Abstract:
PURPOSE:To examine the effect of pelvic stabilization and two lower-limb configurations on the EMG activity of back and hip extensor muscles during a dynamic back extension exercise on a machine and to compare them between sexes. METHODS:Twenty-two healthy volunteers (11 men and 11 women) performed five trunk flexion-extension cycles at 40% of their maximal voluntary contraction (MVC) in a machine designed for back exercise. Two different positions were used: 1) seated position (seat horizontal, knees at 90 degrees ) and 2) semisitting position (seat slightly tilted forward at 15 degrees , knees at 45 degrees of flexion). In each position, three pelvic stabilization conditions were tested: 1) unrestrained (control condition), 2) partially restrained (posteriorly), and 3) totally restrained (posteriorly and anteriorly). EMG signals were recorded bilaterally with 12 pairs of electrodes placed on back muscles as well as on the gluteus maximus and biceps femoris. The muscular activation level, that is, the percentage of EMG amplitude relative to the maximal EMG obtained from MVC, was used to asses the relative contribution of each muscle group across exercises. RESULTS:In both sexes, two main results were found: 1) pelvic stabilization (partially and totally restrained) significantly (P < 0.05) increased the activity of all back muscles (average of 12%) and 2) semisitting position significantly decreased (range = 8-27%) the activity of two hip extensors compared with the seated position. Sex differences were also observed relative to the activity of some back muscles as well as the biceps femoris. CONCLUSIONS:Combining pelvic stabilization and semisitting position in back exercise machines might be a useful way to localize the effects of endurance training at the back muscles and this in both the sexes.
journal_name
Med Sci Sports Exercjournal_title
Medicine and science in sports and exerciseauthors
da Silva RA,Larivière C,Arsenault AB,Nadeau S,Plamondon Adoi
10.1249/MSS.0b013e318188446asubject
Has Abstractpub_date
2009-02-01 00:00:00pages
435-43issue
2eissn
0195-9131issn
1530-0315journal_volume
41pub_type
杂志文章abstract:INTRODUCTION/PURPOSE:Regular aerobic exercise reduces aortic stiffness. However, the mechanisms by which chronic exercise lowers arterial stiffness are not known. To determine the molecular mechanisms of these changes, the alteration of gene expression in the aorta by aerobic exercise training was measured with the mic...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000175052.37087.f8
更新日期:2005-10-01 00:00:00
abstract::It is has been suggested that physical activity may increase bone mineral density (BMD) in children, thereby preventing development of osteoporosis later in life. We studied 14 gymnasts, 14 swimmers, and 17 controls to investigate whether participation in different types of sports among girls 7-9 yr of age is associat...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199610000-00006
更新日期:1996-10-01 00:00:00
abstract::Estimates of muscular efficiency in competitive and recreational cyclists at similar work intensities and cycling frequencies were examined. Twelve healthy college-age male nonsmoker volunteers were grouped as either competitive (CC; N = 6) or recreational (RC; N = 6) cyclists based upon previous cycling experience. S...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章
doi:10.1097/00005768-199611000-00008
更新日期:1996-11-01 00:00:00
abstract::The purpose of this study was to examine the accuracy and quality of a series of cycle ergometry tests used to estimate maximal aerobic capacity (VO2max). One-hundred nine males and 71 females participated in five tests: a maximal exercise test on the treadmill, three Air Force Cycle Ergometry Tests (AF1, AF2, AF3), a...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199711000-00019
更新日期:1997-11-01 00:00:00
abstract:PURPOSE:To compare the total exercise loads (intensity x volume) of the Vuelta a España and Tour de France during the last year. METHODS:Seven professional road cyclists (28 +/- 1 yr; [OV0312]O(2max): 74.6 +/- 2.2 mL.kg-1.min-1) who participated in both Tour and Vuelta during the years 1997, 1999, 2000, or 2001 were c...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.MSS.0000064999.82036.B4
更新日期:2003-05-01 00:00:00
abstract::Knee injuries continue to present a complex set of clinical problems. The answers to these problems have recently been redefined by the application of sophisticated biomechanical research methods to the study of knee ligaments and joint function. This manuscript reviews contributions which our laboratory has made to t...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/00005768-198410000-00002
更新日期:1984-10-01 00:00:00
abstract:PURPOSE:To compare voluntary and electrically evoked knee extensor torque, surface electromyography (EMG), and activation level obtained under seated versus supine position, i.e., with shortened versus lengthened rectus femoris (RF) muscle. METHODS:The knee extensor torque obtained during maximal voluntary contraction...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.MSS.0000084426.03247.93
更新日期:2003-09-01 00:00:00
abstract:PURPOSE:This investigation assessed the effects of a 9-wk regimen of creatine monohydrate (Cr x H2O) supplementation coupled with resistance training on body composition and neuromuscular performance in NCAA Division I football athletes. METHODS:Twenty-five subjects were randomly assigned in a double-blind, randomized...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1097/00005768-200110000-00009
更新日期:2001-10-01 00:00:00
