Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.193
Filtrar
1.
Medicine (Baltimore) ; 100(22): e26208, 2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34087893

RESUMO

ABSTRACT: Sit-to-stand (STS) motion is one of the most important and energy-consuming basic motions in everyday life. Kinematic analysis provides information regarding what strategy or motion pattern is used by the healthy people, and through which, we can understand and obtain the law of the STS motion. The objective of this article is to study the law of STS motion through the experiment to determine a suitable description of STS motion in healthy adults, so as to provide a starting point and bases for future design and control of STS assistive devices.Thirty healthy adult subjects participated in this study and carried out STS motion experiment of standing up naturally. The STS motions were recorded using a high-definition camera. The experimentally collected kinematic data and a link segment model of the human body were used to obtain the coordinates of joints and to calculate the coordinates, velocity, and momentum of center of gravity; the postures of human body during STS are also obtained. The relationship between human body parameters and motion parameters is analyzed by using Pearson correlation method.The STS motion is divided into 4 phases; the phases are differentiated in terms of STS motion characteristics and postures, and momentum of center of gravity of human body. The main factors determining the differences in STS motion among individuals are horizontal distance between hip joint and ankle joint, lower leg length, thigh length, and the length of the transition period. The horizontal distance between hip joint and ankle joint is positively correlated with the duration from motion begin to trunk stops flexing forward (P = .021 < .05), but not so with the duration from motion begin to the end of phase 2 (P = .15 > .05).The results suggest that when designing the sit-to-stand assistive devices, one should pay attention to the whole-body posture control in STS motion, such as the posture guidance of trunk and lower leg, and should carry out specific training according to different STS phases. Sit-to-stand assistive devices should provide the same horizontal distance between hip joint and ankle joint for different individuals during the STS motion. Transition period should be properly controlled, and the degree of freedom of the lower leg should not be limited.


Assuntos
Fenômenos Biomecânicos/fisiologia , Movimento/fisiologia , Postura/fisiologia , Amplitude de Movimento Articular/fisiologia , Adulto , Algoritmos , Articulação do Tornozelo/fisiologia , Trajetória do Peso do Corpo , Discinesias/reabilitação , Articulação do Quadril/fisiologia , Corpo Humano , Humanos , Perna (Membro)/anatomia & histologia , Masculino , Equilíbrio Postural/fisiologia , Equipamentos de Autoajuda/efeitos adversos , Coxa da Perna/anatomia & histologia , Tronco/fisiologia
2.
J Sports Sci ; 39(sup1): 73-80, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34092197

RESUMO

This study examined the reliability of instrumented trunk assessment methods across two experiments to develop and improve evidence-based classification in Para swimming. Trunk coordination, range of motion (ROM), and strength were assessed in 38 non-disabled participants. Each test battery was completed on two occasions to determine inter-session reliability. Intra-session reliability was also determined in Experiment Two. Absolute agreement of two-way mixed intraclass correlation coefficients (ICC 3,1) was calculated to assess reliability. Standard errors of measurement (SEMs) were also reported to facilitate comparisons between different outcomes. Trunk coordination measures had low-to-moderate reliability (inter-session ICCs = 0.00-0.60; intra-session ICCs = 0.14-0.65) and variable SEMs (5-60%). Trunk ROM demonstrated moderate-to-excellent reliability (inter-session ICCs = 0.61-0.93; intra-session ICCs = 0.87-0.95) and good SEMs (<10%). Trunk strength measures demonstrated good-to-excellent reliability (ICCs = 0.87-0.98) and good SEMs (<10%). The strength values obtained for the load cell and hand-held dynamometer (HHD) were significantly different from each other with the HHD underestimating strength. Modifications provided in Experiment Two improved the reliability of strength and ROM assessments but did not improve coordination measures. Further research involving para swimmers is required to establish the validity of the methods.


Assuntos
Força Muscular/fisiologia , Desempenho Psicomotor/fisiologia , Amplitude de Movimento Articular/fisiologia , Natação/fisiologia , Tronco/fisiologia , Adulto , Fenômenos Biomecânicos/fisiologia , Voluntários Saudáveis , Humanos , Dinamômetro de Força Muscular , Paratletas/classificação , Reprodutibilidade dos Testes , Postura Sentada , Coluna Vertebral , Esportes para Pessoas com Deficiência/classificação , Esportes para Pessoas com Deficiência/fisiologia , Natação/classificação , Adulto Jovem
3.
PLoS One ; 16(4): e0249670, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33819316

