargeted to the sample, given the striking prevalence of higher scores (targeting index 1.922) with a distribution-independent Person Separation Index sufficient for individual measurements (0.962). The B1 item estimates were anchored to the confirmatory samples with confirmation of adequate fit (χ² = [19.0, 22.8], value of ps = [0.015, 0.004]) and satisfaction of all ICV requirements for all subsamples. The final BBS-MS directly correlated with the ABC scale (rho = 0.523) and inversely with EDSS (rho = -0.573). The BBS-MS estimates significantly differed across groups according to the pre-specified hypotheses (between the three EDSS groups, between the ABC cut-offs, distinguishing 'fallers' vs. 'non-fallers', and between the 'low' vs. 'moderate' vs. 'high' levels of physical functioning; and, finally, between 'no falls' vs. 'one or more falls').

Conclusion

This study supports the internal construct validity and reliability of the BBS-MS in an Italian multicentre sample of persons with Multiple Sclerosis. However, as the scale is slightly mistargeted to the sample, it represents a candidate tool to assess balance, mainly in more disabled people with an advanced walking disability.

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.

Development of a Berg Balance Scale Short-Form Using a Machine Learning Approach in Patients With Stroke

BACKGROUND AND PURPOSE

The Berg Balance Scale (BBS) is frequently used in routine clinical care and research settings and has good psychometric properties. This study was conducted to develop a short form of the BBS using a machine learning approach (BBS-ML).

METHODS

Data of 408 individuals poststroke were extracted from a published database. The initial (ie, 4-, 5-, 6-, 7-, and 8-item) versions were constructed by selecting top-ranked items based on the feature selection algorithm in the artificial neural network model. The final version of the BBS-ML was chosen by selecting the short form that used a smaller number of items to achieve a higher predictive power R2 , a lower 95% limit of agreement (LoA), and an adequate possible scoring point (PSP). An independent sample of 226 persons with stroke was used for external validation.

RESULTS

The R2 values for the initial 4-, 5-, 6-, 7-, and 8-item short forms were 0.93, 0.95, 0.97, 0.97, and 0.97, respectively. The 95% LoAs were 14.2, 12.2, 9.7, 9.6, and 8.9, respectively. The PSPs were 25, 35, 34, 35, and 36, respectively. The 6-item version was selected as the final BBS-ML. Preliminary external validation supported its performance in an independent sample of persons with stroke ( R2 = 0.99, LoA = 10.6, PSP = 37).

DISCUSSION AND CONCLUSIONS

The BBS-ML seems to be a promising short-form alternative to improve administrative efficiency. Future research is needed to examine the psychometric properties and clinical usage of the 6-item BBS-ML in various settings and samples.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A402 ).

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.

Use of a Single Wearable Sensor to Evaluate the Effects of Gait and Pelvis Asymmetries on the Components of the Timed Up and Go Test, in Persons with Unilateral Lower Limb Amputation

The Timed Up and Go (TUG) test quantifies physical mobility by measuring the total performance time. In this study, we quantified the single TUG subcomponents and, for the first time, explored the effects of gait cycle and pelvis asymmetries on them. Transfemoral (TF) and transtibial (TT) amputees were compared with a control group. A single wearable inertial sensor, applied to the back, captured kinematic data from the body and pelvis during the 10-m walk test and the TUG test. From these data, two categories of symmetry indexes (SI) were computed: One SI captured the differences between the antero-posterior accelerations of the two sides during the gait cycle, while another set of SI quantified the symmetry over the three-dimensional pelvis motions. Moreover, the total time of the TUG test, the time of each subcomponent, and the velocity of the turning subcomponents were measured. Only the TF amputees showed significant reductions in each SI category when compared to the controls. During the TUG test, the TF group showed a longer duration and velocity reduction mainly over the turning subtasks. However, for all the amputees there were significant correlations between the level of asymmetries and the velocity during the turning tasks. Overall, gait cycle and pelvis asymmetries had a specific detrimental effect on the turning performance instead of on linear walking.

