Background: Hip fractures are a major cause for disability in patients. They require immediate attention as they could otherwise cause death. Hip fractures are almost always treated with surgery by implantation. Implants are of various types accounting for the many variations in hip fractures. Objectives: This paper presents the design and analysis of a hip implant using Finite element analysis. Fracture conditions are determined and the optimal design of the implant is obtained for improving healthcare and patient safety. Methods: Anthropometric parameters of the human femur bone are collected from a particular age group. These are then used to obtain a CAD model of the bone using CATIA. The standard Charnley hip implant, used in total hip replacement surgery is also modeled. The proposed models are analyzed using ANSYS software by assigning appropriate material properties to the bone and implant. The stress distribution is observed when loads corresponding to normal gait conditions are applied. The load at which fracture occurs is then determined experimentally. Results: Based on the analysis results of the modeled bone, the implant is optimized by varying the base cross section, the bio-materials used, and the design parameters so that, its stress response mimics that of the actual bone. It is found that the model no 2 as in Table 6 with head diameter 28mm, neck diameter 10mm, neck angle 128 degrees has minimum strain at the neck region with a value of 0.65 and is found to be suitable for implant design. Results show that initiation of fracture in the implant occurs at 2000N and complete fracture occurs at 2400N. Conclusions: The 3D models are very useful in simulation of bone fractures and internal fixations with implants. In this work, the hip joint and implant model, developed in CATIA software, help to understand how these structures adapt to external forces disturbances [15]. This will help the doctors to chose the optimal implant for a particular patient. This leads to greater accuracy and patient specificity.

• MeSH
• antropometrie metody   MeSH
• fraktury kyčle * chirurgie   terapie   MeSH
• lidé MeSH
• muskuloskeletální systém * anatomie a histologie   chirurgie   zranění   MeSH
• ortopedické výkony metody   přístrojové vybavení   trendy   MeSH
• počítače MeSH
• protézy a implantáty * MeSH
• statistika jako téma MeSH
• zobrazování trojrozměrné * metody   přístrojové vybavení   využití   MeSH
• Check Tag
• lidé MeSH

• MeSH
• kvalita života MeSH
• muskuloskeletální nemoci epidemiologie   klasifikace   MeSH
• osobní újma zaviněná nemocí MeSH
• posuzování pracovní neschopnosti MeSH
• ukazatele zdravotního stavu MeSH
• Publikační typ
• kongresy MeSH

• Konspekt
• Ortopedie. Chirurgie. Oftalmologie
• NLK Obory
• ortopedie
• revmatologie
• NLK Publikační typ
• publikace WHO

Lidská chůze je dynamický rys, který je složitý a unikátní pro každou osobu. Její analýze je věnováno stále velké úsilí, neboť porozumnění faktorům, které ji ovlivňují, a jejich vzájemným závislostem, napomáhá k diagnóze i léčení abnormalit chůze. Nalezení příčin postižení a funkčních omezení může vést k optimalizaci rehabilitací či simulaci výsledků chirurgického zákroku. Tento článek se zabývá právě přehledem přístupů k modelování chůze. Obsahuje klasifikaci modelů dle různých kritérií a zaměřuje se jak na širokou škálu minimalistických modelů založených na jednoduchém fyzikálním modelu obráceného kyvadla, tak i komplexní analytické modely, reflektujících skutečnou stavbu dolních končetin.

Human gait is dynamic feature, which is unique, complex and difficult to mimic. Understanding of factors that affect it and their mutual dependencies, helps to diagnose and treat abnormalities of gait. Defining the causes of impairment and functional limitation can lead to optimization of rehabilitation treatment and simulation of surgical intervention. Therefore, gait modeling is devoted great effort. This article deals with an overview of approaches to gait modeling. It contains classes accroding to various criteria. Further, review of minimalistic physics-based models and complex analytical models is included.

• Klíčová slova
• analýza chůze,, model obráceného kyvadla,, muskuloskeletální model,
• MeSH
• biologické modely MeSH
• biomechanika MeSH
• chůze (způsob) MeSH
• financování organizované MeSH
• muskuloskeletální systém - fyziologické jevy MeSH
• muskuloskeletální systém MeSH
• pohyb fyziologie   MeSH

The geometrical representation of muscles in computational models of the musculoskeletal system typically consists of a series of line segments. These muscle anatomies are based on measurements from a limited number of cadaveric studies that recently have been used as atlases for creating subject-specific models from medical images, so potentially restricting the options for personalisation and assessment of muscle geometrical models. To overcome this methodological limitation, we propose a novel, completely automated technique that, from a surface geometry of a skeletal muscle and its attachment areas, can generate an arbitrary number of lines of action (fibres) composed by a user-defined number of straight-line segments. These fibres can be included in standard musculoskeletal models and used in biomechanical simulations. This methodology was applied to the surfaces of four muscles surrounding the hip joint (iliacus, psoas, gluteus maximus and gluteus medius), segmented on magnetic resonance imaging scans from a cadaveric dataset, for which highly discretised muscle representations were created and used to simulate functional tasks. The fibres' moment arms were validated against measurements and models of the same muscles from the literature with promising outcomes. The proposed approach is expected to improve the anatomical representation of skeletal muscles in personalised biomechanical models and finite element applications.

