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1.
Sports Biomech ; 19(1): 1-25, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29781788

RESUMO

The use of isometric strength testing, particularly the isometric mid-thigh pull (IMTP) has increased dramatically over the last decade. The IMTP and isometric squat (ISqT) provide one aspect of performance monitoring with variables such as peak force and rate of force development being derived from the force-time curve. The reliability of some of these variables is conflicting in the literature, and the reporting of the reliability is not standardised across the research. The majority of research only reports intraclass correlation coefficients with very few studies reporting coefficient of variation and 90% confidence intervals. Additionally, methods used to calculate variables from the force-time curve differ across studies. An aim of muscle strength testing is to provide normative values for specific sports, allowing coaches to distinguish between performance levels or evaluate the effects of training on performance. This narrative review aims to evaluate studies that have researched the reliability and/or reported normative data for both tests. Additionally, the testing protocols and the force-time curve analysis techniques utilised are discussed, concluding with practical applications for coaches on the uses and limitations of these tests. Results demonstrate that peak force is the most reliable measure and can be used to determine maximum strength capabilities.


Assuntos
Teste de Esforço/métodos , Força Muscular/fisiologia , Coxa da Perna/fisiologia , Levantamento de Peso , Fenômenos Biomecânicos , Humanos , Contração Isométrica/fisiologia , Valores de Referência , Reprodutibilidade dos Testes , Esportes/fisiologia
2.
Int J Sports Med ; 40(14): 903-908, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31614383

RESUMO

Football players frequently face the occurrence of non-contact injuries. Although there are likely multiple factors that contribute to increased risk of non-contact injury, it remains a challenge to correlate all these factors. However, it is not clear how much of individual training abilities may interfere in these events. As such, the primary aim of the present study was to determine whether the reduction of functional performance of the thigh in the isokinetic knee tests, anthropometric and morbid history can establish risk factors for lower-limb musculoskeletal injuries throughout the season. The incidence of injuries and odds ratios were calculated for suspected risk factors. Hamstring/Quadriceps conventional ratio outside of the safety range (55-64%) may be involved in the occurrence of non-contact muscle injuries and the risk for any musculoskeletal injuries in the lower extremities is 16 times higher when extensor peak of torque exceeds 10% and 12 times higher when flexor peak of torque difference was greater than 10%. This kind of evaluation can result in intervention programs that may decrease the risk of lower-limb musculoskeletal injuries. Based on these results we can establish a specific and individualized exercise program for each athlete and thus protect them during the season.


Assuntos
Extremidade Inferior/lesões , Medição de Risco/métodos , Futebol/lesões , Adolescente , Adulto , Antropometria , Teste de Esforço , Músculos Isquiotibiais/lesões , Músculos Isquiotibiais/fisiologia , Humanos , Joelho/fisiologia , Ligamentos/lesões , Estudos Longitudinais , Extremidade Inferior/fisiologia , Masculino , Condicionamento Físico Humano , Músculo Quadríceps/lesões , Músculo Quadríceps/fisiologia , Fatores de Risco , Futebol/fisiologia , Coxa da Perna/fisiologia , Lesões do Menisco Tibial/fisiopatologia , Adulto Jovem
3.
Hum Mov Sci ; 67: 102514, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31499386

RESUMO

PURPOSE: Foam Rolling (FR), aims to mimic the effects of manual therapy and tackle dysfunctions of the skeletal muscle and connective tissue. It has been shown to induce improvements in flexibility, but the underlying mechanisms are poorly understood. The aim of the present study was to further elucidate the acute, systemic and tissue-specific responses evoked by FR. METHODS: In a crossover study, 16 (34 ±â€¯6y, 6f) participants received all of the following interventions in a random order: a) 2 × 60 seconds of FR at the anterior thigh, b) 2 × 60 seconds of passive static stretching of the anterior thigh (SS), and c) no intervention (CON). Maximal active and passive knee flexion range of motion (ROM), passive stiffness, sliding of fascial layers, as well as knee flexion angle of first subjectively perceived stretch sensation (FSS) were evaluated before and directly after each intervention. RESULTS: Flexibility increased only after, FR (active (+1.8 ±â€¯1.9%) and passive ROM (+3.4 ±â€¯2.7%), p = .006, respectively) and SS (passive ROM (+3.2 ±â€¯3.5%), p = .002). Angle of FSS was altered following FR (+4.3° (95% CI: 1.4°-7.2°)) and SS (+6.7° (3.7°-9.6°)), while tissue stiffness remained unchanged after any intervention compared to baseline. Movement of the deepest layer (-5.7 mm (-11.3 mm to -0.1 mm)) as well as intrafascial sliding between deep and superficial layer (-4.9 mm (-9.mm to -0.7 mm)) decreased only after FR. CONCLUSION: FR improved knee flexion ROM without altering passive stiffness, but modified the perception of stretch as well as the mobility of the deep layer of the fascia lata. The mechanisms leading to altered fascial sliding merit further investigation.


