Lower Limb Loss Research Articles

The experience of self-managing from the perspective of persons with lower limb loss, prosthetists, and physical therapists

Purpose Persons with lower limb loss (PwLLL) must self-manage their residual limb and their prosthesis to prevent self-management related complications (SMRC). However, the experience of PwLLL as it relates to self-management has not been reported. Thus, the purpose of this study was to explore the experience of self-management from the perspective of PwLLL, prosthetists, and physical therapists. Methods This study had a qualitative design. Twenty-three participants were interviewed (PwLLL = 10, prosthetists = 7, physical therapists = 6). Interviews were transcribed and then coded using constant comparison. Results Four prominent themes were developed from the transcripts: (1) embodying the duty of self-management, (2) being a vigilant self-advocate, (3) setting goals collaboratively, and (4) making informed decisions. Each of the four themes were influenced by the health beliefs of the PwLLL, specifically motivation and presence of an internal locus of control. Conclusion Clinicians should emphasize the therapeutic relationship, including open communication, collaborative goal setting, and promoting an internal locus of control in interactions with PwLLL, as it may play a role in decreasing SMRC and improving clinical outcomes. Implications for rehabilitation Self-management is a crucial aspect of preventing secondary complications associated with limb loss and prosthesis use. Self-management requires an internal locus of control, problem-solving abilities, and foundational knowledge Clinicians can promote self-management through collaborative goal setting and systematic education.

Case Report: A case of IgD lambda/lambda Multiple Myeloma in patient with acute renal failure and without monoclonal spike in serum electrophoresis

BackgroundIgD Multiple Myeloma is a rare form of plasma cell dyscrasia and accounts for approximately 1-2% of all cases of Multiple Myeloma. It mainly affects young, male subjects; it is characterized by an aggressive course, a high production of Bence Jones protein, acute renal failure and an often unfortunate outcome compared to the other isotypes of MM. A distinctive feature is the lack of a monoclonal peak on serum protein electrophoresis (SPE).Case reporta 57-year-old man with pain in his left lower limb and weight loss goes to the Emergency Department (Emergency Department). Laboratory tests performed showed normocytic normochromic anemia (Hemoglobin 9.4 g/dL), acute renal failure (s-creatinine 2.85 mg/dL, e-GFR 23 mL/min/1.73 m². serum protein electrophoresis (SPE) detected only mild polyclonal in the gamma zone with no evidence of any monoclonal peak.Resultsserum immunofixation (s-IFE) showed a monoclonal IgD λ band and a monoclonal λ band. The Free Light Chains (s-FLC) measurement showed a ratio of 0.04. The bone marrow biopsy confirmed an infiltration of> 20% of clonal plasma cells; renal biopsy diagnosed “cast nephropathy”.ConclusionIgD λ/λ Multiple Myeloma is a rare form of this disease with a poor prognosis; an early and correct laboratory diagnosis is crucial for appropriate treatment and effective monitoring in order to improve patient outcome.

A Comprehensive, Multidisciplinary Assessment for Knee Osteoarthritis Following Traumatic Unilateral Lower Limb Loss in Service Members.

