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1.
J Occup Health ; 63(1): e12297, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34953000

RESUMO

OBJECTIVE: Military personnel has a large prevalence of back pain, especially those involved in patrolling routines, as they wear heavy protective equipment. Patrolling includes long periods of sustaining the protective equipment in a sitting or in a motor vehicle (motorcycle or car). Thus, understanding spinal loading of military police officers after patrolling by car (CAR; n = 14), motorcycle (MOT; n = 14), and administrative (ADM; n = 14) routines is relevant to establish preventive strategies. METHODS: The torque of the trunk and working and anthropometric characteristics were assessed to explain spinal loading using stature variation measures. Precise stature measures were performed before and after a 6 h journey (LOSS) and 20 min after a resting posture (RECOV). The trunk extensor (PTE BM-1 ) and flexor (PTF BM-1 ) muscles' isometric peak torque were measured before the working journey. RESULTS: The LOSS was similar between CAR and MOT (4.8 and 5.8 mm, respectively) after 6 h of patrolling. The ADM presented the lowest LOSS (2.8 mm; P < .05). No changes in RECOV between groups were observed (P > .05). Vibration may explain the greater spinal loading involved in patrolling in comparison to the ADM. A GLM analysis revealed that BMI was the only explanatory factor for stature loss. No independent variables explained RECOV. The ability of the trunk muscles to produce force did not influence LOSS or RECOV. CONCLUSIONS: Military police officers involved in patrolling may require greater post-work periods and strategies designed to reduce the weight of the protective apparatus to dissipate spinal loading. The external load used in patrolling is a relevant spinal loading factor.


Assuntos
Vértebras Lombares/fisiologia , Força Muscular/fisiologia , Polícia , Coluna Vertebral/fisiologia , Suporte de Carga/fisiologia , Antropometria/instrumentação , Estudos Transversais , Humanos , Militares , Músculo Esquelético , Saúde do Trabalhador , Postura/fisiologia
2.
Res Sports Med ; 29(6): 586-592, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34477036

RESUMO

This study examined the biomechanics of the lower limbs during four typical Tai Chi (TC) movements: wave hand in cloud, leaning fly side, repulse monkey, and brush knee and twist step, in order to provide biomechanical evidence-based recommendations for patients with knee osteoarthritis (OA) practicing TC. Joint angles and joint moments of the hip, knee, and ankle in frontal and sagittal plane as well as ground reaction forces were examined while performing TC and regular walking in an experienced 38 years old TC master. The results showed that relative to walking, the four TC movements are characterized by a wide motion range of lower limbs, slow increase in joint loading, and strong muscle activity during performance. Therefore, these TC movements could be suitable for patients with knee OA to practice for improving the muscle strength of their lower limbs and functional ability.


Assuntos
Extremidade Inferior/fisiologia , Osteoartrite do Joelho/fisiopatologia , Osteoartrite do Joelho/reabilitação , Amplitude de Movimento Articular/fisiologia , Tai Ji/métodos , Caminhada/fisiologia , Suporte de Carga/fisiologia , Adulto , Fenômenos Biomecânicos , Humanos , Cinética , Masculino
3.
Sci Rep ; 11(1): 16786, 2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34408255

RESUMO

Prospective study, Level of evidence II. The aim of the study was to assess the prevalence of scoliosis among children aged 8-15 years old and to identify the impact of schoolbag weight in developing adolescent idiopathic scoliosis (AIS). AIS is a common disease whose prevalence varies between countries and gender, with an increased rate among females compared to males. Screening children in primary school settings for idiopathic scoliosis (IS) is an important public health issue and is crucial for early detection, prevention of further deformity, and healthy child growth. Our sample was composed of 1619 pupils from the municipality of Prishtina, surveyed from March to April 2019. Measurements were made with a scoliometer on the basis of the Adams test process. Three measurements were taken for each of the participants. Additionally, all the pupils were subjected to bare-foot height and weight measurements with and without school bags. The mean ± standard deviation age of pupils was 11.67 ± 2.00 years old and 49% were females. The prevalence of the angle of trunk rotation (ATR) ≥ 5 ° was 26.1%, females had 1.49 higher odds (95%CI 1.19-1.86) to develop an ATR of ≥ 5° compared to males. The highest rate of ATR of ≥ 5° was seen among the ninth-grade students (31.3%). 56.5% of 4th grade students carry a schoolbag weighing over 12.5% of body weight. Relatively high prevalence of idiopathic scoliosis was found in primary schools in Prishtina. The highest prevalence was found in students attending the ninth grade, while females gender dominated.


