Sara J. Morgan

Health-Related Profiles of People With Lower Limb Loss

OBJECTIVES To construct profiles of self-reported health indicators to examine differences and similarities between people with lower limb loss and a normative sample (hereafter called the norm) and to compare health indicators between subgroups based on level and etiology of limb loss. DESIGN Survey. SETTING General community. PARTICIPANTS Adults with unilateral lower limb loss (N=1091) participated in this study. Eligibility criteria included lower limb loss due to trauma or dysvascular complications and regular use of a prosthesis. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES The Patient-Reported Outcomes Measurement Information System 29-item Health Profile version 1.0 measures physical function, pain interference, fatigue, sleep disturbance, anxiety, depression, and satisfaction with participation in social roles. The norm includes 5239 individuals representative of the U.S. general population in sex, age, race, ethnicity, and education. RESULTS People with lower limb loss reported statistically significantly worse physical function, pain interference, and satisfaction with participation in social roles and significantly less fatigue than did the norm. People with transfemoral (ie, above-knee) amputation significantly differed in physical function from people with transtibial (ie, below-knee) amputation. Similarly, people with amputation due to trauma and dysvascular etiology significantly differed in physical function and satisfaction with social roles after adjusting for relevant clinical characteristics. CONCLUSIONS People with lower limb loss generally report worse physical function, pain interference, and satisfaction with social roles than do the norm. People with dysvascular amputation reported worse physical function and satisfaction with social roles than did people with traumatic amputation. Health indicator profiles are an efficient way of providing clinically meaningful information about numerous aspects of self-reported health in people with lower limb loss.

Use of cognitive interviews in the development of the PLUS-M item bank

PurposeMeasuring constructs such as mobility with patient-reported outcomes (PROs) can enhance clinical and scientific understanding of how health conditions, like lower limb amputation, impact patients’ lives. When developing PRO questionnaires, cognitive interviews (CIs) are used to examine whether survey items are understandable, clear, and meaningful. The aim of this study was to use CIs to inform item development for the Prosthetic Limb Users Survey of Mobility (PLUS-M), a PRO that measures mobility in prosthetic limb users.MethodsThirty-six CIs were conducted with 30 prosthetic limb users. Each participant responded to up to 30 items from the PLUS-M candidate item set. Each item was reviewed by a minimum of five participants who differed in self-reported mobility, literacy, level of amputation, and time since amputation. Items were revised based on participant feedback, and substantially revised items were re-evaluated through additional CIs.ResultsFeedback from CIs identified substantial issues in 76 of the total 156 items. These items were subsequently modified or eliminated.ConclusionCognitive interviews were an essential qualitative step in the development of the PLUS-M item bank and resulted in better functioning items.

The effects of a concurrent task on walking in persons with transfemoral amputation compared to persons without limb loss

Background: Many people with lower limb loss report the need to concentrate on walking. This may indicate increased reliance on cognitive resources when walking compared to individuals without limb loss. Objective: This study quantified changes in walking associated with addition of a concurrent cognitive task in persons with transfemoral amputation using microprocessor knees compared to age- and sex-matched controls. Study design: Observational, cross-sectional study. Methods: Quantitative motion analysis was used to assess walking under both single-task (walking alone) and dual-task (walking while performing a cognitive task) conditions. Primary outcomes were walking speed, step width, step time asymmetry, and cognitive task response latency and accuracy. Repeated-measures analysis of variance was used to examine the effects of task (single-task and dual-task) and group (transfemoral amputation and control) for each outcome. Results: No significant interactions between task and group were observed (all p > 0.11) indicating that a cognitive task did not differentially affect walking between groups. However, walking was slower with wider steps and more asymmetry in people with transfemoral amputation compared to controls under both conditions. Conclusion: Although there were significant differences in walking between people with transfemoral amputation and matched controls, the effects of a concurrent cognitive task on walking were similar between groups. Clinical relevance The addition of a concurrent task did not differentially affect walking outcomes in people with and without transfemoral amputation. However, compared to people without limb loss, people with transfemoral amputation adopted a conservative walking strategy. This strategy may reduce the need to concentrate on walking but also contributed to notable gait deviations.

