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When a limb suffers a fracture, rupture, or dislocation, it is traditionally immobilized with plaster. This may induce discomfort in the patient, as well as excessive itching and sweating, which creates the growth of bacteria, leading to an unhygienic environment and difficulty in keeping the injury clean during treatment. Furthermore, if the plaster remains for a long period, it may cause lesions in the joints and ligaments. To overcome all of these disadvantages, orthoses have emerged as important medical devices to help patients in rehabilitation, as well as for self-care of deficiencies in clinics and daily life. Traditionally, these devices are produced manually, which is a time-consuming and error-prone method. From another point of view, it is possible to use imageology (X-ray or computed tomography) to scan the human body; a process that may help orthoses manufacturing but which induces radiation to the patient. To overcome this great disadvantage, several types of 3D scanners, without any kind of radiation, have emerged. This article describes the use of various types of scanners capable of digitizing the human body to produce custom orthoses. Studies have shown that photogrammetry is the most used and most suitable 3D scanner for the acquisition of the human body in 3D. With this evolution of technology, it is possible to decrease the scanning time and it will be possible to introduce this technology into clinical environment.
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Fraturas Ósseas , Aparelhos Ortopédicos , Humanos , Tomografia Computadorizada por Raios X , Tecnologia , ExtremidadesRESUMO
This study aims to assess the musculoskeletal risk of military personnel on a Leopard 2 A6 main battle tank crew and to identify associated factors for future prevention and mitigation strategies. A sample of 57 Portuguese military personnel, who are or were part of the Leopard 2 A6 main battle tank crew, answered a questionnaire on their perception of task performance, considering muscle demands, comfort, posture, movements, and associated symptoms. A subsample of four soldiers from the Armoured Squadron of the Portuguese Mechanized Brigade were assessed using an inertial measurement unit system and underwent a whole-body kinematic analysis coupled with a Rapid Entire Body Assessment during a simulated two-hour mission. The results indicate that soldiers accurately perceive their roles within the crew and that, overall, there is a high risk of musculoskeletal injuries in all tasks. However, tasks directly related to the crew's primary duties carry consistently high risk when considering the time spent on their tasks. This study highlights the need for targeted preventive measures to reduce the incidence and severity of injuries among the crew of the Leopard 2 A6 main battle tank.
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Militares , Movimento , Humanos , Fatores de Risco , Projetos Piloto , Masculino , Adulto , Movimento/fisiologia , Fenômenos Biomecânicos , Doenças Musculoesqueléticas/fisiopatologia , Doenças Musculoesqueléticas/epidemiologia , Feminino , Adulto Jovem , Inquéritos e Questionários , Análise e Desempenho de TarefasRESUMO
A successful high-level gymnastics performance is the result of the coordination and inter-relation of body segments to produce movement prototypes. In this context, the exploration of different movement prototypes, as well as their relations with judges' scores, can aid coaches to design better learning and practice methodologies. Therefore, we investigate if there are different movement prototypes of the technique of the handspring tucked somersault with a half twist (HTB) on a mini trampoline with a vaulting table and its relations with judges' scores. We assessed flexion/extension angles of five joints during fifty trials, using an inertial measurement unit system. All trials were scored by international judges for execution. A multivariate time series cluster analysis was performed to identify movement prototypes and their differential association with judges' scores was statistically assessed. Nine different movement prototypes were identified for the HTB technique, with two of them associated with higher scores. Statistically strong associations were found between scores and movement phases one (i.e., from the last step on the carpet to the initial contact of both feet with the mini trampoline), two (i.e., from the initial contact to the take-off on the mini trampoline) and four (i.e., from the initial contact of both hands with the vaulting table to take-off on the vaulting table) and moderate associations with movement phase six (i.e., from the tucked body position to landing with both feet on the landing mat). Our findings suggest (a) the presence of multiple movement prototypes yielding successful scoring and (b) the moderate-to-strong association of movement variations along phases one, two, four and six with judges' scores. We suggest and provide guidelines for coaches to encourage movement variability that can lead their gymnasts to functionally adapt their performance and succeed when facing different constraints.