abstract::Sixteen untrained males, age 46 +/- 11 yr (mean +/- SD), were studied to determine the effects of 20 wk of strength training on lipoprotein-lipid profiles and post-heparin lipase activities. All subjects had abnormal lipoprotein-lipid profiles and at least two other risk factors for coronary heart disease (CHD). To co...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1991-10-01 00:00:00
abstract:PURPOSE:To determine the effect of dietary antioxidant restriction on oxidative stress, antioxidant defenses, and exercise performance in athletes. Oxidative stress has been shown to increase during exercise. To alleviate oxidative stress, a high intake of antioxidant rich foods or supplements may be required in traine...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章
doi:10.1249/01.mss.0000150016.46508.a1
更新日期:2005-01-01 00:00:00
abstract:PURPOSE:This study established the published prediction equations for the energy expenditure of walking and running compared with the measured values. To make this comparison we first determined whether differences exist in energy expenditure for 1600 m of walking versus running, and whether energy expenditure differen...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000147584.87788.0e
更新日期:2004-12-01 00:00:00
abstract:PURPOSE:Resting cardiac vagal modulation (RCVM) and postexercise vagal reactivation (PEVR) are markers of parasympathetic activity. We investigated whether adaptations in these markers to aerobic training are influenced by baseline autonomic control. METHODS:Forty healthy men (19.2 ± 0.8 yr) of similar cardiorespirato...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,随机对照试验
doi:10.1249/MSS.0000000000000532
更新日期:2015-06-01 00:00:00
abstract::A 25-yr-old female triathlete presented with 4 d of increasing left calf pain that started 1 d after an elective termination of pregnancy during the eighth week of gestation. She had been training with running, bicycling, and swimming but did not recall any injury to the calf muscle. Deep venous thrombosis of the calf...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:
更新日期:1992-01-01 00:00:00
abstract:PURPOSE:To evaluate effectively interventions to increase physical activity among older persons, reliable and valid measures of physical activity are required that can also detect the expected types of physical activity changes in this population. This paper describes a self-report physical activity questionnaire for o...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-200107000-00010
更新日期:2001-07-01 00:00:00
abstract::This study compared the effects of exercise or TXB2 and beta-TG when evaluated by four methods: 1) not adjusted; 2) adjusted for plasma volume changes (PV); 3) standardized per 10(5) platelets (PC); 4) or both PC and PV (PC-PV). Blood was collected from 16 men (41.3 +/- 8.1 yr) at rest after 30 min of exercise (IPE) a...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199705000-00018
更新日期:1997-05-01 00:00:00
abstract:PURPOSE:The study's purpose was to examine the effects of a short-term period with intensified training or training cessation of trained soccer players on VO(2) kinetics at 75% maximal aerobic speed, oxidative enzymes, and performance in repeated high-intensity exercise. METHODS:After the last match of the season, 18 ...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e318211c01a
更新日期:2011-09-01 00:00:00
abstract:PURPOSE:This study investigated the kinetic and the kinematic differences in female athletes in single-leg static jumps in an aquatic environment compared with those performed on dry land. METHODS:Twelve healthy, junior national team handball players participated. Subjects completed a familiarization and a testing ses...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3181a252b7
更新日期:2009-09-01 00:00:00
abstract:PURPOSE:We evaluated the associations between accelerometer-estimated physical activity (PA) intensity and heart rate variability (HRV) and examined mediation of these associations by glycemic control indices and other cardiovascular disease risk factors. METHODS:Data were from 1668 participants (X[Combining Overline]...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000002259
更新日期:2020-06-01 00:00:00
abstract:INTRODUCTION:Despite the widespread utilization of the Balance Error Scoring System (BESS) in the evaluation of concussion, it has been criticized for its error-based scoring that is susceptible to floor and ceiling effects and substantial inter-rater variability. A biomechanical outcome, Cleveland Clinic Postural Stab...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000001660
更新日期:2018-10-01 00:00:00
abstract:UNLABELLED:Two recently identified glucose transporters, GLUT8 and GLUT12, are expressed in human skeletal muscle and may be involved in insulin-mediated sugar transport. PURPOSE:The purpose of this study was to measure GLUT8 and GLUT12 mRNA levels in endurance-trained versus sedentary individuals in an effort to dete...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/01.mss.0000222837.74015.f1
更新日期:2006-06-01 00:00:00
abstract:INTRODUCTION AND PURPOSE:Physical inactivity in postmenopausal women contributes to a rise in atherogenic risk factors associated with the metabolic syndrome. Although regular physical activity positively contributes to health, inactivity progressively increases with age. The Dose Response to Exercise in Women aged 45-...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1249/01.MSS.0000113738.06267.E5
更新日期:2004-02-01 00:00:00
abstract:PURPOSE:This study examined some physiological and performance responses to a 6-d taper, and the influence of training intensity and volume on these responses. METHODS:After 15 wk of training, 8 well-trained male middle-distance runners were randomly assigned to either a moderate volume taper (MVT, N = 4) or a low vol...