Assuntos
Exercícios de Alongamento Muscular/métodos , Músculo Esquelético/fisiologia , Sensação/fisiologia , Adolescente , Adulto , Tecido Conjuntivo/fisiologia , Estudos Cross-Over , Feminino , Humanos , Articulação do Joelho/fisiologia , Masculino , Movimento/fisiologia , Amplitude de Movimento Articular/fisiologia , Coxa da Perna/fisiologia , Adulto Jovem
4.
Hum Mov Sci ; 67: 102510, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31442623

RESUMO

The purpose of this study was to explore the level of inter- and intra-individual variability in the kinematic profiles of the back squat movement among skilled weightlifters. Ten competitive weightlifters volunteered for participation in this study. Barbell velocity (VBarbell) and angular velocity of the ankle (ωAnkle), knee (ωKnee) and hip joint (ωHip) were obtained by kinematic recording of six trials at 90% of 1RM in the back squat. Inter-individual variability was assessed by analysing inter-individual differences in the velocity curves through the statistical parametric mapping method. Intra-individual variability was assessed through a correlation analysis between the barbell velocity curves of each trial for each participant. Partial least squares regression analysis, was performed to relate changes in intra-individual variability to movement and anthropometric characteristics. Significant inter- and intra-individual differences were identified in VBarbell, ωAnkle, ωKnee, and ωHip (p ≤ 0.05). Having a short trunk and thigh, and a long shin in combination with greater anterior-posterior displacement of the barbell and slower velocities during the acceleration phase increased intra-individual movement consistency over movement variability. The results of the present study clearly demonstrate that skilled weightlifters display both significant inter- and intra-individual variability in the successful execution of the back squat.


Assuntos
Movimento/fisiologia , Postura/fisiologia , Levantamento de Peso/fisiologia , Aceleração , Adulto , Análise de Variância , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Articulação do Quadril/fisiologia , Humanos , Articulação do Joelho/fisiologia , Masculino , Desempenho Psicomotor/fisiologia , Coxa da Perna/fisiologia
5.
Int J Behav Nutr Phys Act ; 16(1): 65, 2019 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-31419998

RESUMO

BACKGROUND: Pooling data from thigh-worn accelerometers across multiple studies has great potential to advance evidence on the health benefits of physical activity. This requires harmonization of information on body postures, physical activity types, volumes and time patterns across different brands of devices. The aim of this study is to compare the physical behavior estimates provided by three different brands of thigh-worn accelerometers. METHODS: Twenty participants volunteered for a 7-day free-living measurement. Three accelerometers - ActiGraph GT3X+, Axivity AX3 and ActivPAL Micro4 - were randomly placed in a vertical line on the midsection of the right thigh. Raw data from each accelerometer was processed and classified into 8 physical activities and postures using the Acti4 software. Absolute differences between estimates and the respective coefficient of variation (CV) were calculated. RESULTS: We observed very minor differences between physical behavior estimates from three different accelerometer brands. When averaged over 24 h (1,440 min), the absolute difference (CV) between accelerometers were: 1.2 mins (0.001) for lying/sitting, 3.4 mins (0.02) for standing, 3.5 mins (0.06) for moving, 1.9 mins (0.03) for walking, 0.1 mins (0.19) for running, 1.2 mins (0.19) for stair climbing, 1.9 mins (0.07) for cycling. Moreover, there was an average absolute difference of 282 steps (0.03) per 24 h. CONCLUSIONS: Physical behaviors were classified with negligible difference between the accelerometer brands. These results support harmonization of data from different thigh-worn accelerometers across multiple cohorts when analyzed in an identical manner.


Assuntos
Acelerometria/instrumentação , Exercício/fisiologia , Monitores de Aptidão Física , Monitorização Ambulatorial/instrumentação , Sono/fisiologia , Humanos , Postura/fisiologia , Software , Coxa da Perna/fisiologia
6.
Eur J Appl Physiol ; 119(9): 1981-1999, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31367910