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Ginástica , Julgamento , Movimento , Adulto , Humanos , Adulto Jovem , Mãos , RotaçãoRESUMO
Cerebral palsy (CP) is a common cause of motor disability, and pedobarography is a useful, non-invasive, portable, and accessible tool; is easy to use in a clinical setting; and can provide plenty of information about foot-soil interaction and gait deviations. The reliability of this method in children with CP is lacking. The aim of this study is to investigate test-retest reliability and minimal detectable change (MDC) of plantar pressure insole variables in children with CP. Eight children performed two trials 8 ± 2.5 days apart, using foot insoles to collect plantar pressure data. Whole and segmented foot measurements were analyzed using intraclass correlation coefficients (ICC). The variability of the data was measured by calculating the standard error of measurement (SEM) and the MDC/ICC values demonstrated high test-retest reliability for most variables, ranging from good to excellent (ICC ≥ 0.60). The SEM and the MDC values were considered low for the different variables. The variability observed between sessions may be attributed to the heterogeneous sub-diagnosis of CP.
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Paralisia Cerebral , Pessoas com Deficiência , Transtornos Motores , Criança , Marcha , Análise da Marcha , Humanos , Reprodutibilidade dos TestesRESUMO
This study aimed to quantify and compare the upper limb angular kinematics and its contributions to the racket head speed between the cross-court (CC) and inside-out (IO) attacking tennis forehand of elite tennis players in a competitive environment. A new approach was used to study the forehand drive with mini-inertial sensors of motion capture to record the kinematic data. Six strokes in each direction per participant (72 shots in total) were chosen for analysis. Upper limb kinematics were calculated in the Visual 3D platform (Visual 3D Professional V5.01.21, C-motion, Germantown, MD, USA). The method used to calculate the upper limb's contributions was performed with MATLAB software and used the segment's (upper arm, forearm and hand) angular velocities and their respective displacement vectors obtained through the inertial sensors. Upper limb kinematics demonstrated a higher shoulder rotation in the IO direction with significant differences at the end of the backswing, which could be a key factor in distinguishing the two directions of the shot. Results also demonstrated that the horizontal flexion of the upper arm (around the shoulder joint) was primarily responsible for the racket velocity in the anteroposterior direction (48.1% CC and 45.2% IO), followed by the extension of the forearm (around the elbow joint) (17.3% CC and 20.9% IO) and the internal rotation of the upper arm (around the shoulder joint) (15.6% CC and 14.2% IO). No significant differences were shown in the contributions of upper limbs to the racket head velocity between the two directions of the shot. Tennis coaches and players should develop a specific training programme to perform higher angular velocities in these specific joint rotations.
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Articulação do Ombro , Tênis , Braço , Fenômenos Biomecânicos , Humanos , Amplitude de Movimento Articular , Extremidade SuperiorRESUMO
BACKGROUND: Gait impairments are among the most common and impactful symptoms of Parkinson's disease (PD). Recent technological advances aim to quantify these impairments using low-cost wearable systems for use in either supervised clinical consultations or long-term unsupervised monitoring of gait in ecological environments. However, very few of these wearable systems have been validated comparatively to a criterion of established validity. OBJECTIVE: We developed two movement analysis solutions (3D full-body kinematics based on inertial sensors, and a smartphone application) in which validity was assessed versus the optoelectronic criterion in a population of PD patients. METHODS: Nineteen subjects with PD (7 female) participated in the study (age: 62 ± 12.27 years; disease duration: 6.39 ± 3.70 years; HY: 2 ± 0.23). Each participant underwent a gait analysis whilst barefoot, at a self-selected speed, for a distance of 3 times 10 m in a straight line, assessed simultaneously with all three systems. RESULTS: Our results show excellent agreement between either solution and the optoelectronic criterion. Both systems differentiate between PD patients and healthy controls, and between PD patients in ON or OFF medication states (normal difference distributions pooled from published research in PD patients in ON and OFF states that included an age-matched healthy control group). Fair to high waveform similarity and mean absolute errors below the mean relative orientation accuracy of the equipment were found when comparing the angular kinematics between the full-body inertial sensor-based system and the optoelectronic criterion. CONCLUSIONS: We conclude that the presented solutions produce accurate results and can capture clinically relevant parameters using commodity wearable sensors or a simple smartphone. This validation will hopefully enable the adoption of these systems for supervised and unsupervised gait analysis in clinical practice and clinical trials.
