Enhancing Walking Performance With a Bilateral Hip Exoskeleton Assistance in Individuals With Above-Knee Amputation.

Transfemoral amputation is a debilitating condition that leads to long-term mobility restriction and secondary disorders that negatively affect the quality of life of millions of individuals worldwide. Currently available prostheses are not able to restore energetically efficient and functional gait, thus, recently, the alternative strategy to inject energy at the residual hip has been proposed to compensate for the lack of energy of the missing leg. Here, we show that a portable and powered hip exoskeleton assisting both the residual and intact limb induced a reduction of walking energy expenditure in four individuals with above-knee amputation. The reduction of the energy expenditure, quantified using the Physiological Cost Index, was in the range [-10, -17]% for all study participants compared to walking without assistance, and between [-2, -24]% in three out of four study participants compared to walking without the device. Additionally, all study participants were able to walk comfortably and confidently with the hip exoskeleton overground at both their self-selected comfortable and fast speed without any observable alterations in gait stability. The study findings confirm that injecting energy at the hip level is a promising approach for individuals with above-knee amputation. By reducing the energy expenditure of walking and facilitating gait, a hip exoskeleton may extend mobility and improve locomotor training of individuals with above-knee amputation, with several positive implications for their quality of life.

Modeling and analysis of a prosthetic foot: A numerical simulation case study.

BACKGROUND: The prosthetic foot is an essential component of the prosthetic limb used by people who suffer from amputation. The prosthetic foot or limb is expensive in developing countries and cannot be used by most people with special needs. OBJECTIVE: In this study, an uncomplicated prosthetic foot is designed that can be manufactured at low costs using 3D printer technology and can be provided to a wide range of amputees. The foot was designed using CAD software and analyzed using ANSES. METHODS: Carbon fiber material was chosen to be suitable for the manufacturing process using 3D printer technology. The selected material was tested in tensile and fatigue tests to determine its mechanical properties. The numerical analysis was carried out assuming the use of an artificial foot by a patient weighing 85 kg. RESULTS: The results showed that the material proposed for manufacturing has good mechanical properties for this application. The results of the engineering analysis also showed that the model has successfully passed the design process and is reliable for use by amputees. CONCLUSION: The success model designed in this study in the numerical analysis process gives reliability to the use of this design to manufacture the prosthetic foot.

Intelligent ankle-foot prosthesis based on human structure and motion bionics.

The ankle-foot prosthesis aims to compensate for the missing motor functions by fitting the motion characteristics of the human ankle, which contributes to enabling the lower-limb amputees to take care of themselves and improve mobility in daily life. To address the problems of poor bionic motion of the ankle-foot prosthesis and the lack of natural interaction among the patient, prosthesis, and the environment, we developed a complex reverse-rolling conjugate joint based on the human ankle-foot structure and motion characteristics, the rolling joint was used to simulate the rolling-sliding characteristics of the knee joint. Meanwhile, we established a segmental dynamics model of the prosthesis in the stance phase, and the prosthetic structure parameters were obtained with the optimal prosthetic structure dimensions and driving force. In addition, a carbon fiber energy-storage foot was designed based on the human foot profile, and the dynamic response of its elastic strain energy at different thicknesses was simulated and analyzed. Finally, we integrated a bionic ankle-foot prosthesis and experiments were conducted to verify the bionic nature of the prosthetic joint motion and the energy-storage characteristics of the carbon fiber prosthetic foot. The proposed ankle-foot prosthesis provides ambulation support to assist amputees in returning to social life normally and has the potential to help improve clinical viability to reduce medical rehabilitation costs.

Factors leading to falls in transfemoral prosthesis users: a case series of prosthesis-side stumble recovery responses.