RESUMO

Hip extensor muscle size is related to sprint running performance. However, the mechanisms underlying this relationship remain unclear. To gain insights into this issue, the present study examined the relationships between the individual hip extensor sizes, spatiotemporal variables (step frequency and length, and their determinants), and sprint velocity during maximal velocity sprinting. Magnetic resonance images of the hip and right thigh were obtained from 26 male sprinters to determine the volumes of the gluteus maximus, individual hamstrings and adductors, and gracilis. Muscle volumes were normalized to their respective body mass and recorded as relative muscle volumes. The sprinters performed a 100-m sprint with their maximal effort. Their sprint motions were recorded using cameras to calculate the mean sprint velocity and the spatiotemporal variables at 50-60 m interval. The sprint velocity was significantly correlated with the relative volume of the semitendinosus (r = 0.497, P = 0.010), but not with the volumes of the other examined muscles. The relative volume of semitendinosus significantly correlated with the stance distance (r = 0.414, P = 0.036) and the stance distance adjusted by the stance time (r = 0.490, P = 0.011). Moreover, there were significant correlations between the stance distance and step length (r = 0.592, P = 0.001), and between the step length and sprint velocity (r = 0.509, P = 0.008). These results suggest that the semitendinosus contributes to attaining long stance distance and thereby high sprint velocity during maximal velocity sprinting.


Assuntos
Quadril/fisiologia , Músculos Psoas/fisiologia , Corrida/fisiologia , Desempenho Atlético/fisiologia , Fenômenos Biomecânicos , Nádegas/fisiologia , Músculo Grácil/fisiologia , Músculos Isquiossurais/fisiologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Músculo Esquelético/fisiologia , Coxa da Perna/fisiologia , Tronco/fisiologia , Adulto Jovem
4.
Gait Posture ; 86: 245-250, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33799053

RESUMO

BACKGROUND: Inspite of common lifting advice to maintain a lordotic posture, there is debate regarding optimal lumbar spine posture during lifting. To date, the influence of lumbar posture on trunk muscle recruitment, strength and efficiency during high intensity lifting has not been fully explored. RESEARCH QUESTION: How do differences in lumbar posture influence trunk extensor strength (moment), trunk muscle activity, and neuromuscular efficiency during maximal lifting? METHODS: Twenty-six healthy participants adopted three lumbar postures (maximal extension (lordotic), mid-range (flat-back), and fully flexed) in a free lifting position. Motion analysis and force measurements were used to determine the back extensor, hip and knee moments. Surface electromyography (EMG) of three trunk extensors and the internal obliques were recorded. Neuromuscular efficiency (NME) was expressed as a ratio of normalised extensor moment to normalised EMG. RESULTS: Significantly higher back extensor moments were exerted when moving from an extended to mid-range, and from a mid-range to fully flexed lumbar posture. This was accompanied by a decrease in activity across all three back extensor muscles (P < 0.001) resulting in a higher NME of these muscles in more flexed postures. Change in lumbar posture did not influence hip or knee moments or internal oblique activation. SIGNIFICANCE: A flexed-back posture is associated with increased strength and efficiency of the back muscles compared to a lordotic posture. These findings further question the manual handling advice to lift with a lordotic lumbar spine.


Assuntos
Vértebras Lombares/fisiologia , Postura/fisiologia , Levantamento de Peso/fisiologia , Adulto , Eletromiografia , Feminino , Humanos , Dor Lombar , Masculino , Músculo Esquelético/fisiologia , Tronco/fisiologia , Adulto Jovem
5.
Hum Mov Sci ; 77: 102791, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33866137

RESUMO

The present study investigated how belly dance experts perform the "hip shimmy", a complex rhythmic dance movement consisting in a voluntary oscillation of the pelvis exclusively in the frontal plane with maximised amplitude, with no movement of the upper trunk. The aims of this study were to 1) assess whether the amplitude and stability of the pelvic movement can be maximised in certain postural and frequency conditions; and 2) investigate in a 1 to 3 Hz range whether it is indeed possible to oscillate the pelvis only in the frontal plane and to dissociate this one-axis pelvic rotation from potential spontaneous upper-trunk oscillations. Nineteen belly dance experts performed this task in three frequencies and three knee bending postures. Eight joint angles were calculated using the kinematic data of 20 markers over the entire body collected with a motion capture system. Mean amplitude, frequency, and spatial and temporal variability of frontal pelvic oscillations were analysed to characterise motor performance and movement stability. Five Continuous Relative Phases (CRP) were computed to identify the modes and stability of coordination patterns. The results showed that a low posture enhances amplitude performance and that the pelvic oscillation amplitude tended to decrease at 3 Hz, although between-condition differences remained small. Temporal stability was highest at 2 Hz and significant inter-individual differences emerged at 3 Hz. CRP analysis revealed an unpreventable coupling between pelvis and upper-trunk oscillations in the frontal and transversal planes. A consistent antiphase coordination between transversal pelvis and upper-trunk may have been caused by anatomical and counter-balancing constraints. In the frontal plane, multiple stable pelvis-upper trunk patterns including inphase, out-of-phase and antiphase evolved to antiphase predominance and inphase disappearance upon reaching 3 Hz. In sum, increasing frequency highlighted the concomitance of two control phenomena: the inter-individual differentiation in performance and standardisation of the possible pelvis-upper-trunk patterns.