Assuntos
Cifose/epidemiologia , Escoliose/epidemiologia , Tronco/fisiopatologia , Suporte de Carga/fisiologia , Adolescente , Criança , Feminino , Humanos , Kosovo/epidemiologia , Cifose/diagnóstico por imagem , Cifose/fisiopatologia , Masculino , Programas de Rastreamento , Prevalência , Estudos Prospectivos , Escoliose/diagnóstico por imagem , Escoliose/fisiopatologia , Tronco/diagnóstico por imagem
4.
Medicine (Baltimore) ; 100(32): e26894, 2021 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-34397914

RESUMO

ABSTRACT: Idiopathic flatfoot is common in infants and children, and patients with this condition are frequently referred to pediatric orthopedic clinics. Flatfoot is a physiologic process, and that the arch of the foot elevates spontaneously in most children during the first decade of life. To achieve a consensus as the rate of spontaneous improvement of flatfoot, the present study aimed to estimate the rate of spontaneous improvement of flatfoot and to analyze correlating factors.We reviewed the records of patients examined between May 2013 and May 2019 so as to identify those factors associated with idiopathic flatfoot below 12 years of age. We included patients with who had been followed for >6 months, and those for whom ≥2 (anteroposterior and lateral) weight-bearing bilateral radiographs of the foot had been obtained. The progression rates of the anteroposterior (AP) talo-first metatarsal angle, talonavicular coverage angle, lateral talo-first metatarsal angle, and calcaneal pitch angle were adjusted by multiple factors using a linear mixed model, with sex, body mass index, and Achilles tendon contracture as the fixed effects and age and each subject as the random effects.We found that 4 of the radiographic measurements improved as patients grew older. The AP talo-first metatarsal angle, talonavicular coverage angle, and the lateral talo-first metatarsal angle decreased, while the calcaneal pitch angle increased. The AP talo-first metatarsal angle (P < .001), talonavicular coverage angle (P < .001), and lateral talo-first metatarsal angle (P < .001) improved significantly; however, the calcaneal pitch angle (P = .367) did not show any significant difference. In general, the flatfeet showed an improving trend; after analyzing the factors, no sex difference was observed (P = .117), while body mass index (P < .001) and Achilles tendon contracture (P < .001) showed a negative correlation.The study demonstrated that children's flatfeet spontaneously improved at the age of 12 years. It would be more beneficial if the clinician shows the predicted appearance of the foot at the completion of growth by calculating the radiographic indices and identifying the correlating factors in addition to explaining that flatfoot may gradually improve. This will prevent unnecessary medical expenses and the psychological adverse effects to the children caused by unnecessary treatment.


Assuntos
Pé Chato/diagnóstico , Ossos do Metatarso/diagnóstico por imagem , Radiografia/métodos , Recuperação de Função Fisiológica/fisiologia , Suporte de Carga/fisiologia , Criança , Progressão da Doença , Feminino , Pé Chato/fisiopatologia , Seguimentos , Humanos , Masculino , Estudos Retrospectivos
5.
Scand J Med Sci Sports ; 31(11): 2055-2063, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34275170

RESUMO

The stretch-shortening cycle (SSC) assists in effective force attenuation upon landing and augments force generation at take-off during a drop vertical jump (DVJ). General performance outcomes such as jump height or peak measures have been used to assess SSC function in youth populations; however, these discrete metrics fail to provide insight into temporal jump-landing characteristics. This study assessed DVJ force-time profiles in 1013 middle and high-school female athletes (n = 279 prepubertal, n = 401 pubertal, and n = 333 postpubertal). Maturity status was determined using the Pubertal Maturation Observation Scale. Ground reaction force data were analyzed to extract a range of variables to characterize force-time profiles. SSC function was categorized as poor, moderate, or good dependent on the presence of an impact peak and spring-like behavior. No differences in jump height or ground contact time were observed between maturity groups (p > 0.05). Significant differences in absolute peak landing and take-off force were evident between all maturational statuses (p < 0.05). Relative to bodyweight normalized forces, only peak take-off force was significantly different between prepubertal and postpubertal groups (p < 0.05; d = 0.22). Spring-like behavior showed small improvements from pubertal to postpubertal (p < 0.05; d = 0.25). Most females displayed poor SSC function at prepubertal (79.6%), pubertal (77.3%), and postpubertal (65.5%) stages of maturity. Large increases in absolute forces occur throughout maturation in female athletes; however, only small maturational differences were found in relative force or spring-like behavior. Consequently, most girls display poor SSC function irrespective of maturity.


Assuntos
Desenvolvimento do Adolescente/fisiologia , Movimento/fisiologia , Exercício Pliométrico , Suporte de Carga/fisiologia , Adolescente , Traumatismos em Atletas/prevenção & controle , Fenômenos Biomecânicos , Criança , Feminino , Humanos
6.
Sci Rep ; 11(1): 13395, 2021 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-34183711

RESUMO

A further increase in the number of total hip arthroplasty (THA) is predicted, in particular the number of young THA patients has raised and with it their demands. There is no standardized evidence-based rehabilitation program and no reliable guidelines for sports activities after THA. Stretching and strengthening gymnastics are routinely performed in rehabilitation and aerobics as a sport after THA. The aim of the investigation was to determine the in vivo force and moments acting on the hip prosthesis during gymnastics and aerobic exercises to provide a source for evidence-based recommendations. Hip joint loads were measured in six patients with instrumented hip implants. The resulting force FRes, bending moment MBend at the neck and torsional moment MTors at the stem were examined during seven strengthening (with two different resistance bands) and four stretching gymnastic exercises and seven aerobic exercises with and without an aerobic step board compared to the loads during the reference activity walking. The stretching and strengthening gymnastics exercises and the aerobic exercises with and without a board demonstrated in their median peak force and moments mostly lower or similar values compared to walking. Significantly increased loads were recorded for the flexor stretching exercise in monopod stand (Fres and MBend), the strengthening abduction exercise on the chair (MTors) and the strengthening flexion exercise with the stronger resistance band (MTors). We also found a significant increase in median peak values in aerobic exercises with a board for the "Basic Step" (ipsilateral started Fres and MTors; contralateral started MTors), "Kickstep ipsilateral started" (Fres and MTors) and "Over the Top contralateral started" (Fres). The in vivo loads in THA patients during frequently performed stretching, strengthening and aerobic exercises were demonstrated for the first time. It was proved that stretching gymnastic exercises are safe in terms of resulting force, bending and torque moments for THA patients, although an external assistance for stabilization may be considered. Strengthening gymnastics exercises are reliable in terms of Fres, MBend and MTors, but, based on our data, we recommend to adhere to the communicated specific postoperative restrictions and select the resistance bands with lower tension. Aerobic exercises without an aerobic board can be considered as reliable activity in terms of force and moments for THA patients. Aerobic exercises with a board are not recommended for the early postoperative period and in our opinion need to be adapted to the individual muscular and coordinative resources.


Assuntos
Exercício Físico/fisiologia , Ginástica/fisiologia , Articulação do Quadril/cirurgia , Idoso , Artroplastia de Quadril , Terapia por Exercício/métodos , Feminino , Prótese de Quadril , Humanos , Articulação do Joelho/fisiologia , Articulação do Joelho/cirurgia , Masculino , Pessoa de Meia-Idade , Força Muscular/fisiologia , Amplitude de Movimento Articular/fisiologia , Torque , Caminhada/fisiologia , Suporte de Carga/fisiologia
7.
Med Sci Monit ; 27: e930849, 2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34045428

RESUMO

BACKGROUND Successful treatment of tibial nonunion should lead to a complete bone union, lack of pain, and pathological mobility of the lower extremity, as well as to the achievement of satisfactory joint mobility and muscle strength, which in turn improves its biomechanics. The objective of this study was to assess the load placed on the lower limbs in patients subjected to treatment with the Ilizarov method due to aseptic tibial nonunion. MATERIAL AND METHODS This research involved 24 participants (average age, 55 years). All were diagnosed with aseptic tibia nonunion and treated with the Ilizarov external fixator between 2000 and 2017. The control group was matched to the treated group in terms of sex and age. This study used pedobarography evaluation to assess lower limb load distribution. RESULTS No differences were found in the distribution of the load over the entire foot or of the forefoot and hindfoot of the treated limb in comparison to the non-dominant limb of the controls, or in the healthy limb of the treated group compared to the dominant limb of the control group. Similarly, differences in load distribution between the operated and healthy limbs of the treated group were insignificant. CONCLUSIONS Patients subjected to treatment with the Ilizarov external fixator for aseptic tibial nonunion show symmetrical load distribution on both lower limbs following treatment, which does not differentiate them in this respect from healthy individuals. Treated patients presented with a symmetrical distribution of the load on the lower extremities over the entire foot surface, including the forefoot and hindfoot. Finally, the Ilizarov external fixator enables restoration of correct static biomechanics of the treated limbs over the period of aseptic tibial nonunion therapy.


Assuntos
Fraturas não Consolidadas , Técnica de Ilizarov/instrumentação , Extremidade Inferior , Complicações Pós-Operatórias , Fraturas da Tíbia , Suporte de Carga/fisiologia , Fenômenos Biomecânicos , Fixadores Externos , Feminino , Fraturas não Consolidadas/fisiopatologia , Fraturas não Consolidadas/cirurgia , Humanos , Extremidade Inferior/lesões , Extremidade Inferior/fisiopatologia , Extremidade Inferior/cirurgia , Masculino , Pessoa de Meia-Idade , Força Muscular , Avaliação de Resultados em Cuidados de Saúde/métodos , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/fisiopatologia , Complicações Pós-Operatórias/terapia , Radiografia/métodos , Reprodutibilidade dos Testes , Fraturas da Tíbia/diagnóstico por imagem , Fraturas da Tíbia/reabilitação , Fraturas da Tíbia/cirurgia
8.
J Athl Train ; 56(5): 461-472, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34000019

RESUMO

CONTEXT: Arch height is one important aspect of foot posture. An estimated 20% of the population has pes planus and 20% has pes cavus. These abnormal foot postures can alter lower extremity kinematics and plantar loading and contribute to injury risk. Ankle bracing is commonly used in sport to prevent these injuries, but no researchers have examined the effects of ankle bracing on plantar loading. OBJECTIVE: To evaluate the effects of ankle braces on plantar loading during athletic tasks. DESIGN: Cross-sectional study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: A total of 36 participants (11 men, 25 women; age = 23.1 ± 2.5 years, height = 1.72 ± 0.09 m, mass = 66.3 ± 14.7 kg) were recruited for this study. INTERVENTION(S): Participants completed walking, running, and cutting tasks in 3 bracing conditions: no brace, lace-up ankle-support brace, and semirigid brace. MAIN OUTCOME MEASURE(S): We analyzed the plantar-loading variables of contact area, maximum force, and force-time integral for 2 midfoot and 3 forefoot regions and assessed the displacement of the center of pressure. A 3 × 3 mixed-model repeated-measures analysis of variance was used to determine the effects of brace and foot type (α = .05). RESULTS: Foot type affected force measures in the middle (P range = .003-.047) and the medial side of the foot (P range = .004-.04) in all tasks. Brace type affected contact area in the medial midfoot during walking (P = .005) and cutting (P = .01) tasks, maximum force in the medial and lateral midfoot during all tasks (P < .001), and force-time integral in the medial midfoot during all tasks (P < .001). Portions of the center-of-pressure displacement were affected by brace wear in both the medial-lateral and anterior-posterior directions (P range = .001-.049). CONCLUSIONS: Ankle braces can be worn to redistribute plantar loading. Additional research should be done to evaluate their effectiveness in injury prevention.


Assuntos
Traumatismos do Tornozelo , Braquetes , Pé Chato , Placa Plantar/fisiologia , Pé Cavo , Suporte de Carga/fisiologia , Tornozelo/fisiologia , Traumatismos do Tornozelo/etiologia , Traumatismos do Tornozelo/fisiopatologia , Traumatismos do Tornozelo/prevenção & controle , Fenômenos Biomecânicos , Estudos Transversais , Feminino , Pé Chato/complicações , Pé Chato/diagnóstico , Pé Chato/fisiopatologia , Humanos , Masculino , Corrida/fisiologia , Pé Cavo/complicações , Pé Cavo/diagnóstico , Pé Cavo/fisiopatologia , Caminhada/fisiologia , Adulto Jovem
9.
Med Sci Monit ; 27: e931565, 2021 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-34052826

RESUMO

BACKGROUND Induction of proper weight transfer to the affected lower limb should be considered the most essential factor for successful stroke cane gait training. This study aimed to investigate the effect of walking training with a weight support feedback cane on lower limb muscle activity and gait ability of chronic stroke patients. MATERIAL AND METHODS Thirty stroke patients were randomized into 2 groups: a weight support feedback cane gait training group (WSFC group, n=15) and a conventional cane gait training group (CC group, n=15). All subjects were enrolled in standard rehabilitation programs for 4 weeks. Additionally, the WSFC group participated in WSFC gait training and the CC group participated in conventional cane gait training for 4 weeks. During WSFC gait training, the weight support rate loaded on the cane was reduced by 10% every week from 60% to 30% based on the measured initial cane dependence, while the CC group participated in conventional cane gait training with verbal instruction to reduce cane dependence. Lower limb muscle activity and gait ability were measured using wireless surface electromyography and a 3-axis accelerometer during walking. RESULTS The WSFC group showed significantly greater improvement than the CC group in lower limb muscle activity and gait ability (P<0.05). CONCLUSIONS Cane gait training significantly improved lower limb muscle activity and gait ability in stroke regardless of the training method; however, the addition of real-time weight support feedback to cane gait training appears to provide further benefit compared with conventional cane gait training in chronic stroke patients.