BACKGROUND: Falls due to stumbling are prevalent for transfemoral prosthesis users and may lead to increased injury risk. This preliminary case series analyzes the transfemoral prosthesis user stumble recovery response to highlight key deficits in current commercially-available prostheses and proposes potential interventions to improve recovery outcomes. METHODS: Six transfemoral prosthesis users were perturbed on their prosthetic limb at least three times while walking on a treadmill using obstacle perturbations in early, mid and late swing. Kinematic data were collected to characterize the response, while fall rate and key kinematic recovery metrics were used to assess the quality of recovery and highlight functional deficits in current commercially-available prostheses. RESULTS: Across all participants, 13 (54%) of the 24 trials resulted in a fall (defined as > 50% body-weight support) with all but one participant (83%) falling at least once and two participants (33%) falling every time. In contrast, in a previous study of seven young, unimpaired, non-prosthesis users using the same experimental apparatus, no falls occurred across 190 trials. For the transfemoral prosthesis users, early swing had the highest rate of falling at 64%, followed by mid-swing at 57%, and then late swing at 33%. The trend in falls was mirrored by the kinematic recovery metrics (peak trunk angle, peak trunk angular velocity, forward reach of the perturbed limb, and knee angle at ground contact). In early swing all four metrics were deficient compared to non-prosthesis user controls. In mid swing, all but trunk angular velocity were deficient. In late swing only forward reach was deficient. CONCLUSION: Based on the stumble recovery responses, four potential deficiencies were identified in the response of the knee prostheses: (1) insufficient resistance to stance knee flexion upon ground contact; (2) insufficient swing extension after a perturbation; (3) difficulty initiating swing flexion following a perturbation; and (4) excessive impedance against swing flexion in early swing preventing the potential utilization of the elevating strategy. Each of these issues can potentially be addressed by mechanical or mechatronic changes to prosthetic design to improve quality of recovery and reduce the likelihood a fall.

A high precision laser scanning system for measuring shape and volume of transtibial amputee residual limbs: Design and validation.

Changes in limb volume and shape among transtibial amputees affects socket fit and comfort. The ability to accurately measure residual limb volume and shape and relate it to comfort could contribute to advances in socket design and overall care. This work designed and validated a novel 3D laser scanner that measures the volume and shape of residual limbs. The system was designed to provide accurate and repeatable scans, minimize scan duration, and account for limb motion during scans. The scanner was first validated using a cylindrical body with a known shape. Mean volumetric errors of 0.17% were found under static conditions, corresponding to a radial spatial resolution of 0.1 mm. Limb scans were also performed on a transtibial amputee and yielded a standard deviation of 8.1 ml (0.7%) across five scans, and a 46 ml (4%) change in limb volume when the socket was doffed after 15 minutes of standing.

Continuous neural control of a bionic limb restores biomimetic gait after amputation.

For centuries scientists and technologists have sought artificial leg replacements that fully capture the versatility of their intact biological counterparts. However, biological gait requires coordinated volitional and reflexive motor control by complex afferent and efferent neural interplay, making its neuroprosthetic emulation challenging after limb amputation. Here we hypothesize that continuous neural control of a bionic limb can restore biomimetic gait after below-knee amputation when residual muscle afferents are augmented. To test this hypothesis, we present a neuroprosthetic interface consisting of surgically connected, agonist-antagonist muscles including muscle-sensing electrodes. In a cohort of seven leg amputees, the interface is shown to augment residual muscle afferents by 18% of biologically intact values. Compared with a matched amputee cohort without the afferent augmentation, the maximum neuroprosthetic walking speed is increased by 41%, enabling equivalent peak speeds to persons without leg amputation. Further, this level of afferent augmentation enables biomimetic adaptation to various walking speeds and real-world environments, including slopes, stairs and obstructed pathways. Our results suggest that even a small augmentation of residual muscle afferents restores biomimetic gait under continuous neuromodulation in individuals with leg amputation.

Variable-stiffness prosthesis improves biomechanics of walking across speeds compared to a passive device.