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Transtornos Neurológicos da Marcha , Doença de Parkinson , Fenômenos Biomecânicos , Feminino , Marcha , Análise da Marcha , Humanos , Doença de Parkinson/diagnósticoRESUMO
Muscle coordination in human movement has been assessed through muscle synergy analysis. In sports science, this procedure has been mainly applied to the comparison between highly trained and unexperienced participants. However, the lack of knowledge regarding strength training exercises led us to study the differences in neural strategies to perform the power clean between weightlifters and untrained individuals. Synergies were extracted from electromyograms of 16 muscles of ten unexperienced participants and seven weightlifters. To evaluate differences, we determined the pairwise correlations for the synergy components and electromyographic profiles. While the shape of activation patterns presented strong correlations across participants of each group, the weightings of each muscle were more variable. The three extracted synergies were shifted in time with the unexperienced group anticipating synergy #1 (-2.46 ± 18.7%; p < 0.001) and #2 (-4.60 ± 5.71%; p < 0.001) and delaying synergy #3 (1.86 ± 17.39%; p = 0.01). Moreover, muscle vectors presented more inter-group variability, changing the composition of synergy #1 and #3. These results may indicate an adaptation in intermuscular coordination with training, and athletes in an initial phase of training should attempt to delay the hip extension (synergy #1), as well as the upper-limb flexion (synergy #2).
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Músculo Esquelético , Esportes , Adaptação Fisiológica , Eletromiografia , Exercício Físico , HumanosRESUMO
Understanding the molecular basis of the appearance of life on Earth is an exciting research field. Many factors may have influenced the election of the molecules used by living beings and evolution may have modified those original compounds. In an attempt to understand the role played by intermolecular interactions in the election of CGAT as the alphabet of life, we present here a thorough experimental and computational study on the interaction of theobromine with water. Theobromine is a xanthine derivative, structurally related to the nucleobases, and also present in many living beings. The experimental results demonstrate that the most stable isomer of theobromine-water was formed and detected in supersonic expansions. This isomer very well resembles the structure of the dimers between nucleobases and water, offering similar values of binding energy. A comparison between the results obtained for theobromine-water with those reported in the literature for monohydrates of nucleobases is also offered.
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DNA/química , Teobromina/química , Água/química , Teoria da Densidade Funcional , Dimerização , Estrutura Molecular , Propriedades de SuperfícieRESUMO
We aimed to determine whether blood flow restriction (BFR) alters the characteristics of individual motor units during low-intensity (LI) exercise. Eight men (26.0±3.8 yrs) performed 5 sets of 15 knee extensions at 20% of one-repetition maximum (with and without BFR). Maximal isometric voluntary contractions (MVC) were performed before and after exercise to quantify force decrement. Submaximal isometric voluntary contractions were additionally performed for 18 s, matching trapezoidal target-force trajectories at 40% pre-MVC. EMG activity was recorded from the vastus lateralis muscle. Then, signals were decomposed to extract motor unit recruitment threshold, firing rates and action potential amplitudes (MUAP). Force decrement was only seen after LI BFR exercise (-20.5%; p<0.05). LI BFR exercise also induced greater decrements in the linear slope coefficient of the regression lines between motor unit recruitment threshold and firing rate (BFR: -165.1±120.4 vs. non-BFR: -44.4±33.1%, p<0.05). Finally, there was a notable shift towards higher values of firing rate and MUAP amplitude post-LI BFR exercise. Taken together, our data indicate that LI BFR exercise increases the activity of motor units with higher MUAP amplitude. They also indicate that motor units with similar MUAP amplitudes become activated at higher firing rates post-LI BFR exercise.
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Potenciais de Ação , Constrição , Músculo Quadríceps/fisiologia , Treinamento Resistido , Adulto , Humanos , Contração Isométrica , Masculino , Fluxo Sanguíneo Regional , Adulto JovemRESUMO
Polyurethane (PU)/acrylic waterborne hybrids are an attractive class of materials with wide application possibilities, but their synthesis typically requires significant quantities of solvent which has negative economic and environmental consequences. In this work, solvent-free and surfactant-free polyurethane (PU)/acrylic waterborne hybrids were obtained by synthesizing the PU prepolymer containing carboxylic groups directly in (meth)acrylic monomers that act as solvent. Then, the mixture is dispersed in water; the PU is chain-extended with diamines, and the (meth)acrylic monomers are polymerized. It was found that, against expectations, colloidal stability did not improve with the concentration of carboxylic groups that acted as stabilizing moieties. A combination of MALDI-TOF MS analysis and Monte Carlo simulations revealed that the highly heterogeneous compositions of the short chains of the PU prepolymer and their reaction with the chain-extender in the aqueous phase were responsible for lack of control of the colloidal properties. This problem was overcome by using more hydrophobic chain-extenders that decrease the fraction of PU chains in the water phase. In this way high-solid-content stable dispersions with controlled particle size were obtained. Finally, the properties of the PU/(meth)acrylic films were studied in terms of mechanical properties and water resistance.
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PURPOSE: The purpose of this study was to determine the effect of a 15-week partial range of motion (ROM) resistance training program on the vastus lateralis (VL) architecture and mechanical properties, when the time under tension (TUT) was equalized. METHODS: Nineteen untrained male subjects were randomly assigned to a control (Control; n = 8) or training (TG; n = 11) group. In the TG, the dominant and nondominant legs were randomly selected to be trained with a full ROM (FULL) or a partial ROM (PART) in an isokinetic dynamometer. Training volume was equalized based on the TUT by manipulating sets and repetitions. The VL muscle architecture was assessed by B-mode ultrasonography at rest and during maximal isometric knee extension contractions (MVCs) at ten knee angles. The VL fascicle force and specific tension were calculated from the MVCs with superimposed stimuli, accounting for the moment arm length, muscle architecture, and antagonist coactivation. RESULTS: The FULL training induced changes in fascicle length (FL) (4.9 ± 2.0%, P < 0.001) and specific tension (25.8 ± 18.7%, P < 0.001). There was a moderate effect of PART training on the physiological cross-sectional area (PCSA) (7.8 ± 4.0%, P < 0.001, dav = 0.6) and torque-angle adaptations (average increase 17.7 ± 3.9%, P < 0.05). CONCLUSIONS: These results provide evidence that crucial architectural and mechanical muscle adaptations are dependent on the ROM used in strength training. It seems that muscle FL and specific tension can be increased by pure concentric training if greater ROM is used. Conversely, restricting the ROM to shorter muscle lengths promotes a greater PCSA and angle-specific strength adaptations.
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Articulação do Joelho/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Músculo Quadríceps/fisiologia , Amplitude de Movimento Articular/fisiologia , Adaptação Fisiológica/fisiologia , Humanos , Contração Isométrica/fisiologia , Masculino , Força Muscular/fisiologia , Treinamento Resistido/métodos , Descanso/fisiologiaRESUMO
Organocatalysis is becoming an important tool in polymer science because of its versatility and specificity. To date a limited number of organic catalysts have demonstrated the ability to promote stereocontrolled polymerizations. In this work we report one of the first examples of chirality transfer from a catalyst to a polymer in the organocatalyzed ring-opening polymerization (ROP) of rac-lactide (rac-LA). We have polymerized rac-LA using the diastereomeric densely substituted amino acids (2S,3R,4S,5S)-1-methyl-4-nitro-3,5-diphenylpyrrolidine-2-carboxylic acid (endo-6) and (2S,3S,4R,5S)-1-methyl-4-nitro-3,5-diphenylpyrrolidine-2-carboxylic acid (exo-6), combined with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a cocatalyst. Both diastereoisomers not only showed the ability to synthesize enriched isotactic polylactide with a Pm higher than 0.90 at room temperature but also were able to preferentially promote the polymerization of one of the isomers (l or d) with respect to the other. Thus, exo-6 preferentially polymerized l-lactide, whereas endo-6 preferred d-lactide as the substrate. Density functional theory calculations were conducted to investigate the origins of this unique stereocontrol in the polymerization, providing mechanistic insight and explaining why the chirality of the catalyst is able to define the stereochemistry of the monomer insertion.
