The effect of including a mobile arch, toe joint, and joint coupling on predictive neuromuscular simulations of human walking.

Predictive neuromuscular simulations are a powerful tool for studying the biomechanics of human walking, and deriving design criteria for technical devices like prostheses or biorobots. Good agreement between simulation and human data is essential for transferability to the real world. The human foot is often modeled with a single rigid element, but knowledge of how the foot model affects gait prediction is limited. Standardized procedures for selecting appropriate foot models are lacking. We performed 2D predictive neuromuscular simulations with six different foot models of increasing complexity to answer two questions: What is the effect of a mobile arch, a toe joint, and the coupling of toe and arch motion through the plantar fascia on gait prediction? and How much of the foot's anatomy do we need to model to predict sagittal plane walking kinematics and kinetics in good agreement with human data? We found that the foot model had a significant impact on ankle kinematics during terminal stance, push-off, and toe and arch kinematics. When focusing only on hip and knee kinematics, rigid foot models are sufficient. We hope our findings will help guide the community in modeling the human foot according to specific research goals and improve neuromuscular simulation accuracy.

Diagnosis and management of COVID toes in outpatients: a case report.

BACKGROUND: Since the beginning of the coronavirus disease 2019 pandemic, the most common skin lesions observed due to infection with the severe acute respiratory syndrome coronavirus 2 are pseudochilblains (or coronavirus disease toes). However, this pathology remains infrequent and difficult to diagnose, as no specific test exists. CASE PRESENTATION: Two Caucasian women, 30 and 22 years old, presented to our General Medicine Unit with perniosis lesions on the feet during the first two waves of the coronavirus disease 2019 pandemic. They did not have respiratory or general symptoms of severe acute respiratory syndrome coronavirus 2 infection, the reverse transcription polymerase chain reaction on nasopharyngeal swabs was negative, and the serology was positive only in the first case. The clinical presentation differed for the two cases, as the second patient suffered from swelling and burning after cold application. The diagnosis was based on clinical presentation, temporality, exclusion of other differential diagnoses, and blood test results (positive serology in the first case and high level of CXCL13 and VEGF in the second), supported by current literature. Lesions resolved spontaneously in the first patient. The second case was hospitalized for pain management and received corticosteroid therapy with resolution of the symptoms. CONCLUSION: These two cases with different clinical presentations illustrate the diagnostic approach to coronavirus disease 2019, a challenging disease with diverse manifestations, including, in some cases, coronavirus disease toes. We present a literature review that illustrates the progression of scientific research. Skin lesions associated with coronavirus disease 2019 infection could be the expression of an important interferon type 1 response and should be considered in the differential diagnosis in a primary care setting.

Correlation of Stature with Great Toe Length in 5-10 Years Aged Bangladeshi Children.

The cross sectional, analytic and descriptive type study was conducted among 5-10 years aged Bangladeshi children at different areas of Mymensingh District (Fulbaria, Trisal, Haluaghat, Fulpur and Muktagacha), Bangladesh on 109 Bangladeshi children from January 2016 to December 2016. Nonrandom purposive sampling technique was taken for sample collection. Any kind of foot deformity resulting either from physical injury or congenital anomaly was excluded to construct standard data. The present anthropometric study was designed to construct data of 5 to 10 years aged Bangladeshi children regarding great toe length, to measure correlation of stature with great toe length and comparison of great toe length between male and female children. This study has been made out to grow interest among the researchers for future study of different country. Stature of the subject was measured with the stadiometer and great toe length was measured using slide caliper. The children were requested to stand with weight distributed equally on both feet. The legs were perpendicular to the feet. The mean great toe length of both sides of 5, 6, 7, 8, 9 and 10 years aged male were 2.90±0.51 cm, 3.00±0.38 cm, 3.18±0.42 cm, 3.41±0.26 cm, 3.34±0.32cm and 3.57±0.45 cm respectively and those of female were 2.93±0.70 cm, 2.70±0.43 cm, 3.05±0.37 cm, 3.02±0.25 cm, 3.42±0.55 cm and 3.62±0.44 cm respectively. Great toe length showed non-significant positive correlation with stature in 5 years old female, 7 years old male and female, 8 years old male, 9 and 10 years old male and female children. In 5 years old male, 6 years old male and female and 8 years old female children, great toe length showed non-significant negative correlation with stature. Comparison of great toe length between male and female children was done by Unpaired Students 't' test which was statistically non-significant.

