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1.
Spine (Phila Pa 1976) ; 47(9): E423-E431, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34545044

RESUMO

STUDY DESIGN: Numerical in-silico human spine stability finite element analysis. OBJECTIVE: The purpose of this study was to investigate the contribution of major torso tissues toward static spine stability, mainly the thoracolumbar fascia (TLF), abdominal wall with its intra-abdominal pressure (IAP), and spinal muscles inclusive of their intramuscular pressure. SUMMARY OF BACKGROUND DATA: Given the numerous redundancies involved in the spine, current methodologies for assessing static spinal stability are limited to specific tissues and could lead to inconclusive results. A three-dimensional finite element model of the spine, with structured analysis of major torso tissues, allows for objective investigation of static spine stability. METHODS: A novel previously fully validated spine model was employed. Major torso tissues, mainly the muscles, TLF, and IAP were individually, and in combinations, activated under a 350N external spine perturbation. The stability contribution exerted by these tissues, or their ability to restore the spine to the unperturbed position, was assessed in different case-scenarios. RESULTS: Individual activations recorded significantly different stability contributions, with the highest being the TLF at 75%. Combined or synergistic activations showed an increase of up to 93% stability contribution when all tissues were simultaneously activated with a corresponding decrease in the tensile load exerted by the tissues themselves. CONCLUSION: This investigation demonstrated torso tissues exhibiting different roles toward static spine stability. The TLF appeared able to dissipate and absorb excessive loads, the muscles acted as antagonistic to external perturbations, and the IAP played a role limiting movement. Furthermore, the different combinations explored suggested an optimized engagement and coordination between different tissues to achieve a specific task, while minimizing individual work.Level of Evidence: N/A.


Assuntos
Coluna Vertebral , Tronco , Músculos Abdominais/fisiologia , Fenômenos Biomecânicos/fisiologia , Fáscia , Humanos , Músculo Esquelético/fisiologia , Coluna Vertebral/fisiologia , Tronco/fisiologia , Suporte de Carga/fisiologia
2.
PeerJ ; 10: e14469, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36523476

RESUMO

Background: Adequate trunk muscle endurance is considered to be an important indicator of good low back stability; therefore, its assessment is needed when determining an individual's risk for back pain. Optimal tests to assess each trunk muscle group separately are difficult to find. The objective of this study was to verify if two groups of trunk muscle endurance tests (standard and alternative) show comparable results in terms of muscle endurance ratios, holding times and rated perceived effort to perform each test. Methods: The study was designed as a quasi-experimental repeated-measures design. There was a single group of participants who took part in two different trunk muscle endurance testing. Sixty-eight healthy adult volunteers, aged 20-45 years (31.9 ± 7.2 years), without recent musculoskeletal injury or disorder participated in the study. All participants finished the study. Trunk muscle endurance tests as tested on the Roman chair (B tests) were compared with standard tests as suggested by McGill (A tests). Each group of tests consisted of an endurance test for trunk extensors, trunk flexors, and lateral trunk muscles for left and right side. The order of tests' performances was randomly assigned to each participant, whereby a participant did perform A and B tests in the same order. In each test of A and B the holding time was recorded and a perceived effort in each test performance was also assessed by participants. Post testing performance the four ratios of trunk muscles endurance comparison were calculated for each group of tests to determine if there is a good or poor ratio between muscles. Results of each participant were compared for trunk muscle endurance ratio calculations, holding times and rated perceived effort for A and B tests. Results: Results showed comparable trunk muscle endurance ratios in the three ratios observed, except for the flexors:extensors ratio (AFL:EX: 1.2 (IQR: 0.7-1.6) vs. BFL:EX: 0.6 (IQR: 0.3-0.8); p < 0.001). As compared to A tests, holding times were significantly longer in B tests for the extensors (AEX: 125.5 s (IQR: 104.8-182.8 s) vs. BEX: 284.0 s (IQR: 213.0-342.3 s); p < 0.001) and lateral trunk muscles (AL-LM: 61.0 s (IQR: 48.3-80.8 s) vs. BL-LM: 131.5 s (IQR: 95.5-158.5 s); AR-LM: 63.5 s (IQR: 45.8-77.3 s) vs. BR-LM: 113.0 s (IQR: 86.3-148.8 s); p < 0.001), both were also rated as slightly easier to perform in the extensors (ARPE-EX: 13 (IQR: 12.0-14.0) vs BRPE-EX: 11 (IQR: 10.0-13.0); pRPE-EX < 0.001) and lateral muscles testing (ARPE-LM: 14.0 (IQR: 12.3-15.8) vs. BRPE-LM: 13.0 (IQR: 12.0-15.0); pRPE-LM = 0.001). Conclusions: A and B tests are comparable in three of four trunk muscle endurance ratios, while longer holding times and lower perceived effort to perform were observed in most of the B tests. The Roman chair tests could be used as an alternative to standard tests.