Knee osteoarthritis (KOA) is a primary source of long-term disability and decreased quality of life (QoL) in service members (SM) with lower limb loss (LL); however, it remains difficult to preemptively identify and mitigate the progression of KOA and KOA-related symptoms. The objective of this study was to explore a comprehensive cross-sectional evaluation, at the baseline of a prospective study, for characterizing KOA in SM with traumatic LL. Thirty-eight male SM with traumatic unilateral LL (23 transtibial and 15 transfemoral), 9.5 ± 5.9 years post-injury, were cross-sectionally evaluated at initial enrollment into a prospective, longitudinal study utilizing a comprehensive evaluation to characterize knee joint health, functionality, and QoL in SM with LL. Presences of medial, lateral, and/or patellofemoral articular degeneration within the contralateral knee were identified via magnetic resonance imaging(for medically eligible SM; Kellgren-Lawrence Grade [n = 32]; and Outerbridge classification [OC; n = 22]). Tri-planar trunk and pelvic motions, knee kinetics, along with temporospatial parameters, were quantified via full-body gait evaluation and inverse dynamics. Concentrations of 26 protein biomarkers of osteochondral tissue degradation and inflammatory activity were identified via serum immunoassays. Physical function, knee symptoms, and QoL were collected via several patient reported outcome measures. KOA was identified in 12 of 32 (37.5%; KL ≥ 1) SM with LL; however, 16 of 22 SM presented with patellofemoral degeneration (72.7%; OC ≥ 1). Service members with versus without KOA had a 26% reduction in the narrowest medial tibiofemoral joint space. Biomechanically, SM with versus without KOA walked with a 24% wider stride width and with a negative correlation between peak knee adduction moments and minimal medial tibiofemoral joint space. Physiologically, SM with versus without KOA exhibited elevated concentrations of pro-inflammatory biomarker interleukin-7 (+180%), collagen breakdown markers collagen II cleavage (+44%), and lower concentrations of hyaluronic acid (-73%) and bone resorption biomarker N-telopeptide of Type 1 Collagen (-49%). Lastly, there was a negative correlation between patient-reported contralateral knee pain severity and patient-reported functionality and QoL. While 37.5% of SM with LL had KOA at the tibiofemoral joint (KL ≥ 1), 72.7% of SM had the presence of patellofemoral degeneration (OC ≥ 1). These findings demonstrate that the patellofemoral joint may be more susceptible to degeneration than the medial tibiofemoral compartment following traumatic LL.

Direction of attentional focus in prosthetic training: Current practice and potential for improving motor learning in individuals with lower limb loss.

Adopting an external focus of attention has been shown to benefit motor performance and learning. However, the potential of optimizing attentional focus for improving prosthetic motor skills in lower limb prosthesis (LLP) users has not been examined. In this study, we investigated the frequency and direction of attentional focus embedded in the verbal instructions in a clinical prosthetic training setting. Twenty-one adult LLP users (8 female, 13 male; 85% at K3 level; mean age = 50.5) were recruited from prosthetic clinics in the Southern Nevada region. Verbal interactions between LLP users and their prosthetists (mean experience = 10 years, range = 4-21 years) during prosthetic training were recorded. Recordings were analyzed to categorize the direction of attentional focus embedded in the instructional and feedback statements as internal, external, mixed, or unfocused. We also explored whether LLP users' age, time since amputation, and perceived mobility were associated with the proportion of attentional focus statements they received. We recorded a total of 20 training sessions, yielding 904 statements of instruction from 338 minutes of training. Overall, one verbal interaction occurred every 22.1 seconds. Among the statements, 64% were internal, 9% external, 3% mixed, and 25% unfocused. Regression analysis revealed that female, older, and higher functioning LLP users were significantly more likely to receive internally-focused instructions (p = 0.006, 0.035, and 0.024, respectively). Our results demonstrated that verbal instructions and feedback are frequently provided to LLP users during prosthetic training. Most verbal interactions are focused internally on the LLP users' body movements and not externally on the movement effects. While more research is needed to explore how motor learning principles may be applied to improve LLP user outcomes, clinicians should consider adopting the best available scientific evidence during treatment. Overreliance on internally-focused instructions as observed in the current study may hinder prosthetic skill learning.

Preparing for the Worst or Hoping for the Best? The State of Fall Training in Prosthesis Users

ABSTRACT Introduction The risk of accidental falls is greater in people with lower-limb loss than in their able-bodied peers. Most popular strategies to mitigate injuries from such falls include technical solutions that prevent falls or protect vulnerable body segments from destructive forces. Fall training is another effective intervention, but little evidence on its use in prosthesis users has been published. This research had the goal to investigate to what extent fall training is provided to the target population and what factors may be obstacles to its wider adoption. Methods An online questionnaire was developed and administered nationwide, targeting people with lower-limb loss. Descriptive statistics were used to describe the availability of fall training, and a logistic regression was performed to investigate variables that predict whether an individual receives fall training or not. Results A total of 180 responses was recorded, 166 of which were included in the analysis. More than two-thirds of respondents had not received fall training. Those who had physical therapy as part of their rehabilitation regimen were 3.7 times more likely to also have had fall training. Discussion Our data suggest that the potential benefits of providing fall training to people with lower-limb loss are not being fully realized. Interdisciplinary collaboration between prosthetists and therapists can help expand access to fall training interventions to better prepare patients for the likely event of an accidental fall.

