Impact of Vascular Disease, Amputation Level, and the Mismatch Between Balance Ability and Balance Confidence in a Cross-Sectional Study of the Likelihood of Falls Among People With Limb Loss: Perception Versus Reality

Spatiotemporal gait parameters influencing functional mobility of people with lower limb amputation

BACKGROUND

Walking speed is a measure of functional mobility that is relatively easy to quantify. In people with lower limb amputation, reduced walking speed has been linked with specific atypical spatiotemporal gait parameters. However, the influence of atypical spatiotemporal gait parameters on the walking speed of people with unilateral transtibial amputation (TTA) and transfemoral amputation (TFA) remains unclear.

OBJECTIVES

To identify spatiotemporal gait parameters influencing walking speed of people with unilateral TTA or TFA.

STUDY DESIGN

Cross-sectional.

METHODS

The 10-meter walk test (10mWT) was used to measure walking speed, and an instrumented walkway was used to record spatiotemporal gait parameters. Regression analyses were used to determine the best subset of spatiotemporal gait parameters that influence the walking speed of people with TTA and TFA.

RESULTS

The study included 43 people with TTA and 49 with TFA. In the TTA group, spatiotemporal gait parameters accounted for 65.5% of the variance in walking speed, with prosthetic single limb support accounting for 52.2%, prosthetic terminal double limb support accounting for 8.9%, and stride width accounting for 4.4%. In the TFA group, intact swing accounted for 46.7% of the variance in walking speed. There was no significant difference in walking speed between the TTA and the TFA groups (p > 0.05).

CONCLUSIONS

The study's results highlight specific spatiotemporal gait parameters that affect the walking speed of people with unilateral TTA and TFA. In addition, results suggest that walking speed over short distances is not confounded by amputation level (i.e., TTA and TFA).

Falls perceived as significant by lower limb prosthesis users are generally associated with fall consequences rather than circumstances

PURPOSE

To determine if falls perceived as significant by lower limb prosthesis (LLP) users were associated with fall circumstances and/or consequences.

MATERIALS AND METHODS

The circumstances and consequences of LLP users' most significant fall in the past 12-months were collected using the Lower Limb Prosthesis User Fall Event Survey. Participants rated fall significance from 0 (not significant) to 10 (extremely significant), which was then dichotomized into "low" and "high". Binary logistic regression was used to assess associations between fall significance and fall circumstances and consequences.

RESULTS

Ninety-eight participants were included in the analysis. Five fall consequences were associated with greater significance: major injury (OR = 26.7, 95% CI: 1.6-459.6, p = 0.024), need to seek medical treatment (OR = 19.0, 95% CI: 1.1-329.8, p = 0.043), or allied-health treatment (OR = 18.2, 95% CI: 2.3-142.4, p = 0.006), decreased balance confidence (OR = 10.9, 95% CI: 2.4-49.3, p = 0.002), and increased fear of falling (OR = 7.5, 95% CI: 2.4-23.8, p = 0.001), compared to two fall circumstances: impact to the arm (OR = 5.0, 95% CI: 2.0-12.1, p = 0.001), and impact to the face, head, or neck (OR = 9.7, 95% CI: 1.2-77.4, p = 0.032).

CONCLUSIONS

Significant falls were generally more associated with fall consequence than fall circumstances.

Balance confidence classification in people with a lower limb amputation using six minute walk test smartphone sensor signals

The activities-specific balance confidence scale (ABC) assesses balance confidence during common activities. While low balance confidence can result in activity avoidance, excess confidence can increase fall risk. People with lower limb amputations can present with inconsistent gait, adversely affecting their balance confidence. Previous research demonstrated that clinical outcomes in this population (e.g., stride parameters, fall risk) can be determined from smartphone signals collected during walk tests, but this has not been evaluated for balance confidence. Fifty-eight (58) individuals with lower limb amputation completed a six-minute walk test (6MWT) while a smartphone at the posterior pelvis was used for signal collection. Participant ABC scores were categorized as low confidence or high confidence. A random forest classified ABC groups using features from each step, calculated from smartphone signals. The random forest correctly classified the confidence level of 47 of 58 participants (accuracy 81.0%, sensitivity 63.2%, specificity 89.7%). This research demonstrated that smartphone signal data can classify people with lower limb amputations into balance confidence groups after completing a 6MWT. Integration of this model into the TOHRC Walk Test app would provide balance confidence classification, in addition to previously demonstrated clinical outcomes, after completing a single assessment and could inform individualized rehabilitation programs to improve confidence and prevent activity avoidance.