Assuntos
Doenças Musculoesqueléticas , Resistência Física , Humanos , Adulto , Resistência Física/fisiologia , Tronco/fisiologia , Músculo Esquelético/fisiologia , Dor nas Costas
3.
PLoS One ; 17(12): e0279300, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36584117

RESUMO

Sit-to-stand can be defined as a set of movements that allow humans to rise from a sitting position to a bipedal standing pose. These movements, often categorized as four distinct kinematic phases, must be coordinated for assuring personal autonomy and can be compromised by ageing or physical impairments. To solve this, rehabilitation techniques and assistive devices demand proper description of the principles that lead to the correct completion of this motor task. While the muscular dynamics of the sit-to-stand task have been analysed, the underlying neural activity remains unknown and largely inaccessible for conventional measurement systems. Predictive simulations can propose motor controllers whose plausibility is evaluated through the comparison between simulated and experimental kinematics. In the present work, we modelled an array of reflexes that originate muscle activations as a function of proprioceptive and vestibular feedback. This feedback encodes torso position, displacement velocity and acceleration of a modelled human body with 7 segments, 9 degrees of freedom, and 50 actuators. We implemented two controllers: a four-phases controller where the reflex gains and composition vary depending on the kinematic phase, and a simpler two-phases controller, where three of the kinematic phases share the same reflex gains. Gains were optimized using Covariance Matrix Adaptation. The results of the simulations reveal, for both controllers, human-like sit-to-stand movement, with joint angles and muscular activity comparable to experimental data. The results obtained with the simplified two-phases controller indicate that a simple set of reflexes could be sufficient to drive this motor task.


Assuntos
Movimento , Tronco , Humanos , Movimento/fisiologia , Tronco/fisiologia , Postura Sentada , Posição Ortostática , Músculos , Fenômenos Biomecânicos
4.
J Biomech ; 143: 111299, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36113386

RESUMO

Walking is known to be beneficial for chronic low back pain (LBP) patients and fast walking recruits more trunk muscles. Abdominal bracing has also been shown to improve LBP and facilitate several trunk muscles. We aimed to investigate the effects of walking velocity and abdominal bracing on the activation of trunk muscles in chronic LBP patients during walking. Forty-six volunteers with chronic LBP underwent walking exercise on the treadmill without ("non-braced walking") and with abdominal bracing ("braced walking") at speeds of 4, 5, and 6 km/h, with the surface electrodes placed on their trunk muscles to measure muscle activity. The root mean square values of the surface electromyography amplitude data were obtained at the multifidus of lower (ML) and upper lumbar (MU), erector spinae of lower lumbar (EL) and thoracic (ET), rectus abdominis (RA), and external oblique (EO). All muscles activated significantly more at faster walking. The "braced walking" facilitated the ET and RA significantly more than the "non-braced walking". The interaction between the walking speed and abdominal bracing was significant at ML, MU, and RA. The increase in muscle activation observed at lower speed diminished as speed increased. Since "braced walking" seems to additionally facilitate the trunk muscles especially at slower gait speeds, patients who cannot walk fast may still be able to train their muscles by "braced walking."


Assuntos
Músculos do Dorso , Dor Lombar , Músculos Abdominais/fisiologia , Eletromiografia , Humanos , Dor Lombar/terapia , Músculo Esquelético , Músculos Paraespinais , Tronco/fisiologia , Caminhada/fisiologia
5.
Sci Rep ; 12(1): 11762, 2022 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-35817835