More than Pictures? An Exploration of Visually Dominant Magazine Ads as Arguments

Abstract This paper explores the extent to which individuals infer similar claims from visually dominant magazine advertisements. Past research suggests that consumers interact with visual stimuli in such advertisements and draw meaningful semantic claims based on the pictures presented by connecting the image to a product claim. A basic argument structure is presented to explain the process by which this occurs. Participants (N = 118) were asked to view eight visually dominant magazine advertisements, and to infer what they thought were the product claim or claims. Results suggest that respondents do infer consistently a small set of claims for a given advertisement but that they also can see multiple meanings within an ad.

Characterizing mobility from the prosthetic limb user’s perspective: Use of focus groups to guide development of the Prosthetic Limb Users Survey of Mobility:

Background: Input from target respondents in the development of patient-reported outcome measures is necessary to ensure that the instrument is meaningful. Objectives: To solicit perspectives of prosthetic limb users about their mobility experiences and to inform development of the Prosthetic Limb Users Survey of Mobility. Study design: Qualitative study. Methods: Four focus groups of lower limb prosthesis users were held in different regions of the United States. Focus group transcripts were coded, and themes were identified. Feedback from participants was used to develop a framework for measuring mobility with a lower limb prosthesis. Results: Focus group participants (N = 37) described mobility as a confluence of factors that included characteristics of the individual, activity, and environment. Identified themes were defined as individual characteristics, forms of movement, and environmental situations. Prosthetic mobility was conceptualized as movement activities performed in an environmental or situational context. Conclusion: Respondent feedback used to guide development of Prosthetic Limb Users Survey of Mobility established a foundation for a new person-centered measure of mobility with a prosthetic limb. Clinical relevance Perspectives of target respondents are needed to guide development of instruments intended to measure health outcomes. Focus groups of prosthetic limb users were conducted to solicit experiences related to mobility with a lower limb prosthesis. Results were used to inform development of a clinically meaningful, person-centered instrument.

Self-Reported Cognitive Concerns in People With Lower Limb Loss

OBJECTIVES To investigate differences between self-reported cognitive concerns in people with lower limb loss (LLL) and normative data derived from the U.S. general population, and secondarily to determine whether there were cognitive differences based on amputation etiology or age. DESIGN Survey. SETTING General community. PARTICIPANTS A volunteer sample of persons with LLL (N=1086) resulting from trauma or dysvascular complications who regularly use a prosthetic limb. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURE The Quality of Life in Neurological Disorders Applied Cognition-General Concerns Short Form version 1.0 (Neuro-QoL ACGC), an 8-item self-report measure of general cognitive concerns. RESULTS People with LLL reported significantly more cognitive concerns than the Quality of Life in Neurological Disorders normative sample. Mean Neuro-QoL ACGC scores were significantly lower than normative values (P<.001) across subgroups defined by age (ie, <40, 40-49, 50-59, 60-69, and 70+ years) and subgroups defined by etiology (ie, traumatic and dysvascular LLL). However, there were no significant differences in cognitive concerns among age subgroups (P=.84) or between the etiology subgroups (P=.58). CONCLUSIONS When compared with the Quality of Life in Neurological Disorders normative sample, individuals with LLL report greater concerns with cognitive health. Cognitive concerns were not differentially affected by age or cause of amputation. The presence of cognitive concerns in people with LLL suggests a need to assess perceived cognitive function in order to tailor education and training in prosthetic use and care.

