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Hypertension is a chronic non-communicable pathology. It refers to a multifactorial state, which depends on genetic / epigenetic, environmental and social aspects. Non-adherence to treatment is linked to several factors. Objectives: to assess the scientific literature on the main factors reported by hypertensive patients for non-adherence to blood pressure treatment. Material and Methods: This is an integrative literature review. The Virtual Health Library (VHL), Academic Google and Scielo databases were used, based on the descriptors: “hypertension” and “adherence to treatment” and “primary health care”, including articles published in the last few 5 years in full version. Results and Discussion: 188 articles were found, from which ten were selected that met the objectives of this work. It was observed that the main factors of low adherence to treatment are individual, socioeconomic, and elements related to the health network are also highlighted. Conclusions: Primary Care comprises the place of first contact for patients and where they have access to coordinated, comprehensive and longitudinal care. In this sense, it is necessary to create links to better understand them, mainly through multidisciplinary health education actions. La hipertensión es una patología crónica no transmisible. Se refiere a un estado multifactorial, que depende de aspectos genéticos / epigenéticos, ambientales y sociales. La no adherencia al tratamiento está relacionada con varios factores. Objetivos: evaluar la literatura científica sobre los principales factores reportados por los pacientes hipertensos por la no adherencia al tratamiento de la presión arterial. Material y métodos: Esta es una revisión integradora de la literatura. Se utilizaron las bases de datos biblioteca virtual en salud (BVS), Google Académico y Scielo, con base en los descriptores: "hipertensión" y "adherencia al tratamiento" y "atención primaria de salud", incluyendo artículos publicados en los últimos 5 años en versión completa. Resultados y Discusión: Se encontraron 188 artículos, de los cuales se seleccionaron diez que cumplieron con los objetivos de este trabajo. Se observó que los principales factores de baja adherencia al tratamiento son individuales, socioeconómicos, y también se destacan elementos relacionados con la red de salud. Conclusiones: La Atención Primaria comprende el lugar de primer contacto de los pacientes y donde tienen acceso a una atención coordinada, integral y longitudinal. En este sentido, es necesario crear vínculos para comprenderlos mejor, principalmente a través de acciones multidisciplinarias de educación para la salud. Hipertensão Arterial é uma patologia crônica não transmissível. Refere-se a um estado multifatorial, o qual depende de aspectos genéticos/epigenéticos, ambientais e sociais. A não adesão ao tratamento está ligada a diversos fatores. Objetivos: avaliar na literatura científica os principais fatores assinalados por pacientes hipertensos para não adesão ao tratamento da pressão arterial. Material e Métodos: Trata-se de uma revisão integrativa da literatura. Utilizaram-se as bases de dados Biblioteca Virtual em Saúde (BVS), Google Acadêmico e Scielo, a partir dos descritores: “hipertensão arterial” and “adesão ao tratamento” and “atenção primária à saúde”, sendo incluídos os artigos publicados nos últimos 5 anos em versão integral. Resultados e Discussão: Foram encontrados 188 artigos, dos quais, selecionaram-se dez que atendiam aos objetivos deste trabalho. Observou-se que os principais fatores de baixa adesão ao tratamento são de caráter individual, socioeconômico, destacando-se também elementos relacionados a rede de saúde. Conclusões: A Atenção Primária compreende o local de primeiro contato dos pacientes e onde possuem acesso ao cuidado coordenado, integral e longitudinal. Nesse sentido, faz se necessário a criação de vínculos para melhor entendê-los, principalmente, por meio de ações multiprofissionais de educação em saúde.