Assuntos
Dança , Articulação do Joelho/fisiologia , Movimento , Pelve/fisiologia , Tronco/fisiologia , Adulto , Fenômenos Biomecânicos , Feminino , Articulação do Quadril/fisiologia , Humanos , Postura , Adulto Jovem
6.
J Sports Sci ; 39(15): 1669-1676, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33641596

RESUMO

The aim of this study was to determine the contribution of the upper trunk rotation consisting of roll-pitch-yaw to hand velocity in the forwards-backwards direction during front crawl strokes and to investigate the association of forwards-backwards hand velocity induced by the upper trunk rotation with stroke frequencies. Fifteen skilled swimmers with retro-reflective markers performed front crawl strokes in a swimming pool where a motion capture system was set. Forwards-backwards hand velocity solely induced by the upper trunk rotation was determined during the performance. In the pull and push phases, 28% and 19% of the backward hand velocity was induced by the upper trunk rotation, respectively, while 19% of the forward hand velocity resulted from the upper trunk rotation in the recovery phase. The upper trunk rotation contributed to the forwards-backwards velocity as much as the elbow joint and was the second primary source of backward hand velocity in the pull phase. The forwards-backwards hand velocity created by the upper trunk rotation was associated with the stroke frequencies (r = 0.56, p < 0.05). The forwards-backwards hand velocity induced by the upper trunk would influence hand propulsion and stroke frequency so that a swimmer and coach should consider this performance-enhancing variable.


Assuntos
Mãos/fisiologia , Natação/fisiologia , Tronco/fisiologia , Fenômenos Biomecânicos , Humanos , Masculino , Rotação , Estudos de Tempo e Movimento , Adulto Jovem
7.
Traffic Inj Prev ; 22(3): 236-241, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33688754

RESUMO

OBJECTIVE: The primary aim of this article is to extensively study female occupant kinematics and muscle activations in vehicle maneuvers potentially occurring in precrash situations and with different seat belt configurations. The secondary aim is to provide validation data for active human body models (AHBMs) of female occupants in representative precrash loading situations. METHODS: Front seat female passengers wearing a 3-point seat belt, with either standard or pre-pretensioning functionality, were subjected to multiple autonomously carried-out lane change and lane change with braking maneuvers while traveling at 73 km/h. This article quantifies the head center of gravity and T1 vertebra body (T1) linear and rotational displacements. This article also includes surface electromyography (EMG) data collected from 38 muscles in the neck, torso, and upper and lower extremities, all normalized by maximum voluntary contraction (MVC). The raw EMG data were filtered, rectified, and smoothed. Separate Wilcoxon signed-rank tests were performed on EMG onset and amplitude as well as peak displacements of head and T1 considering 2 paired samples with the belt configuration as an independent variable. RESULTS: Significantly smaller lateral and forward displacements for head and T1 were found with the pre-pretensioner belt versus the standard belt (P < .05). Averaged muscle activity, mainly in the neck, lumbar extensor, and abdominal muscles, increased up to 16% MVC immediately after the vehicle accelerated in the lateral direction. Muscles in the right and left sides of the body displayed differences in activation time and amplitude relative to the vehicle's lateral motion. For specific muscles, lane changes with the pre-pretensioner belt resulted in earlier muscle activation onsets and significantly smaller activation amplitudes compared to the standard belt (P < .05). CONCLUSIONS: The presented results from female passengers complement the previously published results from male passengers subjected to the same loading scenarios. The data provided in this article can be used for validation of AHBMs of female occupants in both sagittal and lateral loading scenarios potentially occurring prior to a crash. Additionally, our results show that a pre-pretensioner belt decreases muscle activation onset and amplitude as well as forward and lateral displacements of head and T1 compared to a standard belt, confirming previously published results.


Assuntos
Acidentes de Trânsito/prevenção & controle , Cabeça/diagnóstico por imagem , Contração Muscular/fisiologia , Músculo Esquelético/diagnóstico por imagem , Pescoço/diagnóstico por imagem , Tronco/diagnóstico por imagem , Adulto , Condução de Veículo , Fenômenos Biomecânicos , Eletromiografia , Feminino , Cabeça/fisiologia , Humanos , Músculo Esquelético/fisiologia , Pescoço/fisiologia , Cintos de Segurança/estatística & dados numéricos , Análise e Desempenho de Tarefas , Tronco/fisiologia , Adulto Jovem
8.
Gait Posture ; 86: 33-37, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33677176