• MeSH
• biologické modely * MeSH
• biomechanika MeSH
• kosterní svaly * diagnostické zobrazování   fyziologie   MeSH
• kyčelní kloub * diagnostické zobrazování   fyziologie   MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• mrtvola MeSH
• počítačová rentgenová tomografie MeSH
• počítačové modelování podle konkrétního pacienta * MeSH
• senioři nad 80 let MeSH
• Check Tag
• lidé MeSH
• senioři nad 80 let MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• biologické modely MeSH
• kolenní kloub anatomie a histologie   patologie   MeSH
• kyčel anatomie a histologie   patologie   MeSH
• muskuloskeletální systém patofyziologie   MeSH
• osteoartróza etiologie   MeSH
• posturální rovnováha MeSH
• svalová slabost komplikace   MeSH

• MeSH
• klinické lékařství MeSH
• muskuloskeletální manipulace MeSH
• muskuloskeletální nemoci terapie   MeSH
• muskuloskeletální systém MeSH
• techniky fyzikální terapie MeSH

• Konspekt
• Fyzioterapie. Psychoterapie. Alternativní lékařství
• NLK Obory
• rehabilitační a fyzikální medicína
• ortopedie
• NLK Publikační typ
• kolektivní monografie

BACKGROUND: Variations observed in biomechanical studies might be attributed to errors made by operators during the construction of musculoskeletal models, rather than being solely attributed to patient-specific geometry. RESEARCH QUESTION: What is the impact of operator errors on the construction of musculoskeletal models, and how does it affect the estimation of muscle moment arms and hip joint reaction forces? METHODS: Thirteen independent operators participated in defining the muscle model, while a single operator performed 13 repetitions to define the muscle model based on 3D bone geometry. For each model, the muscle moment arms relative to the hip joint center of rotation was evaluated. Additionally, the hip joint reaction force during one-legged stance was assessed using static inverse optimization. RESULTS: The results indicated high levels of consistency, as evidenced by the intra- rater and inter-rater agreement measured by the Intraclass Correlation Coefficient (ICC), which yielded values of 0.95 and 0.99, respectively. However, the estimated muscle moment arms exhibited an error of up to 16 mm compared to the reference musculoskeletal model. It was found that muscles attached to prominent anatomical landmarks were specified with greater accuracy than those attached over larger areas. Furthermore, the variability in estimated moment arms contributed to variations of up to 12% in the hip joint reaction forces. SIGNIFICANCE: Both moment arm and muscle force demonstrated significantly lower variability when assessed by a single operator, suggesting the preference for employing a single operator in the creation of musculoskeletal models for clinical biomechanical studies.

• MeSH
• biologické modely MeSH
• biomechanika MeSH
• kosterní svaly * fyziologie   MeSH
• kyčelní kloub * fyziologie   MeSH
• lidé MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• anatomické modely MeSH
• diagnostické zobrazování ekonomika   metody   využití   MeSH
• femur zranění   MeSH
• kostra MeSH
• lebka zranění   MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• muskuloskeletální systém zranění   MeSH
• počítačová rentgenová tomografie MeSH
• statistika jako téma MeSH
• teoretické modely MeSH
• tibie zranění   MeSH
• ultrasonografie MeSH
• zobrazování trojrozměrné metody   využití   MeSH
• Check Tag
• lidé MeSH

• MeSH
• interpretace statistických dat MeSH
• kinetika MeSH
• lidé MeSH
• muskuloskeletální systém - fyziologické jevy MeSH
• svalová kontrakce fyziologie   MeSH
• teoretické modely MeSH
• Check Tag
• lidé MeSH

Low bone mineral density (BMD) and an increased fracture incidence are two extraintestinal complications associated with inflammatory bowel disease (IBD). We aimed to evaluate musculoskeletal traits and assess vertebral fracture (VF) rate in children and adolescents with IBD. Seventy patients with IBD with a median age of 13.8 years were included. The BMD and geometric parameters of the non-dominant tibia were assessed using pQCT. Dynamic muscle functions were evaluated using jumping mechanography. VFs were assessed according to the semiquantitative standardized method by Genant. The muscle functions adjusted for the patients' weight did not differ from the reference population. A low trabecular BMD (Z-score - 1.6; p < 0.001) and cortical thickness (Z-score - 0.7; p < 0.001) were found in children and adolescents with IBD. Conversely, an increased cortical BMD (Z-score 1.1; p < 0.001) was noted. No significant association was found between the 25-OHD serum levels and the bone or muscle measurements. One patient with asymptomatic VF was identified. CONCLUSION: IBD in childhood or adolescents affects bones but not muscles. Bone changes are independent of the 25-OHD serum level. A thoracolumbar spine X-ray should not be routinely recommended in children with IBD. What is Known: • Low bone mineral density and an increased fracture rate are the complications associated with IBD. • Bone strength and structural development is strongly dependent on skeletal muscle stimulation. What is New: • Children with IBD have altered bone density and geometry but normal dynamic muscle functions. • Thoracolumbar spine X-ray should be indicated on an individual basis in children with IBD.

• MeSH
• absorpční fotometrie MeSH
• dítě MeSH
• fraktury páteře diagnostické zobrazování   epidemiologie   etiologie   MeSH
• idiopatické střevní záněty komplikace   patofyziologie   MeSH
• kostní denzita * MeSH
• lidé MeSH
• logistické modely MeSH
• mladiství MeSH
• mladý dospělý MeSH
• prevalence MeSH
• průřezové studie MeSH
• radiografie MeSH
• rizikové faktory MeSH
• svalová síla * MeSH
• trabekulární kostní tkáň patofyziologie   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH