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1.
PLoS One ; 15(11): e0242790, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33253285

RESUMO

Joint constraint could limit the available degrees of freedom in a kinematic chain for maintaining postural stability. This study investigated adaptive changes in postural synergy due to bracing of bilateral knee joints, usually thought to have a trifling impact on upright stance. Twenty-four young adults were requested to maintain balance on a stabilometer plate as steadily as possible while wearing a pair of knee orthoses, either unlocked (the non-constraint (NC) condition) or locked to restrict knee motion (the knee constraint (KC) condition). Knee constraint led to a significant increase in the regularity of the stabilometer angular velocity. More than 95% of the variance properties of the joint angular velocities in the lower limb were explained by the first and second principal components (PC1 and PC2), which represented the ankle strategy and the combined knee and hip strategy, respectively. In addition to the increase trend in PC1 regularity, knee constraint enhanced the mutual information of the stabilometer angular velocity and PC1 (MISTBV-PC1) but reduced the mutual information of the stabilometer angular velocity and PC2 (MISTBV-PC2). The MISTBV-PC1 was also positively correlated to stance steadiness on the stabilometer in the KC condition. In summary, in the knee constraint condition, postural synergy on the stabilometer was reorganized to increase reliance on ankle strategies to maintain equilibrium. In particular, a stable stabilometer stance under knee constraint is associated with a high level of coherent ankle-stabilometer interaction.


Assuntos
Articulação do Joelho/fisiologia , Extremidade Inferior/fisiologia , Equilíbrio Postural/fisiologia , Postura/fisiologia , Adulto , Tornozelo/fisiologia , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Eletromiografia , Feminino , Humanos , Joelho/fisiologia , Masculino
2.
PLoS One ; 15(11): e0242854, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33253292

RESUMO

Today's office chairs are not known to promote active sitting or to activate the lumbar trunk muscles, both of which functions are ergonomically recommended. This study investigated a newly developed dynamic office chair with a moveable seat, specifically designed to promote trunk muscle controlled active sitting. The study aimed to determine the means by which the seat movement was controlled during active sitting. This was accomplished by quantifying trunk and thigh muscular activity and body kinematics. Additionally, the effect of increased spinal motion on muscular activity and body kinematics was analysed. Ten subjects were equipped with reflective body markers and surface electromyography on three lumbar back muscles (multifidus, iliocostalis, longissimus) and two thigh muscles (vastus lateralis and medialis). Subjects performed a reading task during static and active sitting in spontaneous and maximum ranges of motion in a simulated office laboratory setting. The temporal muscle activation pattern, average muscle activity and body segment kinematics were analysed and compared using Friedman and post-hoc Wilcoxon tests (p≤0.05). Active sitting on the new chair significantly affected the lumbar trunk muscles, with characteristic cyclic unloading/loading in response to the seat movement. Neither thigh muscle activity nor lateral body weight shift were substantially affected by active sitting. When participants increased their range of motion, the lumbar back muscles were activated for longer and relaxation times were shorter. The characteristic activity pattern of the lumbar trunk muscles was shown to be the most likely dominant factor in controlling seat movement during active sitting. Consequently, the new chair may have a potential positive impact on back health during prolonged sitting. Further studies are necessary to analyse the frequency and intensity of active sitting during daily office work.


Assuntos
Ergonomia , Postura/fisiologia , Postura Sentada , Coluna Vertebral/fisiologia , Adulto , Músculos do Dorso/fisiologia , Fenômenos Biomecânicos , Eletromiografia , Feminino , Humanos , Decoração de Interiores e Mobiliário , Dor Lombar/fisiopatologia , Região Lombossacral/fisiologia , Masculino , Pessoa de Meia-Idade , Amplitude de Movimento Articular/fisiologia , Adulto Jovem
3.
Bone Joint J ; 102-B(11): 1505-1510, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33135446

RESUMO

AIMS: The complex relationship between acetabular component position and spinopelvic mobility in patients following total hip arthroplasty (THA) renders it difficult to optimize acetabular component positioning. Mobility of the normal lumbar spine during postural changes results in alterations in pelvic tilt (PT) to maintain the sagittal balance in each posture and, as a consequence, markedly changes the functional component anteversion (FCA). This study aimed to investigate the in vivo association of lumbar degenerative disc disease (DDD) with the PT angle and with FCA during postural changes in THA patients. METHODS: A total of 50 patients with unilateral THA underwent CT imaging for radiological evaluation of presence and severity of lumbar DDD. In all, 18 patients with lumbar DDD were compared to 32 patients without lumbar DDD. In vivo PT and FCA, and the magnitudes of changes (ΔPT; ΔFCA) during supine, standing, swing-phase, and stance-phase positions were measured using a validated dual fluoroscopic imaging system. RESULTS: PT, FCA, ΔPT, and ΔFCA were significantly correlated with the severity of lumbar DDD. Patients with severe lumbar DDD showed marked differences in PT with changes in posture; there was an anterior tilt (-16.6° vs -12.3°, p = 0.047) in the supine position, but a posterior tilt in an upright posture (1.0° vs -3.6°, p = 0.005). A significant decrease in ΔFCA during stand-to-swing (8.6° vs 12.8°, p = 0.038) and stand-to-stance (7.3° vs 10.6°,p = 0.042) was observed in the severe lumbar DDD group. CONCLUSION: There were marked differences in the relationship between PT and posture in patients with severe lumbar DDD compared with healthy controls. Clinical decision-making should consider the relationship between PT and FCA in order to reduce the risk of impingement at large ranges of motion in THA patients with lumbar DDD. Cite this article: Bone Joint J 2020;102-B(11):1505-1510.


Assuntos
Artroplastia de Quadril , Articulação do Quadril/diagnóstico por imagem , Degeneração do Disco Intervertebral/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Postura/fisiologia , Feminino , Articulação do Quadril/fisiopatologia , Articulação do Quadril/cirurgia , Humanos , Degeneração do Disco Intervertebral/fisiopatologia , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Amplitude de Movimento Articular , Tomografia Computadorizada por Raios X
4.
PLoS One ; 15(11): e0242009, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33170881

RESUMO

Infants' visual experiences are important for learning, and may depend on how information is structured in the visual field. This study examined how objects are distributed in 12-month-old infants' field of view in a mobile play setting. Infants wore a mobile eye tracker that recorded their field of view and eye movements while they freely played with toys and a caregiver. We measured how centered and spread object locations were in infants' field of view, and investigated how infant posture, object looking, and object distance affected the centering and spread. We found that far toys were less centered in infants' field of view while infants were prone compared to when sitting or upright. Overall, toys became more centered in view and less spread in location when infants were looking at toys regardless of posture and toy distance. In sum, this study showed that infants' visual experiences are shaped by the physical relation between infants' bodies and the locations of objects in the world. However, infants are able to compensate for postural and environmental constraints by actively moving their head and eyes when choosing to look at an object.


Assuntos
Movimentos Oculares/fisiologia , Visão Ocular/fisiologia , Atenção/fisiologia , Feminino , Cabeça/fisiologia , Humanos , Lactente , Comportamento do Lactente/fisiologia , Comportamento do Lactente/psicologia , Aprendizagem/fisiologia , Masculino , Pescoço/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Postura/fisiologia , Campos Visuais/fisiologia , Percepção Visual/fisiologia
5.
PLoS One ; 15(11): e0242580, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33211765

RESUMO

OBJECTIVES: We investigated the incidence and characteristics of pseudo-spontaneous nystagmus (PSN) in benign paroxysmal positional vertigo involving the lateral semicircular canal (LC-BPPV) and evaluated the correlation between PSN and the bow and lean test. METHODS: We examined nystagmus in the sitting position using video-oculography goggles in 131 LC-BPPV patients. The positioning test and bow and lean test were also performed. Patients were divided into canalolithiasis and cupulolithiasis groups according to the character of nystagmus. In each group, the incidence and direction of PSN, correlation with the bow and lean test, and treatment outcome were analyzed. RESULTS: PSN was observed in 25 cases (19.1%) in LC-BPPV patients, 7 of which were canalolithiasis and 18 of which were cupulolithiasis (p = 0.098). Of the 25 patients with PSN, 21 (84%) exhibited nystagmus consistent with the lean test whereas 4 (16%) exhibited nystagmus consistent with the bow test. In patients with PSN, nystagmus was observed in the bow and lean test in all cases (23/23), but in patients without PSN, no nystagmus was observed in 13 cases (13/87) in the bow and lean test (p = 0.048). The number of barbecue maneuvers performed until the end of treatment was 1.4 ± 0.7 in patients with PSN and 1.4 ± 0.9 in those without PSN (p = 0.976). CONCLUSION: We identified PSN in patients with LC-BPPV irrelevant of subtype. Moreover, all patients with PSN showed nystagmus in the bow and lean test. The direction of PSN was mostly consistent with that of the lean test (21/25, 84%). The presence of PSN was not related to the treatment outcome in this study.


Assuntos
Vertigem Posicional Paroxística Benigna/complicações , Nistagmo Patológico/etiologia , Canais Semicirculares/fisiopatologia , Postura Sentada , Adulto , Idoso , Vertigem Posicional Paroxística Benigna/fisiopatologia , Feminino , Movimentos da Cabeça/fisiologia , Humanos , Doenças do Labirinto/complicações , Doenças do Labirinto/fisiopatologia , Litíase/complicações , Litíase/fisiopatologia , Masculino , Pessoa de Meia-Idade , Nistagmo Patológico/fisiopatologia , Postura/fisiologia
6.
Artigo em Inglês | MEDLINE | ID: mdl-33138096

RESUMO

One of the first challenges for many children with physical disabilities is to sit independently. A floor seating positioning system enables this milestone, helping a child to maintain eye level with other children, play and learn on the floor, rectify his or her posture, and, therefore, helps to include the child within his or her social spectrum. Ciranda is the first comprehensive floor seat solution in Brazil to attend to those needs. The project collected anthropometric data from 370 children who were unable to sit without support. A sample of 37 families of these children was visited, observed, and interviewed. A project requirement compiled key insights from the field data to support a multidisciplinary team of collaborators to co-design solutions. The project resulted in two floor seating positioning systems to attend to different needs. One is a social enterprise where the children's parents and the community build the seat while the child in need and his or her friends engage in entertainment. The other is a salable seat that helps to raise funds for the social enterprise. The model also unravels other challenges common to assistive technologies, such as access to a device and training for the use and maintenance of the device.


Assuntos
Crianças com Deficiência/reabilitação , Postura/fisiologia , Equipamentos de Autoajuda , Brasil , Criança , Família , Feminino , Humanos
7.
Sci Rep ; 10(1): 16924, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33060670

RESUMO

The conformation of the German shepherd dog (GSD) varies considerably within the breed. These differences may result in large variation in the movement and limb loading and undesirable consequences to their musculoskeletal health. This study aimed to investigate the relationship between conformation and biomechanical measures in 60 GSDs. Full body kinematic and kinetic measures were computed from 3D motion capture and pressure data. The dogs were divided into groups based on their back slope and curvature. Correlation analysis and statistical differences between groups showed that GSDs with a greater back slope have a greater contact area in their forelimbs and place them closer together when standing (n = 60). During trot, the dogs with sloped back showed a greater vertical force in the forelimbs and a greater mid-thoracic flexion (n = 60). Unilateral differences were found in the stifle flexion, hock flexion and hock adduction, suggesting greater movement asymmetry with an increase in the back slope (n = 30). In conclusion, several biomechanical parameters are affected by the GSD's slope of the back and not by its curvature. Further studies are required to determine whether the variation in movement, posture and conformation within the breed relates to an increased susceptibility to musculoskeletal disorders.


Assuntos
Movimento/fisiologia , Postura/fisiologia , Somatotipos/fisiologia , Animais , Fenômenos Biomecânicos/fisiologia , Cães , Extremidades , Feminino , Membro Anterior , Marcha , Cinética , Masculino , Aparência Física/fisiologia , Fenômenos Fisiológicos/fisiologia , Posição Ortostática
8.
Sci Rep ; 10(1): 16337, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004970

RESUMO

This study aimed to assess the validity and functional relevance of a standardized procedure to assess lower limb muscle power by means of the 30-s sit-to-stand (STS) test when compared to leg extension power (LEP), traditional STS performance and handgrip strength. A total of 628 community-dwelling older subjects (60-93 years) from the Copenhagen Sarcopenia Study were included. Physical performance was assessed by the 30-s STS and 10-m maximal gait speed tests. Handgrip strength and LEP were recorded by a hand-held dynamometer and the Nottingham power rig, respectively. STS muscle power was calculated using the subjects' body mass and height, chair height and the number of repetitions completed in the 30-s STS test. We found a small albeit significant difference between LEP and unilateral STS power in older men (245.5 ± 88.8 vs. 223.4 ± 81.4 W; ES = 0.26; p < 0.05), but not in older women (135.9 ± 51.9 vs. 138.5 ± 49.6 W; ES = 0.05; p > 0.05). Notably, a large positive correlation was observed between both measures (r = 0.75; p < 0.001). Relative STS power was more strongly related with maximal gait speed than handgrip strength, repetition-based STS performance and relative LEP after adjusting for age (r = 0.53 vs 0.35-0.45; p < 0.05). In conclusion, STS power obtained from the 30-s STS test appeared to provide a valid measure of bilateral lower limb power and was more strongly related with physical performance than maximal handgrip strength, repetition-based STS performance and LEP.


Assuntos
Envelhecimento/fisiologia , Força da Mão/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Desempenho Físico Funcional , Postura/fisiologia , Idoso , Idoso de 80 Anos ou mais , Teste de Esforço , Feminino , Avaliação Geriátrica , Humanos , Perna (Membro)/fisiologia , Masculino , Pessoa de Meia-Idade
9.
Niger J Clin Pract ; 23(10): 1437-1442, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33047703

RESUMO

Background: Cardiac autonomic neuropathy (CAN) resulting from seizures has been implicated in sudden unexpected death in epilepsy in persons with epilepsy (PWE), however, there are no previous studies of CAN in PWE from Nigeria. Objectives: This study sought to determine the frequency and pattern of CAN in adult PWE in a tertiary hospital in South-western Nigeria and to determine the relationship between seizure variables and CAN. Methods: A cross-sectional study of 80 adult PWE and 80 matched controls aged between 18 and 60 years was carried out between March 2012 and June 2013 at the Obafemi Awolowo University Teaching Hospital Complex, Ile-Ife, Nigeria. Demographic and clinical data were obtained from all the study participants. Anxiety was excluded using the Hamilton Anxiety Scale. Those with conditions that could affect autonomic function, such as chronic renal failure, heart failure, Parkinson's disease, diabetes mellitus, anxiety, and psychiatric disorders and pregnant women were excluded. Five bedside cardiovascular reflex tests were performed on each subject after baseline heart rate and blood pressure (BP) had been recorded. Results: The mean age of onset of epilepsy was 19 ± 10 years, whereas the mean duration of epilepsy was 10 ± 8 years. The mean seizure frequency was 14 ± 30 per month (median three seizures per month). Of the 80 patients evaluated, 42 (52.5%) had CAN, whereas none of the controls had CAN. Majority (69%) of the PWE with CAN had purely parasympathetic dysfunction, whereas 3% had purely sympathetic dysfunction and 10% had combined autonomic dysfunction. The PWE in this study had significantly lower tilt ratios and diastolic BP change with Isometric Hand grip as well as significantly higher systolic BP change on standing than the controls. Patients who had more than four seizures per month had higher odds of CAN than those with less frequent seizures (odds ratio 0.275, P value 0.023). Also, patients who had received treatment for less than 10 years were found to have greater odds of CAN than those who had received treatment for a longer period (odds ratio 11.676, P value 0.046). Conclusion: CAN is common in adult PWE in South-Western Nigeria and the major predictors are short duration of treatment and frequent seizure episodes. Routine screening of these patients may help with early detection of autonomic dysfunction and provide an opportunity for intervention.


Assuntos
Doenças do Sistema Nervoso Autônomo/epidemiologia , Sistema Nervoso Autônomo/fisiopatologia , Epilepsia/fisiopatologia , Coração/fisiopatologia , Adolescente , Adulto , Anticonvulsivantes/uso terapêutico , Doenças do Sistema Nervoso Autônomo/etiologia , Pressão Sanguínea/fisiologia , Estudos de Casos e Controles , Estudos Transversais , Epilepsia/tratamento farmacológico , Epilepsia/epidemiologia , Feminino , Força da Mão/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Nigéria/epidemiologia , Postura/fisiologia , Gravidez , Fatores de Risco , Convulsões , Centros de Atenção Terciária , Adulto Jovem
10.
Artigo em Inglês | MEDLINE | ID: mdl-33036376

RESUMO

BACKGROUND: There is a paucity of data on the relationship between backpack use and foot posture in children. The aim of this study was to assess the effects of a backpack on foot posture in children with neutral foot posture during three years of follow-up. METHODS: A prospective longitudinal observational study was conducted in a sample of 627 children with neutral foot. For each participant included in the study, age, sex, weight, height, body mass index, type of schoolbag (backpack or non-backpack), foot shape, metatarsal formula and type of shoes were recorded. Foot posture was described by the mean of the foot posture index (FPI) and reassessed after three years in a follow-up study. RESULTS: The average age of the children was 8.32 ± 1.32 years. A total of 458 used a backpack when going to school. Over the three-year follow-up period, 50 children who had neutral foot developed supinated foot (n = 18) or pronated foot (n = 32). Univariate and multivariate analysis showed that the children using a backpack were at a higher risk of developing pronated foot (adjusted Odds Ratio (aOR) = 2.05, 95% IC: 1.08-3.89, p = 0.028). Backpack use was not associated with the change from neutral foot to supinated foot. CONCLUSIONS: We found a positive association between using a backpack and the risk of developing pronated but not supinated foot. Clinical trials should be conducted to analyze the effect of backpack use on the foot among schoolchildren.


Assuntos
Pé/fisiologia , Postura/fisiologia , Criança , Seguimentos , Pé/anatomia & histologia , Humanos , Masculino , Estudos Prospectivos , Sapatos
11.
PLoS One ; 15(9): e0238436, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32877426

RESUMO

Postural control is the ability to maintain equilibrium and orientation in a gravitational environment. Patients with chronic subjective dizziness have some troubles with their postural stability. The present study aimed to assess the benefit of home-based vestibular rehabilitation in patients with chronic subjective dizziness using computerized dynamic posturography. Therefore, 100 subjects, between 19 to 86 years, diagnosed with dizziness were included in the study. Computerized dynamic posturography was performed to assess postural stability. Vestibular rehabilitation programs included exercises tailored to the particular needs of each patient. After vestibular rehabilitation, patients were re-examined using the same tests. Posturographic data were analyzed and compared for before and after vestibular rehabilitation findings. The mean composite scores before the intervention (58,92 ±11,64) was significantly (p<0.01) lower than the mean composite scores after vestibular rehabilitation (73,83 ± 8,26). This result is found to be statistically significant. In conclusion it could be suggested that the effectiveness of vestibular rehabilitation could be verified by means of computerized dynamic posturography as a concrete method.


Assuntos
Tontura/terapia , Terapia por Exercício/métodos , Equilíbrio Postural/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Tontura/diagnóstico , Exercício Físico/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Postura/fisiologia , Resultado do Tratamento , Vertigem/diagnóstico , Vertigem/terapia , Doenças Vestibulares/patologia , Testes de Função Vestibular/métodos , Núcleos Vestibulares/metabolismo
12.
J Sports Med Phys Fitness ; 60(8): 1110-1117, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32955837

RESUMO

BACKGROUND: Vinyasa yoga has been recently promoted as one of the most popular mindful exercises to improve overall health, including body weight management. The purpose of this study was to determine the metabolic response of 24 moderately trained individuals during a 90-min group Vinyasa yoga routine. METHODS: Heart rate (HR) time course of 12 males and 12 females (age: 39±7.33 years) was recorded during two group Vinyasa yoga sessions consisted of four sections (warm-up, high-intensity Surya Namaskar (HSN), no Surya Namaskar postures, and cool-down). Maximal oxygen uptake (V̇O2peak) and maximum HR had been estimated earlier after a maximal treadmill test. V̇O2 during Vinyasa yoga sessions was estimated from individual regression equations using the relationship of V̇O2 and HR values derived from V̇O2peak test, while the metabolic rate (kcal/min) was calculated from the relationship of HR and kcal/min. Total session energy consumption was the average value of the two yoga sessions. RESULTS: The 2 (gender) × 4 (sections) mixed ANOVA revealed no significant interaction between the two factors (P=0.101) for the mean metabolic rate (7.1±2.6 kcal/min). Mean metabolic rate thought was higher (P=0.015) in males compared to females at each section. Also, significant differences were found among the four Vinyasa yoga sections (P<0.001) in the rate of energy expenditure, with HSN presenting the highest mean values (P<0.05). CONCLUSIONS: It seems that systematic participation in Vinyasa yoga may effectively improve cardiorespiratory fitness and promote body weight loss, as an alternative method to traditional aerobic exercise.


Assuntos
Aptidão Cardiorrespiratória , Metabolismo Energético , Perda de Peso , Ioga , Adulto , Exercício de Arrefecimento/fisiologia , Teste de Esforço , Feminino , Frequência Cardíaca , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Postura/fisiologia , Fatores Sexuais , Exercício de Aquecimento/fisiologia
13.
Sci Rep ; 10(1): 15357, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958770

