Search Results (366)

Background: Lower limb exoprostheses often lead to stump dermatological pathologies. The mechanisms by which mechanical microtraumas progress to non-healing ulcerative defects due to dysbiosis remain poorly understood. The objective of this study was to analyze mechanical, inflammatory, and infectious stump skin complications and justify the role of bacterial and mycological dysbiosis in blocking tissue regeneration. Methods: A critical narrative review guided by SANRA principles was conducted (PubMed/Scopus, 1980–2026). Data were extracted with a structured query focusing on amputation stumps, prosthetic interfaces, and skin/microbiological complications (dysbiosis, biofilms, and inflammatory markers). Evidence was graded using predefined clinical matrices and integrated through structured evidence collations to synthesize stump–prosthesis pathogenesis. The PRISMA method was not applied due to study heterogeneity. Results: Skin damage dynamics were categorized into three stages: adaptation (up to 12 months), chronic reactive changes (12–24 months), and late proliferative-infectious destruction (>24 months). The sealed liner space creates 100% humidity and alkalization (pH > 6.5). This causes a mycological shift, where resident Malassezia spp. lose dominance to invasive Candida albicans and non-dermatophyte molds (Aspergillus spp., Fusarium spp.). These pathogens form polymicrobial biofilms with Staphylococcus aureus. At the molecular level, delayed regeneration is driven by “frustrated phagocytosis”: macrophages, unable to engulf large fungal hyphae, continuously release reactive oxygen species and enzymes, trapping the wound in the inflammatory phase. Excessive matrix degradation and suppressed angiogenic factors further block epithelialization. Conclusions: The skin under a prosthesis socket forms a unique pathological biotope. Successful regeneration requires preventive mycobiota correction and targeted management of biophysical parameters (pH, humidity) within the “skin–liner” interface. Full article

Background/Objectives: Studies consistently demonstrate that microprocessor-controlled prosthetic knees (MPKs) improve mobility and quality of life for people with lower limb loss or absence by enhancing balance and reducing falls. However, the extent to which these benefits apply across demographic groups remains unclear. Therefore, we conducted a literature review to evaluate how representative and transferable research on MPKs is across different populations, and which factors influence this. Methods: Using systematic review principles and PRISMA guidelines, 27 studies were analysed from databases including Cochrane, CINAHL, MEDLINE, and PubMed, as of 20th September 2025. The included studies primarily focused on young-to-middle-aged adults, men, individuals with trauma-related amputation, and higher mobility levels. Results: We found that older adults, women, and individuals with amputation caused by vascular disease or diabetes were under-represented in MPK research. Moreover, variability in time since amputation complicates the generalisability of findings, as this factor significantly influences adaptation and functional outcomes. Conclusions: While evidence supports MPKs’ effectiveness in enhancing mobility and reducing the risk of falls, their benefits may not fully apply to under-represented groups, such as older adults, women, or low-activity users. Future research should prioritise more diverse participant samples to improve the generalisation of MPK outcomes across different demographics and functional levels. Full article

Electromyography (EMG)-based pattern recognition is a key enabling technology for intuitive upper-limb prosthetic control; however, amputee EMG signals show substantial intersubject variability and nonstationary characteristics, which can limit the effectiveness of conventional fixed feature representations. This study proposes an Adaptive Multi-Representation Fusion Framework that combines an enhanced Adaptive Linear Series Decomposition Learner (Adaptive LSDL) with Time-Domain Power Spectral Descriptors (TDPSD) for amputee movement classification. The proposed Adaptive LSDL extends conventional decomposition by using adaptive threshold-region optimization and multitransform signal analysis, enabling subject-specific identification of the most discriminative decomposition characteristics while preserving low computational complexity. The complementary properties of TDPSD and Adaptive LSDL are then exploited through feature-level fusion, producing a unified representation that captures both local temporal-spectral complexity and adaptive structural signal information. Experimental evaluation was conducted using the Ninapro DB3 dataset, comprising 11 transradial amputees, and a MYO armband amputee dataset, comprising 6 transradial amputees. Subject-specific five-fold cross-validation was performed using a Linear Discriminant Analysis (LDA) classifier. Adaptive LSDL consistently improved performance relative to the original fixed-threshold LSDL representation, while fusion improved classification accuracy for 7 of 11 DB3 amputees and 5 of 6 MYO amputees. The largest fusion gains reached 4.39 and 5.60 percentage points for the DB3 and MYO cohorts, respectively. Furthermore, the proposed framework demonstrated competitive performance relative to a lightweight real-time convolutional neural network benchmark while requiring substantially lower computational complexity. These findings indicate that adaptive decomposition and representation-level information fusion provide an effective approach for exploiting subject-specific neuromuscular information while remaining suitable for computationally efficient prosthetic control applications. Full article