Pain, Balance-Confidence, Functional Mobility, and Reach Are Associated With Risk of Recurrent Falls Among Adults With Lower-Limb Amputation

Objective

The study evaluated whether pain intensity and extent, balance-confidence, functional mobility, and balance (eg, functional reach) are potential risk factors for recurrent falls among adults with a lower-limb amputation.

Design

Cross-sectional study.

Setting

Research laboratory.

Participants

Eighty-three adults with unilateral lower-limb amputation that occurred >1 year prior (26 transfemoral- and 57 transtibial-level amputation; 44.6% women; 51.8% traumatic cause of amputation; N=83).

Intervention

Not applicable.

Main Outcome Measures

Participants reported on the number of falls in the past year, as well as pain intensity in the low back, residual, and sound limbs. Balance-confidence (per the Activities-Specific Balance-Confidence Scale [ABC]), functional mobility (per the Prosthetic Limb Users Survey of Mobility ([PLUS-M]), and balance (per the Functional Reach and modified Four Square Step Tests) were obtained.

Results

After considering non-modifiable covariates, greater extent of pain, less balance-confidence, worse self-reported mobility, and reduced prosthetic-side reach were factors associated with recurrent fall risk. Adults reporting pain in the low back and both lower-limbs had 6.5 times the odds of reporting recurrent falls as compared with peers without pain. A 1-point increase in ABC score or PLUS-M T score, or 1-cm increase in prosthetic-side reaching distance, was associated with a 7.3%, 9.4%, and 7.1% decrease in odds of reporting recurrent falls in the past year, respectively.

Conclusions

Of the 83 adults, 36% reported recurrent falls in the past year. Presence of pain in the low back and both lower-limbs, less balance-confidence, worse PLUS-M score, and less prosthetic-side reaching distance were identified as modifiable factors associated with an increased odd of recurrent falls.

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.

Risk Factors for Underreporting of Life-Limiting Comorbidity Among Adults With Lower-Limb Loss

Peripheral neuropathy (PN) and peripheral arterial disease (PAD) are life-limiting comorbidities among adults with lower-limb loss that may not be adequately addressed in current care models. The objective of this study was to evaluate underreporting of PN and PAD among adults with lower-limb loss. We conducted a secondary analysis of a cross-sectional dataset of community-dwelling adults with unilateral lower-limb loss seen in an outpatient Limb Loss Clinic (n = 196; mean age = 56.7 ± 14.4 years; 73.5% male). Individuals participated in standardized clinical examinations including Semmes-Weinstein monofilament testing to assess for PN and pedal pulse palpation to assess for PAD. Bivariate regression was performed to identify key variables for subsequent stepwise logistic regression to discern risk factors. Clinical examination results indicated 16.8% (n = 33) of participants had suspected PN alone, 15.8% (n = 31) had suspected PAD alone, and 23.0% (n = 45) had suspected PN and PAD. More than half of participants with clinical examination findings of PN or PAD failed to self-report the condition (57.7% and 86.8%, respectively). Among adults with lower-limb loss with suspected PN, participants with dysvascular amputations were at lower risk of underreporting (odds ratio [OR] = 0.2, 95% CI: 0.1-0.6). For those with suspected PAD, those who reported more medication prescriptions were at lower risk of underreporting (OR = 0.8, 95% CI: 0.7-1.0). Adults with lower-limb loss underreport PN and PAD per a medical history checklist, which may indicate underdiagnosis or lack of patient awareness. Routine assessment is highly recommended in this population and may be especially critical among individuals with non-dysvascular etiology.