Wall-climbing performance of gecko-inspired robot with soft feet and digits enhanced by gravity compensation.

Gravitational forces can induce deviations in body posture from desired configurations in multi-legged arboreal robot locomotion with low leg stiffness, affecting the contact angle between the swing leg's end-effector and the climbing surface during the gait cycle. The relationship between desired and actual foot positions is investigated here in a leg-stiffness-enhanced model under external forces, focusing on the challenge of unreliable end-effector attachment on climbing surfaces in such robots. Inspired by the difference in ceiling attachment postures of dead and living geckos, feedforward compensation of the stance phase legs is the key to solving this problem. A feedforward gravity compensation (FGC) strategy, complemented by leg coordination, is proposed to correct gravity-influenced body posture and improve adhesion stability by reducing body inclination. The efficacy of this strategy is validated using a quadrupedal climbing robot, EF-I, as the experimental platform. Experimental validation on an inverted surface (ceiling walking) highlights the benefits of the FGC strategy, demonstrating its role in enhancing stability and ensuring reliable end-effector attachment without external assistance. In the experiment, robots without FGC only completed 3 out of 10 trials, while robots with FGC achieved a 100% success rate in the same trials. The speed was substantially greater with FGC, achieving 9.2 mm s-1in the trot gait. This underscores the proposed potential of the FGC strategy in overcoming the challenges associated with inconsistent end-effector attachment in robots with low leg stiffness, thereby facilitating stable locomotion even at an inverted body attitude.

A survey of the treatment and management of ingrown toenails by UK podiatrists: A cross-sectional survey.

BACKGROUND: Ingrown toenails are a common pathology. Although a range of conservative and surgical measures are widely used for this condition, little is known about their use in practice. This study explored current practice relating to the treatment or management of ingrown toenails by podiatrists in the UK. METHODS: A cross-sectional online survey (Qualtrics, Provo, UT, USA) conducted between March to June 2020 was distributed to practicing podiatrists treating or managing ingrown toenails in the UK. RESULTS: A total of 396 practicing podiatrists responded (60.1% based in the private sector). The majority (88.6%) performed nail surgery most commonly (54.3%) less than five a month. Nearly all (95%) only performed nail avulsion with or without chemical matrixectomy, universally using phenol (97.2%). Application time and number of applications varied but was most commonly applied three times (61.5%) for a total of 3 minutes (75%). Aftercare varied considerably between public and private sectors, with public sectors offering fewer follow-up appointments. CONCLUSIONS: Although there is a variation in clinical practice throughout the treatment pathway, almost all respondents offered nail avulsion with phenol matrixectomy, whereas very few provided incisional nail surgery. This data provides the most comprehensive description of how UK podiatrists conduct nail surgery for onychocryptosis.

Repair of distal finger soft-tissue defects with free fibular great toe neurovascular flaps.