RESUMO

BACKGROUND: Trunk control during gait in children with cerebral palsy (CP) is known to be impaired. While differentiation of trunk movement between CP subtypes (unilateral/bilateral) has been examined, differentiation of lower lumbar spinal loading has not been considered. Furthermore, the relationship between lower lumbar loading and lower limb pathology has not been reported. RESEARCH QUESTION: How do lower lumbar spinal kinetics differ during unilateral and bilateral CP gait and what is the relationship between trunk kinematics and L5/S1 kinetics with lower limb pathology? METHODS: Three-dimensional thorax kinematics and L5/S1 kinetics were measured during gait with children divided into 3 groups (unilateral CP (n = 21), bilateral CP (n = 31) and typical development (TD) (n = 26)). Differences in thorax kinematics and reactive forces and moments at L5/S1 between groups were analysed using Statistical Parametric Mapping. Correlation coefficients were calculated between Gait Profile Score (GPS) and kinematic measures of the thorax and kinetics at L5/S1. RESULTS: An increased ipsilateral bending moment was present for unilateral CP in the coronal plane (55-70% Gait Cycle (GC), p < 0.001), while children with bilateral CP demonstrated two distinct increased peaks during mid-stance (10-30 % GC, p < 0.001) and mid-swing (60-80% GC, p = 0.004) compared to TD. RMS and RoM thorax flexion, side flexion and L5/S1 lateral bend moment demonstrated significant moderate correlations with GPS. SIGNIFICANCE: This study confirmed an increased involvement at the trunk and of lower lumbar spinal loading for children with bilateral CP compared to unilateral CP. It has been suggested that altered trunk movement in CP gait may be a combination of both a compensation for lower limb pathology and an underlying deficit. Our result of positive yet moderate correlations between GPS and trunk movement and lower spinal loading support this theory.


Assuntos
Paralisia Cerebral/fisiopatologia , Marcha/fisiologia , Extremidade Inferior/patologia , Tronco/fisiologia , Fenômenos Biomecânicos , Criança , Feminino , Humanos , Cinética , Masculino
9.
Gait Posture ; 86: 106-111, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33713896

RESUMO

BACKGROUND: Limited passive ankle dorsiflexion range has been associated with increased knee valgus during functional tasks. Increased knee valgus is considered a contributing factor for musculoskeletal disorders in the lower limb. There is conflicting evidence supporting this association. The extent of passive ankle dorsiflexion range is associated with dynamic ankle dorsiflexion range and the way how these variables are related to lower limb or trunk kinematics is unclear. RESEARCH QUESTION: What is the association between passive ankle dorsiflexion range or dynamic ankle dorsiflexion range with shank, thigh, pelvis or trunk movements during the single-leg squat? METHODS: This is a cross-sectional study with a convenience sample. Thirty uninjured participants performed the single-leg squat with their dominant limb. Ankle, shank, thigh, pelvis and trunk 3D kinematics were recorded. Passive ankle dorsiflexion range was assessed through the weight-bearing lunge test and the dynamic ankle dorsiflexion range was defined as the ankle dorsiflexion range of motion in the sagittal plane during the single-leg squat. RESULTS: Greater passive ankle dorsiflexion range was associated with smaller thigh internal rotation (r= -0.38). Greater dynamic ankle dorsiflexion range was associated with smaller trunk flexion (r = 0.59) and pelvis anteversion (r= -0.47). Passive ankle dorsiflexion range and dynamic ankle dorsiflexion range were not associated. SIGNIFICANCE: Greater passive ankle dorsiflexion range seems to be associated with a better lower limb alignment during the single-leg squat, while dynamic ankle dorsiflexion range seems to reflect different lower limb and trunk kinematic strategies.


Assuntos
Articulação do Tornozelo/fisiologia , Extremidade Inferior/fisiologia , Postura/fisiologia , Amplitude de Movimento Articular/fisiologia , Tronco/fisiologia , Adulto , Fenômenos Biomecânicos , Estudos Transversais , Feminino , Humanos , Perna (Membro)/fisiologia , Masculino
10.
J Sports Sci ; 39(16): 1860-1872, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33775212

RESUMO

This study aimed to explore the inter-session reliability of the measures obtained from 2 trunk extension (Biering-Sorensen and Dynamic Extensor Endurance (DEE) tests) and 3 trunk flexion (Ito, Side Bridge and Bench Trunk Curl-Up (BTC) tests) endurance field-based tests in adolescents. A total of 208 (males, n = 100; females, n = 108) adolescents performed all the field-based tests on 2 separate testing sessions, 7-days apart. The inter-session reliability scores were explored through relative reliability, inter-session differences and precision of measurements. Most of the trunk endurance measures demonstrated acceptable relative reliability (the intraclass correlation coefficients (ICC) ranged from 0.75 to 0.94). However, significant inter-session differences were identified for measures from the DEE and BTC tests. Likewise, the precision of the measurement of each field-based test was poor (the the standard error of measurement expressed as a percentage of the mean score (CVTE) ranged from 11.3 to 24.4%) with the minimal detectable change (MDC95) revealing that changes higher than 42% for trunk extension endurance tests and 31.4% for trunk flexion endurance tests after an intervention are required to indicate a significant change above measurement error. Therefore, the findings from this study indicate that only the BTC test demonstrates acceptable inter-session reliability (ICC > 0.9, CVTE ~ 10%, MDC95 ~ 30%) to monitor the changes in trunk endurance scores that may be expected in adolescents after performing an intervention programme.