Neuromuscular mechanisms of motor adaptation to repeated gait-slip perturbations in older adults

Individuals can rapidly develop adaptive skills for fall prevention after their exposure to the repeated-slip paradigm. However, the changes in neuromuscular control contributing to such motor adaptation remain unclear. This study investigated changes in neuromuscular control across different stages of slip-adaptation by examining muscle synergies during slip training. Electromyography signals during 24 repeated slip trials in gait were collected for 30 healthy older adults. Muscle synergies in no-adaptation (novel slip), early-adaptation (slip 6 to 8), and late-adaptation trials (slip 22 to 24) were extracted. The similarity between the recruited muscle synergies in these different phases was subsequently analyzed. Results showed that participants made significant improvements in their balance outcomes from novel slips to adapted slips. Correspondingly, there was a significant increase in the muscle synergy numbers from no-adaptation slips to the adapted slips. The participants retained the majority of muscle synergies (5 out of 7) used in novel slips post adaptation. A few new patterns (n = 8) of muscle synergies presented in the early-adaptation stage to compensate for motor errors due to external perturbation. In the late-adaptation stage, only 2 out of these 8 new synergies were retained. Our findings indicated that the central nervous system could generate new muscle synergies through fractionating or modifying the pre-existing synergies in the early-adaptation phase, and these synergies produce motor strategies that could effectively assist in recovery from the slip perturbation. During the late-adaptation phase, the redundant synergies generated in the early-adaptation phase get eliminated as the adaptation process progresses with repeated exposure to the slips, which further consolidates the slip adaptation. Our findings improved the understanding of the key muscle synergies involved in preventing backward balance loss and how neuromuscular responses adapt through repeated slip training, which might be helpful to design synergy-based interventions for fall prevention.

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

BACKGROUND

Over a million people live with lower limb amputation (LLA) in the United States, and many of them will experience a fall in the next year. The aim of this study was to use existing theoretical frameworks in an attempt to organize the complex interactions of reported fall history and prosthetic mobility in community-ambulating people with LLA.

METHODS

Self-reported fall rate and fall circumstances were recorded in a cross-section of people with unilateral LLA due to nondysvascular causes. Self-report and performance-based standardized outcome measures assessed prosthetic mobility and balance confidence. All variables were considered and appropriately placed within a proposed International Classification of Functioning, Disability, and Health framework while using a fall-type classification framework to classify fall circumstances.

RESULTS

Information from 69 participants was analyzed. The reported fall rate was at 46%, with those with transfemoral amputation reporting significantly more falls than those with transtibial amputation ( P = 0.001). Tripping over an object was the most common cause (62.5%), and fallers reported significantly lower perceived prosthetic mobility than nonfallers ( P = 0.001). Despite reporting high levels of balance confidence, results indicate that all groups of fallers and nonfallers are at increased fall risk according to performance-based prosthetic mobility score cutoffs.

CONCLUSIONS

Community-dwelling people with nondysvascular LLA are at increased fall risk. Classifying fall-related variables using theoretical frameworks provides a means to structure more informative fall risk surveys for people with LLA in an attempt to identify those at greater risk for falling and its potential detrimental effects.

Automated step detection with 6-minute walk test smartphone sensors signals for fall risk classification in lower limb amputees