RESUMO

This study investigates the contribution of external trunk morphology and posture to running performance in an evolutionary framework. It has been proposed that the evolution from primitive to derived features of torso shape involved changes from a mediolaterally wider into a narrower, and antero-posteriorly deeper into a shallower, more lightly built external trunk configuration, possibly in relation to habitat-related changes in locomotor and running behaviour. In this context we produced experimental data to address the hypothesis that medio-laterally narrow and antero-posteriorly shallow torso morphologies favour endurance running capacities. We used 3D geometric morphometrics to relate external 3D trunk shape of trained, young male volunteers (N = 27) to variation in running velocities during different workloads determined at 45-50%, 70% and 85% of heart rate reserve (HRR) and maximum velocity. Below 85% HRR no relationship existed between torso shape and running velocity. However, at 85% HRR and, more clearly, at maximum velocity, we found highly statistically significant relations between external torso shape and running performance. Among all trained subjects those with a relatively narrow, flat torso, a small thoracic kyphosis and a more pronounced lumbar lordosis achieved significantly higher running velocities. These results support the hypothesis that external trunk morphology relates to running performance. Low thoracic kyphosis with a flatter ribcage may affect positively respiratory biomechanics, while increased lordosis affects trunk posture and may be beneficial for lower limb biomechanics related to leg return. Assuming that running workload at 45-50% HRR occurs within aerobic metabolism, our results may imply that external torso shape is unrelated to the evolution of endurance running performance.


Assuntos
Hominidae , Cifose , Lordose , Corrida , Animais , Fenômenos Biomecânicos , Humanos , Masculino , Corrida/fisiologia , Tronco/fisiologia
6.
Medicina (Kaunas) ; 58(6)2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35744075

RESUMO

Motor control, movement impairment, and postural control recovery targeted in rehabilitation could be affected by pain. The main objective of this comprehensive review is to provide a synthesis of the effect of experimental and chronic pain on postural control throughout the available literature. After presenting the neurophysiological pathways of pain, we demonstrated that pain, preferentially localized in the lower back or in the leg induced postural control alteration. Although proprioceptive and cortical excitability seem modified with pain, spinal modulation assessment might provide a new understanding of the pain phenomenon related to postural control. The literature highlights that the motor control of trunk muscles in patient presenting with lower back pain could be dichotomized in two populations, where the first over-activates the trunk muscles, and the second under-activates the trunk muscles; both generate an increase in tissue loading. Taking all these findings into account will help clinician to provide adapted treatment for managing both pain and postural control.


Assuntos
Dor Crônica , Dor Lombar , Humanos , Dor Lombar/terapia , Equilíbrio Postural/fisiologia , Postura/fisiologia , Tronco/fisiologia
7.
J Bodyw Mov Ther ; 30: 154-159, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35500964

RESUMO

OBJECTIVE: Police officers, particularly the ones who are trained to be on "special forces", perform a wide range of hazardous and physically demanding activities when aiming to protect and serve. The purpose of this study was to investigate the association between lower limb and trunk muscle endurance with drop vertical jump (DVJ) height in a special military police force. METHODS: One hundred and three male military men (age: 36 ± 5.0 years; height: 1.76 ± 0.05 m; weight: 81.8 ± 9.7 kg) volunteered to take part in this study. SIX TESTS WERE PERFORMED: DVJ, McGill core battery (trunk flexion, trunk extension, and side bridge test-right and left), and single-leg squat repetitions. Correlations were analyzed using the Pearson correlation coefficient (r). The level of significance for all analyses was set at p ≤ 0.05. RESULTS: Single-leg squat repetitions were positively associated with DVJ height, contact time and flight time (p = 0.00093∗∗, p = 0.00085∗∗, and p = 0.00098∗∗ respectively). No correlation was observed between trunk muscle endurance and DVJ. CONCLUSION: Therefore, it was concluded that greater endurance of the lower limb muscles, as demonstrated by the single leg squat, was associated with better performance in a DVJ. Individuals should consider incorporating single leg squats into their fitness program to develop muscular endurance and possibly perform better in the DVJ.


Assuntos
Músculo Esquelético , Tronco , Adulto , Exercício Físico/fisiologia , Humanos , Extremidade Inferior/fisiologia , Masculino , Músculo Esquelético/fisiologia , Amplitude de Movimento Articular , Tronco/fisiologia
8.
Artigo em Inglês | MEDLINE | ID: mdl-35409940