Assuntos
Teste de Esforço/normas , Músculo Esquelético/fisiologia , Resistência Física/fisiologia , Tronco/fisiologia , Adolescente , Criança , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Instituições Acadêmicas
11.
J Therm Biol ; 96: 102857, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33627285

RESUMO

The osprey (Pandion haliaetus) is a cosmopolitan and long-distant migrant, found at all thermal extremes ranging from polar to tropical climates. Since ospreys may have an unusually flexible thermal physiology due to their migration over, and use of, a wide range of habitats, they represent an interesting study system to explore thermoregulatory adaptations in a raptor. In this study, we investigated the efficiency of heat exchange between body and environment in ospreys using micro-computed tomography (µ-CT), infrared thermography and behavioral observations. µ-CT revealed that the osprey bill has its largest potential for heat exchange at the proximal bill region, where arteries are situated most closely under the surface. However, thermal images of 10 juvenile ospreys showed that the bill contributes to only 0.3% of the bird's total heat exchange. The long legs and protruding claws played a more prominent role as heat dissipation areas with a contribution of 6% and 7%, respectively. Operative thresholds, i.e. the ambient temperature below which heat is lost, were high (>38.5 °C) in these body parts. However, we found no indication of active regulation of heat exchange. Instead we observed multiple behavioral adaptations starting at relatively low ambient temperatures. At 26.3 °C ospreys had a 50% probability of showing panting behavior and above 27.9 °C they additionally spread their wings to enable heat dissipation from the less insulated ventral side. The thermal images revealed that at an ambient temperature of 32.1 °C ospreys had a 50% probability of developing a ≥2 °C and up to 7.5 °C colder stripe on the head, which was likely caused by cutaneous evaporation. Our observations suggest that ospreys more strongly rely on behavioral mechanisms than on active thermal windows to cope with heat stress. This study not only improves our understanding of the role of different body parts in ospreys' total heat exchange with the environment but further provides an insight about additional adaptations of this raptor to cope with heat stress.


Assuntos
Aves/fisiologia , Regulação da Temperatura Corporal , Animais , Bico/irrigação sanguínea , Bico/diagnóstico por imagem , Bico/fisiologia , Extremidades/diagnóstico por imagem , Extremidades/fisiologia , Olho/diagnóstico por imagem , Feminino , Cabeça/diagnóstico por imagem , Cabeça/fisiologia , Casco e Garras/diagnóstico por imagem , Casco e Garras/fisiologia , Masculino , Fenômenos Fisiológicos Oculares , Temperatura , Termografia , Tronco/diagnóstico por imagem , Tronco/fisiologia , Microtomografia por Raio-X
12.
J Electromyogr Kinesiol ; 57: 102531, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33607359

RESUMO

Repetitive trunk flexion can damage spinal tissues, however its association with low back pain in the workplace may be confounded by factors related to pain sensitivity. Muscle fatigue, exercise-induced hypoalgesia, and creep-induced neuromuscular changes following repetitive trunk flexion may all affect this assumed exposure-pain relationship. This study's purpose was to determine how mechanical pain sensitivity in the low back is affected by a repetitive trunk flexion exposure and identify factors associated with changes in low back pain sensitivity. Pressure pain thresholds, perceptions of sub-threshold stimuli, and muscle fatigue in the trunk and tibia, as well as lumbar spine creep were tracked in 37 young healthy adults before and up to 40 min after a 10-min repetitive trunk flexion exposure. Pressure pain thresholds (p = 0.033), but not perceptions of sub-threshold stimuli (p > 0.102) were associated with approximately a 12.5% reduction in pain sensitivity 10 min after completing the exposure, while creep and local muscle fatigue effects were only observed immediately following the exposure. Creep and fatigue interactions and the corresponding tibial measure co-varied with individual low back pressure pain thresholds. The net hypoalgesic effects of repetitive trunk flexion have the potential to partially mask possibly injurious loads, which could contribute to the severity or incidence of lower back injuries related to these exposures.


Assuntos
Dor Lombar/fisiopatologia , Vértebras Lombares/fisiologia , Contração Muscular/fisiologia , Fadiga Muscular/fisiologia , Tronco/fisiologia , Adulto , Eletromiografia/métodos , Feminino , Humanos , Dor Lombar/diagnóstico , Masculino , Músculo Esquelético/fisiologia , Medição da Dor/métodos , Amplitude de Movimento Articular/fisiologia , Adulto Jovem
13.
J Electromyogr Kinesiol ; 57: 102533, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33621756

RESUMO

Precision of trunk movement has commonly been examined by testing relocation accuracy rather than evaluating accuracy of tracking dynamic movement. In this study we used a 3-D motion capture system to provide a novel real-time tracking task to assess trunk motor control at varying movement speeds between people with and without chronic non-specific low back pain (LBP). Eleven asymptomatic volunteers and 15 participants with chronic non-specific LBP performed 12 continuous cycles of trunk flexion-extension following real time visual feedback, during which, trunk motion was measured using eight optoelectronic infrared cameras. Significant time differences between the feedback and actual trunk motion were found between groups (P = 0.001). Both groups had similar variability of tracking accuracy when following the feedback (P > 0.05). However, tracking variability at a slow speed correlated (P = 0.03; r = 0.55) with the Fear-Avoidance Beliefs Questionnaire (FABQ) scores in those with LBP. This study shows that both asymptomatic people and individuals with LBP displayed anticipatory behaviour, however, the response of those with LBP was consistently delayed in tracking the visual feedback compared to the asymptomatic group. Additionally, the extent of variability of tracking accuracy over repeated tracking cycles was associated with the degree of fear of movement in people with LBP.