journal_title:Medicine and science in sports and exercise
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1097/00005768-200002000-00038
更新日期:2000-02-01 00:00:00
abstract::During the past three to four decades, a significant amount of data was collected to reinforce the notion that mitochondrial function is irrevocably linked to mitochondrial structure. Indeed, data from numerous studies have revealed several salient points of mitochondrial biology that include the following: 1). mitoch...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章,评审
doi:10.1097/00005768-200301000-00014
更新日期:2003-01-01 00:00:00
abstract:PURPOSE:This study examined the effect of exercise training on prepubertal children's (ET, N = 28) lipid-lipoprotein profile, relative to a maturity matched control group (CON, N = 20). METHODS:Training for ET involved stationary cycling for 30 min, 3 times.wk-1 for 12 wk, at 79.3 +/- 1.2% (mean +/- SD) peak heart rat...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199812000-00005
更新日期:1998-12-01 00:00:00
abstract:PURPOSE:The purpose of this study was to compare the predictive accuracy of previously published skinfold (SKF) equations for estimating body density of 134 premenopausal African-American women (18 to 40 yr). METHODS:The equations cross-validated were: the sum of seven skinfolds equation (JPW7) and the sum of three sk...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1097/00005768-199811000-00015
更新日期:1998-11-01 00:00:00
abstract:PURPOSE:This study aimed to determine whether physical activity patterns are associated with sleep later at night and if nighttime sleep is associated with physical activity patterns the next day among adult women. METHODS:Women (N = 353) living throughout the United States wore a wrist and a hip accelerometer for 7 d...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000001000
更新日期:2016-10-01 00:00:00
abstract:PURPOSE:Prolonged sitting time (ST) is associated with higher mortality. However, previous studies used only a single measure of ST at baseline, so they could not directly assess the effect of continued exposure to high ST, or of changes in ST, on mortality. We prospectively assessed the association of continued sedent...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3182897e87
更新日期:2013-08-01 00:00:00
abstract:PURPOSE:This study aimed to evaluate the relationship between race car cockpit temperature and thermal strain indicators among race car drivers. METHODS:Four male racing drivers' heart rate (HR), skin temperature (Tskin), and core temperature (Tcore) were measured continuously using the Equivital Life Monitor bio harn...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0000000000002483
更新日期:2021-02-01 00:00:00
abstract:INTRODUCTION:Competitive female athletes restrict energy intake and increase exercise energy expenditure frequently resulting in ovarian suppression. The purpose of this study was to determine the impact of ovarian suppression and energy deficit on swimming performance (400-m swim velocity). METHODS:Menstrual status w...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e3182a32b72
更新日期:2014-01-01 00:00:00
abstract:PURPOSE:To compare pacing and performance of schoolchildren between running tasks where the end point was defined in units of either distance or time. METHODS:Thirty-eight schoolchildren (age = 12.6 ± 0.5 yr, mass = 46.2 ± 7.5 kg, stature = 150 ± 7 cm) first performed a best-effort 750-m running task on a 150-m runnin...
journal_title:Medicine and science in sports and exercise
pub_type: 杂志文章
doi:10.1249/MSS.0b013e318271edfb
更新日期:2013-02-01 00:00:00