RESUMO

Triassic archosaurs and stem-archosaurs show a remarkable disparity in their ankle and pelvis morphologies. However, the implications of these different morphologies for specific functions are still poorly understood. Here, we present the first quantitative analysis into the locomotor abilities of a stem-archosaur applying 3D modelling techniques. µCT scans of multiple specimens of Euparkeria capensis enabled the reconstruction and three-dimensional articulation of the hindlimb. The joint mobility of the hindlimb was quantified in 3D to address previous qualitative hypotheses regarding the stance of Euparkeria. Our range of motion analysis implies the potential for an erect posture, consistent with the hip morphology, allowing the femur to be fully adducted to position the feet beneath the body. A fully sprawling pose appears unlikely but a wide range of hip abduction remained feasible-the hip appears quite mobile. The oblique mesotarsal ankle joint in Euparkeria implies, however, a more abducted hindlimb. This is consistent with a mosaic of ancestral and derived osteological characters in the hindlimb, and might suggest a moderately adducted posture for Euparkeria. Our results support a single origin of a pillar-erect hip morphology, ancestral to Eucrocopoda that preceded later development of a hinge-like ankle joint and a more erect hindlimb posture.


Assuntos
Articulação do Tornozelo/fisiologia , Membro Posterior/fisiologia , Postura/fisiologia , Amplitude de Movimento Articular/fisiologia , Vertebrados/fisiologia , Animais , Evolução Biológica , Marcha/fisiologia , Locomoção/fisiologia , Músculo Esquelético/fisiologia , Pelve/fisiologia
14.
Sci Rep ; 10(1): 15431, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32963261

RESUMO

Body postures are essential in animal behavioural repertoires and their communicative role has been assessed in a wide array of taxa and contexts. Some body postures function as amplifiers, a class of signals that increase the detection likelihood of other signals. While foraging on the ground, bonobos (Pan paniscus) can adopt different crouching postures exposing more or less of their genital area. To our knowledge, their potential functional role in the sociosexual life of bonobos has not been assessed yet. Here we show, by analysing more than 2,400 foraging events in 21 captive bonobos, that mature females adopt a rear-exposing posture (forelimb-crouch) and do so significantly more often when their anogenital region is swollen than during the non-swollen phase. In contrast, mature males almost completely avoid this posture. Moreover, this strong difference results from a diverging ontogeny between males and females since immature males and females adopt the forelimb-crouch at similar frequencies. Our findings suggest that the forelimb-crouch posture may play a communicative role of amplification by enhancing the visibility of female sexual swellings, a conspicuous signal that is very attractive for both males and females. Given the high social relevance of this sexual signal, our study emphasizes that postural signalling in primates probably deserves more attention, even outside of reproductive contexts.


Assuntos
Comportamento Animal/fisiologia , Pan paniscus/fisiologia , Pan troglodytes/fisiologia , Postura/fisiologia , Animais , Comunicação , Feminino , Masculino , Comportamento Social
15.
J Sports Sci ; 38(19): 2200-2207, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32921248

RESUMO

The aims of this study were (a) to describe the kinematics underlying the phenomenon of the knee of the swing leg passing medially in front of the athlete during the single push (SP) phase of the block sprint start, and (b) to determine the relationships between block phase pelvis range of motion (RoM), 1st step width and block phase performance. Three-dimensional kinematic data (250 Hz) were collected from eleven competitive sprinters (100 m PB: 11.17 ± 0.41) performing maximal effort block starts. The joint angles of the rear hip with respect to the pelvis and the pelvis segment angles with respect to the laboratory coordinate system were calculated during the block start phase to the end of the 1st stance. A combination of pelvis list and rotation (not hip adduction) was coupled with the thigh of the swing leg moving medially during the SP phase. A very high positive correlation was found between pelvic list RoM and 1st step width (r = 0.799, p = 0.003). No other significant correlations were found. Attempting to reduce pelvic RoM or changing frontal and transverse plane hip joint angles to minimise medial thigh motion is unlikely to lead to an improvement to performance.


Assuntos
Articulação do Joelho/fisiologia , Pelve/fisiologia , Corrida/fisiologia , Aceleração , Fenômenos Biomecânicos , Feminino , Análise da Marcha , Articulação do Quadril/fisiologia , Humanos , Masculino , Postura/fisiologia , Amplitude de Movimento Articular , Coxa da Perna/fisiologia , Estudos de Tempo e Movimento , Adulto Jovem
16.
PLoS One ; 15(8): e0237768, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32813742