Assuntos
Fenômenos Biomecânicos/fisiologia , Sistemas Computacionais , Eletromiografia/métodos , Dor Lombar/fisiopatologia , Movimento/fisiologia , Tronco/fisiologia , Adolescente , Adulto , Estudos Transversais , Medo/fisiologia , Medo/psicologia , Feminino , Humanos , Dor Lombar/psicologia , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/fisiologia , Inquéritos e Questionários , Adulto Jovem
14.
Hum Mov Sci ; 76: 102766, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33549936

RESUMO

Cognitive motor interference (CMI) is a psychomotor phenomenon characterized by alterations in kinematic spatial-temporal parameters during concurrent cognitive and motor tasks (i.e. dual-tasking). Previous literature has demonstrated that cognitive-motor dual-tasking induces alterations gait parameters; however, the influence of CMI on spine reflexive motion has yet to be researched. The purpose of this study was to assess the influence of cognitive-motor dual-tasking during unexpected spine loading, in particular focusing on paraspinal muscle responses and spine sub-regional kinematic responses. To do this, the spine was perturbed by unexpectedly dropping a 6.8 kg mass into the participants' hands during cognitive dual-task and control conditions. Intersegmental spine angles, paraspinal muscle onset latencies, baseline activations, and response magnitudes were measured. The results demonstrated that participants experienced greater spine flexion at all intersegmental levels during the cognitive dual-task condition compared to the control condition. Additionally, muscle onset latencies were significantly delayed in three of the four paraspinal muscles studied when performing the cognitive-motor dual-task. These results demonstrate that the additional cognitive load led to delayed muscle activation responses and subsequently greater intersegmental lumbar spine flexion in response to a sudden loading perturbation. This suggests that cognitive-motor dual-tasking may increase the risk of developing an acute spine injury under similar conditions.


Assuntos
Fenômenos Biomecânicos/fisiologia , Cognição/fisiologia , Marcha/fisiologia , Movimento , Amplitude de Movimento Articular , Coluna Vertebral/fisiologia , Tronco/fisiologia , Adulto , Eletromiografia , Feminino , Humanos , Região Lombossacral , Masculino , Postura , Adulto Jovem
15.
Gait Posture ; 85: 171-177, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33592398

RESUMO

BACKGROUND: The double-leg jump-landing (DLJL) task is commonly used as a movement screen that can be implemented in large cohorts of athletes. However, it is debatable whether the DLJL is ecologically valid and reflects sporting requirements or injury-prone situations, such as cutting and pivoting. RESEARCH QUESTION: Which jump-landing movement variation best represents the kinematics of unanticipated side-step cutting? METHODS: Forty-two participants (25 males and 17 females) performed unanticipated side-step cutting and four jump-landing tasks: DLJL, rotated DLJL (DLJLrot), single-leg jump-landing (SLJL), and rotated SLJL (SLJLrot). Ankle, knee, hip, pelvis, and trunk angles and angular velocities, and pelvic linear accelerations were collected at initial contact and during the first 100 milliseconds after initial contact (minimum, maximum, and range values) using a three-dimensional infrared camera system and inertial measurement units. Pre-contact foot-ground angles and subjective task difficulty ratings were also recorded. Intraclass correlation coefficients (ICC) between cutting and jump-landing kinematics were calculated for each participant and jump-landing variation. Friedman tests with pairwise comparisons were then used to compare the degree of association between the four different jump-landing tasks at the specified time events and to compare the difficulty ratings. RESULTS: Considering the ICC values across the events of interest, the kinematics of the DLJL were the least associated with those of cutting (ICC = 0.00 to 0.81), and DLJLrot (ICC = 0.34 to 0.81) and SLJLrot (ICC = 0.31 to 0.80) biomechanics the most. Participants rated the perceived challenge of the single-leg tasks in a similar manner to cutting (p > 0.103), and the SLJLrot as the most difficult task (median = "neutral", mode = "neutral"). SIGNIFICANCE: Due to their biomechanical associations with cutting maneuver and subjectively-rated difficulty levels, both DLJLrot and SLJLrot may be more appropriate and ecologically valid for screening for risk of injury across a range of sports.