Ankle push-off power plays an important role in healthy walking, contributing to center-of-mass acceleration, swing leg dynamics, and accounting for 45% of total leg power. The majority of existing passive energy storage and return prostheses for people with below-knee (transtibial) amputation are stiffer than the biological ankle, particularly at slower walking speeds. Additionally, passive devices provide insufficient levels of energy return and push-off power, negatively impacting biomechanics of gait. Here, we present a clinical study evaluating the kinematics and kinetics of walking with a microprocessor-controlled, variable-stiffness ankle-foot prosthesis (945 g) compared to a standard low-mass passive prosthesis (Ottobock Taleo, 463 g) with 7 study participants having unilateral transtibial amputation. By modulating prosthesis stiffness under computer control across walking speeds, we demonstrate that there exists a stiffness that increases prosthetic-side energy return, peak power, and center-of-mass push-off work, and decreases contralateral limb peak ground reaction force compared to the standard passive prosthesis across all evaluated walking speeds. We demonstrate a significant increase in center-of-mass push-off work of 26.1%, 26.2%, 29.6% and 29.9% at 0.75 m/s, 1.0 m/s, 1.25 m/s, and 1.5 m/s, respectively, and a significant decrease in contralateral limb ground reaction force of 3.1%, 3.9%, and 3.2% at 1.0 m/s, 1.25 m/s, and 1.5 m/s, respectively. This study demonstrates the potential for a quasi-passive microprocessor-controlled variable-stiffness prosthesis to increase push-off power and energy return during gait at a range of walking speeds compared to a passive device of a fixed stiffness.

A novel approach for predicting usability of upper limb prostheses.

Limb amputation can lead to significant functional challenges in daily activities, prompting amputees to use prosthetic devices (PDs). However, the cognitive demands of PDs and usability issues have resulted in user rejections. This study aimed to create a Human Performance Model for Upper-Limb Prosthetic Devices (HPM-UP). The model used formulations of learnability, error rate, memory load, efficiency, and satisfaction to assess usability. The model was validated in an experiment with 30 healthy participants using a bypass prosthetic device. Findings indicated that the HPM-UP successfully predicted the usability of prosthetic devices, aligning with human subject data. This research proposes a quantitative approach to predict upper limb prosthetic device usability by quantifying each dimension and computationally connecting them. The model, available on Github and executable with Rstudio, could enable clinicians to assess and analyze the human performance of various commercial prostheses, aiding in recommending optimal devices for patients.

FHIR-standardized data collection on the clinical rehabilitation pathway of trans-femoral amputation patients.

Lower limb amputation is a medical intervention which causes motor disability and may compromise quality of life. Several factors determine patients' health outcomes, including an appropriate prosthetic provision and an effective rehabilitation program, necessitating a thorough quantitative observation through different data sources. In this context, the role of interoperability becomes essential, facilitating the reuse of real-world data through the provision of structured and easily accessible databases. This study introduces a comprehensive 10-year dataset encompassing clinical features, mobility measurements, and prosthetic knees of 1006 trans-femoral amputees during 1962 hospital stays for rehabilitation. The dataset is made available in both comma-separated values (CSV) format and HL7 Fast Healthcare Interoperability Resources (FHIR)-based representation, ensuring broad utility and compatibility for researchers and healthcare practitioners. This initiative contributes to advancing community understanding of post-amputation rehabilitation and underscores the significance of interoperability in promoting seamless data sharing for meaningful insights into healthcare outcomes.

Development of the ECLIPSE model of meaningful outcome domains following lower limb amputation and prosthetic rehabilitation, through systematic review and best fit framework synthesis.

BACKGROUND: Little is known about which outcome domains characterise meaningful recovery following prosthetic rehabilitation and should be measured. Our previous qualitative work developed a conceptual model of outcome domains which are meaningful to patients. This qualitative synthesis aims to develop that model by exploring views and experiences of recovery captured in the limb loss literature, and use these to produce a second iteration of the model describing outcome domains of importance following prosthetic rehabilitation from the patient's perspective. METHODS: Systematic searches were conducted using CINAHL, Psychinfo and Web of Science from 2011 to early 2023. Studies with a qualitative design focusing on views and experiences of lower limb prosthetic users were eligible for inclusion. Quality was assessed using the CASP tool. 'Best Fit' framework synthesis was used to synthesise the evidence and develop the conceptual model. RESULTS: 40 studies were included, describing the experiences of 539 participants. Data supported the pre-existing conceptual model and led to development of four of the five domains. The newly named ECLIPSE model describes meaningful outcome domains as 1) Being able to participate in important activities and roles, 2) Participating in the way I want to, 3) My prosthesis works for me, 4) If I am in pain, I can manage it, and 5) I am able to accept my new normal. Studies came from 15 countries showing good coverage of high-income settings. Few participants from low-and-middle-income countries were included, it is unclear if the ECLIPSE model describes outcome domains of importance in these settings. CONCLUSIONS: This synthesis provides a rigorous foundation for understanding outcome domains of importance following lower limb prosthetic rehabilitation from the patient's perspective. The ECLIPSE model is an accessible representation of recovery which could direct rehabilitation programmes, as well as inform the evaluation of prosthetic care through the selection of outcome measures.