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Aminoácidos/química , Dioxanos/química , Poliésteres/síntese química , Estrutura Molecular , Poliésteres/química , Polimerização , EstereoisomerismoRESUMO
Functional fitness (FF) and gait ability in older populations have been associated with increased survival rates, fall prevention, and quality of life. One possible intervention for the improvement of FF is well-structured exercise programs. However, there are inconsistent findings regarding the effects of exercise interventions in the maintenance of gait parameters. The aim of this protocol is to develop a community-based exercise intervention targeting an older population. The intervention aim is the improvement of gait parameters and FF. A control trial with follow-up will be performed. The primary outcome variables will be plantar pressure gait parameters. The secondary outcome variables will be aerobic endurance, lower limb strength, agility, and balance. These variables will be recorded at baseline and after 12, 24, and 36 weeks, in the intervention and control groups. If effective, this protocol can be used by exercise professionals in improving community exercise programs.
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Serviços de Saúde Comunitária/organização & administração , Terapia por Exercício/métodos , Marcha/fisiologia , Envelhecimento Saudável/fisiologia , Aptidão Física/fisiologia , Idoso , Feminino , Humanos , Masculino , Portugal , Desenvolvimento de ProgramasRESUMO
High levels of gait asymmetry are associated with many pathologies. Our long-term goal is to improve gait symmetry through real-time biofeedback of a symmetry index. Symmetry is often reported as a single metric or a collective signature of multiple discrete measures. While this is useful for assessment, incorporating multiple feedback metrics presents too much information for most subjects to use as visual feedback for gait retraining. The aim of this article was to develop a global gait asymmetry (GGA) score that could be used as a biofeedback metric for gait retraining and to test the effectiveness of the GGA for classifying artificially-induced asymmetry. Eighteen participants (11 males; age 26.9 y [SD = 7.7]; height 1.8 m [SD = 0.1]; body mass 72.7 kg [SD = 8.9]) walked on a treadmill in 3 symmetry conditions, induced by wearing custom-made sandals: a symmetric condition (identical sandals) and 2 asymmetric conditions (different sandals). The GGA score was calculated, based on several joint angles, and compared between conditions. Significant differences were found among all conditions (P < .001), meaning that the GGA score is sensitive to different levels of asymmetry, and may be useful for rehabilitation and assessment.
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Transtornos Neurológicos da Marcha/diagnóstico , Transtornos Neurológicos da Marcha/fisiopatologia , Marcha , Perna (Membro)/fisiopatologia , Exame Físico/métodos , Amplitude de Movimento Articular , Adulto , Feminino , Humanos , Masculino , Oscilometria/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , CaminhadaRESUMO
The purpose of this research was to study the sensitivity of lower limb joint kinematics and kinetics, calculated during different functional tasks (walking, stair descent and stair ascent) in a sample of older adults, to different pose estimation algorithms and models' joint constraints. Three models were developed and optimized differently: in one model, each segment had 6 degrees of freedom (segment optimization, SO), while in the other two, global optimization (GO) was used, with different joint constraints: (1) GO, allowing all joint rotations; (2) GOR, allowing three rotations at the hip, one at the knee (flexion/extension) and two at the ankle (dorsi/plantar flexion and eversion/inversion). The results showed that joint angles are more sensitive to the model's constraints than joint moments and, the more restrictive the model, the higher the differences between models, especially for the frontal and transverse planes (max. RMS difference during gait: 11.7 degrees (64%) vs 0.12 N·m/kg (35.4%). In addition, except for knee abduction/adduction angle, differences between SO and GO models were relatively low. Since GO avoids the nonanatomical dislocations sometimes observed in SO, choosing this model seems to be reasonable for future studies with a similar sample and study design.