RESUMO

INTRODUCTION: In cycling, the utilization of the drops position (i.e. the lowest handlebar position relative to the ground) allows for reduced frontal area, likely improved aerodynamics and thus performance compared to the tops (i.e. the position producing the most upright trunk). The reduced trunk angle during seated submaximal cycling has been shown to influence cardiorespiratory factors but the effects on pedalling forces and joint specific power are unclear. The purpose of this study was to investigate the effect of changing handgrip position on joint specific power and cycling kinematics at different external work rates in recreational and professional cyclists. METHOD: Nine professional and nine recreational cyclists performed cycling bouts using three different handgrip positions and three external work rates (i.e. 100W, 200W and external work rate corresponding to the lactate threshold (WRlt)). Joint specific power was calculated from kinematic measurements and pedal forces using 2D inverse dynamics. RESULTS: We found increased hip joint power, decreased knee joint power and increased peak crank torque for the professional cyclist compared to the recreational cyclists, but only at WRlt where the professional cyclists were working at a higher external work rate. There was no main effect of changing handgrip position on any joint, but there was a small interaction effect of external work rate and handgrip position on hip joint power contribution (Generalized eta squared (ηg2) = 0.012). At 100W, changing handgrip position from the tops to the drops decreased the hip joint contribution (-2.0 ± 3.9 percentage points (pct)) and at the WRlt, changing handgrip position increased the hip joint power (1.6 ± 3.1 pct). There was a small effect of handgrip position with the drops leading to increased peak crank torque (ηg2 = 0.02), increased mean dorsiflexion (ηg2 = 0.05) and increased hip flexion (ηg2 = 0.31) compared to the tops. DISCUSSION: The present study demonstrates that there is no main effect of changing handgrip position on joint power. Although there seems to be a small effect on hip joint power when comparing across large ranges in external work rate, any potential negative performance effect would be outweighed by the aerodynamic benefit of the drops position.


Assuntos
Atletas , Desempenho Atlético/fisiologia , Ciclismo/fisiologia , Postura/fisiologia , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Mãos/fisiologia , Articulação do Quadril/fisiologia , Humanos , Articulação do Joelho/fisiologia , Masculino , Torque , Adulto Jovem
17.
J Sports Sci ; 38(22): 2603-2610, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32734844

RESUMO

Much research has investigated whole-body postures and associated knee joint loading during unanticipated sidestepping (UnSS). However, no research has considered sport-specific postures in field hockey. The purpose of this study was to investigate differences in trunk and lower limb angle and lower extremity joint moment waveforms during UnSS while holding a hockey stick in a flexed posture (HS-UnSS) and traditional UnSS. Additionally, we aimed to determine if differences in posture during HS-UnSS were associated with changes in knee joint moments. Twelve elite female field hockey athletes underwent 3D motion analysis during UnSS and HS-UnSS. Athletes increased trunk (0-100% of stance phase, hip (0-15%), knee (12-29%; 39-59%; 78-100%) and ankle (41-57%) flexion angles, and increased hip flexion (19-24%; 42-45%; 75-84%) and external rotation moments (75-80%) during HS-UnSS compared with UnSS (p < 0.05). Flexed postures observed during HS-UnSS did not influence knee flexion and valgus moments when compared with UnSS (p > 0.05), however knee external rotation moments reduced. Changes in trunk flexion were positively associated with peak knee internal rotation moments from UnSS to HS-UnSS (r = 0.779, p = 0.005). These findings indicate that field hockey players sidestep with significantly different techniques when holding a hockey stick, which should be considered in injury prevention training protocols.


Assuntos
Lesões do Ligamento Cruzado Anterior/prevenção & controle , Lesões do Ligamento Cruzado Anterior/fisiopatologia , Hóquei/lesões , Extremidade Inferior/fisiopatologia , Movimento , Postura/fisiologia , Tronco/fisiopatologia , Adulto , Articulação do Tornozelo/fisiopatologia , Lesões do Ligamento Cruzado Anterior/etiologia , Fenômenos Biomecânicos , Feminino , Articulação do Quadril/fisiopatologia , Humanos , Articulação do Joelho/fisiopatologia , Rotação , Estudos de Tempo e Movimento , Adulto Jovem
18.
Sci Rep ; 10(1): 13921, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32811875