Assuntos
Bengala , Terapia por Exercício , Transtornos Neurológicos da Marcha , Extremidade Inferior/fisiopatologia , Reabilitação do Acidente Vascular Cerebral , Caminhada/fisiologia , Terapia por Exercício/instrumentação , Terapia por Exercício/métodos , Feminino , Análise da Marcha/métodos , Transtornos Neurológicos da Marcha/etiologia , Transtornos Neurológicos da Marcha/fisiopatologia , Transtornos Neurológicos da Marcha/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico , Reabilitação do Acidente Vascular Cerebral/instrumentação , Reabilitação do Acidente Vascular Cerebral/métodos , Resultado do Tratamento , Velocidade de Caminhada , Suporte de Carga/fisiologia
11.
PLoS One ; 16(5): e0251939, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34010359

RESUMO

The main aim was to examine the load bearing of individual hamstring muscles in different contraction types and intensities, through local stiffness measurement by shear wave elastography (SWE). A secondary aim was to examine the relationship between the SWE stiffness measure and hamstrings morphology. Ten healthy males (age 22.1±4.1 years; height 173.7±5.9 cm; body mass 68.6±12.4 kg; mean ± SD) performed knee flexions on an isokinetic dynamometer at different intensities (20-70%MVC, random order) in three separate, randomized conditions: isometric (ISO), concentric (CON) and eccentric (ECC). SWE was used to measure muscle shear wave velocity (SWV) in biceps femoris long head (BFlh), semitendinosus (ST) and semimembranosus (SM) during contraction. Muscle anatomical cross-sectional area (ACSA) was measured with magnetic resonance imaging and muscle architecture with B-mode ultrasonography. Muscle SWV increased linearly with contraction intensity, but at a varying rate among muscles and contraction types. ST exhibited greater SWV than BFlh and SM in all contraction types, however, there was an upward shift in the SM SWV-torque relationship in ECC compared to ISO and CON. Strong negative correlations were found between peak ISO SWV and ST ACSA (r = -0.81, p = 0.005) and BFlh pennation angle (r = -0.75, p = 0.012). These results suggest that ST has a primary role in hamstrings load bearing in all contraction types, likely due to its morphology; however, there is evidence of increased contribution from SM in eccentric muscle actions.


Assuntos
Técnicas de Imagem por Elasticidade/métodos , Músculos Isquiossurais/diagnóstico por imagem , Músculos Isquiossurais/fisiologia , Contração Isométrica/fisiologia , Suporte de Carga/fisiologia , Adolescente , Adulto , Músculos Isquiossurais/anatomia & histologia , Voluntários Saudáveis , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Força Muscular/fisiologia , Torque , Adulto Jovem
12.
Int J Mol Sci ; 22(5)2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33806315

RESUMO

Systemic injection of a nerve growth factor (NGF) antibody has been proven to have a significant relevance in relieving osteoarthritis (OA) pain, while its adverse effects remain a safety concern for patients. A local low-dose injection is thought to minimize adverse effects. In this study, OA was induced in an 8-week-old male Sprague-Dawley (SD) rat joint by monoiodoacetate (MIA) injection for 2 weeks, and the effect of weekly injections of low-dose (1, 10, and 100 µg) NGF antibody or saline (control) was evaluated. Behavioral tests were performed, and at the end of week 6, all rats were sacrificed and their knee joints were collected for macroscopic and histological evaluations. Results showed that 100 µg NGF antibody injection relieved pain in OA rats, as evidenced from improved weight-bearing performance but not allodynia. In contrast, no significant differences were observed in macroscopic and histological scores between rats from different groups, demonstrating that intra-articular treatment does not worsen OA progression. These results suggest that local administration yielded a low effective NGF antibody dose that may serve as an alternative approach to systemic injection for the treatment of patients with OA.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Artrite Experimental/terapia , Fator de Crescimento Neural/antagonistas & inibidores , Osteoartrite/terapia , Manejo da Dor/métodos , Animais , Artrite Experimental/patologia , Artrite Experimental/fisiopatologia , Cartilagem Articular/patologia , Relação Dose-Resposta Imunológica , Hiperalgesia/fisiopatologia , Hiperalgesia/terapia , Injeções Intra-Articulares , Ácido Iodoacético/toxicidade , Masculino , Fator de Crescimento Neural/imunologia , Osteoartrite/patologia , Osteoartrite/fisiopatologia , Ratos , Ratos Sprague-Dawley , Suporte de Carga/fisiologia
13.
Sci Rep ; 11(1): 7324, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33795710

RESUMO

There is an urgent need for the development of ways to address the major issue of falls among today's globally aging population. The authors here outline a new approach referred to as virtual light-touch contact to mitigate postural sway during ambulatory and stationary periods, and propose a wearable light-touch (WLT) system featuring a virtual partition around the user that allows determination of virtual forces resulting from related contact. The data produced are used to create vibrotactile fingertip feedback, which supports comprehensive perception of the partition. Non-impaired subjects were recruited to support evaluation of the prototype system (incorporating tactile stimulation and motion-capture technology), with outcomes showing successful mitigation of postural sway in a heel-to-toe tandem stance. Research performed with 150 able-bodied volunteers to validate the performance of the new set-up (incorporating an acceleration sensor and a voice coil motor to render the light-touch effect) suggested that the proposed WLT approach supports human balance on a level comparable to that of the light-touch effect.