Usability of Self-Management for Amputee Rehabilitation using Technology (SMART): An online self-management program for users with lower limb loss.

Individuals with lower limb loss (LLL) need education to adapt to their amputation. Self-management programs provide education and supportive skills to manage health-related physical and psychological challenges. eHealth technologies, such as online platforms, are increasing access to educational resources. We designed an online self-management program for individuals with LLL called Self-Management for Amputee Rehabilitation using Technology (SMART); however, before evaluating its efficacy, we wanted to understand its appropriateness in the target population. To assess the usability of SMART among individuals with LLL. The study used a concurrent and retrospective think-aloud process. Individuals with LLL, aged 18 years or older (n = 9), reviewed the modules during an online video conferencing session with an assessor. SMART included four stakeholder-informed modules with 18 total sections. Participants were asked to think aloud while completing 11 SMART tasks, such as entering SMART, goal setting, finding skin care, and reading the content of 10 sections, including limb care, diet, fatigue, and energy. The interviews were transcribed verbatim and analyzed using directed content analysis. The median age was 58 (range: 30-69) years. Overall, SMART was perceived as straightforward, easy to navigate, and an accessible resource for education and skills. Difficulties were identified with navigation (e.g. skipping the "Foot care for diabetes" section), presentation (e.g. unclear audio), and language (e.g. pistoning and contracture). SMART was redesigned to address the usability issues. The next step is to explore the perceived usefulness of SMART for content and intention to use.

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.

ПАТОФИЗИОЛОГИЧЕСКАЯ РОЛЬ ОСТЕОПРОТЕГЕРИНА ПРИ АТЕРОСКЛЕРОЗЕ И САХАРНОМ ДИАБЕТЕ

Diabetes mellitus is rightly called non-infectious epidemic of the 21st century. At the same time, cardiovascular diseases still remain the leading cause of death in the world. A combination of diabetes mellitus and peripheral arterial disease increases the risk of the lower limb loss and death many times over. There are many concepts concerning the mechanism of development of these diseases. In recent years, there is more and more data evidencing the similarity of the processes of atherosclerosis and osteoporosis development. The connecting link between these processes may be osteoprotegerin (OPG). Information has been obtained on osteoprotegerin as an antiresorptive factor participating in the RANKL-RANK-OPG system. Under pathophysiological conditions, OPG is expressed in the vascular wall, including being found at different stages of atherosclerotic plaque formation. The RANKL-RANK-OPG signaling pathway is involved in the process of bone tissue remodeling. The mechanisms of atherosclerosis and osteoporosis development are similar; nevertheless, they require further study.