Background/Objectives: Lower-limb amputation significantly impacts autonomy and daily functioning. Microprocessor-controlled prosthetic knees (MPKs) improve mobility, safety, and quality of life compared with non-microprocessor prosthetic knees (nMPKs). Despite general benefits, differences among MPK models remain unclear. The goal of this investigation was to evaluate functional mobility and patient-reported outcomes in active transfemoral amputees using a new MPK (PROTEOR QUATTRO) compared with existing MPKs. Methods: In this multicenter cross-over clinical trial, active transfemoral amputees were assessed using patient-specific functional scales (PSFS), standardized locomotor capacity tests (6MWT, 10mWT, HAI, SAI) and satisfaction and quality-of-life questionnaires (PEQ-A, SF-36, ESAT). Biomechanical data collection was performed during walking test, to examine gait symmetry indices. Results: The QUATTRO MPK was associated with significantly higher PSFS scores, reflecting higher self-rated ability in performing chosen daily life activities compared with patient’s current prosthesis. Standardized locomotor tests revealed comparable performance between devices. Biomechanical analyses showed similar symmetry indices for QUATTRO and other MPKs. Patient-reported outcomes showed an improvement in physical health with QUATTRO, while overall satisfaction remained similar. Conclusions: QUATTRO improved patient-perceived ability to perform meaningful daily-life activities while maintaining comparable performance on standardized locomotor tests. These results highlight the importance of patient-centered assessments in identifying functional benefits that may guide individualized prosthetic prescriptions for active transfemoral amputees. Full article

Background: Lower limb prosthesis users commonly exhibit gait asymmetry that may increase metabolic demand. Gait asymmetry, therefore, is frequently targeted in rehabilitation to improve walking efficiency. This review aimed to investigate whether interventions that improve gait asymmetry reduce metabolic demand in unilateral lower limb prosthesis users. Methods: A search of relevant English-language articles was conducted using PubMed and CINAHL, yielding a total of 1067 records. Following title, abstract, and full-text screening, 10 studies met eligibility requirements and were included in the qualitative synthesis. Data extraction focused on participant characteristics, gait asymmetry measures, metabolic outcomes, and intervention characteristics. Results: Four main intervention categories were identified: advanced prosthetic knees and ankles, prosthetic mass manipulation, feedback-based gait interventions, and exercise-based training. Across studies, changes in gait symmetry were not consistently associated with reductions in metabolic demand. Interventions targeting ankle function showed the most consistent reductions in metabolic demand, particularly during demanding walking tasks. In contrast, distal prosthetic mass addition consistently increased metabolic demand and worsened gait symmetry. Conclusion: Current evidence does not support a consistent or direct relationship between gait symmetry and metabolic demand in lower limb prosthesis users. Gait asymmetry may not be inherently metabolically disadvantageous and may represent an energetically optimal adaptation. Full article