Shoulder-Specific Patient-Reported Outcome Measures for Use in Patients With Head and Neck Cancer: An Assessment of Reliability, Construct Validity, and Overall Appropriateness of Test Score Interpretation Using Rasch Analysis

OBJECTIVES

The purpose of this study was to investigate the construct validity and overall appropriateness of test score interpretation of 4 shoulder-related patient-reported outcome (PRO) measures for use in a population of patients with head and neck cancer using Rasch analysis.

METHODS

One hundred eighty-two individuals who had received a neck dissection procedure within the past 2 weeks to 18 months were recruited for this cross-sectional psychometric study. Rasch methodologies were used to investigate scale dimensionality, scale hierarchy, response scale structure, and reliability of Disabilities of the Arm, Shoulder and Hand (DASH), QuickDASH, Shoulder Pain and Disability Index (SPADI), and Neck Dissection Impairment Index (NDII).

RESULTS

DASH did not meet criteria for unidimensionality and was deemed inappropriate for use in this sample. The QuickDASH, SPADI, and NDII were all determined to be unidimensional. All scales had varying issues with person and item misfit, differential item functioning, coverage of ability levels, and optimal rating scale requirements. The NDII met most requirements. All measures were found to meet thresholds for person and item separation as well as reliability statistics.

CONCLUSIONS

Rasch analysis indicates the NDII is the most appropriate measure studied for this population. The QuickDASH and SPADI are recommended with reservation, whereas the DASH is not recommended.

IMPACT

This study demonstrates the use of objective methodologies, using Rasch analysis, to validate PRO recommendations provided by clinical experts in forums such as the Evaluation Database to Guide Effectiveness (EDGE) TaskForce, which are based upon a comprehensive literature review, consideration of published psychometric properties, and expert consensus. Use of Rasch methodologies demonstrates weaknesses in this model and provides opportunities to strengthen recommendations for clinicians.

The feasibility and validity of a wearable sensor system to assess the stability of high-functioning lower-limb prosthesis users

Introduction

Lower-limb prosthesis users (LLPUs) experience increased fall risk due to gait and balance impairments. Clinical outcome measures are useful for measuring balance impairment and fall risk screening but suffer from limited resolution and ceiling effects. Recent advances in wearable sensors that can measure different components of gait stability may address these limitations. This study assessed feasibility and construct validity of a wearable sensor system (APDM Mobility Lab) to measure postural control and gait stability.

Materials and Methods

Lower-limb prosthesis users (n=22) and able-bodied controls (n=24) completed an Instrumented Stand-and-Walk Test (ISAW) while wearing the wearable sensors. Known-groups analysis (prosthesis versus controls) and convergence analysis (Prosthetic Limb Users Survey of Mobility [PLUS-M] and Activity-specific Balance Confidence [ABC] Scale) were performed on 20 stability-related measures.

Results

The system was applied without complications; however missing anticipatory postural adjustment data points for nine subjects affected the analysis. Of the 20 analyzed measures output by the sensors, only three significantly differed (p≤.05) between cohorts, and two demonstrated statistically significant correlations with the self-report measures.

Conclusions

The results of this study suggest the clinical feasibility but only partial construct validity of the wearable sensor system in conjunction with the ISAW test to measure LLPU stability and balance. The sample consisted of high-functioning LLPUs, so further research should evaluate a more representative sample with additional outcome measures and tasks.

Selecting, Administering, and Interpreting Outcome Measures among Adults with Lower-Limb Loss: An Update for Clinicians

Purpose of review

To summarize outcome measurement research among adults with lower-limb loss (LLL) for clinicians.

Recent findings

Houghton Scale, Prosthetic Evaluation Questionnaire-mobility subscale (PEQ-m), Prosthetic Limb Users Survey of Mobility (PLUS-M™), Activities-Specific Balance Confidence Scale (ABC), Amputee Mobility Predictor (AMP), Comprehensive High-Level Activity Mobility Predictor, Four Square Step Test (FSST), Narrowing Beam Walking Test (NBWT), L Test, 10 Meter Walk Test (10MWT), and 6 Minute Walk Test (6MWT) are appropriate for evaluating individual patient changes post-LLL. Post-LLL, Socket Comfort Score, Patient-Specific Functional Scale, Patient-Reported Outcomes Measurement Information System 29-Item Profile, Timed Up and Go, and 2 Minute Walk Test may be more appropriate for evaluating groups. Minimal detectable change is available for 15/20 reviewed measures. Many measures differ between mobility levels.

Summary

Quick, reliable measures for evaluating patient functional change include ABC, PEQ-m, PLUS-M™, FSST, and L Test; when resources allow, NBWT, 10MWT, 6WMT and AMP may be considered.

POSTURAL STABILITY STRATEGIES IN TRANSTIBIAL AMPUTEES DURING QUIET STANDING IN ALTERED SENSORY CONDITIONS WEARING THREE TYPES OF PROSTHETIC FEET

Individuals with transtibial amputation exhibit altered movement strategy to sustain stability during quiet standing due to reduced proprioception on the amputated limb. The aim of this study is to determine the movement strategies in anterior–posterior and medial–lateral directions in predicting the overall postural stability. In this crossover study, postural stability of ten transtibial amputees was assessed using computed posturography while wearing different prosthetic foot types: solid ankle cushion heel (SACH), single axis (SA) and energy storage and return (ESAR). Three stability indices were measured during four conditions: standing with eyes opened and closed, standing on compliant surface and standing with tilted head. From the standard multiple regression analysis, 63% to 99% of the OSI score in all sensory conditions were explained from the MLSI score, while 11% to 56% from the APSI score. The Pearson’s [Formula: see text] indicated significant strong positive relationship between OSI and MLSI [Formula: see text]–[Formula: see text] during all sensory conditions. The APSI score was significantly lower than OSI during eyes-closed and head extended conditions for all prosthetic feet [Formula: see text]. Adjustments in postural stability strategies in transtibial amputees mostly occurred in medial–lateral direction regardless of prosthetic feet types and altered sensory conditions.

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.

Neuromuscular adaptations and sensorimotor integration following a unilateral transfemoral amputation

BACKGROUND

Following an amputation, the human postural control system develops neuromuscular adaptations to regain an effective postural control. We investigated the compensatory mechanisms behind these adaptations and how sensorimotor integration is affected after a lower-limb transfemoral amputation.

METHODS

Center of pressure (CoP) data of 12 unilateral transfemoral amputees and 12 age-matched able-bodied subjects were recorded during quiet standing with eyes open (EO) and closed (EC). CoP adjustments under each leg were recorded to study their contribution to posture control. The spatial structure of the CoP displacements was characterized by measuring the mean distance, the mean velocity of the CoP adjustments, and the sway area. The Entropic Half-Life (EnHL) quantifies the temporal structure of the CoP adjustments and was used to infer disrupted sensory feedback loops in amputees. We expanded the analysis with measures of weight-bearing imbalance and asymmetry, and with two standardized balance assessments, the Berg Balance Scale (BBS) and Timed Up-and-Go (TUG).

RESULTS

There was no difference in the EnHL values of amputees and controls when combining the contributions of both limbs (p = 0.754). However, amputees presented significant differences between the EnHL values of the intact and prosthetic limb (p <  0.001). Suppressing vision reduced the EnHL values of the intact (p = 0.001) and both legs (p = 0.028), but not in controls. Vision feedback in amputees also had a significant effect (increase) on the mean CoP distance (p <  0.001), CoP velocity (p <  0.001) and sway area (p = 0.007). Amputees presented an asymmetrical stance. The EnHL values of the intact limb in amputees were positively correlated to the BBS scores (EO: ρ = 0.43, EC: ρ = 0.44) and negatively correlated to the TUG times (EO: ρ = - 0.59, EC: ρ = - 0.69).

CONCLUSION

These results suggest that besides the asymmetry in load distribution, there exist neuromuscular adaptations after an amputation, possibly related to the loss of sensory feedback and an altered sensorimotor integration. The EnHL values suggest that the somatosensory system predominates in the control of the intact leg. Further, suppressing the visual system caused instability in amputees, but had a minimal impact on the CoP dynamics of controls. These findings points toward the importance of providing somatosensory feedback in lower-limb prosthesis to reestablish a normal postural control.

TRIAL REGISTRATION

DRKS00015254 , registered on September 20th, 2018.

Traumatic quadruple amputee rehabilitation: from amputation to prosthetic functionality: a case report

INTRODUCTION

Traumatic quadruple amputations limit daily living activities; however, the current literature regarding rehabilitation treatment for multi-limb amputations is scant. The patient showed adaptation to prosthetic fittings, acquiring a level of functional independence that enabled the patient to lead a nearly independent life.

METHODS

The patient's therapeutic intervention was divided into a pre-prosthetic phase, which consisted of functional physical adaptation to the amputation and preparation for the prostheses, and a prosthetic phase, in which different myoelectric and microprocessor limb prostheses were integrated to be used functionally. Its functional use was favored by the training with contact electromyography feedback carried out with the Biometrics E-Link System^® for the upper extremities that has made it possible to obtain many grip options in a natural way, for the lower extremities the use of the intelligent passive prostheses has overcome the functional capacity achieved in this type of patients referenced in the literature who had used prostheses of previous generations such as mechanical passive prostheses.

RESULTS

With rehabilitation, the patient showed improvements in the following scales and questionnaires (initial vs. final values): Disabilities of the Arm, Shoulder, and Hand Questionnaire; Functional Independence Measure; Berg Balance Scale; Locomotor Capabilities Index in Amputees (an assessment of overall motor capacity); and Special Interest Group in Amputee Medicine scale (an assessment of the degree of mobility).

CONCLUSIONS

The patient's age, psychological status, and family and personal support, in addition to technical and economic resources used for next-generation prostheses adapted to this clinical case, were crucial for his progress. IMPLICATIONS FOR REHABILITATION The use of next-generation myoelectric and microprocessor prostheses makes it possible to achieve greater end functionality in quadruple amputees. Proximal amputation levels present greater difficulty in achieving good functionality. Early and intensive rehabilitation could favour and contribute towards improving psychological states. Age, psychological status, and pain management are aspects to take into account during the rehabilitation process.

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.

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.

Minimally invasive treatment for fractures of lower extremity amputees using a rapid reductor

PURPOSE

A traction table is recommended for lower limb fractures, while it is unavailable for amputees to immobilize the ipsilateral foot to remain stationary and reduce the fracture. For these patients, our rapid reductor can be applied to guarantee stable fixation and optimal reduction, allowing satisfactory implant positioning. This study aims to evaluate the prognosis of amputee patients with lower limb fractures treated by minimally invasive techniques that employ a rapid reductor to reduce the fracture.

METHODS

Between 2013 and 2014, 11 cases of amputees suffering from a lower limb fracture were enrolled in the study, including four transtibial amputees with a tibial plateau fracture, three transtibial amputees with a femoral shaft fracture, and four transfemoral amputees with a femoral neck fracture. All fractures involved the amputated ipsilateral lower limbs, which were all reduced in a closed fashion using a rapid reductor. During the operation, the rapid reductor was connected to the injured limb for skeleton traction to reduce the fracture and then used to maintain the reduction for subsequent minimally invasive fixation. The operation time, reduction time, fluoroscopy time, and intra-operative blood loss were recorded. Follow-ups were conducted to evaluate the union of the fractures and the functional recovery.

RESULTS

All 11 cases were treated successfully using this minimally invasive technique, with anatomical or nearly anatomical reduction reached in all fractures. The average operative time, reduction time, fluoroscopy time, and intra-operative blood loss were 60 minutes (range, 46-90 minutes), 13.2 minutes (range, 7-20 minutes), 19.8 seconds (range, 6-65 seconds), and 95 mL (range, 80-170 mL), respectively. No incidents of reductor-induced complications occurred during the operation. Patients were followed up for an average of 20.8 months (range, 18-24 months). All fractures healed well on an average of six months. At the latest follow-up, all 11 cases reported satisfactory functional recovery of the fixed limbs, which were similar to that before the fractures.

CONCLUSIONS

The rapid reductor can be used to efficiently reduce and maintain ipsilateral fractures of the amputated lower extremity in a closed fashion, which can facilitate minimally invasive fixation of the fractures. The patients can achieve excellent outcomes.

Validation of the Narrowing Beam Walking Test in Lower Limb Prosthesis Users

OBJECTIVE

To evaluate the content, construct, and discriminant validity of the Narrowing Beam Walking Test (NBWT), a performance-based balance test for lower limb prosthesis users.

DESIGN

Cross-sectional study.

SETTING

Research laboratory and prosthetics clinic.

PARTICIPANTS

Unilateral transtibial and transfemoral prosthesis users (N=40).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Content validity was examined by quantifying the percentage of participants receiving maximum or minimum scores (ie, ceiling and floor effects). Convergent construct validity was examined using correlations between participants' NBWT scores and scores or times on existing clinical balance tests regularly administered to lower limb prosthesis users. Known-groups construct validity was examined by comparing NBWT scores between groups of participants with different fall histories, amputation levels, amputation etiologies, and functional levels. Discriminant validity was evaluated by analyzing the area under each test's receiver operating characteristic (ROC) curve.

RESULTS

No minimum or maximum scores were recorded on the NBWT. NBWT scores demonstrated strong correlations (ρ=.70‒.85) with scores/times on performance-based balance tests (timed Up and Go test, Four Square Step Test, and Berg Balance Scale) and a moderate correlation (ρ=.49) with the self-report Activities-specific Balance Confidence scale. NBWT performance was significantly lower among participants with a history of falls (P=.003), transfemoral amputation (P=.011), and a lower mobility level (P<.001). The NBWT also had the largest area under the ROC curve (.81) and was the only test to exhibit an area that was statistically significantly >.50 (ie, chance).

CONCLUSIONS

The results provide strong evidence of content, construct, and discriminant validity for the NBWT as a performance-based test of balance ability. The evidence supports its use to assess balance impairments and fall risk in unilateral transtibial and transfemoral prosthesis users.

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.

Comparison of the Berg Balance Scale and the Mini-BESTest for Assessing Balance in Ambulatory People With Spinal Cord Injury: Validation Study

BACKGROUND

The Berg Balance Scale (BBS) has several constraints-ceiling effect, low responsiveness, and uncertain predictability of falls-in neurological populations. The Mini-BESTest, which has not yet been validated in spinal cord injury (SCI) populations, has shown no ceiling effect, slightly better responsiveness, and could in some neurological populations predict falls.

OBJECTIVE

Validate and compare psychometric performances of the BBS and Mini-BESTest in individuals with chronic SCI.

DESIGN

Cross-sectional validation study.

METHODS

Forty-six individuals able to walk 10 meters (85% American Spinal Injury Association Impairment Scale grade D) with mean age of 55±17 years and median 7 years (range: 1-41) postinjury were included. Floor/ceiling effects were inspected; internal consistency, construct validity, and receiver operating characteristics were analyzed.

RESULTS

The Mini-BESTest had no ceiling effect; 28% of participants achieved the maximum score on the BBS. Both scales showed excellent internal consistency (α > .93). Strong correlations between both scales (r s = 0.90, P < .001) and between both scales and Timed Up and Go (r s > .70), Spinal Cord Independence Measure-mobility items (r s > .80), and 10-Meter Walk Test (r s > .80) support high construct validity. Both scales could differentiate community walkers without walking aids from participants using aids (AUC > .86) and individuals with low/high concerns about falling (AUC > 0.79) but not recurrent (>2 falls/year) and infrequent fallers (AUC < 0.55). The BBS and Mini-BESTest separated 2 and more than 3 different levels of balance control, respectively.

LIMITATIONS

Small sample.

CONCLUSIONS

Both the BBS and Mini-BESTest were found to be valid scales for assessing balance control in individuals with chronic SCI. The Mini-BESTest may be preferable for this group primarily due to the lack of a ceiling effect.