RESUMO

PURPOSE: This study aimed at investigating how prior knowledge of drop heights affects proactive and reactive motor control in drop jumps (DJ). METHODS: In 22 subjects, the effect of knowledge of three different drop heights (20, 30, 40 cm) during DJs was evaluated in seven conditions: three different drop heights were either known, unknown or cheated (announced 40 cm, but actual drop height was 20 cm). Peak ground reaction force (Fmax) to body weight (BW) ratio (Fmax/BW) and electromyographic (EMG) activities of three shank and five thigh muscles were assessed 150 ms before and during ground contact (GC). Ankle, knee and hip joint kinematics were recorded in the sagittal plane. RESULTS: Leg stiffness, proactive and reactive EMG activity of the leg muscles diminished in unknown and cheat conditions for all drop heights (7-33% and 2-26%, respectively). Antagonistic co-activation increased in unknown (3-37%). At touchdown, increased flexion in knee (~ 5.3° ± 1.9°) and hip extension (~ 2° ± 0.6°) were observed in unknown, followed by an increased angular excursion in hip (~ 2.3° ± 0.2°) and knee joints (~ 5.6° ± 0.2°) during GC (p < 0.05). Correlations between changes in activation intensities, joint kinematics, leg stiffness and Fmax/BW (p < 0.05) indicate that anticipation changes the neuromechanical coupling of DJs. No dropouts were recorded. CONCLUSION: These findings underline that anticipation influences timing and adjustment of motor responses. It is argued that proactive and reactive modulations associated with diminished activation intensities in leg extensors are functionally relevant in explaining changes in leg stiffness and subsequent decline in performance.


Assuntos
Perna (Membro)/fisiologia , Movimento/fisiologia , Contração Muscular/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Adulto , Tornozelo/fisiologia , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos/fisiologia , Eletromiografia/métodos , Feminino , Articulação do Quadril/fisiologia , Humanos , Joelho/fisiologia , Articulação do Joelho/fisiologia , Masculino , Coxa da Perna/fisiologia , Adulto Jovem
7.
Gait Posture ; 73: 140-146, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31325738

RESUMO

PURPOSE: Standing up, sitting down and walking require considerable effort and coordination, which are crucial indicators to rehabilitation (e.g. stroke), and in older populations may indicate the onset of frailty and physical and cognitive decline. Currently, there are few reports robustly quantifying sit-to-stand and stand-to-sit transitions in free-living environments. The aim of this study was to identify and quantify these transitions using the peak velocity of sit-to-stand and stand-to-sit transitions to determine if these velocities were different in a healthy cohort and a mobility-impaired population. METHODS: Free-living sit-to-stand and stand-to-sit acceleration data were recorded from 21 healthy volunteers and 34 stroke survivors using activPAL3™ monitors over a one-week period. Thigh inclination velocity was calculated from these accelerometer data. Maximum velocities were compared between populations. RESULTS: A total of 10,299 and 11,392 sit-to-stand and stand-to-sit transitions were recorded in healthy volunteers and stroke survivors, respectively. Healthy volunteers had significantly higher overall mean peak velocities for both transitions compared with stroke survivors [70.7°/s ± 52.2 versus 44.2°/s ± 28.0 for sit-to-stand, P < 0.001 and 74.7°/s ± 51.8 versus 46.0°/s ± 31.9 for stand-to-sit; P < 0.001]. Mean peak velocity of transition was associated with increased variation in peak velocity across both groups. CONCLUSION: There were significant differences in the mean peak velocity of sit-to-stand and stand-to-sit transitions between the groups. Variation in an individual's mean peak velocity may be associated with the ability to perform these transitions. This method could be used to evaluate the effectiveness of interventions following injury such as stroke, as well as monitor decline in functional ability.


Assuntos
Acelerometria/métodos , Atividade Motora/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Coxa da Perna/fisiologia , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Estudos de Casos e Controles , Feminino , Monitores de Aptidão Física , Humanos , Masculino , Pessoa de Meia-Idade , Postura/fisiologia , Posição Ortostática
8.
J Strength Cond Res ; 33(8): 2145-2152, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31344011

RESUMO

Hintzy, F, Gregoire, N, Samozino, P, Chiementin, X, Bertucci, W, and Rossi, J. Effect of thigh-compression shorts on muscle activity and soft-tissue vibration during cycling. J Strength Cond Res 33(8): 2145-2152, 2019-This study examined the effects of different levels of thigh compression (0, 2, 6, and 15 mm Hg) in shorts on both vibration and muscle activity of the thigh during cycling with superimposed vibrations. Twelve healthy males performed a 18-minute rectangular cycling test per shorts condition (randomized cross-over design) on a specifically designed vibrating cycloergometer. Each test was composed of 2 intensity levels (moderate then high) and 3 vibration frequencies of 18.3, 22.4, and 26.3 Hz, corresponding to cadences of 70, 85, and 100 rpm, respectively. Muscle vibrations were measured with 2 triaxial accelerometers located before and on the lower-body compression garment, to quantify, respectively, the input and output vibrations, and vastus lateralis muscle activity was measured using surface electromyography. Both vibration and electromyography signals were measured throughout the tests and quantified using root-mean-square analyses. The study showed that the use of a thigh-compression shorts at 6-15 mm Hg significantly reduced both the vibration transmissibility to the thigh and the muscle activity, with higher effect size at higher superimposed vibrations. The thigh-compression shorts garment therefore seems to be 1 way to dampen vibrations transmitted to the cyclists and then to reduce the negative consequences of these vibrations on muscles.