BACKGROUND: This work aimed to investigate the change in fingerprint depth and the recovery rule of fingerprint biological recognition function after repairing finger abdominal defects and rebuilding fingerprint with a free flap. METHOD: From April 2018 to March 2023, we collected a total of 43 cases of repairing finger pulp defects using the free flap of the fibular side of the great toe with the digital nerve. After surgery, irregular follow-up visits were conducted to observe fingerprint clarity, perform the ninhydrin test or detect visible sweating with the naked eye. We recorded fingerprint clarity, nail shape, two-point discrimination, cold perception, warm perception and fingerprint recognition using smartphones. The reconstruction process of the repaired finger was recorded to understand the changes in various observation indicators and their relationship with the depth of the fingerprint. The correlation between fingerprint depth and neural repair was determined, and the process of fingerprint biological recognition function repair was elucidated. RESULT: All flaps survived, and we observed various manifestations in different stages of nerve recovery. The reconstructed fingerprint had a clear fuzzy process, and the depth changes of the fingerprint were consistent with the changes in the biological recognition function curve. CONCLUSION: The free flap with the digital nerve is used to repair finger pulp defects. The reconstructed fingerprint has a biological recognition function, and the depth of the fingerprint is correlated with the process of nerve repair. The fingerprint morphology has a dynamic recovery process, and it can reach a stable state after 6-8 months.

Advances in the Causes and Treatment of Floating Toes after the Weil Osteotomy: A Scoping Review.

The floating toe deformity is classified as a forefoot deformity wherein the distal portion of the toe does not establish touch with the ground, resulting in a suspended or elevated position while the finger is in a relaxed state. At first, it garnered considerable interest as a complication It is worth noting that this condition is particularly common in children under the age of 8, which usually disappears as the individual reaches maturity. Studies have shown that with the aggravation of floating toe deformity, its adverse effects on patients' gait and overall quality of life also increase. Despite the prevalence of floating toe deformity in clinical settings, there is a lack of comprehensive literature investigating its underlying causes and potential preventive strategies. This scope review follows the preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews (PRISMA-ScR) statement guidelines for scope reviews. The literature was obtained from various full-text databases, including China National Knowledge Infrastructure Database (CNKI), Wanfang Database, PubMed, and Web of Science Database. Our search focused on published literature related to floating toes, Weil osteotomy, and distal metatarsal osteotomy, up until March 1, 2023. The literature search and data analysis are conducted by two independent reviewers. If there are any disagreements, a third researcher will participate in the discussion and negotiate a decision. Furthermore, two experienced foot and ankle surgeons conducted a thorough literature analysis for this review. Sixty-two articles were included. Through the clinical analysis of the structural changes of the forefoot before and after operation, the classification of floating toe was described, the causes of pathological floating toe were summarized, and the possible intervention measures for the disease were put forward under the advice of foot and ankle surgery experts. We comprehensively summarize the current knowledge system about the etiology of floating toe and put forward the corresponding intervention strategy. We recommend that future studies will focus on the improvement of surgical procedures, such as the combination of Weil osteotomy, proximal interphalangeal (PIP) arthrodesis and flexor tendon arthrodesis.

Subungual Osteochondroma of the Great Toe: A Case Report.

Bony outgrowths of the distal phalanx of the great toe have been described in the literature but rarely. These subungual bony outgrowths can be caused by subungual exostosis or subungual osteochondromas. Both of these abnormalities are bony outgrowths with differences in the cartilage cap wherein the exostoses have fibrocartilage, and osteochondromas have hyaline cartilage. The subungual exostosis and osteochondroma that are protruding present symptoms of pain, redness, and deformed nail bed, whereas the nonprotruding osteochondromas have only a lump as the presenting symptom. In both conditions, excision of the lesion and curettage of the base helps prevent a recurrence. Curettage at the end of the excision of the bony outgrowth is required to avoid recurrence. After excision, the specimen should be sent for histopathologic examination to differentiate between the exostosis and osteochondromas, which are underreported in subungual locations, and to rule out malignant transformation. We present a 13-year-old girl with an isolated subungual nonprotruding exostosis of the great toe that was treated by excisional biopsy. The histopathologic examination confirmed it as osteochondroma, which is underreported.

Isolated Toe Tremor Associated with Antiphospholipid Syndrome.