Predictive models for fall risk classification are valuable for early identification and intervention. However, lower limb amputees are often neglected in fall risk research despite having increased fall risk compared to age-matched able-bodied individuals. A random forest model was previously shown to be effective for fall risk classification of lower limb amputees, however manual labelling of foot strikes was required. In this paper, fall risk classification is evaluated using the random forest model, using a recently developed automated foot strike detection approach. 80 participants (27 fallers, 53 non-fallers) with lower limb amputations completed a six-minute walk test (6MWT) with a smartphone at the posterior pelvis. Smartphone signals were collected with The Ottawa Hospital Rehabilitation Centre (TOHRC) Walk Test app. Automated foot strike detection was completed using a novel Long Short-Term Memory (LSTM) approach. Step-based features were calculated using manually labelled or automated foot strikes. Manually labelled foot strikes correctly classified fall risk for 64 of 80 participants (accuracy 80%, sensitivity 55.6%, specificity 92.5%). Automated foot strikes correctly classified 58 of 80 participants (accuracy 72.5%, sensitivity 55.6%, specificity 81.1%). Both approaches had equivalent fall risk classification results, but automated foot strikes had 6 more false positives. This research demonstrates that automated foot strikes from a 6MWT can be used to calculate step-based features for fall risk classification in lower limb amputees. Automated foot strike detection and fall risk classification could be integrated into a smartphone app to provide clinical assessment immediately after a 6MWT.

Near-Fall Detection in Unexpected Slips during Over-Ground Locomotion with Body-Worn Sensors among Older Adults

Slip-induced falls are a growing health concern for older adults, and near-fall events are associated with an increased risk of falling. To detect older adults at a high risk of slip-related falls, this study aimed to develop models for near-fall event detection based on accelerometry data collected by body-fixed sensors. Thirty-four healthy older adults who experienced 24 laboratory-induced slips were included. The slip outcomes were first identified as loss of balance (LOB) and no LOB (NLOB), and then the kinematic measures were compared between these two outcomes. Next, all the slip trials were split into a training set (90%) and a test set (10%) at sample level. The training set was used to train both machine learning models (n = 2) and deep learning models (n = 2), and the test set was used to evaluate the performance of each model. Our results indicated that the deep learning models showed higher accuracy for both LOB (>64%) and NLOB (>90%) classifications than the machine learning models. Among all the models, the Inception model showed the highest classification accuracy (87.5%) and the largest area under the receiver operating characteristic curve (AUC), indicating that the model is an effective method for near-fall (LOB) detection. Our approach can be helpful in identifying individuals at the risk of slip-related falls before they experience an actual fall.

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.

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

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

Performance-based balance tests, combined with the number of falls recalled in the past year, predicts the incidence of future falls in established unilateral transtibial prosthesis users

BACKGROUND

Falls are common and consequential events for lower limb prosthesis (LLP) users. Currently, there are no models based on prospective falls data that clinicians can use to predict the incidence of future falls in LLP users. Assessing who is at risk for falls, and thus most likely to need and benefit from intervention, remains a challenge.

OBJECTIVE

To determine whether select performance-based balance tests predict future falls in established, unilateral transtibial prosthesis users (TTPU).

DESIGN

Multisite prospective observational study.

SETTING

Research laboratory and prosthetics clinic.

PARTICIPANTS

Forty-five established, unilateral TTPU.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

The number of falls reported over a prospective 6-month period. Timed Up-and-Go (TUG) and Four-Square Step Test (FSST) times, as well as Narrowing Beam Walking Test scores were recorded at baseline, along with the number of falls recalled over the past 12 months and additional potential fall-risk factors.

RESULTS

The final negative binomial regression model, which included TUG (P = .044) and FSST (P = .159) times, as well as the number of recalled falls (P = .009), was significantly better than a null model at predicting the number of falls over the next 6 months (X² [3] = 11.6, P = .009) and fit the observed fall count data (X² [41] = 36.12, P = .20). The final model provided a significant improvement in fit to the prospective fall count data over a model with fall recall alone X² (1) = 4.342, P < .05.

CONCLUSION

No combination of performance-based balance tests alone predicted the incidence of future falls in our sample of established, unilateral TTPU. Rather, a combination of the number of falls recalled over the past 12 months, along with TUG and FSST times, but not NBWT scores, was required to predict the number of "all-cause" falls over the next 6 months. The resulting predictive model may serve as a suitable method for clinicians to predict the incidence of falls in established, unilateral TTPU.