Background/Objectives: To determine user-reported comfort, function, and overall satisfaction among pediatric lower limb amputees with conventional prosthetic devices and to identify possible factors associated with overall satisfaction. Methods: A cross-sectional observational study was conducted at three tertiary orthotic and prosthetic centers in the Eastern Cape, South Africa. Caregiver–child dyads completed a structured questionnaire evaluating perceived prosthetic comfort, functionality, and satisfaction. There were fifty-two unilateral pediatric lower limb amputees aged 4–17 years who had used conventional prosthetic appliances for at least one year. Questionnaire responses were summarized using descriptive statistics. Spearman’s rank correlation and non-parametric tests were used to examine associations among study variables. Multiple linear regression analysis was performed to identify factors independently associated with overall satisfaction. Results: Mean comfort was 3.54 (SD = 0.87), functionality satisfaction was 3.42 (SD = 0.78), and overall satisfaction was 2.73 (SD = 0.79). Comfort had strong correlations with functionality (ρ = 0.63, p < 0.001) and overall satisfaction (ρ = 0.69, p < 0.001). The satisfaction difference between congenital and acquired amputations was statistically significant (p = 0.006), with those with congenital amputation reporting substantially greater satisfaction than those with acquired amputation. Multiple linear regression analysis showed that perceived prosthetic functionality (β = 0.383, p < 0.001) and comfort (β = −0.535, p < 0.001) were independently associated with overall satisfaction. Conclusions: Perceived comfort and prosthetic functionality were independently associated with overall satisfaction among pediatric users of conventional prosthetic devices. These findings support patient-centered prosthetic design and rehabilitation strategies that prioritize socket comfort and functional performance to improve children’s overall satisfaction with their prosthetic devices. Full article

Polyethylene Terephthalate Glycol (PETG) is a thermoplastic material used in Fused Deposition Modelling for prosthetic applications, where mechanical properties are strongly dependent on process parameters. This study investigated the effects of carbon fibre (CF) content, print orientation (PO), and print temperature (PT) on the mechanical performance of PETG, fabricated using a Bambu Lab A1 printer. Tensile, three-point bending and impact testing were conducted to characterise the mechanical response of printed specimens. A Taguchi L9 array was employed to evaluate parameter effects while minimising experimental runs, and factor effects were quantified using per-response general linear models. Findings indicated that PO and PT significantly affected tensile behaviour, while CF content dominated flexural stiffness and impact response, with the strongest tensile response at 240 °C attributed to improved interlayer bonding. CF reinforcement increased stiffness and flexural strength but had limited effect on tensile strength and a reduced impact resistance at higher loadings, indicating increased brittleness. PO was identified as the most influential factor, with upright specimens exhibiting superior tensile performance, consistent with more favourable alignment of filament deposition with the loading direction. These findings demonstrate that the mechanical behaviour of CF-PETG is strongly process-dependent, informing its future application within prosthetic limb design. Full article

This work presents the design, development, and experimental validation of an inductive sensing system for monitoring prosthetic socket fit variations caused by residual limb volume fluctuations. The system aims to reduce the risk of discomfort and tissue injury by measuring the distance between the outer rigid socket and the inner silicone elastomeric liner worn in direct contact with the residual limb. The sensing architecture consists of a portable data acquisition unit, an LC resonator sensor mounted on the inner surface of the rigid socket, and a magnetic silicone target attached to the external surface of the liner. Multiple configurations of LC resonators and magnetic targets were designed and evaluated. The results indicate that a medium-sized coil (outer diameter = 28 mm, capacitance = 181 pF) combined with a 1 mm thick silicone target made of Ecoflex™ 00-50 with 70 wt% NdFeB microparticles provides the most stable and sensitive performance. Experiments demonstrated stable distance detection up to 7 mm, with the resonant-frequency shift (relative to the baseline condition) varying from −31.37 kHz at 0 mm to −2.94 kHz at 7.00 mm, for a total shift range of 29.84 kHz. Environmental tests showed minimal drift, with frequency variations below 0.40 kHz across temperature (25–60 °C) and humidity (50–90% RH) changes. In vitro validation using a high-fidelity residual limb simulator and an adjustable socket reproduced controlled residual limb volume variations of 300 mL (i.e., +7.5%), resulting in repeatable resonant-frequency changes within 3.15–3.17 MHz with measurement variability ($u_A$, Type A) below 0.13 kHz. Full article