Assuntos
Engenharia Biomédica/métodos , Equilíbrio Postural/fisiologia , Propriocepção/fisiologia , Tato/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Impedância Elétrica , Dedos/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Percepção , Postura/fisiologia , Pressão , Medicina Preventiva/métodos , Suporte de Carga/fisiologia , Adulto Jovem
14.
Sci Rep ; 11(1): 8594, 2021 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-33883591

RESUMO

This study evaluated the association of contact point locations with the knee medial and lateral contact force (Fmed, Flat) alterations in OA and healthy subjects. A musculoskeletal model of the lower limb with subject-specific tibiofemoral contact point trajectories was used to estimate the Fmed and Flat in ten healthy and twelve OA subjects during treadmill gait. Regression analyses were performed to evaluate the correlation of the contact point locations, knee adduction moment (KAM), knee flexion moment (KFM), frontal plane alignment, and gait speed with the Fmed and Flat. Medial contact point locations in the medial-lateral direction showed a poor correlation with the Fmed in OA (R2 = 0.13, p = 0.01) and healthy (R2 = 0.24, p = 0.001) subjects. Anterior-posterior location of the contact points also showed a poor correlation with the Fmed of OA subjects (R2 = 0.32, p < 0.001). Across all subjects, KAM and KFM remained the best predictors of the Fmed and Flat, respectively (R2 between 0.62 and 0.69). Results suggest different mechanisms of contact force distribution in OA joints. The variations in the location of the contact points participate partially to explains the Fmed variations in OA subjects together with the KFM and KAM.


Assuntos
Joelho/fisiopatologia , Osteoartrite do Joelho/fisiopatologia , Suporte de Carga/fisiologia , Adulto , Idoso , Feminino , Marcha/fisiologia , Humanos , Articulação do Joelho/fisiopatologia , Masculino , Pessoa de Meia-Idade , Amplitude de Movimento Articular/fisiologia , Caminhada/fisiologia
15.
J Sports Sci ; 39(16): 1873-1881, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33874850

RESUMO

The aim of this study was threefold (1) to assess the reliability of three upper-extremity performance tests: a countermovement push up, press jump and drop box land, performed on a set of dual-force plates (2) to examine whether there was an association between isokinetic dynamometry and the performance tests in a non-injured cohort of collision/contact athletes and (3) to establish a normal descriptive profile of the vertical ground reaction forces from the performance tests, in a cohort of contact/collision athletes. The study was split into two sub-sections; the inter-day reliability of three upper-extremity performance tests (n = 21) and a descriptive, correlation study investigating the relationship between isokinetic dynamometry and performance tests metrics (n = 39). We used intraclass correlation coefficients (absolute agreement, 2-way mixed-effects model) with 95% confidence intervals to quantify inter-day reliability of all variables. We used Pearson correlation coefficients to investigate associations between isokinetic strength and vertical ground reaction force asymmetry variables. Inter-day reliability was moderate-to-excellent for the upper-extremity performance tests (ICC 0.67-0.97). There was no statistically significant correlation between external and internal rotational peak torque and the variables of CPMU, PJ and BDL (r range = .02-.24).These upper-extremity tests are reliable for use with male contact/collision athletes.


Assuntos
Atletas , Teste de Esforço/normas , Força Muscular/fisiologia , Extremidade Superior/fisiologia , Suporte de Carga/fisiologia , Adolescente , Adulto , Fenômenos Biomecânicos , Estudos Transversais , Humanos , Masculino , Dinamômetro de Força Muscular , Reprodutibilidade dos Testes , Volta ao Esporte , Adulto Jovem
16.
Nutrients ; 13(3)2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33802283