Assuntos
Antecipação Psicológica/fisiologia , Atletas , Traumatismos em Atletas/etiologia , Extremidade Inferior/fisiologia , Movimento/fisiologia , Tronco/fisiologia , Adolescente , Adulto , Atletas/psicologia , Traumatismos em Atletas/fisiopatologia , Traumatismos em Atletas/psicologia , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Medição de Risco , Adulto Jovem
16.
Gait Posture ; 85: 211-216, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33610824

RESUMO

BACKGROUND: Kinematic parameters of the trunk, pelvis and lower limbs are frequently associated with both running injuries and performance, and the target of clinical interventions. Currently there is limited evidence reporting the between-day repeatability of discrete kinematic parameters of the trunk, pelvis and lower limbs during treadmill running. RESEARCH QUESTION: What is the between-day repeatability, standard error of measurement and minimal detectable change of discrete kinematic parameters of the trunk, pelvis and lower limbs during treadmill running? METHODS: 16 healthy participants attended two kinematic data collection sessions two weeks apart. Three-dimensional kinematic data were collected while participants ran on a motorised treadmill at 3.2 m/s. The interclass correlation coefficient, standard error of measurement and minimal detectable change were calculated for discrete kinematic parameters at initial contact, toe off, peak angles and joint excursions during the stance phase of running. RESULTS: Good to excellent repeatability with low standard error of measurement and minimal detectable change values were observed for sagittal and frontal plane kinematics at initial contact (Range: ICC, 0.829-0.941; SEM, 0.6°- 2.6°; MDC, 1.5°- 7.2) and peak angles during stance (Range: ICC, 0.799 - 0.946; SEM, 0.6°- 2.6°; MDC, 1.7°- 7.1°). Peak transverse plane kinematics of the hip (ICC, 0.783; SEM, 3.2°; MDC, 8.7°) and knee (ICC, 0.739; SEM, 3°; MDC, 8.4°) demonstrated moderate between-day repeatability with large SEM and MDC values. Kinematics at toe off demonstrated the lowest ICC values and largest measurement errors of all parameters (Range: ICC, 0.109 - 0.900; SEM, 0.8°- 5.7°; MDC, 2.5°- 15.7°). SIGNIFICANCE: This is the first study detailing the measurement error and minimal detectable change for discrete kinematic parameters of the trunk and pelvis during treadmill running. The reported values may provide a useful reference point for future studies investigating between-day differences in running kinematics.


Assuntos
Marcha/fisiologia , Corrida/fisiologia , Adulto , Fenômenos Biomecânicos , Teste de Esforço , Feminino , Voluntários Saudáveis , Humanos , Extremidade Inferior/fisiologia , Masculino , Pelve/fisiologia , Reprodutibilidade dos Testes , Tronco/fisiologia
17.
Gait Posture ; 85: 131-137, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33549967

RESUMO

BACKGROUND: Emerging research has suggested a plausible relationship may exist between lower limb coordination and musculoskeletal injury. A small number of studies have investigated the link between coordination and anterior cruciate ligament (ACL) injury during sidestep cutting. While prior work has shown unanticipated sidestep cutting to exhibit a more 'at risk' kinematic profile compared to anticipated tasks, a detailed understanding of the coordination between multiple joints and how they differ during unanticipated actions is lacking, particularly in females. RESEARCH QUESTION: The purpose of this study was to observe the difference in trunk, pelvis and lower limb coordination and coordination variability during a dynamic, sidestep cutting task under anticipated and unanticipated conditions in a healthy female cohort. METHODS: Three-dimensional motion analysis data were recorded during anticipated and unanticipated sidestep cutting for nineteen healthy female participants (age, 24 ±â€¯3yrs; height, 164 ±â€¯5 cm; and weight, 58 ±â€¯6 kg). Vector coding methodology was used to calculate coordination and coordination variability values and statistical parametric and non-parametric mapping was used to comprehensively determine differences between anticipated and unanticipated conditions. RESULTS: Differences were observed between anticipated and unanticipated conditions in the hip flexion - knee abduction angle (89 % of stance), hip rotation - knee abduction angle (55 % of stance), knee flexion - knee abduction angle (81-83 %, 86 % and 88-89 %) and knee flexion - ankle flexion angle (14-18 %) coupling angles. Differences in coupling angle variability were also observed with only one cluster of significance seen in hip abduction - knee abduction variability (27-30 % of stance). SIGNIFICANCE: Healthy females exhibit significant differences in lower limb coupling angles and coupling angle variability between anticipated and unanticipated sidestep cutting. Interventions aimed at reducing ACL injury risk may need to consider that anticipated and unanticipated sidestep cutting tasks present unique demands, and therefore should both be trained specifically.


Assuntos
Lesões do Ligamento Cruzado Anterior/etiologia , Antecipação Psicológica/fisiologia , Articulação do Joelho/fisiologia , Extremidade Inferior/fisiologia , Movimento/fisiologia , Pelve/fisiologia , Tronco/fisiologia , Adulto , Lesões do Ligamento Cruzado Anterior/prevenção & controle , Lesões do Ligamento Cruzado Anterior/psicologia , Fenômenos Biomecânicos , Feminino , Voluntários Saudáveis , Humanos , Articulação do Joelho/fisiopatologia , Extremidade Inferior/fisiopatologia , Modelos Estatísticos , Desempenho Psicomotor , Medição de Risco , Rotação , Adulto Jovem
18.
J Sport Rehabil ; 30(6): 899-904, 2021 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-33596542