Personalized digital humans for rehabilitation and assistive devices

Introduction: Ultrasound is routinely used by rehabilitation specialists to establish differential diagnosis of the residuum’s neuromusculoskeletal issues experienced by former and active Service Members suffering from limb loss1. Ultrasound offers real-time, non-ionizing, unspecialised facility assessment. Conventional imaging modalities record a qualitative static image. More fundamental signal/data display modalities such as the raw radio-frequency signal and A-mode are rarely utilised, although offer specialised opportunities, particularly for quantitative tissue characterisation, when the subject is mobile, and when several anatomical locations need to be synchronously assessed. Our aim is to develop a wearable ultrasound biosensor system that provides real-time assessment of various anatomical compartment dimensions within a post-amputation residual lower limb of former and active Service Members, termed Dynamic Anatomical Ultrasonography (DAU). Methods and results: The Olympus Omniscan MX is a highly-portable and rugged ultrasound instrument aimed primarily at the industrial sector. It incorporates the facility to connect up to eight individual single-element ultrasound transducers. A custom pseudo prosthetic socket was created for an asymptomatic subject, to which were attached two 1 MHz, 19 mm diameter ultrasound transducers, as shown in Fig. 1A. Ultrasound signal data was recorded for a defined measurement period of 10 seconds as the subject repeatedly lifted and lowered their thigh. Utilising the semi-automated time-gate signal detection facility, the depth of the femur bone surface was recorded, shown in Fig. 1B. Discussion/future directions: We have demonstrated the ability to monitor motions of the femur; of particular note is that measurements were obtained through the socket and silicone liner in addition to the overlying soft tissues. It is hypothesised that knowledge of the dynamic behaviour of the various tissue compartments will improve our understanding of the biomechanics associated with the residual limb of individuals suffering from limb loss and, furthermore, facilitate the fitting and development of bionics prostheses for former and active Service Members2. Our long-term aim is to investigate whether a combination of ultrasound and mechanical load biomarker data, fed into a ‘Digital Twin’ computational simulation will improve socket design, restore mobility, facilitate return to active duty, and, ultimately, enhance users’ quality of life. Acknowledgements: This work was supported by the FY19 Defense Medical Research and Development Program through the Joint Program Committee 8 / Clinical and Rehabilitative Medicine Research Program Restoring Warfighters with Neuromusculoskeletal Injuries Research Award (RESTORE) under Award No. W81XWH2110215-DM190659. Opinions, interpretations, conclusions and recommendations are those of the author and are not necessarily endorsed by the FY19 Defense Medical Research and Development Program. References 1Frossard LA, Powrie R, Langton CM. In-vivo kinestic system to sustain residuum health of service members with lower limb loss: from proof-of-concept to digital twin. Military Health System Research Symposium. Abstract #MHSRS-19-00882. Kissimmee, FL, US 2019:111 2Frossard LA, Lloyd DG. The future of bionic limbs. Res Feat 2021; 134:74-77. https://doi.org/10.26904/RF-134-7477

Other physical and functional markers of bone stress injury

Introduction: Rehabilitation specialists need to improve differential diagnosis of the neuromusculoskeletal health issues of the residuum experienced by former and active Service Members suffering from limb loss1. The development of a portable and non-invasive diagnostic device seeks to help maintain residuum health and support bionic solutions. Here, we outline the latest developments of an In-vivo Kinetic system 2.0 (Fig. 1), a diagnostic device that combines:•Measurements of the mechanical loading applied to the site of amputation using portable wireless sensors2,•Measurement of the tissue distribution within the residuum made by the newly developed Dynamic Anatomical Ultrasonography,•Neuromusculoskeletal modelling or “digital twinning” of the residuum for a real-time personalized animation of the residuum during static and dynamic loading conditions3. Technology readiness levels (TRL) were estimated at 7, 2, and 4 for the loading, ultrasound, and modelling parts, respectively. Thus, demonstrating feasibility to develop an integrated, wearable and non-invasive In-vivo Kinetic system 2.0 capable of performing patient-specific differential diagnosis of residuum health under real world conditions4. However, barriers inherent to biosensors (e.g., ultrasound measurements, synchronisation), the creation of a digital twin (e.g., tissues mechanical property) and integration (e.g., discrepancies of TRLs) continue to be challenging. The clinical roll-out of the device will require overcoming these issues and consideration of discrepancies between the skills of practitioners and siloed health care organizations. Discussion/future directions: This system will provide unparalleled holistic insight into residuum health and productively disrupt the current model of health care. Hopefully, this diagnostic device will facilitate restoration of mobility, return to active duty, and, ultimately, improve life of the growing population suffering from limb loss considering bionic solutions. Acknowledgements: This work was supported by the FY19 Defense Medical Research and Development Program through the Joint Program Committee 8 / Clinical and Rehabilitative Medicine Research Program Restoring Warfighters with Neuromusculoskeletal Injuries Research Award (RESTORE) under Award No. W81XWH2110215-DM190659. Opinions, interpretations, conclusions, and recommendations are those of the author and are not necessarily endorsed by the FY19 Defense Medical Research and Development Program. References 1Frossard LA, Lloyd DG. The future of bionic limbs. Res Feat 2021; 134:54-57. https://doi.org/10.26904/RF-134-7477 2Pather S, Vertriest S, Sondergeld P, et al. Load characteristics following transfemoral amputation in individuals fitted with bone-anchored prostheses: a scoping review protocol. JBI Data Sys Rev Imp Rep 2018; 16(6):1286-1310. https://doi.org/10.11124/JBISRIR-2017-003398 3Sartori M, Lloyd DG, Farina D. Neural data-driven musculoskeletal modelling for personalized neurorehabilitation technologies. IEEE Trans Biomed Eng 2016; 63(5):879-893. https://doi.org/10.1109/TBME.2016.2563138 4Frossard LA, Powrie R, Langton CM. In-vivo kinestic system to sustain residuum health of service members with lower limb loss: from proof-of-concept to digital twin. Military Health System Research Symposium. Abstract #MHSRS-19-00882. Kissimmee, FL, US 2019:111