Accurate gesture recognition is crucial for precision control of upper limb prostheses. High-density surface electromyography (HD-sEMG) enhances spatial resolution and information richness of human gesture representation, thus improving myoelectric control of bionic limbs. Recently, deep learning has been increasingly applied to HD-sEMG to enhance gesture recognition performance. However, the black-box nature of neural networks limits their interpretability and model optimization, hindering their practical application. In this paper, we developed a spatiotemporal dual-channel interpretable hybrid neural network (STDC-Net), and validated it using the Capgmyo DB-a dataset. STDC-Net uses Feature Channels and Spatial Channels to process the feature and spatial information of sEMG signals respectively for increased interpretability. SHapley Additive exPlanations (SHAP) values are used to rank the feature importance, aiding feature filtering and reducing the impact of irrelevant features. Graph attention layers are used to calculate the connections between each Spatial Channel, illustrating the relationships between channels. Our results demonstrated the superior performance of our STDC-Net compared to state-of-the-art (SOTA) methods. STDC-Net achieved 99.8% accuracy with a 150 ms sliding window, exceeding real-time implementation requirements for intra-subject tasks. It reached an accuracy of 97.33 ± 2.53% after fine-tuning for inter-subject tasks, outperforming the SOTA methods. Importantly, the SHAP value maps and the channel connection maps enhance the interpretability of the neural networks by offering detailed insights into the contribution of input features and parameter interactions of the network. These findings suggest STDC-Net holds significant promise for real-time prosthetic control. Full article

Background: Phantom limb pain, poor sleep, musculoskeletal pain, and psychological distress are common in patients following traumatic lower-limb amputations. Nevertheless, there is still a lack of research on the connections between these variables and rehabilitation service accessibility. Evidence on phantom limb pain and related rehabilitation factors remains limited in conflict-affected settings, where access to timely prosthetic and rehabilitation services may be substantially disrupted. Objective: The study aimed to determine the prevalence of phantom limb pain and chronic musculoskeletal pain, and to assess their correlation with sleep quality, depression, anxiety and access to rehabilitation services in individuals with traumatic lower-limb amputation. Methods: Between August 2025 and April 2026, 491 patients with unilateral traumatic lower-limb amputations who were receiving outpatient rehabilitation services participated in the study. The Pittsburgh Sleep Quality Index was used to measure sleep quality, while the Hospital Anxiety and Depression Scale was used to measure anxiety and depression. In addition, participants reported delays in physiotherapy and prosthetic fitting, phantom limb pain, and chronic musculoskeletal pain. Mann–Whitney U tests were used for group comparisons, while multiple regression analysis and Spearman correlations were used to assess the relationships. Results: Phantom limb pain was reported by 78.8% of participants, while 46.2% experienced chronic musculoskeletal pain. Among patients who had not received a prosthesis, the mean delay to prosthetic provision was 472.9 days, while the median delay was 502 days. Poorer sleep quality (β = 0.480, p < 0.001) and longer delays to prosthetic fitting (β = 0.184, p = 0.002) were independently associated with greater phantom limb pain intensity. Participants with chronic musculoskeletal pain and those who had not received a prosthesis experienced poorer sleep quality, greater depression and anxiety, and more severe phantom pain than participants without musculoskeletal pain and those who had received a prosthesis. Conclusions: Phantom limb and chronic musculoskeletal pain are highly prevalent after lower-limb amputation. Delayed prosthetic fitting and sleep disturbances are associated with greater phantom pain. Full article