RESUMO

OBJECTIVES: To investigate the biomechanics of Ukemi in relation to head and neck injury in adult judokas with varying skill sets. DESIGN: Narrative systematic review. METHODS: An extensive literature search was performed using PubMed, Google Scholar, Science direct and EMBASE from inception to April 2021. Studies were included if they: (1) reported biomechanical analysis of judo throws and Ukemi; (2) were on adult judoka populations; (3) discussed injury related to judo technique. The included studies were assessed for risk of bias using a five-part modified STROBE checklist. A narrative synthesis was performed due to the heterogeneity of included studies. RESULTS: 173 titles and abstracts were screened with 16 studies (158 judokas, 9 of which were female) included. All studies used 3D biomechanical analysis to assess Ukemi. Ukemi implementation produced reduced kinematic data in comparison to direct occipital contact, which was always below the injury threshold. Analysis of lower limb and trunk kinematics revealed variances in Ukemi between novice and experienced judoka. Whilst no significant differences were seen in neck flexion angles, hip, knee and trunk angle time plots revealed greater extension angles in experienced judokas. CONCLUSIONS: Ukemi is essential in preventing head and neck injuries; however, technique differs between experienced and novice judoka. Larger flexion angles of the hip, knee and trunk are seen in novice judoka, which correlate with increased kinematic data. The association of greater neck muscle strength with improved Ukemi is weak. However, a negative correlation was established between fatigue and breakfall skill by one study.


Assuntos
Artes Marciais , Fenômenos Biomecânicos/fisiologia , Feminino , Humanos , Extremidade Inferior/fisiologia , Artes Marciais/fisiologia , Força Muscular , Tronco/fisiologia
9.
J Sports Sci Med ; 21(1): 120-126, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35250341

RESUMO

The abdominal muscles are vital in providing core stability for functional movements during most activities. There is a correlation between side asymmetry of these muscles and dysfunction. Thus, the purpose of this study was to evaluate and compare trunk muscle morphology and trunk rotational strength between sprint hurdlers, an asymmetrical sport, and sprinters, a symmetrical sport. Twenty-one trained collegiate sprint hurdlers and sprinters were recruited for the study (Hurdlers: 4M, 7F; Sprinters: 8M, 2F), average age (years) hurdlers: 20 ± 1.2; sprinters: 20.4 ± 1.9, height (cm) hurdlers: 172.6 ± 10.2; sprinters: 181.7 ± 4.5, and weight (kg) hurdlers: 67.6 ± 12.0; sprinters: 73.9 ± 5.6. Using real-time ultrasound, panoramic images of the internal oblique (IO) and external oblique (EO) were obtained at rest and contracted (flexion and rotation) in a seated position for both right and left sides of the trunk. While wearing a specially crafted shoulder harness, participants performed three maximal voluntary trunk rotational contractions (MVC). The three attempts were then averaged to obtain an overall MVC score for trunk rotation strength. Average MVC trunk rotational strength to the right was greater among all participants, p < 0.001. The IO showed greater and significant thickness changes from resting to contracted state than the EO, this was observed in all participants. The IO side asymmetry was significantly different between groups p < 0.01. Hurdlers, involved in a unilaterally demanding sport, exhibited the expected asymmetry in muscle morphology and in trunk rotational strength. Interestingly, sprinters, although involved in a seemingly symmetrical sport, also exhibited asymmetrical trunk morphology and trunk rotational strength.


Assuntos
Músculos Abdominais , Músculos Abdominais Oblíquos , Músculos Abdominais/diagnóstico por imagem , Músculos Abdominais/fisiologia , Estudos Transversais , Humanos , Músculo Esquelético/fisiologia , Tronco/fisiologia
10.
Artigo em Inglês | MEDLINE | ID: mdl-35294353

RESUMO

Performance of trunk rehabilitation exercises while sitting on movable surfaces with feet on the ground can increase trunk and leg muscle activations, and constraining the feet to move with the seat isolates control of the trunk. However, there are no detailed studies on the effects of these different leg supports on the trunk and leg muscle activations under unstable and forcefully perturbed seating conditions. We have recently devised a trunk rehabilitation robot that can generate unstable and forcefully perturbed sitting surfaces, and can be used with ground-mounted or seat-connected footrests. In this study, we have evaluated the differences in balance performance, trunk movement and muscle activation (trunk and legs) of fourteen healthy adults caused by the use of these different footrest configurations under the different seating scenarios. The center of pressure and trunk movement results show that the seat-connected footrest may be a more suitable choice for use in a balance recovery focused rehabilitation protocol, while the ground-mounted footrest may be a more suitable choice for a trunk movement focused rehabilitation protocol. Although it is difficult to make a clear selection between footrests due to the mixed trends observed in the muscle activation results, it appears that the seat-connected footrest may be preferable for use with the unstable seat as it causes greater muscle activations. Furthermore, the results provide limited evidence that targeting of a particular muscle group may be possible through careful selection of the seat and footrest conditions. Therefore, it may be possible to utilize the trunk rehabilitation robot to maximize the training outcomes for a wide range of patients through careful selection of training protocols.