Within-subject effects of standardized prosthetic socket modifications on physical function and patient-reported outcomes

BackgroundAmong the challenges of living with lower limb loss is the increased risk of long-term health problems that can be either attributed directly to the amputation surgery and/or prosthetic rehabilitation or indirectly to a disability-induced sedentary lifestyle. These problems are exacerbated by poorly fit prosthetic sockets. There is a knowledge gap regarding how the socket design affects in-socket mechanics and how in-socket mechanics affect patient-reported comfort and function. The objectives of this study are (1) to gain a better understanding of how in-socket mechanics of the residual limb in transfemoral amputees are related to patient-reported comfort and function, (2) to identify clinical tests that can streamline the socket design process, and (3) to evaluate the efficacy and cost of a novel, quantitatively informed socket optimization process.MethodsUsers of transfemoral prostheses will be asked to walk on a treadmill wearing their current socket plus 8 different check sockets with designed changes in different structural measurements that are likely to induce changes in residual limb motion, skin strain, and pressure distribution within the socket. Dynamic biplane radiography and pressure sensors will be used to measure in-socket residual limb mechanics. Patient-reported outcomes will also be collected after wearing each socket. The effects of in-socket mechanics on both physical function and patient-reported outcomes (aim 1) will be assessed using a generalized linear model. Partial correlation analysis will be used to examine the association between research-grade measurements and readily available clinical measurements (aim 2). In order to compare the new quantitative design method to the standard of care, patient-reported outcomes and cost will be compared between the two methods, utilizing the Wilcoxon-Mann-Whitney non-parametric test (aim 3).DiscussionKnowledge on how prosthetic socket modifications affect residual bone and skin biomechanics itself can be applied to devise future socket designs, and the methodology can be used to investigate and improve such designs, past and present. Apart from saving time and costs, this may result in better prosthetic socket fit for a large patient population, thus increasing their mobility, participation, and overall health-related quality of life.Trial registrationClinicalTrials.gov NCT05041998. Date of registration: Sept 13, 2021.

Relationships Among Phantom Limb Pain, Peripheral Sensations, and Cognition in People with Lower-Limb Loss

ABSTRACT Introduction After amputation, altered sensory input leads to cortical reorganization that partly explains phantom limb pain (PLP). However, many factors impact the PLP phenomenon, and modern conceptualizations of chronic pain including PLP integrate both peripheral inputs and central interpretation. Clinicians without functional MRI could benefit from clinical measures related to PLP to assess clinical presentations. The purpose of this pilot study was to identify peripheral sensation and cognition measures related to PLP to inform outcome measure selection in future PLP research. Methods This cross-sectional analysis included people with PLP of any age, sex, and amputation cause or level. Assessments included patient-reported residual limb pain and PLP using the Prosthesis Evaluation Questionnaire, peripheral sensation measures (light touch, temperature, vibration, two-point discrimination), and cognition measures (laterality recognition, trail making, clock drawing). Unadjusted Spearman ρ coefficients were reported. Results Eleven volunteers (48.5 ± 13.2 years) with lower-limb amputations (seven transtibial) of various causes (nine medical) participated. More severe PLP symptoms were associated with impaired peripheral sensation (light touch, ρ = 0.514; temperature, ρ = 0.756) and poorer cognition (laterality recognition, ρ = 0.524; trail making, ρ = 0.565). Residual limb pain was not correlated with cognition measures (ρ &lt; 0.4). Conclusions This pilot study identified clinical measures assessing cognition and peripheral sensation impairments associated with worse PLP symptoms. Phantom limb pain was related to temperature and light touch sensation measures, but two-point discrimination was not associated with PLP consistent with past research. Laterality recognition was associated with PLP per prior research, and the association of PLP with the Trail Making Test in this pilot study suggests that the Trail Making Test may be an additional cognition measure potentially useful in future clinical research to document the PLP experience.