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Algoritmos , Articulação do Tornozelo/fisiologia , Marcha/fisiologia , Articulação do Quadril/fisiologia , Articulação do Joelho/fisiologia , Modelos Biológicos , Amplitude de Movimento Articular/fisiologia , Idoso , Simulação por Computador , Feminino , Humanos , Perna (Membro)/fisiologia , Masculino , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Ankle-foot orthoses (AFOs) are vital in gait rehabilitation for patients with stroke. However, many conventional AFO designs may not offer the required precision for optimized patient outcomes. With the advent of 3D scanning and printing technology, there is potential for more individualized AFO solutions, aiming to enhance the rehabilitative process. OBJECTIVE: This nonrandomized trial seeks to introduce and validate a novel system for AFO design tailored to patients with stroke. By leveraging the capabilities of 3D scanning and bespoke software solutions, the aim is to produce orthoses that might surpass conventional designs in terms of biomechanical effectiveness and patient satisfaction. METHODS: A distinctive 3D scanner, complemented by specialized software, will be developed to accurately capture the biomechanical data of leg movements during gait in patients with stroke. The acquired data will subsequently guide the creation of patient-specific AFO designs. These personalized orthoses will be provided to participants, and their efficacy will be compared with traditional AFO models. The qualitative dimensions of this experience will be evaluated using the Quebec User Evaluation of Satisfaction With Assistive Technology (QUEST) assessment tool. Feedback from health care professionals and the participants will be considered throughout the trial to ensure a rounded understanding of the system's implications. RESULTS: Spatial-temporal parameters will be statistically compared using paired t tests to determine significant differences between walking with the personalized orthosis, the existing orthosis, and barefoot conditions. Significant differences will be identified based on P values, with P<.05 indicating statistical significance. The Statistical Parametric Mapping method will be applied to graphically compare kinematic and kinetic data across the entire gait cycle. QUEST responses will undergo statistical analysis to evaluate patient satisfaction, with scores ranging from 1 (not satisfied) to 5 (very satisfied). Satisfaction scores will be presented as mean and SD values. Significant variations in satisfaction levels between the personalized and existing orthosis will be assessed using a Wilcoxon signed rank test. The anticipation is that the AFOs crafted through this innovative system will either match or outperform existing orthoses in use, with higher patient satisfaction rates. CONCLUSIONS: Embracing the synergy of technology and biomechanics may hold the key to revolutionizing orthotic design, with the potential to set new standards in patient-centered orthotic solutions. However, as with all innovations, a balanced approach, considering both the technological possibilities and individual patient needs, will be paramount to achieving optimal outcomes. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/52365.
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This study aimed to determine whether changes in hamstrings passive and active shear modulus after a warmup protocol are correlated. Twenty males without a history of hamstring strain injury participated. Muscle shear modulus was assessed using ultrasound-based shear wave elastography at rest and during isometric contractions at 20% of maximal voluntary isometric effort before and immediately after a warmup protocol. Changes in passive shear modulus did not seem to be associated with changes in active shear modulus. The results of this study suggest that changes in passive and active hamstring shear modulus are not associated after a standardized warmup intervention.