Background: Endovascular repair with covered stent is an established minimally invasive treatment for popliteal artery lesions, particularly in elderly or high-risk patients. Infectious complications are exceptionally rare but may result in arterial destruction, limb loss, and death. Salmonella species demonstrate a well-recognized affinity for diseased arterial walls and prosthetic vascular material. Case Presentation: An 82-year-old man with stage G4 chronic kidney disease and previous nephrectomy for renal cell carcinoma, complicated by Salmonella Enteritidis septic shock 20 years earlier, presented with acute left lower limb ischemia caused by a post-traumatic popliteal artery pseudoaneurysm. Urgent endovascular repair was performed using a 6 × 100 mm covered stent (Viabahn) with adjunctive angioplasty of the anterior tibial artery. Two weeks later, he was readmitted with fever, severe popliteal pain, local erythema, and elevated inflammatory markers. Imaging demonstrated early stent occlusion with a large peri-graft abscess and contained arterial rupture. Emergency open conversion included radical debridement, complete graft explantation, and popliteal-to-posterior tibial bypass using an autologous great saphenous vein. Cultures grew Salmonella Enteritidis. Retrospective history revealed a previously undocumented episode of Salmonella Enteritidis bacteremia approximately 20 years earlier. At 2-year follow-up, the patient remained free of recurrent infection with a patent vein graft and preserved ambulatory function. Conclusions: Early Salmonella Enteritidis infection of a popliteal covered stent is an exceptionally rare but life-threatening complication. This case suggests that remote Salmonella bacteremia may represent a potential, hypothesis-generating risk factor for prosthetic graft infection. Prompt graft explantation followed by radical debridement and autologous venous reconstruction remain essential for durable limb salvage. Full article

Background: Irreversible brachial plexus injury can leave patients with a painful, insensate, and nonfunctional flail limb, often after failed reconstructive attempts and with limited remaining surgical options. This study describes a modified transhumeral amputation technique incorporating a passive biceps brachii traction sling to improve residual limb stability and prosthetic readiness in this challenging setting. Methods: This retrospective, uncontrolled five-case series assessed the feasibility, perioperative safety, descriptive clinical outcomes, and early prosthetic integration of transhumeral amputation with a biceps brachii-based traction sling. Eligible patients had irreversible brachial plexus palsy, complete loss of useful upper-limb function, chronic shoulder instability or traction-related symptoms, pain, and persistent distress related to the paralysed limb as a burdensome nonfunctional appendage. Outcomes included the Disabilities of the Arm, Shoulder and Hand (DASH) score, Visual Analog Scale (VAS) for pain, and SF-36 Physical Functioning and Emotional Well-Being domains. Results are reported descriptively as individual values and medians without hypothesis testing. Results: All five patients completed follow-up, which reached 30 months. After combined transhumeral amputation, biceps sling construction, RPNI, rehabilitation, and prosthetic fitting, patient-reported scores changed in this small uncontrolled series as follows. The median DASH score changed from 64 preoperatively to 50 postoperatively; in this context, DASH reflects global perceived disability and may be influenced by pain relief, altered expectations, prosthetic compensation, psychosocial adaptation, and the removal of a burdensome limb rather than restoration of upper-limb function. Median VAS pain score changed from 7 to 0; VAS captured overall pain intensity only and did not separately measure phantom limb pain, mechanical pain, neuropathic pain, deafferentation pain, or traction-related symptoms. SF-36 Physical Functioning changed from 75 to 100, and Emotional Well-Being from 75 to 100. Four patients were fitted with a myoelectric prosthesis, and one elected to use a cosmetic prosthesis. No postoperative surgical complications, socket-related complications, prosthesis abandonment, clinical shoulder dislocation, or obvious failure of the construct were observed. Two Paralympic athletes returned to competitive sport after rehabilitation. Conclusions: The combined procedure was technically feasible in five highly selected patients and was not associated with observed surgical or prosthetic complications during follow-up. After combined transhumeral amputation, biceps sling construction, RPNI, rehabilitation, and prosthetic fitting, patient-reported scores improved in this small uncontrolled series. The specific contribution of the biceps sling relative to amputation itself, RPNI, prosthetic rehabilitation, and patient selection remains unknown. Larger prospective studies with objective assessment of shoulder and stump stability are needed to validate these preliminary findings and refine patient-selection criteria. Full article