Anatomical custom-made prostheses make it possible to reconstruct complicated bone defects following excision of bone tumors, thanks to 3D-printed technology. To date, clinical measures have been used to report clinical-functional outcome and provide evidence for the effectiveness of this new surgical approach. However, there are no studies that quantified the achievable recovery during common activities by using instrumental clinical-functional evaluation in these patients.What is the motor performance, functional outcome and quality of life in patients with custom-made 3D-printed pelvic prostheses following bone tumor?To analyze motor performance, six patients performed motion analysis during five motor activities at follow-up of 32 ± 18 months. Joint angles, ground reaction forces and joint moments of the operated and contralateral limbs were compared. On-off activity of lower-limb muscles were calculated from electromyography and compared to a healthy matched population. To analyze functional outcome and quality of life, differences in measured hip abductor strength between limbs were evaluated, as well as clinical-functional scores (Harris Hip Score, Barthel Index, Musculoskeletal Tumor Society score), and quality of life (SF-36 health survey).We found only slight differences in joint kinematics when comparing operated and contralateral limb. The activity of gluteal muscles was normal, while hamstrings showed out-of-phase activities. Ground reaction forces and hip moments showed asymmetries between limbs, particularly in more demanding motor activities. We found a mean difference in hip abductor strength of 48 ± 82 N between limbs, good clinical-functional scores, and quality of life scores within normative.Our study showed optimal long-term results in functional recovery, mainly achieved through recovery of the gluteal function, although minor impairments were found, which may be considered for future improvement of this innovative surgery. The effect of a more loaded contralateral limb on internal loads and long-term performance of the implant remains unknown and deserves further investigation.

Objective: In developmental hip dysplasia (DDH) patients, the chronic dislocation of the femoral head with respect to the true acetabulum determines muscle contracture and atrophy, particularly of the abductor muscles, and leads to secondary osteoarthritis (OA) with severe motor dysfunction, pain and disability. The correct positioning when a total hip replacement (THR) is performed is fundamental to the recovery of gait function. Also, inadequate rehabilitation of the abductor muscles for pelvic stabilisation can be responsible for residual dysfunction. Consensus on a programme for abductor muscle strengthening in these patients is not currently available. The aim of this study was to evaluate the effectiveness of a specific program of exercises for strengthening the abductor muscles in these patients. Methods: A multicentre, prospective, randomised clinical trial was carried out in an outpatient rehabilitation setting on 103 patients given THR for DDH through a minimally-invasive anterolateral approach. Patients were randomly divided into a Study Group, including 46 patients, and a Control Group, including 57 patients. All patients underwent standard early postoperative rehabilitation. In addition, the Study Group were given an extra 2-week rehabilitation once full weight-bearing on the operated limb was allowed, aimed at strengthening the abductor muscles. All patients were evaluated preoperatively, and at about 3 and 6 months postoperatively. Clinical measures (lower limb-length differences, hip range of motion, abductor muscle strength), and functional measures (WOMAC, HHS, 10mt WT, SF-12) were taken. Results: Hip range of motion and functional outcome measures showed a progressive improvement at follow ups in both groups, significantly higher in the Study Group. In particular, abductor strength at 6 months post-op improved by 92.5% with respect to 35.7% in the Control Group. Conclusion: In addition to standard rehabilitation, a rehabilitation programme for strengthening the gluteal muscles in DDH patients who underwent THR determined an increase in muscle strength that improved functional performance and patient satisfaction.

Rupture of anterior cruciate ligament (ACL) is a common injury, generally treated by reconstruction surgery. Despite good clinical outcomes, achieving a long-term success for this procedure is still a challenge: young patients could face in fact early degenerative processes, including knee osteoarthritis (OA). The altered biomechanics of the reconstructed joint could affect knee anatomical structures varying – for instance – the loads on the intra-articular cartilage, definitely inducing its degeneration. To better understand the factors that can compromise the long-term success of this procedure, this study investigated the ACL transtibial reconstruction effects on overall knee biomechanics and on articular cartilage, by integrating dynamic radiostereophotogrammetry, inferior limb multi-body modelling and MRI T2 mapping, in order to correlate knee joint loads to its physiopathological status