RESUMO

This study assessed the effects of a 7-day creatine (CRE) supplementation on the load-velocity profile and repeated sub-maximal bouts in the deep squat using mean propulsive velocity (MPV) and mean propulsive power (MPP). Eleven strength-trained men (31.4 ± 5.4 years) supplemented 0.3 g·kg-1·d-1 CRE or a placebo (PLA, maltodextrin) for seven days in a randomized order, separated by a 30-day washout period. Prior to and after the supplementation, the subjects performed an incremental maximal strength (1RM) test, as well as 3 × 10 repetitions and a repetitions-to-failure test (RFT), all at 70% 1RM. Maximal strength remained statistically unaltered in CRE (p = 0.107) and PLA (p = 0.568). No statistical main effect for time (p = 0.780) or interaction (p = 0.737) was observed for the load-velocity profile. The number of repetitions during RFT remained statistically unaltered in both conditions (CRE: +16.8 ± 32.8%, p = 0.112; PLA: +8.2 ± 47.2%, p = 0.370), but the effect size was larger in creatine compared to placebo (g = 0.51 vs. g = 0.01). The total work during RFT increased following creatine supplementation (+23.1 ± 35.9%, p = 0.043, g = 0.70) but remained statistically unaltered in the placebo condition (+15.0 ± 60.8%, p = 0.801, g = 0.08; between conditions: p = 0.410, g = 0.25). We showed that CRE loading over seven days did not affect load-velocity characteristics but may have increased total work and power output during submaximal deep squat protocols, as was indicated by moderate effect sizes.


Assuntos
Creatina/administração & dosagem , Suplementos Nutricionais , Tolerância ao Exercício/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Suporte de Carga/fisiologia , Adulto , Estudos Cross-Over , Método Duplo-Cego , Humanos , Masculino , Força Muscular/efeitos dos fármacos , Treinamento de Força/métodos
17.
PLoS One ; 16(4): e0250456, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33901222

RESUMO

In computational biomechanics, two separate types of models have been used predominantly to enhance the understanding of the mechanisms of action of the lumbosacral spine (LSS): Finite element (FE) and musculoskeletal multibody (MB) models. To combine advantages of both models, hybrid FE-MB models are an increasingly used alternative. The aim of this paper is to develop, calibrate, and validate a novel passive hybrid FE-MB open-access simulation model of a ligamentous LSS using ArtiSynth. Based on anatomical data from the Male Visible Human Project, the LSS model is constructed from the L1-S1 rigid vertebrae interconnected with hyperelastic fiber-reinforced FE intervertebral discs, ligaments, and facet joints. A mesh convergence study, sensitivity analyses, and systematic calibration were conducted with the hybrid functional spinal unit (FSU) L4/5. The predicted mechanical responses of the FSU L4/5, the lumbar spine (L1-L5), and the LSS were validated against literature data from in vivo and in vitro measurements and in silico models. Spinal mechanical responses considered when loaded with pure moments and combined loading modes were total and intervertebral range of motions, instantaneous axes and centers of rotation, facet joint contact forces, intradiscal pressures, disc bulges, and stiffnesses. Undesirable correlations with the FE mesh were minimized, the number of crisscrossed collagen fiber rings was reduced to five, and the individual influences of specific anatomical structures were adjusted to in vitro range of motions. Including intervertebral motion couplings for axial rotation and nonlinear stiffening under increasing axial compression, the predicted kinematic and structural mechanics responses were consistent with the comparative data. The results demonstrate that the hybrid simulation model is robust and efficient in reproducing valid mechanical responses to provide a starting point for upcoming optimizations and extensions, such as with active skeletal muscles.


Assuntos
Vértebras Lombares/fisiologia , Modelos Biológicos , Sacro/fisiologia , Fenômenos Biomecânicos , Calibragem , Análise de Elementos Finitos , Humanos , Disco Intervertebral/fisiologia , Dinâmica não Linear , Amplitude de Movimento Articular/fisiologia , Suporte de Carga/fisiologia , Articulação Zigapofisária/fisiologia
18.
Phys Ther ; 101(8)2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-33909896

RESUMO

OBJECTIVE: This study aimed to clarify whether an exercise involving weight shifting to the nonparetic side while standing on an inclined surface improves standing balance in the early phase after stroke. METHODS: This assessor-blinded, randomized controlled trial included people undergoing inpatient rehabilitation at a university hospital. Participants (N = 52) with hemiparesis caused by a stroke were randomly assigned to an experimental group (n = 26) or control group (n = 26). Participants performed a weight-shifting exercise to the nonparetic side using a goal-directed reaching strategy while standing on an inclined surface that was elevated 5 degrees to the nonparetic side in the experimental group or a flat surface in the control group. The reaching exercise was conducted 30 times per day for 5 days. Primary outcome was the Berg Balance Scale. Secondary outcomes were the posturographic examination (static standing and lateral weight shifting to the nonparetic and paretic sides), Trunk Control Test, Trunk Impairment Scale, Functional Ambulation Category, and Functional Independent Measure motor item scores. RESULTS: Through intention-to-treat analysis, no significant intervention effects were observed between groups on the Berg Balance Scale. A significant intervention effect was observed, however, with the experimental group on the lateral weight shifting to the nonparetic side in the mean percentage bodyweight values and center-of-pressure moving distance and to the paretic side in center-of-pressure moving distance and Functional Ambulation Category. There were no significant interaction effects concerning other outcomes. CONCLUSION: These results suggest that standing reaching exercises to the nonparetic side while standing on an inclined surface could improve lateral weight-shifting capacity and gait ability in participants in the early poststroke phase. IMPACT: This intervention should be incorporated into standard treatment programs focusing on the paretic side during early stroke rehabilitation.


