Laboratory- and community-based health outcomes in people with transtibial amputation using crossover and energy-storing prosthetic feet: A randomized crossover trial

The development of rating scales to evaluate experiential prosthetic foot preference for people with lower limb amputation

BACKGROUND

Selection of a foot is an important aspect of prosthetic prescription and vital to maximizing mobility and functional goals after lower limb amputation. Development of a standardized approach to soliciting user experiential preferences is needed to improve evaluation and comparison of prosthetic feet.

OBJECTIVE

To develop rating scales to assess prosthetic foot preference and to evaluate use of these scales in people with transtibial amputation after trialing different prosthetic feet.

DESIGN

Participant-blinded, repeated measures crossover trial.

SETTING

Veterans Affairs and Department of Defense Medical Centers, laboratory setting.

PARTICIPANTS

Seventy-two male prosthesis users with unilateral transtibial amputation started, and 68 participants completed this study.

INTERVENTIONS

Participants trialed three mobility-level appropriate commercial prosthetic feet briefly in the laboratory.

MAIN OUTCOME MEASURES

"Activity-specific" rating scales were developed to assess participants' ability with a given prosthetic foot to perform typical mobility activities (eg, walking at different speeds, on inclines, and stairs) and "global" scales to rate overall perceived energy required to walk, satisfaction, and willingness to regularly use the prosthetic foot. Foot preference was determined by comparing the rating scale scores, after laboratory testing.

RESULTS

The greatest within-participant differences in scores among feet were observed in the "incline" activity, where 57% ± 6% of participants reported 2+ point differences. There was a significant association (p < .05) between all "activity-specific" rating scores (except standing) and each "global" rating score.

CONCLUSIONS

The standardized rating scales developed in this study could be used to assess prosthetic foot preference in both the research and clinical settings to guide prosthetic foot prescription for people with lower limb amputation capable of a range of mobility levels.

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.

Effects of high-profile crossover feet on gait biomechanics in 2 individuals with Syme amputation

BACKGROUND

Prosthetic treatment options for people with ankle disarticulation (i.e., Syme amputation) are limited. Prosthetic feet designed for people with Syme amputation are often low profile to accommodate build-height restrictions, resulting in decreased energy return during gait. High-profile crossover feet that attach to the posterior proximal aspect of the prosthetic socket can bypass these restrictions and may promote a more physiologic gait pattern.

OBJECTIVES

To compare level-ground gait biomechanics and patient-reported outcomes between crossover and traditional energy-storing feet in people with Syme amputation.

STUDY DESIGN

Within-participant pilot study.

METHODS

Both participants were fit with energy-storing and crossover feet and were randomized to the order they used the feet. Participants used each foot for 2 weeks before assessment. Step length symmetry, prosthetic ankle range of motion, prosthetic-side energy return, and peak sound-side loading were determined from motion capture data obtained in a laboratory. Mobility and balance confidence were measured using standardized patient-reported outcome measures. Foot preference was assessed with an ad hoc survey.

RESULTS

Two participants with Syme amputations completed the study. Prosthetic ankle peak dorsiflexion and push-off power increased with the crossover foot compared with the energy-storing foot for both participants. Both participants reported an overall preference of the crossover foot. Changes in patient-reported outcomes did not exceed published minimum detectable change values.

CONCLUSION

Crossover feet increased prosthetic ankle range of motion and energy return compared with traditional energy-storing feet in this pilot investigation of 2 participants. Crossover feet seem to promote physiologic gait and may be a promising alternative to traditional low-profile feet for people with Syme amputation.

Use of Physical Activity Measures in Rehabilitation Interventions Following Lower Extremity Amputation

Purpose of Review

This systematic review aims to evaluate physical performance outcome tools that are used most frequently to assess rehabilitation interventions. The scope of this paper focused on outcomes used with established lower limb amputees when assessing interventions such as exercise programs or changes in prescription published in the last 5 years.

Recent Findings

The most recorded outcome measures used across all the papers were timed walk tests and the Activity Balance Confidence Scale. Many outcomes did not produce statistically significant results with established amputee cohorts. Understanding the minimal important clinical difference is key.

Summary

The use of outcome measures is essential. Training and education are likely to increase the use of outcome measures. Quality of life measures are important in conjunction with physical outcomes. Simple timed walk tests are commonly used. These are in general easy to administer requiring a small space, limited equipment, and a short time frame.