Determining 1-Yr Prosthetic Use for Mobility Prognoses for Community-Dwelling Adults with Lower-Limb Amputation: Development of a Clinical Prediction Rule

OBJECTIVE

The objective of this study was to develop a prognostic clinical prediction rule to identify people not achieving community walking level prosthetic use after 1 yr.

DESIGN

This is a prospective longitudinal cohort study of community-dwelling adults with lower-limb amputations recruited from support groups and prosthetic clinics. Participants completed Activities-specific Balance Confidence and Houghton prosthetic use for mobility self-report scales and the Berg Balance Scale. The clinical prediction rule was developed using multivariate logistic regression, receiver operating curves, and probability statistics to identify people not achieving community walking level prosthetic use (Houghton scores <9) at 1 yr.

RESULTS

Forty (74.1%) of 54 participants provided follow-up data. Participants averaged 57.0 ± 11.9 yrs old, and the most recent amputation had occurred an average of 6.6 ± 11.0 yrs ago. Seventy percent had vascular amputations and 52.5% had transtibial amputations. The clinical prediction rule predicted who would not reach the community prosthetic walking level with excellent accuracy (area under the curve >0.96) using four criteria: initial Houghton, Activities-specific Balance Confidence, and Berg Balance Scale tasks 9 (retrieve object from floor) and 10 (look behind over shoulders). Failure to exceed cutoff scores in two or more criteria yielded posttest probability of not reaching community walking prosthetic use 1 yr later for 90% of participants or higher.

CONCLUSIONS

Accurate 1-yr prosthetic use for mobility prognoses can be obtained by screening prosthetic use, balance confidence, and balance ability to identify community-dwelling people with lower-limb amputations unlikely to achieve community walking prosthetic use.

Understanding responses to gait instability from plantar pressure measurement and the relationship to balance and mobility in lower-limb amputees

BACKGROUND

Measuring responses to a more unstable walking environment at the point-of-care may reveal clinically relevant strategies, particularly for rehabilitation. This study determined if temporal measures, center of pressure-derived measures, and force impulse measures can quantify responses to surface instability and correlate with clinical balance and mobility measures.

METHODS

Thirty-one unilateral amputees, 11 transfemoral and 20 transtibial, walked on level and soft ground while wearing pressure-sensing insoles. Foot-strike and foot-off center of pressure, center of pressure path, temporal, and force impulse variables were derived from F-Scan pressure-sensing insoles.

FINDINGS

Significant differences (P<0.05) between level and soft ground were found for temporal and center of pressure path measures. Twenty regression models (R(2) ≤ 0.840), which related plantar-pressure-derived measures with clinical scores, consisted of nine variables. Stride time was in eight models; posterior deviations per stride in six models; mean CoP path velocity in five models; and anterior-posterior center of pressure path coefficient of variation, percent double-support time, and percent stance in four models.

INTERPRETATION

Center of pressure-derived parameters, particularly temporal and center of pressure path measures, can differentiate between level and soft ground walking for transfemoral and transtibial amputees. Center of pressure-derived parameters correlated with clinical measures of mobility and balance, explaining up to 84.0% of the variability. The number of posterior deviations per stride, mean CoP path velocity stride time, anterior-posterior center of pressure path coefficient of variation, percent double-support time, and percent stance were frequently related to clinical balance and mobility measures.

Evaluation of postural steadiness in below-knee amputees when wearing different prosthetic feet during various sensory conditions using the Biodex® Stability System