Background In ceramic-on-ceramic (CoC) total hip arthroplasty (THA), component positioning demonstrated to influence the bearing damage: however the connection between angles and clinical outcomes at long-term follow-ups is currently lacking. Aims of this study were: the computer tomography (CT) assessment of component positioning in CoC THAs; the correlation analysis between positioning and ceramic damage; the identification of safe zones. Methods 91 consecutive post-operative CT scans including two types of CoC implants, with a mean follow-up of 12 ± 4.4 years, were evaluated. III generation (74.2%) and IV generation (25.8%) CoC surfaces were included. The angle measurements (cup abduction, anteversion, cup tilt, stem antetorsion, sacral slope) were automated using a CT-based software. The combined anteversion was assessed as well as the cup-neck position at −15°, 0°, 45° and 90° of flexion. Ceramic damage was diagnosed using synovial fluid analyses and radiological criteria. Results 63.7% of THAs was inside the cup abduction target 30°–45° and 68.1% was inside the cup anteversion target 5°–25°. 19 patients (20.9%) showed signs of ceramic damage. High cup abduction and high cup-neck 45° minimum angle (which stood for high abduction and extreme combined version) significantly correlated with ceramic damage. No demographical features apart III generation ceramic bearings influenced the results. No safe zones could be detected. Conclusions In CoC THA, no safe zones can be described. However it is important to avoid cup inclination over 45° and a combination of steep cup and extreme combined version.

The paper focuses on the gait analysis for the investigation of the typical events occurring in human movements and validate its use as a method for musculoskeletal disease evaluation and for the improvement of athletic training. In the present research the motion capture system is combined with an in-house developed prototype of uniaxial force plates for the measurement of the vertical component of ground reaction forces during movement. While similar techniques are implemented for gait, this equipment can be employed to investigate running, thus, covering a larger number of possible applications and providing a deeper insight either of the athlete performance or the disease analysis. For the prevention and the treatment of those events occurring during running, a thorough understanding of its mechanisms is critical; therefore, a method for evaluating both the kinematic behavior of the human body and the ground reaction forces combined to a model for determining the muscle forces is proposed. An infrared motion capture technique is adopted for measuring accurately the body motion and a multiple force-plate system is used to calculate the force exerted by the ground and sub-divided in the three components by an ad-hoc developed routine. Moreover, the data are used as input parameters for the OpenSim software to derive muscles forces. Finally, the potential of the proposed protocol is determined by an experimental campaign on healthy subjects and a significant database of muscle forces is constructed for different running speeds.

Background Biomechanical interpretations of bone adaptation in biological reconstructions following bone tumors would be crucial for orthopedic oncologists, particularly if based on quantitative observations. This would help plan for surgical treatments, rehabilitative programs and communication with the patients. We aimed to analyze the biomechanical adaptation of a femoral reconstruction after Ewing sarcoma according to an increasingly-used surgical technique, and to relate in-progress bone resorption to the mechanical stimulus induced by different motor activities. Methods We created a multiscale musculoskeletal and finite element model from CT scans and motion analysis data at a 76-month follow-up of a patient, to analyze muscle and joint loads, and to compare the mechanical competence of the reconstructed bone with the contralateral limb, in the current real condition and in a possible revision surgery that removed proximal screws. Findings Our results showed strategies of muscle coordination that led to differences in joint loads between limbs more marked in more demanding motor activities, and generally larger in the contralateral limb. The operated femur presented a markedly low ratio of physiological strain due to load-sharing with the metal implant, particularly in the lateral aspect. The possible revision surgery would help restore a physiological strain configuration, while the safety of the reconstruction would not be threatened. Interpretation We suggest that bone resorption is related to load-sharing and to the internal forces exerted during movement, and the mechanical stimulus should be improved by adopting modifications in the surgical treatment and by promoting physical therapy aimed at specific muscle strengthening.