The antiphospholipid syndrome (APS) is defined by the presence of antiphospholipid antibodies and related disorders, generally thromboses, miscarriages, livedo reticularis or heart valve abnormalities. It is thought to have a prevalence of about 40-50 cases per 100,000 in the general population.1 Several neurological disorders have been associated with APS, most commonly stroke, but non-stroke complications, thought due to auto- immune problems, have been noted, with chorea being the most common. Isolated toe tremor, that is, without any other neurological signs or symptoms, has not been reported. We describe a case of recurrent isolated uni- lateral toe tremor in an otherwise healthy woman with long-standing APS.

Navigating diagnostic challenges-distinguishing malignant melanoma and clear cell sarcoma of soft tissues: a case report and review of the literature.

BACKGROUND: Within the spectrum of melanocytic-differentiated tumors, the challenge faced by pathologists is discerning accurate diagnoses, with clear cell sarcoma of soft tissues standing out as a rare and aggressive neoplasm originating from the neural crest. Accounting for 1% of all soft tissue sarcomas, clear cell sarcoma of soft tissues poses diagnostic complexities, often misidentified owing to its phenotypic resemblance to malignant melanoma. This chapter delves into the intricacies of clear cell sarcoma of soft tissues, its epidemiology, characteristic manifestations, and the imperative need for a comprehensive diagnostic approach involving immunohistochemical and molecular analyses. CASE PRESENTATION: A compelling case unfolds as a 25-year-old male from Morocco, initially misdiagnosed with malignant melanoma, experiences tumor recurrence on the second toe. With no history of trauma or familial neoplasia, the patient's clinical journey is explored, emphasizing the importance of detailed clinical examinations and radiological assessments. The chapter elucidates the histopathological findings, immunohistochemical spectrum, and the correlation between clinical parameters and diagnostic inference, ultimately leading to metatarsal amputation. This clinical vignette highlights the multidimensional diagnostic process in soft tissue neoplasms, emphasizing the synergistic role of clinical, radiological, and histopathological insights. CONCLUSION: The diagnostic challenges inherent in melanocytic-differentiated tumors, exemplified by the rarity of soft tissue clear cell sarcoma, underscore the essential role of an integrated diagnostic approach. This concluding chapter emphasizes the perpetual collaboration required across pathology, clinical medicine, and radiology for nuanced diagnostic precision and tailored therapeutic strategies. The rarity of these soft tissue malignancies necessitates ongoing interdisciplinary engagement, ensuring the optimization of prognosis and treatment modalities through a comprehensive understanding of the diagnostic intricacies presented by clear cell sarcoma of soft tissues.

Digital Gangrene as a Paraneoplastic Manifestation of Peripheral T-cell Lymphoma Not Otherwise Specified Type.

BACKGROUND: Peripheral T cell lymphoma (PTCL), not otherwise specified (NOS) is a heterogenous group of predominantly nodal T cell lymphomas that generally presents with lymphadenopathy with or without extra nodal involvement. Acral vascular syndrome clinically presents as digital ischemia with Raynaud's phenomenon and acral cyanosis. Although, this condition is commonly associated with connective tissue disorder, smoking and vasculitis, its association with lymphoid malignancy is very rare. Here, we present a case report of a patient with digital gangrene of all toes and fingers as a presenting symptom of PTCL-NOS. CASE DESCRIPTION: A 62 year old male presented with digital ischemia associated with pain, low grade fever, loss of appetite and significant weight loss of 6 kilograms over a period of 3 months. On examination, he was found to have bilateral inguinal and axillary lymph nodes with gangrenous changes over toes and fingers but peripheral pulses were palpable. On evaluation he had anemia, elevated ESR and CRP. CT angiogram revealed thinned out digital arteries with multifocal areas of narrowing. Patient was screened for other causes of digital gangrene and was tested negative for ANCA, ANA, cryoglobulins and viral markers. Lymph node biopsy with IHC was suggestive of peripheral T-cell lymphoma-NOS and was started on CHOP regimen. Lymph nodes size decreased and gangrenous changes resolved. CONCLUSION: Though digital ischemia is a rare paraneoplastic presentation of lymphoma, it should be considered if there is a rapid progression of gangrene. Early initiation of chemotherapy may result in the reduction of further progression of digital gangrene and thus prevent permanent disability. In our patient, progression of gangrene was prevented even though it was an aggressive variant of T cell lymphoma.