Dynamic gait stability and stability symmetry for people with transfemoral amputation: A case-series of 19 individuals with bone-anchored limbs.

For some individuals with severe socket-related problems, prosthesis osseointegration directly connects a prosthesis to the residual limb creating a bone-anchored limb (BAL). We compared dynamic gait stability and between-limb stability symmetry, as measured by the Margin of Stability (MoS) and the Normalized Symmetry Index (NSI), for people with unilateral transfemoral amputation before and one-year after BAL implantation. The MoS provides a mechanical construct to assess dynamic gait stability and infer center of mass and limb control by relating the center of mass and velocity to the base of support. Before and one-year after BAL implantation, 19 participants walked overground at self-selected speeds. We quantified dynamic gait stability anteriorly and laterally at foot strike and at the minimum lateral MoS value. After implantation, we observed decreased lateral MoS at foot strike for the amputated (MoS mean(SD) %height; pre: 6.6(2.3), post: 5.9(1.3), d = 0.45) and intact limb (pre: 6.2(1.2), post: 5.8(1.0), d = 0.38) and increased between-limb MoS symmetry at foot strike (NSI mean(SD) %; anterior-pre: 10.3(7.3), post: 8.4(3.6), d = 0.23; lateral-pre: 18.8(12.4), post: 12.4(4.9), d = 0.47) and at minimum lateral stability (pre: 28.1(18.1), post: 19.2(6.8), d = 0.50). Center of mass control using a BAL resulted in dynamic gait stability more similar between limbs and may have reduced the adoption of functional asymmetries. We suggest that improved between-limb MoS symmetry after BAL implantation is likely due to subtle changes in individual limb MoS values at self-selected walking speeds resulting in an overall positive impact on fall risk through improved center of mass and prosthetic limb control.

Effects of prosthetic stiffness and added mass on metabolic power and asymmetry in female runners with a leg amputation.

Similar to nonamputees, female athletes with unilateral transtibial amputation (TTA) using running-specific leg prostheses (RSPs) may have worse running economy and higher rates of running-related injury than male athletes. Optimizing RSP configuration for female athletes could improve running economy and minimize biomechanical asymmetry, which has been associated with running-related injury. Nine females with a TTA ran at 2.5 m/s while we measured metabolic rates and ground reaction forces. Subjects used an RSP with a manufacturer-recommended stiffness category, one category less stiff and two categories less stiff than recommended. Use of an RSP two categories less stiff resulted in 3.0% lower net metabolic power (P = 0.04), 7.8% lower affected leg stiffness (P = 6.01 × 10-4), increased contact time asymmetry (P = 0.04), and decreased stance average vertical ground reaction force asymmetry (P = 0.04) compared with a recommended stiffness category RSP. Lower RSP stiffness (kN/m) values were associated with lower net metabolic power (P = 0.02), lower affected leg stiffness (P = 1.36 × 10-4), longer affected leg contact time (P = 1.46 × 10-4), and similar affected leg peak and stance-average vertical ground reaction force compared with higher RSP stiffness values. Subjects then used the RSP stiffness category that elicited the lowest net metabolic power with 100 g, 200 g, and 300 g added distally. We found no significant effects of added mass on net metabolic power, biomechanics, or asymmetry. These results suggest that female runners with a TTA could decrease metabolic power during running while minimizing biomechanical asymmetries, which have been associated with running-related injury, by using an RSP two categories less stiff than manufacturer recommended.NEW & NOTEWORTHY Females with unilateral transtibial amputation can improve running performance through reductions in net metabolic power by using a running-specific prosthesis (RSP) that is less stiff than manufacturer-recommended. Lower RSP stiffness values are associated with greater leg stiffness and contact time asymmetry, and lower stance-average vertical ground reaction force asymmetry. However, we found that adding mass to the RSP did not affect net metabolic power and stance-phase biomechanical asymmetries during running.