Falls After Dysvascular Transtibial Amputation: A Secondary Analysis of Falling Characteristics and Reduced Physical Performance

INTRODUCTION

Over half of all people with lower limb amputation (LLA) experience at least one fall annually. Furthermore, the majority of LLAs result from dysvascular health complications, contributing to balance deficits. However, fall-related research specific to dysvascular LLA remains limited.

OBJECTIVE

To characterize falls among adults with dysvascular LLA, using an existing Fall-Type Classification Framework and to describe the functional characteristics of participants across the framework categories.

DESIGN

Secondary data analysis from two randomized controlled trials.

SETTING

Outpatient setting.

PARTICIPANTS

People (n = 69) 6 months to 5 years from dysvascular lower extremity amputation, who were ≥50 years of age and independently ambulatory using a prosthesis.

INTERVENTION

None.

OUTCOME

Descriptions of self-reported falls were collected on a weekly basis for 12 weeks, and analyzed using an existing Fall-Type Classification Framework. Fall frequencies, estimated count, and estimated proportions were compared across all framework categories, with 95% confidence intervals. Functional measures (Timed Up and Go, Two Minute Walk, Five Meter Walk, and average step count) were collected, and averages for each participant who experienced a fall were calculated.

RESULTS

Thirty participants (43.5%) reported 42 falls within 12 weeks. A variety of fall types were described. Incidence of falls was highest for intrinsic destabilization sources, from incorrect weight shift patterns during transfer activities.

CONCLUSION

Patients with dysvascular LLAs experience a variety of fall types. The high frequency of intrinsically sourced, incorrect weight-shift falls during transfer activities emphasizes the need to focus rehabilitation efforts on improving postural control in patients with dysvascular LLAs during activities such as reaching, turning, and transferring.

Validation of the Activities-Specific Balance Confidence Scale With 5-Option Response Format in Slovene Lower-Limb Prosthetic Users

OBJECTIVE

To examine the psychometric properties of the Activities-specific Balance Confidence (ABC) scale administered in the Slovene version with a simplified 5-option response format (ABC-5/SLO) using Rasch analysis.

DESIGN

Methodological research on data gathered in a cross-sectional study.

SETTING

Outpatient university rehabilitation clinic.

PARTICIPANTS

A convenience sample of adults with unilateral lower-limb amputation (N=138; 75% men) longer than 6 months who regularly wear a prosthesis.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

We evaluated functioning of rating scale categories, internal construct validity, reliability indices, and dimensionality using the ABC-5/SLO (0=no confidence to 4=complete confidence).

RESULTS

The ABC-5/SLO rating scale fulfilled the category functioning criteria. All items fit the underlying scale construct (balance confidence) except item 8 ("walk outside the house to a car parked in the driveway"), which was overfitting. The person abilities-item difficulty matching (targeting) was good. The person separation reliability was .92, and the item separation reliability was .99. Analysis of the standardized Rasch residuals showed the scale's unidimensionality and absence of high item dependency (residual correlations, <.30). The correlation between the ABC-5/SLO and the Prosthetic Mobility Questionnaire (Rasch measures) was high (ρ=.84), as expected. Minor signs of item redundancy were found.

CONCLUSIONS

The simplified ABC-5/SLO scale is a valid and reliable measure of balance confidence for individuals with lower-limb amputation. It is possible to transform the ordinal summed raw scores of the ABC-5/SLO into interval-level measurements using a nomogram.

The Role of the Podiatrist in Assessing and Reducing Fall Risk: An Updated Review

Falls present a tremendous challenge to health care systems. This article reviews the literature from the previous 5 years (2014-2019) in terms of methods to assess fall risk and potential steps that can be taken to reduce fall risk for patients visiting podiatric clinics. With regard to assessing fall risk, we discuss the role of a thorough medical history and podiatric assessments of foot problems and deformities that can be performed in the clinic. With regard to fall prevention we consider the role of shoe modification, exercise, pain relief, surgical interventions, and referrals.

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.