Assuntos
Perna (Membro) , Robótica , Adulto , Humanos , Equilíbrio Postural/fisiologia , Postura/fisiologia , Tronco/fisiologia
11.
Sensors (Basel) ; 22(4)2022 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-35214287

RESUMO

In this study, a novel wearable system for the identification of compensatory trunk movements (CTMs) in post-stroke hemiplegic patients is presented. The device is composed of seven soft sensing elements (SSEs) based on fiber Bragg grating (FBG) technology. Each SSE consists of a single FBG encapsulated into a flexible matrix to enhance the sensor's robustness and improve its compliance with the human body. The FBG's small size, light weight, multiplexing capability, and biocompatibility make the proposed wearable system suitable for multi-point measurements without any movement restriction. Firstly, its manufacturing process is presented, together with the SSEs' mechanical characterization to strain. Results of the metrological characterization showed a linear response of each SSE in the operating range. Then, the feasibility assessment of the proposed system is described. In particular, the device's capability of detecting CTMs was assessed on 10 healthy volunteers and eight hemiplegic patients while performing three tasks which are representative of typical everyday life actions. The wearable system showed good potential in detecting CTMs. This promising result may foster the use of the proposed device on post-stroke patients, aiming at assessing the proper course of the rehabilitation process both in clinical and domestic settings. Moreover, its use may aid in defining tailored strategies to improve post-stoke patients' motor recovery and quality of life.


Assuntos
Qualidade de Vida , Dispositivos Eletrônicos Vestíveis , Hemiplegia , Humanos , Movimento/fisiologia , Tronco/fisiologia
12.
J Shoulder Elbow Surg ; 31(6): 1282-1293, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35121120

RESUMO

BACKGROUND AND HYPOTHESIS: Early trunk rotation (ETR), which is a unique kinematics of the trunk that occurs during baseball throwing, is thought to be related to shoulder injuries. Pelvic rotation is a confounder when studying the effects of trunk rotation on shoulder biomechanics. The purpose of this study was to understand the "pure" effects of trunk rotation on shoulder biomechanics, with pelvic rotation under control. Our hypotheses were as follows: (1) throwers with ETR have a different shoulder kinematics pattern compared with throwers without ETR; (2) throwers with ETR have a lower ball speed performance than do throwers without ETR; and (3) throwers with ETR have a greater value of shoulder forces and moments, which may increase risks of shoulder injury, than do throwers without ETR. METHODS: Fifty-seven elite throwers were enrolled and divided into 2 groups (non-ETR and ETR) using an outdoor motion analysis. Several kinematics and kinetics parameters of the shoulder were analyzed and compared between the 2 groups. RESULTS: Ball velocity was faster in the non-ETR group (127 km/h) compared with the ETR group (120 km/h). The shoulders of throwers in the ETR group showed pathokinematics of "horizontal adduction lag" and "dropped elbow." The increases in maximal posterior force, inferior force, horizontal abduction moment, and vertical adduction moment were 9.2%, 13.6%, 21.3%, and 24.3%, respectively, in the shoulders of throwers in the ETR group. These results indicate that ETR may be hazardous for the throwing shoulder. With lower ball velocity and higher shoulder joint loading, ETR is not a proper pitching pattern for kinetic energy transfer. CONCLUSION: Improper pitching mechanics among baseball throwers, such as ETR, may result in higher shoulder joint loading and increased risk of shoulder injuries. When treating throwers with shoulder injuries, it is important not only to address shoulder anatomy and pathology but also to understand the possible pathomechanics and pathogenesis of the shoulder caused by ETR. Furthermore, special training programs focusing on trunk flexibility and core muscle strengthening should be implemented to prevent ETR and decrease the risk of shoulder injuries. Motion analysis is useful for the screening and early detection of improper pitching mechanics in throwers.