Understanding the validity of using musculoskeletal models is critical, making important to assess how model parameters affect predictions. In particular, assumptions on joint models can affect predictions from simulations of movement, and the identification of image-based joints is unavoidably affected by uncertainty that can decrease the benefits of increasing model complexity. We evaluated the effect of different lower-limb joint models on muscle and joint contact forces during four motor tasks, and assessed the sensitivity to the uncertainties in the identification of anatomical four-bar-linkage joints. Three MRI-based musculoskeletal models having different knee and ankle joint models were created and used for the purpose. Model predictions were compared against a baseline model including simpler and widely-adopted joints. In addition, a probabilistic analysis was performed by perturbing four-bar-linkage joint parameters according to their uncertainty. The differences between models depended on the motor task analyzed, and there could be marked differences at peak loading (up to 2.40 BW at the knee and 1.54 BW at the ankle), although they were rather small over the motor task cycles (up to 0.59 BW at the knee and 0.31 BW at the ankle). The model including more degrees of freedom showed more discrepancies in predicted muscle activations compared to measured muscle activity. Further, including image-based four-bar-linkages was robust to simulate walking, chair rise and stair ascent, but not stair descent (peak standard deviation of 2.66 BW), suggesting that joint model complexity should be set according to the imaging dataset available and the intended application, performing sensitivity analyses.

Subject-specific musculoskeletal models have become key tools in the clinical decision-making process. However, the sensitivity of the calculated solution to the unavoidable errors committed while deriving the model parameters from the available information is not fully understood. The aim of this study was to calculate the sensitivity of all the kinematics and kinetics variables to the inter-examiner uncertainty in the identification of the lower limb joint models. The study was based on the computer tomography of the entire lower-limb from a single donor and the motion capture from a body-matched volunteer. The hip, the knee and the ankle joint models were defined following the International Society of Biomechanics recommendations. Using a software interface, five expert anatomists identified on the donor's images the necessary bony locations five times with a three-day time interval. A detailed subject-specific musculoskeletal model was taken from an earlier study, and re-formulated to define the joint axes by inputting the necessary bony locations. Gait simulations were run using OpenSim within a Monte Carlo stochastic scheme, where the locations of the bony landmarks were varied randomly according to the estimated distributions. Trends for the joint angles, moments, and the muscle and joint forces did not substantially change after parameter perturbations. The highest variations were as follows: (a) 11 degrees calculated for the hip rotation angle, (b) 1% BW x H calculated for the knee moment and (c) 0.33 BW calculated for the ankle plantarflexor muscles and the ankle joint forces. In conclusion, the identification of the joint axes from clinical images is a robust procedure for human movement modelling and simulation.