'It's more than just a running leg': a qualitative study of running-specific prosthesis use by children and youth with lower limb absence

PURPOSE

The purpose of this study was to investigate the use of running-specific prostheses (RSPs) by children with lower limb absence (LLA) along with the benefits and challenges of RSPs.

MATERIALS AND METHODS

In this descriptive qualitative study, eight children (ages 8-20 years) and their parents participated in semi-structured interviews. The interviews were audio-recorded and transcribed. Coded data were the foundation for central theme development.

RESULTS

Three main themes were generated. "Run faster, jump higher, do more" (the benefits of RSP use), "Every leg serves its purpose" (comparing functionality between daily use prostheses and RSPs), and "A lot more to think about" (additional considerations with RSP use).

CONCLUSIONS

RSPs have a positive impact in promoting children's engagement in sports and physical activities. While some children used their RSP primarily for running, others wore it for a broader range of physical activities. Issues with balance and discomfort caused by leg length discrepancies and/or ill-fitting sockets limited daily wear time. Limitations related to current RSP designs and clinical implementation should be addressed to optimize the functional potential of children with unilateral or bilateral LLA.Implications for rehabilitationRunning-specific prostheses (RSPs) positively impacted children's ability to participate in some sports with peers promoting their physical and social well-being.The main issues that children faced were discomfort, difficulty balancing, and inability to use RSPs for certain sports, while parents' issues focused on supporting prosthesis use and transport, and adjustments of different prostheses to keep up with their child's growth.Clinicians should be aware of the challenges of RSP use to best support children and their families.Designers should focus on addressing limitations with current RSPs to facilitate the diverse needs of pediatric users.

Reported Outcome Measures in Studies of Real-World Ambulation in People with a Lower Limb Amputation: A Scoping Review

BACKGROUND

The rapidly increasing use of wearable technology to monitor free-living ambulatory behavior demands to address to what extent the chosen outcome measures are representative for real-world situations. This scoping review aims to provide an overview of the purpose of use of wearable activity monitors in people with a Lower Limb Amputation (LLA) in the real world, to identify the reported outcome measures, and to evaluate to what extent the reported outcome measures capture essential information from real-world ambulation of people with LLA.

METHODS

The literature search included a search in three databases (MEDLINE, CINAHL, and EMBASE) for articles published between January 1999 and January 2022, and a hand-search.

RESULTS AND CONCLUSIONS

98 articles met the inclusion criteria. According to the included studies' main objective, the articles were classified into observational (n = 46), interventional (n = 34), algorithm/method development (n = 12), and validity/feasibility studies (n = 6). Reported outcome measures were grouped into eight categories: step count (reported in 73% of the articles), intensity of activity/fitness (31%), type of activity/body posture (27%), commercial scores (15%), prosthetic use and fit (11%), gait quality (7%), GPS (5%), and accuracy (4%). We argue that researchers should be more careful with choosing reliable outcome measures, in particular, regarding the frequently used category step count. However, the contemporary technology is limited in providing a comprehensive picture of real-world ambulation. The novel knowledge from this review should encourage researchers and developers to engage in debating and defining the framework of ecological validity in rehabilitation sciences, and how this framework can be utilized in the development of wearable technologies and future studies of real-world ambulation in people with LLA.

A Scoping Review of Physical Activity in People With Lower-Limb Loss: 10,000 Steps Per Day?

OBJECTIVE

After amputation, people with lower-limb loss (PLL) face challenges to regain their previous physical activity level. Assessing the scope of evidence regarding physical activity in PLL can identify sources of evidence and gaps within the literature that can influence amputation-related research, outcome assessment choices, and wellness activities. The purpose of this scoping review was to map the evidence regarding steps per day as a physical activity measure for PLL. Specific aims were to (1) identify research designs, (2) catalog population subgroups, (3) document steps per day measurement methods, and (4) provide descriptive data for steps per day in PLL.

METHODS

The MEDLINE, CINAHL, Embase, Web of Science, and AMED databases; and the Journal of Prosthetics and Orthotics archive were searched without language or time limits. Exclusion criteria included no PLL subjects, not peer-reviewed, and no direct step count measure. Inclusion criteria allowed any sample size, nonprosthetic use, and self-reported step count. As a scoping review, only descriptive statistics were compiled, and no methodologic quality assessment was performed.