Effects of walking speeds on lower extremity kinematic synergy in toe vertical position control: An experimental study.

BACKGROUND: This study aimed to investigate whether lower limb joints mutually compensate for each other, resulting in motor synergy that suppresses toe vertical position fluctuation, and whether walking speeds affect lower limb synergy. METHODS: Seventeen male university students walked at slow (0.85 ±â€…0.04 m/s), medium (1.43 ±â€…0.05 m/s) and fast (1.99 ±â€…0.06 m/s) speeds on a 15-m walkway while lower limb kinematic data were collected. Uncontrolled manifold analysis was used to quantify the strength of synergy. Two-way (speed × phase) repeated-measures analysis of variance was used to analyze all dependent variables. RESULTS: A significant speed-by-phase interaction was observed in the synergy index (SI) (P  < .001). At slow walking speeds, subjects had greater SI during mid-swing (P  < .001), while at fast walking speeds, they had greater SI during early-swing (P  < .001). During the entire swing phase, fast walking exhibited lower SI values than medium (P  = .005) and slow walking (P  = .027). CONCLUSION: Kinematic synergy plays a crucial role in controlling toe vertical position during the swing phase, and fast walking exhibits less synergy than medium and slow walking. These findings contribute to a better understanding of the role of kinematic synergy in gait stability and have implications for the development of interventions aimed at improving gait stability and reducing the risk of falls.

Refinement of Surgery for Postaxial Polysyndactyly of the Toes: Esthetic Outcome in Japanese Feet.

PURPOSE: Treatment for polysyndactyly of the toes aims at cosmetic improvement but the lateroplantar rotation of the new fifth toe remains challenging. This study evaluated our novel surgical procedure for postaxial polysyndactyly of the toes. MATERIALS AND METHODS: Patients with postaxial polysyndactyly involving the fourth, fifth, and sixth toes treated in 2007 to 2017 with a minimum follow-up duration of 1 year were retrospectively investigated. Our aims of surgery for this condition were to avoid excessive lateroplantar rotation of the new fifth toe by using a proximally elongated plantar "shark-fin flap" and to make the tip of this toe appear to be naturally pointing inward by using the dog-ear component of the flap on the tip of the toe. The excess skin of the shark-fin flap was grafted onto the lateral surface of the fourth toe. Lateroplantar rotation of the fifth toe in these patients was compared with that in photographs of the feet of 96 normal 4-year-old children. RESULTS: A total of 11 feet in 10 patients (6 male, 4 female; mean age 1.3 years) were analyzed. Syndactyly between the fourth and fifth toes was complete in 3 feet, incomplete at the level of the distal interphalangeal joint of the fifth toe in 5, and incomplete at the level of the proximal interphalangeal joint of the fifth toe in 3. Lateroplantar rotation of the fifth toe, evaluated by the mean angle between 2 intersecting lines extending from the proximal nail fold of the third and fifth toes, was 25 ± 10° in normal feet and 0 ± 12° in operated feet with polysyndactyly. The absolute left-right difference in this angle was 7 ± 5° in normal children and 22 ± 12° in patients with polysyndactyly. Valgus deformity of the new fifth toe improved in all patients during a mean postoperative follow-up of 3.8 years. CONCLUSIONS: Using our procedure, no excessive lateroplantar rotation has been observed when the tip of the fifth toe is inclined inward using a dog-ear flap component. This procedure could be useful in patients in whom the cosmetic outcome is a priority.