Assuntos
Transtornos Neurológicos da Marcha/reabilitação , Equilíbrio Postural/fisiologia , Reabilitação do Acidente Vascular Cerebral/métodos , Suporte de Carga/fisiologia , Idoso , Feminino , Humanos , Pacientes Internados , Masculino , Pessoa de Meia-Idade , Método Simples-Cego , Posição Ortostática
19.
Scand J Med Sci Sports ; 31(8): 1657-1665, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33864288

RESUMO

Achilles tendinopathy and patellofemoral pain are common running injuries associated with increased Achilles tendon (AT) forces and patellofemoral joint (PFJ) stresses. This study examined AT forces and PFJ stresses at different running speeds in high-performing endurance runners. Twenty runners ran overground at four running speeds (3.3, 3.9, 4.8, and 5.6 m/s). AT forces and PFJ stresses were estimated from kinematic and kinetic data. Repeated measures ANOVA with partial eta squared effect sizes was conducted to assess differences between running speeds. Increased peak AT forces (19.5%; p < 0.001) and loading rates (57.3%; p < 0.001) from 3.3 m/s to 5.6 m/s were observed. Cumulative AT loading was greater in the faster speeds compared to the slower speeds. Faster running speeds resulted in increased peak plantar flexor moments, increased peak plantar flexion angles, and a more flexed knee and an anterior center of pressure position at touchdown. Peak PFJ stress was lower in the slowest speed (3.3 m/s) compared to the faster running speeds (3.9-5.6 m/s; p = 0.005). PFJ stress loading rate significantly increased (43.6%; p < 0.001). Greater AT loading observed could be associated with strategies such as increased plantar flexor moments and altered lower body position at touchdown which are commonly employed to generate greater ground contact forces. Greater AT and PFJ loading rates were likely due to shorter ground contact times and therefore less time available to reach the peak. Running at faster speeds could increase the risk of developing Achilles tendinopathy and patellofemoral pain or limit recovery from these injuries without sufficient recovery.


Assuntos
Tendão do Calcâneo/fisiologia , Articulação Patelofemoral/fisiologia , Corrida/fisiologia , Adolescente , Adulto , Fenômenos Biomecânicos , Feminino , Humanos , Cinética , Masculino , Suporte de Carga/fisiologia , Adulto Jovem
20.
Scand J Med Sci Sports ; 31(8): 1674-1682, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33864294

RESUMO

Rehabilitation is an important treatment for non-insertional Achilles tendinopathy. To date, eccentric loading exercises (ECC) have been the predominant choice; however, mechanical evidence underlying their use remains unclear. Other protocols, such as heavy slow resistance loading (HSR), have shown comparable outcomes, but with less training time. This study aims to identify the effect of external loading and other variables that influence Achilles tendon (AT) force in ECC and HSR. Ground reaction force and kinematic data during ECC and HSR were collected from 18 healthy participants for four loading conditions. The moment arms of the AT were estimated from MRIs of each participant. AT force then was calculated using the ankle torque obtained from inverse dynamics. In the eccentric phase, the AT force was not larger than in the concentric phase in both ECC and HSR. Under the same external load, the force through the AT was larger in ECC with the knee bent than in HSR with the knee straight due to increased dorsiflexion angle of the ankle. Multivariate regression analysis showed that external load and maximum dorsiflexion angle were significant predictors of peak AT force in both standing and seated positions. Therefore, to increase the effectiveness of loading the AT, exercises should apply adequate external load and reach maximum dorsiflexion during the movement. Peak dorsiflexion angle affected the AT force in a standing position at twice the rate of a seated position, suggesting standing could prove more effective for the same external loading and peak dorsiflexion angle.


Assuntos
Tendão do Calcâneo/fisiologia , Terapia por Exercício/métodos , Amplitude de Movimento Articular/fisiologia , Tendinopatia/fisiopatologia , Tendinopatia/reabilitação , Tendão do Calcâneo/lesões , Adulto , Fenômenos Biomecânicos , Feminino , Voluntários Saudáveis , Humanos , Masculino , Suporte de Carga/fisiologia
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