Assuntos
Beisebol , Lesões do Ombro , Articulação do Ombro , Beisebol/lesões , Fenômenos Biomecânicos/fisiologia , Humanos , Articulação do Ombro/fisiologia , Tronco/fisiologia
13.
J Biomech ; 134: 111001, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35193062

RESUMO

Although it has already been demonstrated that Nordic walking has some peculiar biomechanical features with respect to walking, the effects on balance and trunk coordination are still unknown. Our aim here was to compare margins of stability, hip stabilizer muscle activation and scapular-pelvis coordination (mean and variability of continuous relative phase) between walking and two different pole walking techniques (observational design). Eleven Nordic walking instructors were asked to walk at 5.5 km·h-1 on a flat treadmill while 1) walking, 2) Nordic walking and 3) pole walking with just elbow flexion-extension motion allowed and constrained shoulder motion (elbow technique). The 3D movements of limbs and poles were measured by an optoelectronic motion capture system, and gluteus medius activation was measured through surface electromyography. Both techniques using poles show larger mediolateral margins of stability and similar anterior-posterior margins of stability in comparison with walking (p < 0.001). The larger mediolateral margin of stability using poles (conditions 2 and 3) is accompanied by greater trunk coordination stability (greater continuous relative phase variability) than walking. Although the Nordic walking (condition 2) technique results in a similar range of scapular and pelvis transverse rotation, the general pattern of scapular-pelvis coordination was temporally delayed by approximately 20% of the gait cycle in relation to other conditions (1 and 3). In conclusion, Nordic walking provides enhanced mediolateral support and coordination stability of trunk compared with walking, suggesting that it could be proposed as a safer exercise modality than walking.


Assuntos
Marcha , Caminhada Nórdica , Fenômenos Biomecânicos/fisiologia , Marcha/fisiologia , Tronco/fisiologia , Caminhada/fisiologia
14.
Eur J Sport Sci ; 22(6): 817-825, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33980124

RESUMO

Success in sprint kayaking depends on the propulsive power generated by trunk, pelvis, shoulder and lower limb movements. However, no studies have examined whole-body kinematics over a simulated distance. We aimed to study the changes in movement patterns of kayakers performing a 500-m kayak sprint. Eleven young K1 sprint kayakers (three females; age: 16.5 ± 1.9 years, height: 174.1 ± 7.1 cm and weight: 66.1 ± 6.2 kg) performed an incremental test on a kayak ergometer to assess their Peak Oxygen Uptake (V̇O2peak). They then performed a 500-m sprint trial on the same ergometer, and the positions of 40 reflective markers were recorded to assess whole-body kinematics. Joint angles over time were computed for the trunk and right shoulder, hip, knee, and ankle. Changes of joint kinematics during the test were assessed with Statistical Parametric Mapping, calculating at each time node the linear regression between joint angles waveforms and the time of the rowing cycle, p < .05. Cardiometabolic responses confirmed that the participants achieved a maximal effort (V̇O2 and HR reached 99 ± 11% and 94 ± 6% of peak values, respectively). Paddle velocity negatively correlated with sprint time. The shoulder (elevation, rotation and flexion), trunk (lateral flexion and rotation) and hip (abduction) angles significantly changed over time in different phases of the stroke cycle during the simulated sprint. No significant differences over time were found for knee and ankle flexion. A high-intensity sprint may affect the shoulder, trunk and hip kinematics of kayak paddling. The kinematic analysis of kayakers' paddling during simulated metabolic-demanding tasks can provide useful insights to coaches and athletes.


Assuntos
Esportes Aquáticos , Adolescente , Fenômenos Biomecânicos , Ergometria , Feminino , Humanos , Tronco/fisiologia , Esportes Aquáticos/fisiologia
15.
J Back Musculoskelet Rehabil ; 35(3): 605-614, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34542061

RESUMO

BACKGROUND: Given the characteristics of the superficial trunk muscles that cross the chest and pelvis, their excessive contraction might limit chest mobility. OBJECTIVE: To examine the immediate effects of two types of trunk muscle exercises on chest mobility and trunk muscle activities. METHODS: Fourteen healthy men (age: 21.1 ± 1.0 years, height: 172.7 ± 5.6 cm, weight: 61.0 ± 7.1 kg, body mass index: 20.4 ± 1.7 kg/m2; mean ± SD) randomly performed trunk side flexion and draw-in exercises using a cross-over design. The chest kinematic data and trunk muscle activities were measured before and after each intervention during the following tasks: maximum inspiration/expiration and maximum pelvic anterior/posterior tilt while standing. Two-way repeated measures analysis of variance was used for statistical analysis (P< 0.05). RESULTS: After the side flexion, upper and lower chest mobility significantly decreased, and superficial trunk muscle activity significantly increased during the maximum pelvic anterior tilt (P< 0.05). Additionally, after the draw-in, upper chest mobility significantly increased during the maximum pelvic anterior tilt (P< 0.05). CONCLUSIONS: Increased activity of the superficial abdominal muscles might limit chest mobility during maximum pelvic anterior tilt. Conversely, the facilitation of deep trunk muscles might increase upper chest mobility during the maximum pelvic anterior tilt.