EMG gesture signal analysis towards diagnosis of upper limb using dual-pathway convolutional neural network.

This research introduces a novel dual-pathway convolutional neural network (DP-CNN) architecture tailored for robust performance in Log-Mel spectrogram image analysis derived from raw multichannel electromyography signals. The primary objective is to assess the effectiveness of the proposed DP-CNN architecture across three datasets (NinaPro DB1, DB2, and DB3), encompassing both able-bodied and amputee subjects. Performance metrics, including accuracy, precision, recall, and F1-score, are employed for comprehensive evaluation. The DP-CNN demonstrates notable mean accuracies of 94.93 ± 1.71% and 94.00 ± 3.65% on NinaPro DB1 and DB2 for healthy subjects, respectively. Additionally, it achieves a robust mean classification accuracy of 85.36 ± 0.82% on amputee subjects in DB3, affirming its efficacy. Comparative analysis with previous methodologies on the same datasets reveals substantial improvements of 28.33%, 26.92%, and 39.09% over the baseline for DB1, DB2, and DB3, respectively. The DP-CNN's superior performance extends to comparisons with transfer learning models for image classification, reaffirming its efficacy. Across diverse datasets involving both able-bodied and amputee subjects, the DP-CNN exhibits enhanced capabilities, holding promise for advancing myoelectric control.

The lived experience of military beneficiaries with amputations at the hip and pelvic level.

BACKGROUND: Hip- and pelvic-level amputations are devastating injuries that drastically alter patient function and quality of life. This study examined the experience of military beneficiaries with a hip- or pelvic-level amputation to better characterize their challenges and specific needs and to optimize treatment in the future. METHODS: We conducted a retrospective review of the Military Health System and identified 118 patients with a history of one or more amputation(s) at the hip or pelvic level between October 2001 and September 2017. Surviving participants (n = 97) were mailed a letter which explained the details of the study and requested participation in a telephonic interview. A total of six individuals (one female, five males) participated in structured interviews. RESULTS: The study group included four participants with hip disarticulations and two participants with hemipelvectomies (one internal, one external). All six participants reported significant challenges with activities related to prosthetic use, mobility, residual limb health, pain, gastrointestinal and genitourinary function, psychiatric health, and sexual function. CONCLUSIONS: These interviews highlight the unique needs of individuals with hip- and pelvic-level amputations and may improve access to higher echelons of care that would enhance the function and quality of life for these participants.

Asymmetry of peak plantar pressure in transfemoral amputees during indoor and outdoor walking.

This study investigates the differences in peak plantar pressure between the amputated and intact limbs of transfemoral amputees when walking outdoors. Ten non-amputees (aged 24.4 ± 2.0 years, 176.9 ± 2.5 cm, 72.3 ± 7.9 kg) and six transfemoral amputees (48.5 ± 6.3 years, 173.8 ± 4.2 cm, 82.0 ± 11.9 kg) participated in the study. Over approximately 1.6 km, the participants encountered various obstacles, including stairs, uneven surfaces, hills, and level ground, both indoors and outdoors. Throughout the walking session, the peak plantar pressure in both feet was monitored using wearable insole sensors. For all terrains, the percentage asymmetry was determined. Significant changes in peak plantar pressure asymmetry were found between the intact and amputated limbs, particularly when walking on level ground indoors, uneven terrains, descending stairs, and on steep slopes outdoors (all p < 0.05). These findings highlight the greater peak plantar pressure asymmetry in transfemoral amputees when walking outside. In addition, this study revealed that not all terrains contribute uniformly to this asymmetry.

Resting state neurophysiology of agonist-antagonist myoneural interface in persons with transtibial amputation.