RESULTS

Twenty-one articles using crossover (8), cohort (4), cross-section (8), and case-study (1) designs were included that reported accelerometer (19) or pedometer (2) data. Studies often mixed amputation etiologies (15/21) and most (13/21) excluded transfemoral amputations. Studies primarily examined people with transtibial amputations (81.2%) and people at independent community walking levels (Medicare functional classifications: K3 = 49.2%, K4 = 36.3%). All 21 studies had fewer than 100 participants, and overall included 515 subjects (343, 66.6% male), mean (SD) age 53.2 (22.1) years. Mean (SD) number of pooled steps per day for PLL was 5087 (2998): 5929 (3047) for transtibial amputations and 3553 (2030) for transfemoral amputations.

CONCLUSIONS

Most PLL have low activity levels compared with the 10,000 steps per day generally recommended or 6000 common in people with diabetes. Research with larger samples, defined subgroups, and data along the recovery continuum would enhance knowledge of physical activity level in PLL.

IMPACT

This scoping review has identified gaps in the research related to steps per day as a measure of physical activity in people with lower-limb loss to guide future research.

LAY SUMMARY

People with lower-limb loss take fewer steps per day than suggested for general health. Increasing steps per day may be a useful goal for this population, and this study is a first step in improving knowledge of physical activity levels in people with lower-limb loss.

Locomotor activities of individuals with lower-limb amputation

BACKGROUND

Ambulatory individuals with lower-limb amputation perform a variety of locomotor activities, but the step count distribution of these activities is unknown.

OBJECTIVE

To describe a novel method for activity monitoring and to use it to count steps taken while walking straight ahead on level ground, turning right and left, up and down stairs, and up and down ramps.

STUDY DESIGN

This is an observational study.

METHODS

A portable instrument to record leg motion was placed on or inside the prosthetic pylon of 10 individuals with unilateral transtibial amputations. Participants first walked a defined course in a hospital environment to train and validate a machine learning algorithm for classifying locomotor activity. Participants were then free to pursue their usual activities while data were continuously collected over 1-2 d.

RESULTS

Overall classification accuracy was 97.5% ± 1.5%. When participants were free to walk about their home, work, and community environments, 82.8% of all steps were in a straight line, 9.0% were turning steps, 4.8% were steps on stairs, and 3.6% were steps on ramps.

CONCLUSION

A novel activity monitoring method accurately classified the locomotion activities of individuals with lower-limb amputation. Nearly 1 in 5 of all steps taken involved turning or walking on stairs and ramps.

STEPFORWARD study: a randomised controlled feasibility trial of a self-aligning prosthetic ankle-foot for older patients with vascular-related amputations

OBJECTIVES

To determine the feasibility of conducting a full-scale randomised controlled trial (RCT) of the effectiveness and cost-effectiveness of a self-aligning prosthetic ankle-foot compared with a standard prosthetic ankle-foot.

DESIGN

Multicentre parallel group feasibility RCT.

SETTING

Five prosthetics centres in England recruiting from July 2018 to August 2019.

PARTICIPANTS

Adults aged ≥50 years with a vascular-related or non-traumatic transtibial amputation for 1 year or longer, categorised as having 'limited community mobility' and using a non-self-aligning ankle-foot.

INTERVENTION

Participants were randomised into one of two groups for 12 weeks: self-aligning prosthetic ankle-foot or existing non-self-aligning prosthetic ankle-foot.

OUTCOMES

Feasibility measures: recruitment, consent and retention rates; and completeness of questionnaire and clinical assessment datasets across multiple time points. Feasibility of collecting daily activity data with wearable technology and health resource use data with a bespoke questionnaire.

RESULTS

Fifty-five participants were randomised (61% of the target 90 participants): n=27 self-aligning ankle-foot group, n=28 non-self-aligning ankle-foot group. Fifty-one participants were included in the final analysis (71% of the target number of participants). The consent rate and retention at final follow-up were 86% and 93%, respectively. The average recruitment rate was 1.25 participants/site/month (95% CI 0.39 to 2.1). Completeness of questionnaires ranged from 89%-94%, and clinical assessments were 92%-95%, including the activity monitor data. The average completion rates for the EQ-5D-5L and bespoke resource use questionnaire were 93% and 63%, respectively.