Assuntos
Postura , Tronco , Adulto , Estudos Cross-Over , Eletromiografia , Terapia por Exercício , Humanos , Masculino , Músculo Esquelético/fisiologia , Tronco/fisiologia , Adulto Jovem
16.
J Back Musculoskelet Rehabil ; 35(3): 589-596, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34397401

RESUMO

BACKGROUND: Abdominal bracing is effective in strengthening the trunk muscles; however, assessing performance can be challenging. We created a device for performing abdominal trunk muscle exercises. The effectiveness of this device has not yet been evaluated or comparedOBJECTIVE: We aimed to quantify muscle activity levels during exercise using our innovative device and to compare them with muscle activation during abdominal bracing maneuvers. METHODS: This study included 10 men who performed abdominal bracing exercises and exercises using our device. We measured surface electromyogram (EMG) activities of the rectus abdominis (RA), external oblique, internal oblique (IO), and erector spinae (ES) muscles in each of the exercises. The EMG data were normalized to those recorded during maximal voluntary contraction (%EMGmax). RESULTS: During the bracing exercise, the %EMGmax of IO was significantly higher than that of RA and ES (p< 0.05), whereas during the exercises using the device, the %EMGmax of IO was significantly higher than that of ES (p< 0.05). No significant difference was observed in the %EMGmax of any muscle between bracing exercises and the exercises using the device (p= 0.13-0.95). CONCLUSIONS: The use of our innovative device results in comparable activation to that observed during abdominal bracing.


Assuntos
Músculos Abdominais , Tronco , Músculos Abdominais/fisiologia , Eletromiografia/métodos , Exercício Físico/fisiologia , Terapia por Exercício/métodos , Humanos , Masculino , Contração Muscular/fisiologia , Músculos Paraespinais , Tronco/fisiologia
17.
J Stroke Cerebrovasc Dis ; 31(2): 106242, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34915305

RESUMO

OBJECTIVES: In post-stroke patients, shifts in the center of gravity may affect joint movement patterns of the paraplegic lower limb during walking. The impact of changes in ankle dorsiflexion angle and trailing limb angle due to slight weight-shifting is unknown. This study aimed to investigate the effect of the abovementioned parameters on gait characteristics measured by trunk acceleration. MATERIALS AND METHODS: During walking, the ankle dorsiflexion angle and trailing limb angle were assessed using two-dimensional motion analysis. Shifts in the center of gravity were assessed to evaluate symmetry, regularity, and sway of trunk movements by calculating the harmonic ratio, autocorrelation coefficient, and root mean square using a wearable trunk accelerometer. RESULTS: Ankle dorsiflexion angle showed a significant negative correlation with the root mean square of the anteroposterior axis (r = -0.460, p = 0.005). Trailing limb angle was significantly correlated with the autocorrelation coefficient of the vertical axis (r = 0.585, p < 0.001) and root mean square of the vertical (r = -0.579, p < 0.001), mediolateral (r = -0.474, p = 0.004), and anteroposterior axes (r = -0.548, p = 0.001). Trailing limb angle was a significant predictor (autocorrelation coefficient vertical axis, p = 0.001; root mean square vertical axis, p = 0.001; mediolateral axis, p = 0.007; anteroposterior axis, p = 0.001). CONCLUSIONS: Trailing limb angle can indicate the acquisition of forward propulsion during walking; an increase in it may contribute to improvements of the regular vertical movement ability and stability of the center of gravity sway.