Prosthetists’ perceptions and use of outcome measures in clinical practice: Long-term effects of focused continuing education

Background: Continuing education is intended to facilitate clinicians’ skills and knowledge in areas of practice, such as administration and interpretation of outcome measures. Objective: To evaluate the long-term effect of continuing education on prosthetists’ confidence in administering outcome measures and their perceptions of outcomes measurement in clinical practice. Design: Pretest–posttest survey methods. Methods: A total of 66 prosthetists were surveyed before, immediately after, and 2 years after outcomes measurement education and training. Prosthetists were grouped as routine or non-routine outcome measures users, based on experience reported prior to training. Results: On average, prosthetists were just as confident administering measures 1–2 years after continuing education as they were immediately after continuing education. In all, 20% of prosthetists, initially classified as non-routine users, were subsequently classified as routine users at follow-up. Routine and non-routine users’ opinions differed on whether outcome measures contributed to efficient patient evaluations (79.3% and 32.4%, respectively). Both routine and non-routine users reported challenges integrating outcome measures into normal clinical routines (20.7% and 45.9%, respectively). Conclusion: Continuing education had a long-term impact on prosthetists’ confidence in administering outcome measures and may influence their clinical practices. However, remaining barriers to using standardized measures need to be addressed to keep practitioners current with evolving practice expectations. Clinical relevance Continuing education (CE) had a significant long-term impact on prosthetists’ confidence in administering outcome measures and influenced their clinical practices. In all, approximately 20% of prosthetists, who previously were non-routine outcome measure users, became routine users after CE. There remains a need to develop strategies to integrate outcome measurement into routine clinical practice.

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

Dual-task walking over a compliant foam surface: A comparison of people with transfemoral amputation and controls

People with lower limb amputation are unable to reliably sense ground characteristics due to compromised sensory inputs from the missing limb. As a result, they may rely on compensatory strategies, such as use of cognitive resources, when walking over complex surfaces. This study examined interactions between cognition and walking over a compliant surface in 14 people with transfemoral amputation (TFA) and 14 controls using a dual-task paradigm. Walking was assessed with quantitative motion analysis in both single-task (walking alone) and dual-task (walking while performing a cognitive task) conditions over a compliant foam surface. Outcomes were walking speed, step width, step time asymmetry, step time variability, and the speed and accuracy of cognitive task performance. For each outcome, effects of task (single-task, dual-task) and group (TFA, control) were examined with repeated-measures analysis of variance. No significant group-by-task interactions were observed for cognitive task performance. A significant group-by-task interaction for step time asymmetry indicated that participants with TFA increased temporal asymmetry in dual-task relative to single-task conditions, while control participants maintained symmetrical gait. The addition of a concurrent cognitive task did not differentially affect other aspects of gait between groups. Significant main effects of group for all walking outcomes indicated that participants with TFA walked slower, with wider, more asymmetric, and more variable steps than controls. Results suggest that gait quality degrades in challenging dual-task conditions for people with TFA, but not controls, consistent with the idea that people with TFA may use increased cognitive resources to control walking in complex environments.

Dual-task standing and walking in people with lower limb amputation: A structured review:

Background: People with lower limb amputation report the need to concentrate on walking. Dual-task paradigms are often used to study such interactions between cognition and the control of balance and gait in people with lower limb amputation. Objectives: To summarize evidence related to dual-task standing and walking in people with lower limb amputation and discuss implications for future research. Study design: Structured review. Methods: A structured search was completed in PubMed, CINAHL, and Web of Science from database inception to May 2017. Eligible articles were in English, included participants with lower limb amputation, and assessed dual-task standing or walking. Study information was extracted by one reviewer and assessed for accuracy by a second. Results: A total of 12 articles met eligibility criteria. Seven examined differences in dual-task standing or walking, and five assessed dual-task walking across microprocessor-controlled and non-microprocessor-controlled prosthetic knee conditions. Conclusion: Results suggest that (1) dual-task interference in standing is greater for people with lower limb amputation than non-amputees and (2) the use of microprocessor-controlled knees improves dual-task performance for people with limited mobility compared to non-microprocessor-controlled knees. The small number of studies, diversity of dual-task methods, and methodological limitations challenge the synthesis of study results. Future research should assess specific clinical characteristics that can affect dual-task performance in people with lower limb amputation. Clinical relevance Understanding how people with lower limb amputation use increased attention in balance and gait to compensate for limb loss can inform prosthetic interventions and training. Dual-task research suggests that people with amputation use increased cognitive control for standing compared to controls and microprocessor-controlled knees improve dual-task walking in people with limited mobility.