Main topics: Musculoskeletal modelling; Mathematical simulation in human movement science; Orthopaedics Introduction and aim: Subject-specific musculoskeletal modelling can be applied to study musculoskeletal disorders, providing a valuable approach to calculating muscle and joint forces during movement. The choice of the lower-limb joint models can significantly affect joint contact loads during walking [1]; however, the degree of joint model complexity according to the application has not been extensively studied. The aim of this study is twofold: first, to compare muscle and joint contact forces during common daily activities, using four subject-specific models including different joint models; second, to investigate how the uncertainties in the identification of subject-specific kinematic constraints affect the model outputs using a probabilistic modelling approach. Patients/materials and methods: Experimental data were collected on a healthy volunteer subject, including lower-body MRI scans and gait data (marker trajectories, ground reaction forces and EMG recordings) during walking, chair rising, stair ascending and descending. A baseline musculoskeletal model (M1) was created, which included a 7-segment 3D articulated linkage with spherical joints at the hips, hinge joints at both knees and ankles [2], and 84 musculotendon actuators. More complex knee and ankle models were built upon the baseline model as follows: planar hinge and universal joint [3] (M2), modified spherical and universal joint [4] (M3), and subject-specific planar 4-bar-linkage knee and ankle [5,6] (M4). To test the sensitivity to parameter identification, five operators virtually palpated the anatomical landmarks necessary to create the M4 model. The joint parameters were statistically sampled according to inter-operator palpation variability, and a set of perturbed models was then created. Simulations of movements solving a typical inverse dynamics and static optimization problem were performed using OpenSim, to calculate muscle and joint contact forces. The predicted forces were compared between the different motor tasks and the robustness to the joint parameter identification was analyzed. Results: M2 and M4 tended to predict lower knee forces (Table 1), as coupling planar translations to flexion increased knee extensor moment arms. Forces obtained using M4 were more robust to palpation uncertainties at the knee than at the ankle, where, for high dorsiflexion angles (such as in stair descending), M4 predicted unrealistically high contact forces with high variability (Table 1). Hip contact forces were slightly affected by the degree of knee and ankle joint complexity, except for the M3 model, in all simulated motor tasks. Table 1. peak joint contact loads (BW). M4: mean ± SD. Gait Chair rising Stair ascending Stair descending Hip Knee Ankle Hip Knee Ankle Hip Knee Ankle Hip Knee Ankle M1 3.63 3.40 5.44 3.15 2.96 1.21 3.68 5.30 4.88 4.08 5.13 7.04 M2 3.77 3.80 5.82 3.05 2.54 1.46 3.61 4.61 4.99 4.07 4.80 7.57 M3 4.47 5.80 5.58 3.23 2.59 1.50 3.88 5.87 5.05 3.83 4.39 7.18 M4 4.00 ± 0.14 4.45 ± 0.25 4.96 ± 0.26 3.14 ± 0.02 2.26 ± 0.07 1.12 ± 0.07 3.75 ± 0.01 4.14 ± 0.14 4.61 ± 0.32 4.11 ± 0.01 4.91 ± 0.99 9.28 ± 2.77 Discussion and conclusions: The models predicted different joint loads, and behaved differently in different motor tasks. In the absence of direct validation methods of the predicted forces, the choice of implementing complex subject-specific joints should be justified only when the predictions are robust to the uncertainties in parameter identification. Therefore, before implementing subject-specific kinematic constraints, it is advisable to analyze the sensitivity of predictions over the joint range of motion and, if this choice appears weak (as in the stair descending task), opting for less complex, but more robust and reproducible joint models.

The weakness of hip abductor muscles is related to lower-limb joint osteoarthritis, and joint overloading may increase the risk for disease progression. The relationship between muscle strength, structural joint deterioration and joint loading makes the latter an important parameter in the study of onset and follow-up of the disease. Since the relationship between hip abductor weakness and joint loading still remains an open question, the purpose of this study was to adopt a probabilistic modeling approach to give insights into how the weakness of hip abductor muscles, in the extent to which normal gait could be unaltered, affects ipsilateral joint contact forces. A generic musculoskeletal model was scaled to each healthy subject included in the study, and the maximum force-generating capacity of each hip abductor muscle in the model was perturbed to evaluate how all physiologically possible configurations of hip abductor weakness affected the joint contact forces during walking. In general, the muscular system was able to compensate for abductor weakness. The reduced force-generating capacity of the abductor muscles affected joint contact forces to a mild extent, with 50th percentile mean differences up to 0.5 BW (maximum 1.7 BW). There were greater increases in the peak knee joint loads than in loads at the hip or ankle. Gluteus medius, particularly the anterior compartment, was the abductor muscle with the most influence on hip and knee loads. Further studies should assess if these increases in joint loading may affect initiation and progression of osteoarthritis.

Modelling the mechanical effect of muscles is important in several research and clinical contexts. However, few studies have investigated the effect of different muscle discretizations from a mechanical standpoint. The present study evaluated the errors of a reduced discretization of the lower-limb muscles in reproducing the muscle loading transferred to bones. Skeletal geometries and a muscle data collection were derived from clinical images and dissection studies of two cadaver specimens. The guidelines of a general method previously proposed for a different anatomical district were followed. The data collection was used to calculate the mechanical effect of muscles, i.e. the generalized force vectors, and the errors between a large and a reduced discretization, in a reference skeletal pose and in the extreme poses of the range of motion of joints. The results showed that the errors committed using a reduced representation of muscles could be significant and higher than those reported for a different anatomical region. In particular, the calculated errors were found to be dependent on the individual anatomy and on the skeletal pose. Since different biomechanical applications may require different discretization levels, care is suggested in identifying the number of muscle lines of action to be used in musculoskeletal models.