The agonist-antagonist myoneural interface (AMI) is an amputation surgery that preserves sensorimotor signaling mechanisms of the central-peripheral nervous systems. Our first neuroimaging study investigating AMI subjects conducted by Srinivasan et al. (2020) focused on task-based neural signatures, and showed evidence of proprioceptive feedback to the central nervous system. The study of resting state neural activity helps non-invasively characterize the neural patterns that prime task response. In this study on resting state functional magnetic resonance imaging in AMI subjects, we compared functional connectivity in patients with transtibial AMI (n = 12) and traditional (n = 7) amputations (TA). To test our hypothesis that we would find significant neurophysiological differences between AMI and TA subjects, we performed a whole-brain exploratory analysis to identify a seed region; namely, we conducted ANOVA, followed by t-test statistics to locate a seed in the salience network. Then, we implemented a seed-based connectivity analysis to gather cluster-level inferences contrasting our subject groups. We show evidence supporting our hypothesis that the AMI surgery induces functional network reorganization resulting in a neural configuration that significantly differs from the neural configuration after TA surgery. AMI subjects show significantly less coupling with regions functionally dedicated to selecting where to focus attention when it comes to salient stimuli. Our findings provide researchers and clinicians with a critical mechanistic understanding of the effect of AMI amputation on brain networks at rest, which has promising implications for improved neurorehabilitation and prosthetic control.

Prosthesis usability experience is associated with extent of upper limb prosthesis adoption: A Structural Equation Modeling (SEM) analysis.

Factors associated with upper limb prosthesis adoption are not well understood. In this study, we explored how prosthesis usability experience relates to the extent of prosthesis adoption through the development of a structural equation model (SEM). First, items related to prosthesis usability were developed and refined using cognitive testing and pilot testing and employed in a survey of 402 prosthesis users (mean age 61.7 (sd 14.4), 77.1% Veterans). The SEM examined two unidimensional latent constructs: Prosthesis Usability Experience and Prosthesis Adoption-and each had multiple measured indicators. SEMs tested direct as well as moderating and mediating effects between the latent constructs and covariates related to demographics and prosthesis type. SEM found a significant positive association between Prosthesis Usability Experience and Extent of Prosthesis Adoption. Several covariates had direct effects on prosthesis adoption: 1) Extent of Prosthesis Adoption was lower for those with transhumeral and shoulder amputation, and higher for those with bilateral amputation, compared to the reference group with unilateral transradial amputation and 2) Myoelectric multiple degree of freedom (multi-DOF) prosthesis use was associated with lower Extent of Prosthesis Adoption, compared to body-powered prosthesis use. Myoelectric multi-DOF use also modified the effect of Prosthesis Usability Experience on Extent of Prosthesis Adoption. For those with bilateral ULA, the strength of the relationship between Prosthesis Usability Experience and Extent of Prosthesis Adoption was reduced. Findings suggest that in order to increase prosthesis adoption, prosthetics developers and rehabilitation providers should focus on implementing strategies to improve prosthesis usability experience. New Prosthesis Usability Experience measures could be used to identify persons at greater risk for poor prosthesis adoption and target interventions to increase prosthesis use.

The Response of the Amputee Athlete Heart to Chronic Core Exercise: A Study on Hematological and Biochemical Parameters, and N-Terminal Pro Brain Natriuretic Peptide.