In recent years, computerized posturography has become an essential tool in quantitative assessment of postural steadiness in the clinical settings. The purpose of this study was to explore the ability of the Biodex(®) Stability System (BSS) to quantify postural steadiness in below-knee amputees. A convenience sample of 10 below-knee amputees participated in the study. The overall (OSI), anterior-posterior (APSI) and medial-lateral (MLSI) stability indexes as well as the percentage of time spent in left and right quadrants and four concentric zones were measured under altered sensory conditions while standing with solid ankle cushion heel (SACH), single-axis (SA) and energy storage and release (ESAR) feet. Significant difference was found between sensory conditions in SACH and ESAR feet for OSI (SACH, p = 0.002; ESAR, p = 0.005), APSI (SACH, p = 0.036; ESAR, p = 0.003) and MLSI (SACH, p = 0.008; ESAR, p = 0.05) stability indexes. The percentage of time spent in Zone A (0°-5°) was significantly greater than the other three concentric zones (p < 0.01). The loading time percentage on their intact limb (80%-94%) was significantly longer than the amputated limb (20%-6%) in all conditions for all three prosthetic feet. Below-knee amputees showed compromised postural steadiness when visual, proprioceptive or vestibular sensory input was altered. The findings highlight that the characteristics of postural stability in amputees can be clinically assessed by utilizing the outcomes produced by the BSS.

Total hip arthroplasty after lower extremity amputation

There are approximately 1.6 million lower extremity amputees in the United States. Lower extremity amputees are subject to increased physical demands proportional to their level of amputation. Lower extremity amputees have a 6-fold higher risk of developing radiographic osteoarthritis in the ipsilateral hip and a 2-fold risk of developing radiographic osteoarthritis in contralateral hip when compared with the non-amputee population. Additionally, there is a 3-fold increased risk of developing radiographic osteoarthritis in the ipsilateral hip after an above knee amputation when compared with a below knee amputation. The authors retrospectively reviewed 35 total hip arthroplasties after lower extremity amputation. The mean clinical follow-up was 5.3±4.0 years. The mean time from lower extremity amputation to total hip arthroplasty was 12.2±12.8 years after a contralateral amputation and 5.4±6.0 years after an ipsilateral amputation (P=.050). The mean time to total hip arthroplasty was 15.6±15.4 years after an above knee amputation and 6.4±6.1 years after a below knee amputation (P=.021). There was a statistically significant improvement in the mean Harris Hip Score from 35.9±21.8 to 76.8±12.8 with total hip arthroplasty after a contralateral amputation (P<.001). There also was a statistically significant improvement in the mean Harris Hip Score from 25.4±21.7 to 78.6±17.1 with total hip arthroplasty after an ispilateral amputation (P<.001). Three (17.7%) total hip arthroplasties after a contralateral amputation and 2 (11.1%) total hip arthroplasties after an ipsilateral amputation required revision total hip arthroplasty. Patients with an ipsilateral amputation or a below knee amputation progress to total hip arthroplasty faster than those with a contralateral amputation or an above knee amputation, respectively. Lower extremity amputees experience clinically significant improvements with total hip arthroplasty after lower extremity amputation.

Postural stability characteristics of transtibial amputees wearing different prosthetic foot types when standing on various support surfaces

PURPOSE

This study aimed to evaluate the effects of prosthetic foot types on the postural stability among transtibial amputees when standing on different support surfaces.

MATERIALS AND METHODS

The postural stability of 10 transtibial amputees wearing solid ankle cushion heel (SACH) foot, single-axis (SA) foot, and energy-saving and return (ESAR) foot was assessed. Results were compared with able-bodied participants. Anterior-posterior stability index (APSI), mediolateral stability index (MLSI), and overall stability index (OSI) were measured by computed posturography in an upright stance on firm, foam, and unstable support surfaces.

RESULTS

The mean OSI score of SACH foot was significantly lower than that of an ESAR foot when the participants were standing on a compliant surface. When compared to able-bodied group, MLSI score was significantly higher for each of the prosthetic foot groups while OSI score was significantly higher for ESAR foot only in foam condition.

CONCLUSIONS

Differences between prosthetic foot types and groups (amputees versus able-bodied) can only be distinguished when individuals were standing on a compliant surface. Amputees exhibited an increased postural instability in the mediolateral direction than able-bodied individuals. Hence, the restoration of stability in the frontal plane and the enhancement of proprioception at the residual limb should be the basis of rehabilitation programs.