A Novel Clinically Based Classification System for the Profunda Femoris Artery and the Circumflex Femoral Arteries

The profunda femoris artery (PFA) supplies important collateral branches to both the ipsilateral internal iliac artery and the distal superficial femoral artery (SFA). The size and patency of these collateral pathways can determine the risk of pelvic malperfusion, spinal cord ischemia, and lower extremity limb loss following vascular interventions. Despite its importance, the anatomy of the PFA is rarely characterized in clinical studies involving the pelvic or lower extremity circulation. This discussion may be limited by the lack of a comprehensive classification system. Our objective was to describe the most common PFA anatomic variants and present a classification system based on its branching patterns. We dissected 155 fixed and nonfixed femoral artery systems from 88 cadavers. Seventy-seven female and 78 male femoral exposures were performed. Vessel diameters, branch configurations, and relative distances between the inguinal ligament, PFA, lateral circumflex femoral artery (LCFA), and medial circumflex femoral artery (MCFA) were recorded. The mean diameters of the common femoral artery, SFA, and PFA were 10.3mm, 8.0mm, and 6.9mm in males and 8.9mm, 6.9mm, and 6.1mm in females, respectively (P<0.05). The mean distances from the inguinal ligament for PFA, MCFA, and LCFA were 41mm, 41.7mm, and 52.5mm, respectively. No significant differences were noted relative to laterality or fixation. We developed a clinically applicable classification system based on the orientation of the PFA, LCFA, and MCFA. Six PFA, 5 LCFA, and 5 MCFA variations were identified and ranked by frequency. The 5 most common combinations accounted for 56.1% of our cadaver series. The anatomic orientation of the PFA and its branches is highly variable. We propose a novel classification system of this rich collateral system to facilitate consistent communication in academic and clinical vascular surgery.

Peer-mentorship Following Lower-limb Loss in Small Communities: Implications for Occupational Therapists

<h3>Research Objectives</h3> Peer-mentorship is an important accompaniment to occupational therapy practice, integrating lived expertise of practical and social-emotional knowledge. However, there is a paucity of research on peer-mentorship among individuals with lower-limb loss living in small communities. The objective of this study was to identify the impact of peer-mentorship during the amputation process and the adjustment to life afterward within small communities. <h3>Design</h3> Qualitative description. <h3>Setting</h3> Small communities through use of telephone and video conferencing. <h3>Participants</h3> Study participants (n=8) were 19 years of age or older with lower-limb loss who lived in a small community and had experience as either a peer-mentor, or mentee. <h3>Interventions</h3> Peer-mentorship program for people with lower-limb loss. <h3>Main Outcome Measures</h3> Participants completed a 60-90 minute one-on-one semi-structured interview. Data was transcribed verbatim and analyzed thematically. <h3>Results</h3> Our analysis identified the following themes: (i) "satisfying an unmet need" explores the desire for individuals to learn from others who have similar experiences living with lower-limb loss; (ii) "improving independence" describes the unique guidance offered by peer-mentors for returning to daily activities and building self-efficacy; (iii) "friendship" examines peer-mentors' unique therapeutic delivery and how it provided long-lasting accessible guidance in small communities, and (iv) "advocating for supports and resources" examines how peer-mentors fulfilled support roles to navigate healthcare and community services. <h3>Conclusions</h3> This study demonstrates the role peer-mentorship has toward improving recovery outcomes and social enablement during adjustment to lower-limb loss. Occupational therapists may consider collaborating with peer mentors for person-centered initiatives following lower limb loss in small communities. <h3>Author(s) Disclosures</h3> No conflict of interests to declare.

Body image and perception among adults with and without phantom limb pain.

Following lower-limb amputation, phantom limb pain (i.e., pain perceived as coming from the amputated portion of the limb) is common. Phantom limb pain may be associated with impaired body image and perception, which may be targets for rehabilitative intervention. To compare measures of body image and perception between adults with and without phantom limb pain post amputation and evaluate associations between measures of body image and perception and phantom limb pain. Survey. Online, remote assessment. Seventy-two adults ≥1 year post unilateral lower-limb loss (n=42 with phantom limb pain, n=30 without phantom limb pain or pain in the remaining portion of the limb). Not applicable. Self-reported outcome measures assessing body image (i.e., Amputee Body Image Scale-Revised), perceptual disturbances associated with the phantom limb (i.e., a modified Bath Complex Regional Pain Syndrome Body Perception Disturbance Scale), and prosthesis satisfaction (i.e., Trinity Amputation and Prosthesis Experience Scale) were administered; participants with phantom limb pain reported pain interference via the Brief Pain Inventory-Short Form. Between-group comparisons of self-reported outcome measure scores were conducted using Mann Whitney U or chi-square tests, as appropriate (a=.05). Compared to peers without phantom limb pain, adults with phantom limb pain reported more negative body image; increased phantom limb ownership, attention, and awareness; and reduced prosthesis satisfaction and embodiment (U=175.50-364.00, p < .001 to .034). Disturbances in phantom limb perception (i.e., size, weight, pressure, temperature) were similar between groups (p=.086 to >.999). More negative body image was associated with increased phantom limb pain interference (τb =.25, p=.026). Adults with phantom limb pain demonstrate more negative body image and hypervigilance of the phantom limb as compared to peers with nonpainful phantom sensations. Mind-body treatments that target impaired body image and perception may be critical interventions for adults with phantom limb pain.

Acute myelitis with multicranial neuritis caused by Varicella zoster virus: a case report

BackgroundVaricella zoster virus (VZV) can remain lifelong in the latent state in ganglionic neurons and adrenal glands after the initial infection. However, it can be reactivated anytime and can trigger several severe neurological manifestations such as encephalitis, meningitis, Ramsay-Hunt syndrome, cerebellitis, myelitis, and stroke. In addition, due to the diversity of clinical manifestations, clinical diagnosis of VZV can be difficult, especially in the absence of varicella. Here, we describe the case of a 52-year-old male who presented with symptoms of acute myelitis as well as polycranial neuritis, and was finally diagnosed with VZV infection through metagenomic next-generation sequencing (mNGS).Case presentationA 52-year-old male came to our hospital with complaint of headache, fever, weakness of right lower limb, abdominal distension, and hearing loss. T2-weighted MRI revealed a hyperintense lesion in the spinal cord extending from T8 to T11. In addition, enhanced MRI showed small patches and strips hyperintensities in both the spinal cord and meninges. Plain abdominal radiographs and abdominal computed tomography (CT) scan displayed air-fluid levels and incomplete bowel obstruction. Moreover, electrophysiological evaluation of the peripheral neuropathy in the extremities was found to be normal. Finally, by using metagenomic next-generation sequencing (mNGS) we found that the copy number of VZV DNA in cerebrospinal fluid (CSF) was significantly increased and IgG antibody against VZV in CSF was also noted to be positive. Hence, VZV infection was identified in patient’s central neuron system. Finally, after a few days of low dose steroid treatment, the patient's symptoms were found to be significantly improved.ConclusionsThe findings indicate that we should pay proper attention to the various symptoms caused by VZV infection due to the clinical heterogeneity, especially in the absence of cutaneous lesions.

Survey of physical activity in persons with limb loss during the COVID-19 pandemic in the United States.

Physical activity has been shown to be fundamental in the prevention of numerous diseases and disorders. Achieving and maintaining physical activity levels can be particularly challenging in those with impairments, such as those experiencing a lower limb amputation. To slow the spread of the virus, COVID-19 lockdown mandates imposed by the US state governments may have inadvertent consequences on physical activity levels of those dependent on specific forms of exercise. Understanding how physical activity levels may have affected persons with limb loss can inform intervention strategies for this vulnerable population. Examine the effects of the COVID-19 pandemic on physical activity levels in persons with limb loss. Mixed-method design. A 20-item logic web-based survey and semistructured interviews were administered to individuals who were 18 years or older, spoke English, and had a history of lower limb loss. Quantitative data were analyzed using SPSS v25, whereas qualitative data were analyzed using constant comparison to formulate themes. There were a significant effect on the amount of physical activity minutes performed per day, a negative effect on the ability to exercise and participate in societal engagements, and a series of barriers to performing physical activity because of the pandemic. Physical activity was reduced significantly in persons with limb loss during the COVID-19 pandemic. A combination of health concerns, fitness center closures, and social distancing mandates were the primary drivers behind the decrease in activity.