CONCLUSIONS

This feasibility trial recruited and retained participants who were categorised as having 'limited community mobility' following a transtibial amputation. The high retention rate of 93% indicated the trial was acceptable to participants and feasible to deliver as a full-scale RCT. The findings support a future, fully powered evaluation of the effectiveness and cost-effectiveness of a self-aligning prosthetic ankle-foot compared with a standard non-self-aligning version with some adjustments to the trial design and delivery.

TRIAL REGISTRATION NUMBER

ISRCTN15043643.

Experimental Demonstration of the Lower Leg Trajectory Error Framework Using Physiological Data as Inputs

While many studies have attempted to characterize the mechanical behavior of passive prosthetic feet to understand their influence on amputee gait, the relationship between mechanical design and biomechanical performance has not yet been fully articulated from a fundamental physics perspective. A novel framework, called lower leg trajectory error (LLTE) framework, presents a means of quantitatively optimizing the constitutive model of prosthetic feet to match a reference kinematic and kinetic dataset. This framework can be used to predict the required stiffness and geometry of a prosthesis to yield a desired biomechanical response. A passive prototype foot with adjustable ankle stiffness was tested by a unilateral transtibial amputee to evaluate this framework. The foot condition with LLTE-optimal ankle stiffness enabled the user to replicate the physiological target dataset within 16% root-mean-square (RMS) error. Specifically, the measured kinematic variables matched the target kinematics within 4% RMS error. Testing a range of ankle stiffness conditions from 1.5 to 24.4 N·m/deg with the same user indicated that conditions with lower LLTE values deviated the least from the target kinematic data. Across all conditions, the framework predicted the horizontal/vertical position, and angular orientation of the lower leg during midstance within 1.0 cm, 0.3 cm, and 1.5 deg, respectively. This initial testing suggests that prosthetic feet designed with low LLTE values could offer benefits to users. The LLTE framework is agnostic to specific foot designs and kinematic/kinetic user targets, and could be used to design and customize prosthetic feet.

The effect of prosthetic foot stiffness on foot-ankle biomechanics and relative foot stiffness perception in people with transtibial amputation

BACKGROUND

Prosthetic feet are available in a range of stiffness categories, however, there is limited evidence to guide optimal selection during prosthetic foot prescription. The aim of this study was to determine the effect of commercial prosthetic foot stiffness category on foot-ankle biomechanics, gait symmetry, community ambulation, and relative foot stiffness perception.

METHODS

Participants were fit in randomized order with three consecutive stiffness categories of a commonly-prescribed prosthetic foot. Prosthetic foot roll-over shape and ankle push-off power and work were determined via data collected during walking in a motion analysis laboratory. Step activity was recorded during community use of each foot. Self-reported perception of relative foot stiffness was assessed with an ad hoc survey.

FINDINGS

Seventeen males with transtibial amputation completed the study. Prosthetic foot roll-over radius increased with increased prosthetic foot stiffness categories (p < 0.001). Both prosthetic ankle push-off peak power and work decreased with increased foot stiffness categories (p = 0.002). There was no association between prosthetic foot stiffness category and step length symmetry or steps per day. When assessed post-accommodation, there was no association between relative foot stiffness perception and the stiffness category across prosthetic foot conditions.

INTERPRETATION

Prosthetic foot stiffness category was significantly associated with changes in prosthetic foot-ankle biomechanical variables, however, was not associated with changes in gait symmetry or community ambulation. Relative prosthetic foot stiffness perception after accommodation was generally inconsistent with the order of prosthetic foot stiffness categories.

CLINICAL RELEVANCE

While there were quantifiable differences in prosthetic foot-ankle biomechanics across stiffness categories, no significant differences were detected in gait symmetry or mean daily step count in the community. Furthermore, after community use, participants perceptions of relative stiffness across feet were generally inconsistent with the order of prosthetic foot stiffness categories. These findings raise questions as to whether changes in commercial prosthetic foot stiffness category (within a clinically relevant range) affect subjective and objective measures relevant to successful outcomes from prosthetic foot prescription.

Effectiveness of a crossover prosthetic foot in active children with a congenital lower limb deficiency: an explorative study

BACKGROUND

Children with lower limb prostheses cannot always keep up with their peers during active play. A pediatric crossover foot may be a promising prosthetic alternative for children engaging in high-intensity movements necessary for active play.

OBJECTIVES

To compare children's walking performance, running performance, experienced competence, and cosmesis using their prescribed prosthesis compared with the crossover foot.

STUDY DESIGN

Pretest-posttest study.

METHODS

Children with lower limb amputation or deficiency were recruited. Measurements were taken at baseline with the prescribed prosthesis and 6 weeks later with the crossover foot. Walking speed, energy cost of walking, anaerobic muscle power, stair climbing speed, ankle power, and cosmesis were evaluated.

RESULTS

Four children participated in the study. Two children had increased walking speed with the same energy cost, one child had decreased speed with increased energy cost, and one child had the same speed with decreased energy cost. Muscle power increased for three of the four children and ankle power increased for all children while using the crossover foot compared to the prescribed prosthesis. Two children reported knee pain or feeling excessive knee flexion when running with the crossover foot. One child reported negative feelings toward cosmesis of the crossover foot.

CONCLUSIONS

This study suggests crossover foot may benefit active children by improving walking and running performance, and decreasing energy cost. However, knee pain reports or negative feelings toward the atypical design suggest the crossover foot may not be ideal for every child. Further research is needed to determine which pediatric users would benefit from this type of prosthetic foot.

CLINICAL RELEVANCE

Children with lower limb deficiencies are active prosthetic users who often switch between low- and high-intensity movements in their daily activities. Therefore, they might benefit from a crossover prosthetic design. The preliminary findings of this study suggest the crossover foot (XF) may be a promising foot for active children.

Technology for monitoring everyday prosthesis use: a systematic review

BACKGROUND

Understanding how prostheses are used in everyday life is central to the design, provision and evaluation of prosthetic devices and associated services. This paper reviews the scientific literature on methodologies and technologies that have been used to assess the daily use of both upper- and lower-limb prostheses. It discusses the types of studies that have been undertaken, the technologies used to monitor physical activity, the benefits of monitoring daily living and the barriers to long-term monitoring, with particular focus on low-resource settings.

METHODS

A systematic literature search was conducted in PubMed, Web of Science, Scopus, CINAHL and EMBASE of studies that monitored the activity of prosthesis users during daily-living.

RESULTS

Sixty lower-limb studies and 9 upper-limb studies were identified for inclusion in the review. The first studies in the lower-limb field date from the 1990s and the number has increased steadily since the early 2000s. In contrast, the studies in the upper-limb field have only begun to emerge over the past few years. The early lower-limb studies focused on the development or validation of actimeters, algorithms and/or scores for activity classification. However, most of the recent lower-limb studies used activity monitoring to compare prosthetic components. The lower-limb studies mainly used step-counts as their only measure of activity, focusing on the amount of activity, not the type and quality of movements. In comparison, the small number of upper-limb studies were fairly evenly spread between development of algorithms, comparison of everyday activity to clinical scores, and comparison of different prosthesis user populations. Most upper-limb papers reported the degree of symmetry in activity levels between the arm with the prosthesis and the intact arm.

CONCLUSIONS

Activity monitoring technology used in conjunction with clinical scores and user feedback, offers significant insights into how prostheses are used and whether they meet the user's requirements. However, the cost, limited battery-life and lack of availability in many countries mean that using sensors to understand the daily use of prostheses and the types of activity being performed has not yet become a feasible standard clinical practice. This review provides recommendations for the research and clinical communities to advance this area for the benefit of prosthesis users.

The Use of Physical Activity Outcomes in Rehabilitation Interventions for Lower Limb Amputees: a Systematic Review

BACKGROUND

Interventions which have focused on improving the physical activity of individuals with lower limb amputation can be mostly categorized into behavioural-based and prosthetic-based interventions. The aim of this review was to assess the quality of these interventions, and to identify the key gaps in research in this field.

METHODOLOGY

The databases of Scopus, Pubmed, Embase, Medline and Web of Science were searched between September and December of 2019 for articles relating to physical activity, amputees and interventions. Articles were assessed quantitively based on internal validity, external validity and intervention intensity.

FINDINGS

Sixteen articles (5 behavioural, 11 prosthetic) were assessed. Both approaches had comparable methodological quality and mixed efficacy for producing a significant change in physical activity outcomes. Almost all interventions used a simplistic measurement of activity as their outcome.