Assuntos
Ciclismo/fisiologia , Bandagens Compressivas , Músculo Esquelético/fisiologia , Coxa da Perna/fisiologia , Vibração , Adulto , Eletromiografia , Humanos , Masculino , Fenômenos Fisiológicos Musculoesqueléticos , Modalidades de Fisioterapia , Músculo Quadríceps/fisiologia , Adulto Jovem
9.
J Electromyogr Kinesiol ; 47: 96-104, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31154172

RESUMO

Between-session reliability of electromyographic data is important for confidence in interpreting the role of muscles in functional tasks but critical if these data are to be compared before and after an intervention that seeks to change pathological patterns of muscle activity. The gluteus medius (GMed) and minimus (GMin) are known to have functionally discrete segments that are highly active during stance phase of gait and stepping tasks. This study measured the between-session reliability of activity patterns, mean amplitudes and time to peak (TTP) activity of these muscle segments. Intramuscular electrodes were placed in 3 segments of GMed and 2 segments of GMin in 10 healthy young adults for each of two testing sessions held two weeks apart. Participants completed six repetitions of comfortable speed walking trials, step-up and step-down tasks with activity patterns for each muscle segment time- and amplitude-normalized and averaged across trials. Re-test reliability for was high for activity patterns (coefficient of mean correlation ranging from 0.890 to 0.998) across all tasks and muscle segments and only two pairwise comparisons showing differences in amplitude between sessions. With standardized data collection and analysis procedures, GMed and GMin muscle segment activity patterns show good between-session reliability for weightbearing tasks.


Assuntos
Eletromiografia/métodos , Eletromiografia/normas , Marcha/fisiologia , Músculo Esquelético/fisiologia , Suporte de Carga/fisiologia , Nádegas/fisiologia , Eletrodos , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Coxa da Perna/fisiologia , Velocidade de Caminhada/fisiologia , Adulto Jovem
10.
Sports Health ; 11(4): 324-331, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31173697

RESUMO

BACKGROUND: The impact of maturation on lower extremity strength and function after anterior cruciate ligament reconstruction (ACLR) may help guide future studies of age-specific rehabilitation. HYPOTHESIS: Pediatric ACLR patients would demonstrate higher thigh strength symmetry and knee-related function at return to sport (RTS) compared with adolescent and young adult participants who underwent traditional ACLR. STUDY DESIGN: Prospective cohort study. LEVEL OF EVIDENCE: Level 2. METHODS: A total of 144 young athletes at the time of RTS clearance post-ACLR were classified into 3 maturational groups (pediatric, n = 16 with physeal-sparing ACLR [mean age = 12.3 years; range = 9.2-14.6 years]; adolescent, n = 113 [mean age = 16.5 years; range = 14.1-19.8 years]; young adult, n = 15 [mean age = 22.0 years; range = 20.5-24.9 years]). Quadriceps and hamstring strength were measured using an electromechanical dynamometer. Knee-related function was measured using the International Knee Documentation Committee (IKDC) subjective form and single-leg hop tests. The Limb symmetry Index (LSI) was used in calculations for hop and strength tests. Group differences were compared with Kruskal-Wallis tests and Mann-Whitney U post hoc tests. Proportions of participants meeting literature-recommended RTS criterion cutoffs were compared among the groups using chi-square tests. RESULTS: The pediatric group demonstrated higher quadriceps LSI (P = 0.01), IKDC scores (P < 0.01), single-hop LSI (P < 0.01), and crossover-hop LSI (P = 0.02) compared with the young adult group. In addition, the pediatric group demonstrated higher IKDC scores (P < 0.01) and single-hop LSI (P = 0.02) compared with the adolescent group. The adolescent group demonstrated higher IKDC scores (P < 0.01), single-hop LSI (P = 0.02), and crossover-hop LSI (P = 0.03) compared with the young adult group. The proportions of participants meeting all RTS criterion cutoffs were highest in the pediatric group and lowest in the young adult group (P = 0.03). CONCLUSION: Young athletes at RTS clearance after pediatric ACLR demonstrated higher quadriceps strength symmetry and knee-related function than adolescents and young adults after traditional ACLR. CLINICAL RELEVANCE: These findings demonstrate the need for further study regarding the impact of these group differences on longitudinal outcomes after ACLR, including successful RTS and risk of second ACL injury.