Background. Orthotic and prosthetic devices for general-use and activity-specific function can provide critical preventive health benefits for individuals with limb loss, limb difference, and mobility impairments, and yet coverage remains inconsistent across U.S. states. Objective. To evaluate the fiscal impact of clarifying insurance coverage for orthotic and prosthetic devices across 23 states lacking comprehensive coverage. Methods. A cost consequence analysis was conducted using data from the U.S. Census Bureau, Kaiser Family Foundation, Government Accountability Office, and a recent actuarial analysis informing baseline cost, coverage, and prevalence assumptions. Per-member-per-month (PMPM) cost increases were compared against device enabled preventive health savings to estimate net fiscal impact. Sensitivity analyses modeled three scenarios based upon a combination of uptake (% eligible individuals accessing device) and physical activity equivalent annual cost saving, respectively: conservative (25% uptake, $1000), moderate (50% uptake, $2500), and high-impact (75% uptake, $5000). Return on investment (ROI) was calculated for the moderate scenario as the ratio of annual savings to implementation cost. Results. Under the assumptions of the moderate scenario, projected ROI remained positive across all states, ranging from approximately 1.5× in Florida to over 114× in Vermont, with 78% of states (18 of 23 states) demonstrating returns greater than 4×. Moderate scenario annual net savings ranged from approximately $10.8 million in Vermont to $437.0 million in California, with substantial projected savings also observed in Florida ($235.5 million), New York ($225.2 million), and Virginia ($143.8 million). PMPM cost increases for 70% of states range between $0.03 and $0.43, with all modeled states remaining below $1.46. Discussion. In our healthcare system dominated by high-cost and reactive care, the ROI obtained by this cost-consequence analysis (CCA) using evidence-based assumptions supports orthotic and prosthetic coverage clarification as preventive interventions to restore function. Full article

Background: The Mercer Universal Prosthesis (MUP), designed with a default “neutral” (vertical) socket alignment, was developed to simplify transtibial prosthetic fitting, reduce labor costs, and improve access to prosthetic care in low-resource settings. Methods: This present longitudinal study evaluated biomechanical and functional outcomes at baseline, 6 months, and 12 months in 20 transtibial amputees fitted with the MUP. Results: Functional outcomes, assessed using the SF-36, showed significant improvement in overall health scores at 12 months (p < 0.001), while physical function and energy/fatigue domains remained unchanged (p = 0.686 and p = 0.211, respectively). Biomechanically, sagittal kinematics, measured using inertial motion capture, revealed significant limb × time interactions for hip flexion, knee flexion, and ankle plantarflexion. At 6 months, maximum hip flexion (−7°, p = 0.008) and knee flexion (−11°, p = 0.005) of the prosthetic limb were decreased versus baseline. At 12 months, the only observed difference was increased maximum ankle plantarflexion of the intact limb (+5° vs. baseline, p = 0.016). Muscle effort, quantified via the integral of EMG throughout the gait cycle, did not differ significantly between prosthetic and intact limbs across time points. Gait symmetry index (GSI) scores for hip, knee, and ankle range of motion trended toward gradual improvement but without statistical significance (p > 0.05). Conclusions: The MUP performance was maintained over 12 months, with stable biomechanical performance and meaningful quality-of-life gains. These findings support its potential as a cost-effective solution to expand prosthetic accessibility in low- and middle-income countries. Full article

This study investigated the feasibility and biomechanical effects of volitional electromyography (EMG)-based control of a powered transtibial ankle prosthesis. Four male participants completed static and dynamic EMG assessments and gait analysis while using both their prescribed passive prosthesis and an EMG-controlled powered prototype during level walking at self-selected and fast speeds, as well as ramp ascent and descent. Selective activation of residual tibialis anterior and gastrocnemius muscles was quantified using a co-contraction index, and lower-limb kinematics and kinetics were compared between prosthetic conditions. Participants were able to generate task-dependent residual muscle activity, supporting the feasibility of EMG-based volitional control. However, muscle selectivity was reduced during dynamic tasks, with higher co-contraction during gait than during seated static contractions, and substantial inter-subject variability was observed. Compared to the prescribed passive prosthesis, the EMG-controlled prototype generally produced lower prosthetic-side ankle range of motion and ankle power, although ankle moments were sometimes slightly greater. These findings suggest that EMG control is feasible, but that future controller design must remain flexible to individual users’ neuromuscular abilities and dynamic control limitations. The results provide important guidance for the development and testing of more adaptive, personalized, and functionally effective EMG-controlled prosthetic ankle systems. Full article