RESUMO

CONTEXT: A limitation of previous studies on squatting mechanics is that the influence of trunk and shank inclination on the knee-extensor moment (KEM) has been studied in isolation. OBJECTIVE: The purpose of the current study was to determine the influence of segment orientation on the KEM during freestanding barbell squatting. DESIGN: Repeated-measures cross sectional. SETTING: University research laboratory. PARTICIPANTS: Sixteen healthy individuals (8 males and 8 females). INTERVENTION: Each participant performed 8 squat conditions in which shank and trunk inclinations were manipulated. MAIN OUTCOME MEASURES: 3D kinematic and kinetic data were collected at 250 and 1500 Hz, respectively. Regression analysis was conducted to identify the individual relationships between the KEM and the trunk and shank inclination at 60° and 90° of knee flexion. To identify the best predictor(s) of the KEM, stepwise regression was implemented. RESULTS: Increased shank inclination increased the KEM (P < .001, R2 = .21-.25). Conversely, increased trunk inclination decreased the KEM (P < .001, R2 = .49-.50). For the stepwise regression, trunk inclination entered first and explained the greatest variance in the KEM (all P < .001, R2 = .49-.50). Shank inclination entered second (all P < .010, R2 = .53-.54) and explained an additional 3% to 5% of the variance. CONCLUSIONS: Our results confirm that inclination of the trunk and shank have an opposing relationship with the KEM. Increased forward shank posture increases the KEM, while increased forward trunk posture decreases the KEM. However, when viewed in combination, the trunk was the superior predictor of the KEM, highlighting the fact that increased quadriceps demand created by a forward shank can be offset by trunk inclination.


Assuntos
Articulação do Joelho/fisiologia , Movimento/fisiologia , Músculo Quadríceps/fisiologia , Amplitude de Movimento Articular/fisiologia , Treinamento de Força , Tronco/fisiologia , Adulto , Fenômenos Biomecânicos , Feminino , Voluntários Saudáveis , Humanos , Cinética , Masculino , Adulto Jovem
19.
Am J Phys Med Rehabil ; 100(10): 983-989, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33443856

RESUMO

OBJECTIVE: The aims of the study were to reliably determine the two main phases of manual wheelchair propulsion via a simple wearable sensor and to evaluate the effects of modulated trunk and hip stimulation on manual wheelchair propulsion during the challenging tasks of ramp assent and level sprint. DESIGN: An offline tool was created to identify common features between wrist acceleration signals for all subjects who corresponded to the transitions between the contact and recovery phases of manual wheelchair propulsion. For one individual, the acceleration rules and thresholds were implemented for real-time phase-change event detection and modulation of stimulation. RESULTS: When pushing with phase-dependent modulated stimulation, there was a significant (P < 0.05) increase in the primary speed variable (5%-6%) and the subject rated pushing as "moderately or very easy." In the offline analysis, the average phase-change event detection success rate was 79% at the end of contact and 71% at the end of recovery across the group. CONCLUSIONS: Signals from simple, wrist-mounted accelerometers can detect the phase transitions during manual wheelchair propulsion instead of elaborate and expensive, instrumented systems. Appropriately timing changes in muscle activation with the propulsion cycle can result in a significant increase in speed, and the system was consistently perceived to be significantly easier to use.


Assuntos
Pessoas com Deficiência/reabilitação , Músculo Esquelético/fisiologia , Tronco/fisiologia , Cadeiras de Rodas , Acelerometria , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Dispositivos Eletrônicos Vestíveis
20.
NeuroRehabilitation ; 48(1): 59-66, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33386820

RESUMO

BACKGROUND: The Functional Assessment for Control of Trunk (FACT) was developed to evaluate trunk function after stroke. However, only a few studies used FACT to show functional outcome. OBJECTIVE: This study aimed to validate the FACT predictive ability for functional outcome following stroke and create an English version of the FACT. METHODS: This retrospective, observational study was conducted with patients aged≥65 years with stroke. Patients were divided into two groups according to the median FACT score at admission: trunk impairment or high trunk function group. Multiple regression analysis was performed for Functional Independence Measure (FIM) gain and FIM efficiency to examine the relationship between trunk function assessed by FACT at admission and functional prognosis. RESULTS: 105 participants (mean age, 80.2±7.6, 57.1%were men) were included. Of these, 48 (45.7%) and 57 (54.3%) were categorized to the trunk impairment group and high trunk function group, respectively. FACT score at admission was associated with FIM gain (coefficient = 0.875, P = 0.001) and FIM efficiency (coefficient = 0.015, P = 0.016) after adjusting for confounders. CONCLUSIONS: Trunk impairment at admission assessed by FACT could predict functional prognosis. The English version of FACT was created and further demonstrated the validity of FACT.


Assuntos
Força Muscular/fisiologia , Recuperação de Função Fisiológica/fisiologia , Reabilitação do Acidente Vascular Cerebral/métodos , Acidente Vascular Cerebral/diagnóstico , Tronco/fisiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Hospitalização/tendências , Humanos , Masculino , Análise Multivariada , Análise de Regressão , Estudos Retrospectivos , Acidente Vascular Cerebral/fisiopatologia , Reabilitação do Acidente Vascular Cerebral/tendências , Tronco/fisiopatologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...