Assuntos
Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior , Traumatismos em Atletas/cirurgia , Extremidade Inferior/fisiologia , Força Muscular , Volta ao Esporte , Maturidade Sexual , Adolescente , Fatores Etários , Lesões do Ligamento Cruzado Anterior/fisiopatologia , Traumatismos em Atletas/fisiopatologia , Criança , Teste de Esforço/métodos , Feminino , Músculos Isquiotibiais/fisiologia , Humanos , Joelho/fisiologia , Masculino , Dinamômetro de Força Muscular , Músculo Quadríceps/fisiologia , Coxa da Perna/fisiologia , Adulto Jovem
11.
J Electromyogr Kinesiol ; 48: 17-23, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31185341

RESUMO

Patellofemoral pain syndrome (PPS) is characterized by anterior knee pain and affects young female adults. Physiotherapy is the most indicated treatment. The objective of the study was to analyze electromyographic activity of the quadriceps and gluteus medius muscles during different open and closed kinetic chain exercises in women with PPS. Twenty-two clinically healthy women and 24 women with symptomatic PPS were assessed through surface electromyography of the quadriceps and gluteus medius during the following exercises: straight leg raise with and without lateral hip rotation; squats; squats with adduction and hip abduction; and squats combined with lateral hip rotation. When comparing the groups, only the quadriceps muscle showed higher activity in the PPS group. In the comparisons between the exercises, in relation to gluteus medius and quadriceps muscle activity, the straight leg raise and straight leg raise with lateral hip rotation exercises showed more activity than squats in both groups. Among the squats, squats with adduction generated more gluteus medius activity in both groups, and no difference was noted among the squats for the quadriceps muscle. Therefore, rehabilitation programs that include exercises such as straight leg raises, straight leg raises with lateral hip rotation, and squats with adduction may be used for PPS patients.


Assuntos
Síndrome da Dor Patelofemoral/fisiopatologia , Músculo Quadríceps/fisiopatologia , Adolescente , Adulto , Nádegas/fisiologia , Eletromiografia , Exercício , Terapia por Exercício , Feminino , Humanos , Cinética , Joelho/fisiologia , Articulação do Joelho/fisiologia , Postura , Rotação , Comportamento Sedentário , Processamento de Sinais Assistido por Computador , Coxa da Perna/fisiologia , Adulto Jovem
12.
Eur J Appl Physiol ; 119(9): 1933-1942, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31230110

RESUMO

PURPOSE: The purpose of this study was to compare the effects of squat training with different depths on lower limb muscle volumes. METHODS: Seventeen males were randomly assigned to a full squat training group (FST, n = 8) or half squat training group (HST, n = 9). They completed 10 weeks (2 days per week) of squat training. The muscle volumes (by magnetic resonance imaging) of the knee extensor, hamstring, adductor, and gluteus maximus muscles and the one repetition maximum (1RM) of full and half squats were measured before and after training. RESULTS: The relative increase in 1RM of full squat was significantly greater in FST (31.8 ± 14.9%) than in HST (11.3 ± 8.6%) (p = 0.003), whereas there was no difference in the relative increase in 1RM of half squat between FST (24.2 ± 7.1%) and HST (32.0 ± 12.1%) (p = 0.132). The volumes of knee extensor muscles significantly increased by 4.9 ± 2.6% in FST (p < 0.001) and 4.6 ± 3.1% in HST (p = 0.003), whereas that of rectus femoris and hamstring muscles did not change in either group. The volumes of adductor and gluteus maximus muscles significantly increased in FST (6.2 ± 2.6% and 6.7 ± 3.5%) and HST (2.7 ± 3.1% and 2.2 ± 2.6%). In addition, relative increases in adductor (p = 0.026) and gluteus maximus (p = 0.008) muscle volumes were significantly greater in FST than in HST. CONCLUSION: The results suggest that full squat training is more effective for developing the lower limb muscles excluding the rectus femoris and hamstring muscles.