RESUMO

Hemodynamic alteration with postural change from supine to sitting has been unclear in the young. In the cross-sectional study, 686 participants (371 boys and 315 girls, aged 6-18 years) were recruited from 4 schools in Kaifeng city, the central area of China. The active sitting test was performed to obtain heart rate (HR) and blood pressure (BP) changes from supine to sitting in children and adolescents. Hemodynamic change-associated sitting intolerance was analyzed. In the study participants, the 95th percentile (P95) values of changes in HR and BP within 3 min from supine to sitting were 25 beats/min and 18/19 mm Hg, respectively. Sixty-six participants had sitting intolerance symptoms. Compared with participants without sitting intolerance symptoms, those with symptoms more frequently had HR increase ≥ P95 or BP increase ≥ P95 within 3 min from supine to sitting (P < 0.001). Risk factors for sitting intolerance were age (odds ratio 1.218, 95% confidence interval 1.072-1.384, P = 0.002) and changes in HR or BP ≥ P95 within 3 min after sitting (odds ratio 2.902, 95% confidence interval 1.572-5.357, P = 0.001). We firstly showed hemodynamic changing profiles from supine to sitting and their association with sitting intolerance in children and adolescents. Sitting tachycardia is likely suggested with a change in HR ≥ 25 beats/min and sitting hypertension with a change in BP ≥ 20/20 mm Hg when changing from supine to sitting within 3 min. The age and changes in HR or BP were independent risk factors for sitting intolerance.


Assuntos
Hemodinâmica/fisiologia , Postura Sentada , Adolescente , Pressão Sanguínea/fisiologia , Determinação da Pressão Arterial , Criança , China , Estudos Transversais , Feminino , Frequência Cardíaca/fisiologia , Humanos , Hipertensão/fisiopatologia , Masculino , Postura/fisiologia , Fatores de Risco , Decúbito Dorsal/fisiologia
19.
Physiotherapy ; 109: 1-3, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32791333

RESUMO

Since the outbreak of the 2019 novel coronavirus (COVID-19), the role of physiotherapy for patients with COVID-19 infection has been highlighted by various international guidelines. Despite that, clinical information regarding the rehabilitation of patients with COVID-19 infection remains limited. In this case series, we provide a novel insight into the physiotherapy management in patients infected with COVID-19 in Singapore. The main findings are: (1) Respiratory physiotherapy interventions were not indicated in the majority of the patients with COVID-19 in this case series; (2) During rehabilitation, exertional or position-related desaturation is a common feature observed in critically ill patients with COVID-19 infection locally. This clinical phenomenon of exertional or positional-related desaturation has significantly slowed down the progression of rehabilitation in our patients. As such, it can potentially result in a significant burden on healthcare resources to provide rehabilitation to these patients. Based on these findings, we have highlighted several recommendations for the provision of rehabilitation in patients who are critically ill with COVID-19.


Assuntos
/reabilitação , Modalidades de Fisioterapia , Idoso , Estado Terminal , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Pandemias , Esforço Físico/fisiologia , Postura/fisiologia , Terapia Respiratória , Estudos Retrospectivos , Singapura
20.
Phys Ther Sport ; 45: 181-187, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32823213

RESUMO

OBJECTIVES: To investigate validity and between-session reliability of frontal plane trunk, hip, and knee kinematics during three functional tasks in females with patellofemoral pain (PFP). DESIGN: Observational. SETTING: Research Laboratory. PARTICIPANTS: 20 females with PFP (22.7 ± 3.2 years, 69.9 ± 9.2 kg, 167.7 ± 9.6 cm). MAIN OUTCOME MEASURES: Trunk, hip, and knee frontal plane peak angles during the single leg squat (SLS), drop vertical jump (DVJ), and single leg hop (SLH) kinematics were evaluated using 2-dimensional (2D) and 3-dimensional (3D) motion capture. Participants returned to the lab one week later and competed a second 2D analysis of the functional tasks. Concurrent validity was assessed by evaluating relationship between 2D and 3D frontal plane kinematics with Pearson correlations. Between-session reliability was assessed by evaluating 2D kinematics with intraclass correlation coefficients by a single assessor. RESULTS: Moderate to strong correlations (r = 0.55-0.76, p < .05) were found for frontal plane hip kinematics during all three tasks and the trunk during the SLH. Frontal plane kinematics demonstrated good to excellent test-retest reliability for each of the three tasks, (ICC (2,1) = 0.70-0.90). CONCLUSION: 2D hip joint angles during the three functional tasks were the only valid frontal plane angles. Trunk, hip, and knee 2D frontal plane kinematics ranged between good-excellent reliability.


Assuntos
Articulação do Quadril/fisiopatologia , Articulação do Joelho/fisiopatologia , Perna (Membro)/fisiopatologia , Síndrome da Dor Patelofemoral/fisiopatologia , Postura/fisiologia , Tronco/fisiopatologia , Fenômenos Biomecânicos , Feminino , Humanos , Reprodutibilidade dos Testes , Adulto Jovem
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