CONCLUSIONS

There is an insufficient amount of studies to assess the overall efficacy of behavioural interventions in regard to how they impact on physical activity behaviour. However, the increase of quality of the methodology in the more recent studies could indicate that future interventions will retain similar levels of quality. Prosthetic interventions have shown no major improvement in efficacy compared to similar reviews and may need to utilise more advanced prosthetic components to attain significant changes in physical activity. Activity outcomes should expand into more complex activity measurements to properly understand the physical activity profile of people with lower limb amputation.

Mobility analysis of AmpuTees (MAAT 5): Impact of five common prosthetic ankle-foot categories for individuals with diabetic/dysvascular amputation

Introduction

Diabetes and vascular disease represent the most common etiologies for lower limb amputations. In lower limb loss rehabilitation, the prosthetic ankle-foot mechanism is the most common major component needed to restore function. The purpose of this study was to examine the impact of five common prosthetic ankle-foot mechanisms on functional mobility in a large sample of individuals with amputation due to diabetes/dysvascular disease.

Methods

A retrospective analysis of the Prosthetic Limb Users' Survey of Mobility (PLUS-M®) captured in the patient care setting. A total of 738 individuals were included and subsequently subdivided into five groups based on the ankle-foot mechanism of their current prosthesis. Groups were compared using a general linear univariate model with age, body mass index, comorbid health status, time since amputation, and amputation level entered as covariates.

Results

The microprocessor ankle-foot group had the highest mobility (F_4,728 = 3.845, p=0.004), which was followed by the vertical loading pylon type ankle-foot, the hydraulic ankle-foot, the flex-walk-type ankle-foot, and lastly the flex-foot-type ankle-foot.

Conclusion

These results demonstrate that the selection of different prosthetic ankle-foot technology directly impacts functional mobility for the patient with an amputation due to diabetes and/or vascular disease.

Assessment of low- and high-level task performance in people with transtibial amputation using crossover and energy-storing prosthetic feet: A pilot study

BACKGROUND:

Crossover feet incorporate features of energy-storing feet and running-specific feet. As such, crossover feet may be suitable for both daily ambulation and participation in physically demanding activities.

OBJECTIVES:

To compare crossover feet and energy-storing feet on performance-based tests including a range of low-level (e.g. sit-to-stand) and high-level (e.g. jogging) activities.

STUDY DESIGN:

Cross-sectional, repeated measures.

METHODS:

Participants with transtibial amputation completed a battery of performance-based outcome measures, including the Five Times Sit-to-Stand, Timed-Up-and-Go, Four Square Step Test, and the Comprehensive High-level Activity Mobility Predictor. Participants wore duplicate prostheses fit with crossover feet and energy-storing feet to perform the tests; the order of foot conditions was randomized. Paired t tests were used to evaluate differences between feet and order of testing.

RESULTS:

Data from seven participants showed improvements in all measures while using crossover feet. Improvements in the second foot condition were also observed, indicating a practice effect for all measures. However, differences between feet and order of conditions were not statistically significant ( p > 0.05).

CONCLUSION:

Results of this study suggest that crossover feet may improve low- and high-level mobility outcomes. However, intervention effects are small and practice effects were observed in all outcomes. Future research is needed to evaluate the influence of practice effects on performance-based mobility measures.

CLINICAL RELEVANCE

Crossover feet may improve transtibial prosthesis users' performance compared to energy-storing feet across a range of activities, but additional research is needed. Practice effects may be an influential factor in the measurement of performance-based mobility outcomes and should be considered when performing a clinical assessment.

Prosthesis satisfaction in lower limb amputees: A systematic review of associated factors and questionnaires

BACKGROUND

Factors influencing patient satisfaction with a transtibial prosthesis have been studied fragmentarily. The aims of this systematic review were to review the literature regarding factors of influence on patient satisfaction with a transtibial prosthesis, to report satisfaction scores, to present an overview of questionnaires used to assess satisfaction and examine how these questionnaires operationalize satisfaction.

METHODS

A literature search was performed in PubMed, Embase, PsycInfo, CINAHL, Cochrane, and Web of Knowledge databases up to February 2018 to identify relevant studies.