Assuntos
Exercício/fisiologia , Músculos Isquiotibiais/fisiologia , Joelho/fisiologia , Força Muscular/fisiologia , Postura/fisiologia , Músculo Quadríceps/fisiologia , Coxa da Perna/fisiologia , Adulto , Eletromiografia/métodos , Humanos , Masculino , Treinamento de Resistência/métodos , Adulto Jovem
13.
J Strength Cond Res ; 33(8): 2053-2056, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30946266

RESUMO

Lawrence, MA, Chin, A, and Swanson, BT. Biomechanical comparison of the reverse hyperextension machine and the hyperextension exercise. J Strength Cond Res 33(8): 2053-2056, 2019-The purpose of this study was to compare activation of the erector spinae, gluteus maximus, and biceps femoris muscles, lower back extension moment, and lower extremity range of motion (ROM) between the reverse hyperextension (RHE) and hyperextension (HE) exercises. Motion and muscle activation of the trunk and lower extremity were measured while 20 recreationally active individuals performed 2 sets of 10 repetitions of each exercise. Equivalent loads were used for each exercise. Peak, average, and integrated muscle activity, low back moment, and ROM between the trunk and pelvis and the thigh and trunk were calculated. A Wilcoxon signed-rank test (p = 0.05) revealed significantly greater integrated activity of the biceps femoris and gluteus maximus during the HE exercise. The RHE exercise generated greater peak (+129%), integrated (+63%), and mean (+78%) low back moment as compared to the HE exercise. The RHE resulted in a significantly greater thigh to trunk ROM, 76.6 compared with 64.7. However, the RHE used less lumbar flexion, 20.4 compared with 31.1 for the HE. The RHE movement profile is preferable because it provides greater hip ROM with less angular stress and equivalent erector spinae activity.


Assuntos
Exercício/fisiologia , Músculo Esquelético/fisiologia , Adulto , Nádegas/fisiologia , Eletromiografia , Feminino , Músculos Isquiotibiais/fisiologia , Humanos , Região Lombossacral/fisiologia , Masculino , Movimento , Músculos Paraespinais/fisiologia , Pelve/fisiologia , Amplitude de Movimento Articular/fisiologia , Coxa da Perna/fisiologia , Adulto Jovem
14.
Int Wound J ; 16(4): 940-945, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31016851

RESUMO

This was a prospective observational pilot study of a unique intermittent pneumatic compression (IPC) device designed to be applied in the thigh region of the affected limb in patients with lower limb ulceration of both venous and mixed (venous and arterial) aetiologies. This compression system consists of a circumferential three-chamber thigh garment and an electronic pneumatic compression pump operating over a repeated 4-minute cycle. Patients were recruited from outpatient wound clinics. Those recruited were treated with standard therapy in addition to IPC, which was applied for 2 hours per day, and followed up for a total of 8 weeks. The primary objective of the study was to examine the effects of IPC on wound healing over an 8-week period. The other objectives were to assess patients' experiences of pain and the acceptability of IPC device. Twenty-one patients were recruited, and wounds progressed towards healing in 95.24% (20/21) of the patients. Pain scores decreased in 83.33% (15/18) of the patients. Most patients felt that the thigh-applied IPC device was comfortable and easy to apply and remove. The thigh-administered IPC device can be recommended for use in routine clinical practice, especially when other treatment options are limited.


Assuntos
Dispositivos de Compressão Pneumática Intermitente , Extremidade Inferior/fisiopatologia , Coxa da Perna/fisiologia , Úlcera Varicosa/terapia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos
15.
Int J Sports Med ; 40(6): 390-396, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30965375

RESUMO

The aim of this study was to investigate the perception of vibrotactile signals during physical exercise by comparing differences in recognition between stationary and cycling positions. The impact of physical exercise on the ability to perceive vibrotactile cues is unknown, whereas the recognition in stationary position has been shown previously. Vibrating elements were positioned at 3 locations on the thighs and spine of 9 athletes to apply various vibrotactile cues. Subjects performed at 0, 50, 70 and 90% of their maximal cycling power output and denoted the interpretation of the vibration signals on a touchscreen. The results show a similarity in correct recognition between stationary position and physical exercise for the thighs and spine (p>0.1) and demonstrate a decrease in response time for 70 and 90% levels of physical exercise compared to 0 and 50% (p<0.001). Furthermore, vibrotactile signals at the spine are noticed more accurately and more rapidly compared to the thighs (p<0.01). These results suggest that vibrotactile feedback also has potential in applications during physical exercise. The potential use of vibrotactile feedback can be in cycling for, among other, correcting the aerodynamic position. Applications in other sports and health-related domains are feasible as well.