Frequency Shapes the Quality of Tactile Percepts Evoked through Electrical Stimulation of the Nerves.

Electrical stimulation of the peripheral nerves of human participants provides a unique opportunity to study the neural determinants of perceptual quality using a causal manipulation. A major challenge in the study of neural coding of touch has been to isolate the role of spike timing—at the scale of milliseconds or tens of milliseconds—in shaping the sensory experience. In the present study, we address this question by systematically varying the pulse frequency (PF) of electrical stimulation pulse trains delivered to the peripheral nerves of seven participants with upper and lower extremity limb loss via chronically implanted neural interfaces. We find that increases in PF lead to systematic increases in perceived frequency, up to ∼50 Hz, at which point further changes in PF have little to no impact on sensory quality. Above this transition frequency, ratings of perceived frequency level off, the ability to discriminate changes in PF is abolished, and verbal descriptors selected to characterize the sensation change abruptly. We conclude that sensation quality is shaped by temporal patterns of neural activation, even if these patterns are imposed on a fixed neural population, but this temporal patterning can only be resolved up to ∼50 Hz. These findings highlight the importance of spike timing in shaping the quality of a sensation and will contribute to the development of encoding strategies for conveying touch feedback through bionic hands and feet.SIGNIFICANCE STATEMENT A major challenge in the study of neural coding of touch has been to understand how temporal patterns in neuronal responses shape the sensory experience. We address this question by varying the pulse frequency (PF) of electrical pulse trains delivered through implanted nerve interfaces in seven amputees. We concomitantly vary pulse width to separate the effect of changing PF on sensory quality from its effect on perceived magnitude. We find that increases in PF lead to increases in perceived frequency, a qualitative dimension, up to ∼50 Hz, beyond which changes in PF have little impact on quality. We conclude that temporal patterning in the neuronal response can shape quality and discuss the implications for restoring touch via neural interfaces.

Evidence-Based Amputee Rehabilitation: a Systematic Approach to the Restoration of Function in People with Lower Limb Loss

Evidence-Based Amputee Rehabilitation: a Systematic Approach to the Restoration of Function in People with Lower Limb Loss

Low back pain influences trunk-lower limb joint coordination and balance control during standing in persons with lower limb loss

BackgroundBalance is sustained through multi-joint coordination in response to postural perturbations. Low back pain alters postural responses; however, it is unknown how coordination between the trunk and lower extremities affects center of mass control during standing balance among persons with limb loss, particularly those with back pain. MethodsForty participants with unilateral lower limb loss (23 with back pain) stood with eyes open and closed on a firm surface, while wearing IMUs on the sternum, pelvis, and bilaterally on the thigh, shank, and foot. A state-space model with Kalman filter calculated sagittal trunk, hip, knee, and ankle joint angles. Fuzzy entropy quantified center of mass variability of sagittal angular velocity at the sacrum. Normalized cross-correlation functions identified coordination patterns (trunk-hip, trunk-knee, trunk-ankle). Multiple linear regression predicted fuzzy entropy from cross-correlation values for each pattern, with body mass and amputation level as covariates. FindingsWith eyes open, trunk-lower limb joint coordination on either limb did not predict fuzzy entropy. With eyes closed, positive trunk-hip coordination on the intact limb predicted fuzzy entropy in the pain group (p = 0.02), but not the no pain group. On the prosthetic side, inverse trunk-hip coordination patterns predicted fuzzy entropy in pain group (p = 0.03) only. InterpretationPersons with limb loss and back pain demonstrated opposing coordination strategies between the lower limbs and trunk when vision was removed, perhaps identifying a mechanism for pain recurrence. Vision is the dominant source of balance stabilization in this population, which may increase fall risk when visual feedback is compromised.