The effects of prosthetic foot type and visual alteration on postural steadiness in below-knee amputees

Background

Achieving independent upright posture has known to be one of the main goals in rehabilitation following lower limb amputation. The purpose of this study was to compare postural steadiness of below knee amputees with visual alterations while wearing three different prosthetic feet.

Methods

Ten male below-knee amputees were instructed to stand quietly on the Biodex® balance platform while wearing solid ankle cushion heel (SACH), single axis (SA) and energy storage and release (ESAR) prosthetic foot under different visual input conditions (eyes-opened and eyes-closed). The overall stability index (OSI), anterior- posterior stability index (APSI), and medial-lateral stability index (MLSI) were computed. Perceived balance assessment of each foot was evaluated using Activities-specific Balance Confidence (ABC) score.

Results

The findings highlights that SACH showed lowest overall stability index (indicating less body sway) during eyes-opened (OSI: SACH = 1.09, SA = 1.58, ESAR = 1.59) and SA showed lowest overall stability index during eyes-closed (OSI: SACH = 2.52, SA = 2.30, ESAR = 2.76) condition. However, overall stability indexes between foot types did not differ significantly during eyes-opened or eyes-closed (p = 0.651). There was a trend of instability which occurred more in medial-lateral compared to anterior-posterior direction for all foot types, with significant result in ESAR foot(eyes-opened: MLSI = 1.59, APSI = 0.65, p = 0.034; eyes-closed: MLSI = 2.76, APSI = 1.80, p = 0.017, respectively). When comparing between visual conditions, stability score was significantly higher during eyes-closed compared to eyes-opened situations for SACH and ESAR foot (eyes-closed vs opened; SACH OSI: 3.43 vs 1.71, p = 0.018 and MLSI: 3.43 vs 1.71, p = 0.018; ESAR OSI: 3.58 vs 1.86, p = 0.043 and APSI: 1.80 vs 0.65, p = 0.027).

Conclusions

The results of this study suggested postural steadiness in below-knee amputees was not affected by the types of prosthetic foot during quiet upright standing, but was significantly affected when visual cues was absent.

Interrater reliability of the Berg Balance Scale when used by clinicians of various experience levels to assess people with lower limb amputations

BACKGROUND

People with lower limb amputations frequently have impaired balance ability. The Berg Balance Scale (BBS) has excellent psychometric properties for people with neurologic disorders and elderly people dwelling in the community. A Rasch analysis demonstrated the validity of the BBS for people with lower limb amputations of all ability strata, but rater reliability has not been tested.

OBJECTIVE

The study objective was to determine the interrater reliability and intrarater reliability of BBS scores and the differences in scores assigned by testers with various levels of experience when assessing people with lower limb amputations.

DESIGN

This reliability study of video-recorded single-session BBS assessments had a cross-sectional design.

METHODS

From a larger study of people with lower limb amputations, 5 consecutively recruited participants using prostheses were video recorded during an in-person BBS assessment. Sixteen testers independently rated the video-recorded assessments. Testers were 3 physical therapists, 1 occupational therapist, 3 third-year and 4 second-year doctor of physical therapy (DPT) students, and 5 first-year DPT students without clinical training. Rater reliability was calculated using intraclass correlation coefficients (ICC [2,k]). Differences in scores assigned by testers with various levels of experience were determined by use of an analysis of variance with Tukey post hoc tests.

RESULTS

The average age of the participants was 53.0 years (SD=15.7). Amputations had occurred at the ankle disarticulation, transtibial, and transfemoral levels because of vascular, trauma, and medical etiologies an average of 8.2 years earlier (SD=7.9). Berg Balance Scale scores spanned all ability strata. Interrater reliability (ICC [2,k]=.99) and intrarater reliability of scores determined in person and through video-recorded assessments by the same testers (ICC [2,k]=.99) were excellent. For participants with the lowest levels of ability, licensed professionals assigned lower scores than did DPT students without clinical training.

LIMITATIONS

Intrarater reliability calculations were based on 2 testers.

CONCLUSIONS

Berg Balance Scale scores assigned to people using prostheses by testers with various levels of clinical experience had excellent interrater reliability and intrarater reliability.