Assuntos
Sinais (Psicologia) , Exercício/fisiologia , Retroalimentação Sensorial , Percepção do Tato/fisiologia , Vibração , Feminino , Humanos , Masculino , Estimulação Física/métodos , Coluna Vertebral/fisiologia , Coxa da Perna/fisiologia , Adulto Jovem
16.
Gait Posture ; 70: 317-322, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30939339

RESUMO

BACKGROUND: Differences in coordinative variability have been previously reported between healthy and injured runners. Many running-related injuries have a sex bias, particularly patellofemoral pain (PFP), as female runners are approximately twice as likely to develop PFP compared to males. However, very little is currently known regarding sex differences in coordinative variability during running. RESEARCH QUESTION: Are there sex differences in continuous relative phase (CRP) variability for pelvis-thigh and thigh-shank couplings during the stance phase of running? METHODS: Pelvis, thigh, and shank segment kinematics were collected on 15 female and 15 male subjects during overground running at a self-selected easy pace (2.39-3.56 m/s) using a 10-camera 3D motion capture system. Continuous relative phase (CRP) variability was calculated between the pelvis-thigh and thigh-shank, and averaged during four distinct stance sub-phases. A mixed effects linear model compared CRP variability between sexes at each stance sub-phase. RESULTS: Compared to males, females displayed significantly lower pelvis-thigh CRP variability in the transverse plane during the loading response phase, and significantly lower thigh-shank CRP variability in the sagittal plane during the loading response and pre-swing phases. SIGNIFICANCE: Lower coordinative variability in females during the loading response for two couplings may provide additional insight into the sex bias for developing certain running-related injuries. However, any injury implications from these results are speculative and should be interpreted with caution.


Assuntos
Extremidade Inferior/fisiologia , Corrida/fisiologia , Caracteres Sexuais , Adolescente , Adulto , Fenômenos Biomecânicos , Feminino , Articulação do Quadril/fisiologia , Humanos , Articulação do Joelho/fisiologia , Masculino , Pessoa de Meia-Idade , Pelve/fisiologia , Coxa da Perna/fisiologia , Adulto Jovem
17.
NMR Biomed ; 32(5): e4072, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30861224

RESUMO

Aging is associated with impaired endothelium-dependent vasodilation that leads to muscle perfusion impairment and contributes to organ dysfunction. Impaired muscle perfusion may result in inadequate delivery of oxygen and nutrients during and after muscle contraction, leading to muscle damage. The ability to study the relationship between perfusion and muscle damage has been limited using traditional muscle perfusion measures, which are invasive and risky. To overcome this limitation, we optimized a diffusion-weighted MRI sequence and validated an intravoxel incoherent motion (IVIM) analysis based on Monte Carlo simulation to study muscle perfusion impairment with aging during post-exercise hyperemia. Simulation results demonstrated that the bias of IVIM-derived perfusion fraction (fp ) and diffusion of water molecules in extra-vascular tissue (D) ranged from -3.3% to 14% and from -16.5% to 0.002%, respectively, in the optimized experimental condition. The dispersion in fp and D ranged from 3.2% to 9.5% and from 0.9% to 1.1%, respectively. The mid-thigh of the left leg of four younger (21-30 year old) and four older (60-90 year old) healthy females was studied using the optimized protocol at baseline and at seven time increments occurring every 3.25 min following in-magnet dynamic knee extension exercise performed using a MR-compatible ergometer with a workload of 0.4 bar for 2.5 min. After exercise, both fp and D significantly increased in the rectus femoris (active muscle during exercise) but not in adductor magnus (inactive muscle), reflecting the fact that the local increase in perfusion with both groups showed a maximum value in the second post-exercise time-point. A significantly greater increase in perfusion from the baseline (p < 0.05) was observed in the younger group (37 ± 12.05%) compared with the older group (17.57 ± 15.92%) at the first post-exercise measurement. This work establishes a reliable non-invasive method that can be used to study the effects of aging on dynamic changes in muscle perfusion as they relate to important measures of physical function.


Assuntos
Imagem de Difusão por Ressonância Magnética , Exercício/fisiologia , Hiperemia/fisiopatologia , Movimento (Física) , Músculo Esquelético/fisiologia , Perfusão , Coxa da Perna/fisiologia , Adulto , Idoso , Simulação por Computador , Humanos , Processamento de Sinais Assistido por Computador , Razão Sinal-Ruído , Adulto Jovem
18.
J Strength Cond Res ; 33(4): 910-921, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30789578

RESUMO

Dariusz, M, Krzysztof, M, Pawel, C, Edward, S, Marek, K, Tomasz, S, Dorota, B, Rektor, Z, and Jan, C. Effects of plyometrics training on muscle stiffness changes in male volleyball players. J Strength Cond Res 33(4): 910-921, 2019-We investigated whether 6 weeks of specific plyometric training (PT) impacts on changes in muscle stiffness and enhances the vertical jumping ability as the indirect evaluation of the explosive power of the lower extremities of male volleyball players. Sixteen male collegiate volleyball players participated in this experiment. Regular PT was performed twice per week for 60-90 minutes each time. During each PT session, heart rate and muscle stiffness data were collected. Two series of 10 single measurements of each muscle (23 points of the front and back legs) were measured the day before the first enhanced training session and after completing each week of PT. Participants were tested for maximum effort in vertical jumping using the squat jump (SJ) with hands on thighs, countermovement jump (CMJ), and CMJ with a 2-step to 3-step approach. Jumping motor ability tests were completed. Data were collected 1 day before PT. The last measurement was performed 3 days after completing the last week of PT. The 6-week PT program only had an effect on the statistically relevant increase in muscle stiffness in the tibialis anterior (highest value, 593.86 ± 60.24 N·m) and quadriceps. Improvements in the explosive power of leg muscles resulted in a significant increase in the vertical jumping ability; there were improvements in SJ and CMJ (p = 0.0338 and p = 0.0007, respectively). If PT involves a moderate workload and if players never exceed the intensity target of the workout, then less muscle stiffness and muscle soreness may occur.