RESULTS

Twelve of 1832 studies met the inclusion criteria. Sample sizes ranged from 14 to 581 participants, mean age ranged from 18 to 70 years, and time since amputation ranged from 3 to 39 years. Seven questionnaires assessed different aspects of satisfaction. Patient satisfaction was influenced by appearance, properties, fit, and use of the prosthesis, as well as aspects of the residual limb. These influencing factors were not relevant for all amputee patients and were related to gender, etiology, liner use, and level of amputation. No single factor was found to significantly influence satisfaction or dissatisfaction. Significant associations were found between satisfaction and gender, etiology, liner use, and level of amputation.

CONCLUSION

Relevance of certain factors for satisfaction was related to specific amputee patient groups. Questionnaires assessing satisfaction use different operationalizations, making comparisons between studies difficult.

Energy expenditure in people with transtibial amputation walking with crossover and energy storing prosthetic feet: A randomized within-subject study

BACKGROUND

Energy storing feet are unable to reduce the energy required for normal locomotion among people with transtibial amputation. Crossover feet, which incorporate aspects of energy storing and running specific feet, are designed to maximize energy return while providing stability for everyday activities.

RESEARCH QUESTION

Do crossover prosthetic feet reduce the energy expenditure of walking across a range of speeds, when compared with energy storing feet among people with transtibial amputation due to non-dysvascular causes?

METHODS

A randomized within-subject study was conducted with a volunteer sample of twenty-seven adults with unilateral transtibial amputation due to non-dysvascular causes. Participants were fit with two prostheses. One had an energy storing foot (Össur Variflex) and the other a crossover foot (Össur Cheetah Xplore). Other components, including sockets, suspension, and interface were standardized. Energy expenditure was measured with a portable respirometer (Cosmed K4b2) while participants walked on a treadmill at self-selected slow, comfortable, and fast speeds with each prosthesis. Gross oxygen consumption rates (VO₂ ml/min) were compared between foot conditions. Energy storing feet were used as the baseline condition because they are used by most people with a lower limb prosthesis. Analyses were performed to identify people who may benefit from transition to crossover feet.

RESULTS

On average, participants had lower oxygen consumption in the crossover foot condition compared to the energy storing foot condition at each self-selected walking speed, but this difference was not statistically significant. Participants with farther six-minute walk test distances, higher daily step counts, and higher Medicare Functional Classification Levels at baseline were more likely to use less energy in the crossover foot.

SIGNIFICANCE

Crossover feet may be most beneficial for people with higher activity levels and physical fitness. Further research is needed to examine the effect of crossover feet on energy expenditure during high-level activities.

Laboratory- and community-based health outcomes in people with transtibial amputation using crossover and energy-storing prosthetic feet: A randomized crossover trial

Contemporary prosthetic feet are generally optimized for either daily or high-level activities. Prosthesis users, therefore, often require multiple prostheses to participate in activities that span a range of mobility. Crossover feet (XF) are designed to increase the range of activities that can be performed with a single prosthesis. However, little evidence exists to guide clinical prescription of XF relative to traditional energy storing feet (ESF). The objective of this study was to assess the effects of XF and ESF on health outcomes in people with transtibial amputation. A randomized crossover study was conducted to assess changes in laboratory-based (endurance, perceived exertion, walking performance) and community-based (step activity and self-reported mobility, fatigue, balance confidence, activity restrictions, and satisfaction) outcomes. Twenty-seven participants were fit with XF and ESF prostheses with standardized sockets, interfaces, and suspensions. Participants were not blinded to the intervention, and wore each prosthesis for one month while their steps were counted with an activity monitor. After each accommodation period, participants returned for data collection. Endurance and perceived exertion were measured with the Six-Minute Walk Test and Borg-CR100, respectively. Walking performance was measured using an electronic walkway. Self-reported mobility, fatigue, balance confidence, activity restrictions, and satisfaction were measured with survey instruments. Participants also reported foot preferences upon conclusion of the study. Differences between feet were assessed with a crossover analysis. While using XF, users experienced improvements in most community-based outcomes, including mobility (p = .001), fatigue (p = .001), balance confidence (p = .005), activity restrictions (p = .002), and functional satisfaction (p < .001). Participants also exhibited longer sound side steps in XF compared to ESF (p < .001). Most participants (89%) reported an overall preference for XF; others (11%) reported no preference. Results indicate that XF may be a promising alternative to ESF for people with transtibial amputation who engage in a range of mobility activities.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02440711.