Background and Objectives: mortality and morbidity due to cardiovascular causes are frequently experienced in amputees. Research on the effects of chronic exercise on biomarkers and cardiac damage indicators in these individuals is limited. The aim of this study was to investigate the effects of a core training program on brain natriuretic-related peptide, as well as hematological and biochemical parameters in amputee soccer players. Materials and Methods: The participants were randomly allocated to the following two groups: a core exercise group (CEG) and a control group (CG). While the CG continued routine soccer training, the CEG group was included in a core exercise program different from this group. During the study, routine hemogram parameters of the participants, various biochemical markers, and the concentration of brain natriuretic-related peptide (NT-pro-BNP) were analyzed. Results: after the training period, notable improvements in various hematological parameters were observed in both groups. In the CEG, there were significant enhancements in red blood cell count (RBC), hematocrit (HCT), mean corpuscular hemoglobin concentration (MCHC), and mean corpuscular hemoglobin (MCH) values. Similarly, the CG also showed substantial improvements in RBC, HCT, mean corpuscular volume (MCV), MCHC, MCH, red cell distribution width-standard deviation (RDW-SD), platelet-to-lymphocyte ratio (PLCR), mean platelet volume (MPV), and platelet distribution width (PDW). Moreover, in the CEG, serum triglycerides (TG) and maximal oxygen uptake (MaxVO2) exhibited significant increases. Conversely, TG levels decreased in the CG, while high-density lipoprotein (HDL), low-density lipoprotein (LDL), and MaxVO2 levels demonstrated substantial elevations. Notably, the N-terminal pro-brain natriuretic peptide (BNP) levels did not undergo significant changes in either the CEG or the CG following the core exercise program (p > 0.05). However, in the CEG, a meaningful positive correlation was observed between NT-pro-BNP and creatine kinase (CK) levels before and after the core exercise program. Conclusions: the findings emphasized the potential benefits of core training in enhancing specific physiological aspects, such as erythrocyte-related parameters and lipid metabolism, as well as aerobic capacity. Furthermore, the observed correlation between NT-pro-BNP and CK levels in the CEG provides intriguing insights into the unique physiological adaptations of amputee athletes.

Risk of Heart Disease in Patients With Amputation: A Nationwide Cohort Study in South Korea.

BACKGROUND: Amputation confers disabilities upon patients and is linked to substantial morbidity and death attributed to heart disease. While some studies have focused on traumatic amputees in veterans, few studies have focused on traumatic amputees within the general population. Therefore, the present study aimed to assess the risk of heart disease in patients with traumatic amputation with disability within the general population using a large-scale nationwide population-based cohort. METHODS AND RESULTS: We used data from the Korean National Health Insurance System. A total of 22 950 participants with amputation were selected with 1:3 age, sex-matched controls between 2010 and 2018. We used Cox proportional hazard models to calculate the risk of myocardial infarction, heart failure, and atrial fibrillation among amputees. Participants with amputation had a higher risk of myocardial infarction (adjusted hazard ratio [aHR], 1.30 [95% CI, 1.14-1.47]), heart failure (aHR, 1.27 [95% CI, 1.17-1.38]), and atrial fibrillation (aHR, 1.17 [95% CI, 1.03-1.33]). The risks of myocardial infarction and heart failure were further increased by the presence of disability (aHR, 1.43 [95% CI, 1.04-1.95]; and aHR, 1.38 [95% CI, 1.13-1.67], respectively). CONCLUSIONS: We demonstrate an increased risk of myocardial infarction, heart failure, and atrial fibrillation among individuals with amputation, and the risk further increased in those with disabilities. Clinicians should pay attention to the increased risk for heart disease in patients with amputation.

Botulinum toxin and hyperhidrosis of the amputation stump in war amputees.

INTRODUCTION: Stump hyperhidrosis is a common condition after lower limb amputation. It affects the prosthesis use, and the quality of life of patients. Several case reports tried to prove benefit of using Botulinum toxin in its treatment. AIM: This study was to conduct a larger workforce clinical trial and to demonstrate benefits of botulinum toxin injection in the treatment of stump hyperhidrosis. METHODS: A prospective study was conducted. War amputees who complained of annoying excessive sweating of the stump were included. They received intradermal injection of botulinum toxin A in the residual limb area in contact with prosthetic socket. Abundance of sweating and degree of functional discomfort associated with it were assessed before, after 3 weeks, 6 and 12 months. RESULTS: Seventeen male patients, followed for post-traumatic limb amputation were included in the study. Discomfort and bothersome in relation to Hyperhidrosis did decrease after treatment (p<0,001). Reported satisfaction after 3 weeks was 73,33%. Improvement of prothesis loosening up after 3 weeks was 72,5% [±15,6]. Mean injection-induced pain on the visual analogue scale was 5.17/10 (±1.58). The mean interval after the onset of improvement was 5.13 days [min:3, max:8]. The mean time of improvement was 10.4 months after the injection [min:6, max:12]. No major adverse events were reported following treatment. CONCLUSION: Intradermal injections of botulinum toxin in the symptomatic treatment of stump hyperhidrosis are effective and have few adverse effects. It improves the quality of life of our patients thanks to a better tolerance of the prosthesis.