Assuntos
Elasticidade , Força Muscular/fisiologia , Exercício Pliométrico , Músculo Quadríceps/fisiologia , Voleibol/fisiologia , Humanos , Perna (Membro)/fisiologia , Masculino , Movimento/fisiologia , Coxa da Perna/fisiologia , Adulto Jovem
19.
Hum Mov Sci ; 64: 181-190, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30743163

RESUMO

Impaired hip muscle function has often been cited as a contributing factor to the development of iliotibial band syndrome (ITBS), yet our full understanding of this relationship is not well established. The objective of this study was to examine the effect of fatigue on hip abductor muscle function in females with ITBS. Female runners, 20 healthy and 12 with a current diagnosis of ITBS, performed a treadmill run to fatigue. Prior-to and following the run to fatigue, gluteus medius strength and median frequency values (an indicator of fatigue resistance) were measured. Additionally, onset activation timing of the gluteus medius and tensor fascia latae was measured during overground running. Both healthy and injured runners demonstrated decreased gluteus medius strength following the run to fatigue (p = 0.01), but there was no interaction between groups (p = 0.78). EMG onset activation timing did not differ between groups for the gluteus medius (P = 0.19) and tensor fascia latae muscles (P = 0.52). Injured runners demonstrated decreased gluteus medius initial median frequency values suggestive of fatigue (P = 0.01). These findings suggest that the gluteus medius muscle of female runners with ITBS does not demonstrate gross strength impairments but does demonstrate less resistance to fatigue. Clinicians should consider implementation of a gluteus medius endurance training regimen into a runner's rehabilitation program.


Assuntos
Quadril/fisiologia , Síndrome da Banda Iliotibial/fisiopatologia , Músculo Esquelético/fisiologia , Corrida/fisiologia , Adolescente , Adulto , Eletromiografia , Feminino , Articulação do Quadril/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Fadiga Muscular/fisiologia , Coxa da Perna/fisiologia , Adulto Jovem
20.
NMR Biomed ; 32(5): e4076, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30811753

RESUMO

Quantitative mapping of oxygen tension (pO2 ), noninvasively, could potentially be beneficial in cancer and stroke therapy for monitoring therapy and predicting response to certain therapies. Intracellular pO2 measurements may also prove useful in tracking the health of labeled cells and understanding the dynamics of cell therapy in vivo. Proton Imaging of Siloxanes to map Tissue Oxygenation Levels (PISTOL) is a relatively new oximetry technique that measures the T1 of administered siloxanes such as hexamethyldisiloxane (HMDSO), to map the tissue pO2 at various locations with a temporal resolution of 3.5 minutes. We have now developed a siloxane-selective Look-Locker imaging sequence equipped with an echo planar imaging (EPI) readout to accelerate PISTOL acquisitions. The new tissue oximetry sequence, referred to as PISTOL-LL, enables the mapping of HMDSO T1 , and hence tissue pO2 in under one minute. PISTOL-LL was tested and compared with PISTOL in vitro and in vivo. Both sequences were used to record dynamic changes in pO2 of the rat thigh muscle (healthy Fischer rats, n = 6), and showed similar results (P > 0.05) as the other, with each sequence reporting a significant increase in pO2 (P < 0.05) under hyperoxia compared with steady state normoxia. This study demonstrates the ability of the new sequence in rapidly and accurately mapping the pO2 changes and accelerating quantitative 1 H MR tissue oximetry by approximately 4-fold. The faster PISTOL-LL technique could enable dynamic 1 H oximetry with higher temporal resolution for assesing tissue oxygentation and tracking the health of transplanted cells labeled with siloxane-based probes. With minor modifications, this sequence can be useful for 19 F applications as well.


Assuntos
Oximetria/métodos , Oxigênio/análise , Espectroscopia de Prótons por Ressonância Magnética , Siloxanas/análise , Animais , Músculos/metabolismo , Imagens de Fantasmas , Ratos Endogâmicos F344 , Coxa da Perna/fisiologia
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