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Técnicas de Imagem por Elasticidade , Músculos Isquiossurais , Masculino , Humanos , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/fisiologia , Módulo de Elasticidade/fisiologia , Músculos Isquiossurais/diagnóstico por imagem , Músculos Isquiossurais/fisiologia , Técnicas de Imagem por Elasticidade/métodos , UltrassonografiaRESUMO
In older adults, gait analysis may detect changes that signal early disease states, yet challenges in biomechanical screening limit widespread use in clinical or community settings. Recently, a markerless method from multi-camera video data has become accessible, making screenings less challenging. This study evaluated the test-retest reliability and measurement error of markerless gait kinematics and kinetics in healthy older adults. Twenty-nine healthy older adults performed gait analysis on two occasions, at preferred walking speed, using their everyday clothes. Lower limb angles and moments were averaged from 8 gait cycles. Integrated pointwise indices [Intraclass Correlation Coefficient (ICCA,K) and Standard Error of Measurement (SEM)] were calculated for curve data, as well as ICCA,K, and SEM [95 % confidence intervals] for selected peaks. Generally, kinematic ICCs were good (>0.75) and reasonably stable throughout the gait cycle, except for the hip kinematics during the swing phase in the sagittal plane and pelvis tilt and rotation. The integrated and peaks SEM were <2.4°. The reliability of kinetics was similar (ICC>0.75), except for the transverse hip moment and abduction peak, fluctuating more during the swing than through the stance phase. SEM were < 0.07Nm/Kg. In conclusion, these results showed good overall test-retest reliability for markerless gait kinematics and kinetics for the hip, knee, and ankle joints, moderate for the pelvis angles, and error levels of ≤5°, and SEM%≤5% for the sagittal plane. This supports this method's use in assessing gait in healthy older adults, including kinetics, for which reliability data from markerless systems is difficult to find reported.
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Análise da Marcha , Marcha , Humanos , Idoso , Masculino , Feminino , Fenômenos Biomecânicos , Análise da Marcha/métodos , Reprodutibilidade dos Testes , Marcha/fisiologia , Pessoa de Meia-Idade , Idoso de 80 Anos ou maisRESUMO
PURPOSE: This study compares the acute effects of a static stretching and a warmup protocol on the active and passive shear modulus of the hamstring muscles. METHODS: Muscle shear modulus was assessed at rest and during isometric contractions at 20â¯% of maximal voluntary isometric contraction (MVIC). RESULTS: After stretching, the passive shear modulus pattern was not altered, while at 20â¯% MVIC the biceps femoris short head (BFsh) and semimembranosus showed a shear modulus increase and decrease, respectively, which resulted on BFsh-SM pair differences (pre: 3.8⯱â¯16.8 vs. post: 39.3⯱â¯25.1â¯kPa; pâ¯<â¯0.001; dâ¯=â¯1.66) which was accompanied by a decrease of 18.3â¯% on MVIC. Following the warmup protocol, passive shear modulus remained unchanged, while active shear modulus was decreased for the semitendinosus (pre: 65.3⯱â¯13.5 vs. post: 60.3⯱â¯12.3â¯kPa; pâ¯=â¯0.035; dâ¯=â¯0.4). However, this difference was within the standard error of measurement (10.54â¯kPa), and did not impact the force production, since it increased only 1.4â¯% after the warmup. CONCLUSIONS: The results of this study suggest that the passive and active shear modulus responses of the individual hamstring muscles to static stretching are muscle-specific and that passive and active hamstring shear modulus are not changed by a standard warmup intervention.
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Músculos Isquiossurais , Contração Isométrica , Exercícios de Alongamento Muscular , Exercício de Aquecimento , Humanos , Músculos Isquiossurais/fisiologia , Exercícios de Alongamento Muscular/fisiologia , Contração Isométrica/fisiologia , Masculino , Adulto Jovem , Exercício de Aquecimento/fisiologia , Adulto , Módulo de Elasticidade , UltrassonografiaRESUMO
Animals have been used as models to help to better understand biological and anatomical systems, and pathologies in both humans and non-human species, and sheep are often used as an in vivo experimental model for orthopedic research. Gait analysis has been shown to be an important tool in biomechanics research with clinical applications. The purpose of this study was to perform a kinematic analysis using a tridimensional (3D) reconstruction of the sheep hindlimb. Seven healthy sheep were evaluated for natural overground walking, and motion capture of the right hindlimb was collected with an optoelectronic system while the animals walked in a track. The analysis addressed gait spatiotemporal variables, hip, knee and ankle angle and intralimb joint angle coordination measures during the entire walking cycle. This study is the first that describes the spatiotemporal parameters from the hip, knee and ankle joints in a tridimensional way: flexion/extension; abduction/adduction and inter/external rotation. The results of this assessment can be used as an outcome indicator to guide treatment and the efficacy of different therapies for orthopedic and neurological conditions involving the locomotor system of the sheep animal model.