Assuntos
Hemiplegia , Tronco , Caminhada , Hemiplegia/etiologia , Hemiplegia/fisiopatologia , Humanos , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/fisiopatologia , Tronco/fisiologia , Caminhada/fisiologia
18.
Eur J Appl Physiol ; 122(2): 425-435, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34797437

RESUMO

PURPOSE: Many studies have investigated postural reactions (PR) to body-delivered perturbations. However, attention has been focused on the descriptive variables of the PR rather than on the characterization of the perturbation. This study aimed to test the hypothesis that the impulse rather than the force magnitude of the perturbation mostly affects the PR in terms of displacement of the center of foot pressure (ΔCoP). METHODS: Fourteen healthy young adults (7 males and 7 females) received 2 series of 20 perturbations, delivered to the back in the anterior direction, at mid-scapular level, while standing on a force platform. In one series, the perturbations had the same force magnitude (40 N) but different impulse (range: 2-10 Ns). In the other series, the perturbations had the same impulse (5 Ns) but different force magnitude (20-100 N). A simple model of postural control restricted to the sagittal plane was also developed. RESULTS: The results showed that ΔCoP and impulse were highly correlated (on average: r = 0.96), while the correlation ΔCoP-force magnitude was poor (r = 0.48) and not statistically significant in most subjects. The normalized response, ΔCoPn = ΔCoP/I, was independent of the perturbation magnitude in a wide range of force amplitude and impulse and exhibited good repeatability across different sets of stimuli (on average: ICC = 0.88). These results were confirmed by simulations. CONCLUSION: The present findings support the concept that the magnitude of the applied force alone is a poor descriptor of trunk-delivered perturbations and suggest that the impulse should be considered instead.


Assuntos
Equilíbrio Postural/fisiologia , Posição Ortostática , Tronco/fisiologia , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Pressão , Adulto Jovem
19.
Medicine (Baltimore) ; 101(52): e31915, 2022 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-36595990

RESUMO

Appropriate trunk muscle activity is needed to perform functional activities in cerebral palsy, this study analyzed the activity of trunk muscles during horseback riding machine exercise in children with spastic cerebral palsy. 10 children with spastic cerebral palsy were participated, the activity of the trunk muscles, including both sides of the rectus abdominis, external oblique, latissimus dorsi, and erector spinae in sitting posture and during horseback riding machine exercise were evaluated using a surface electromyography. The activity of bilateral rectus abdominis, external oblique, latissimus dorsi, and erector spinae increased during horseback riding machine exercise than quiet sitting posture. Moreover, there were significant differences in activities of the trunk muscles between the sitting posture and horseback riding machine exercise, with the exception of the left external oblique and the left latissimus dorsi. Horseback riding machine exercise provides more opportunities to use the trunk muscles for children with spastic cerebral palsy than general sitting posture. In future, it will be of use to investigate the effect of horseback riding machine exercise in patients with cerebral palsy.


Assuntos
Paralisia Cerebral , Humanos , Criança , Músculo Esquelético/fisiologia , Tronco/fisiologia , Exercício Físico , Eletromiografia , Reto do Abdome
20.
Med Sci Monit ; 27: e934022, 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34811344

RESUMO

BACKGROUND Spinal and pelvic injuries during an unexpected perturbation are closely related to spinal stability, which is known to be controlled by abdominal stabilization maneuvers. This study aimed to evaluate the effects of unexpected perturbations on trunk stability and abdominal stabilization strategies in 42 sedentary adults while sitting. MATERIAL AND METHODS Abdominal stabilization strategies consisted of bracing and hollowing maneuvers. Abdominal bracing maneuvers (ABM) were focused on the abdominal wall muscles [inferior oblique (IO), exterior oblique (EO)], and abdominal hollowing maneuvers (AHM) were focused on deep muscle (TrA) activation. The subjects were instructed in abdominal stabilization maneuvers. Afterward, subjects were seated in a chair that could be moved forward or backward suddenly with the support surface. RESULTS Angular displacements of the upper thorax, lower thorax, and lumbopelvic during unexpected perturbation, with different abdominal stabilization maneuvers, were measured. During forward perturbation (d=0.71, F=10.324, P=0.001) and backward perturbation in high speed (d=0.62, F=9.265, P=0.011), there were significant differences in angular displacements of the upper thorax between hollowing and bracing maneuvers. Additionally, significant differences were found in the lumbopelvic angular displacement between the hollowing and bracing maneuvers (d=0.62, F=4.071, P=0.044). CONCLUSIONS Our findings indicate that the ABM is a better stabilizing technique for the upper thorax, and the AHM is a better stabilizing technique for the lumbopelvic region during unexpected perturbations at high speed in the seated position.


Assuntos
Músculos Abdominais/fisiologia , Contração Muscular/fisiologia , Postura Sentada , Tronco/fisiologia , Adulto , Eletromiografia , Feminino , Humanos , Masculino
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