摘要:

BUCK, JOE A, LOUIS R. AMUNDSEN, and DAVID H. NIELSEN. Systolic blood pressure responses during isometric contractions of large and small muscle groups.Med. Sci. Sports Exercise.Vol. 12, No. 3, pp. 145–147, 1980. The purpose of this study was to test for a difference between the systolic blood pressure responses to voluntary contractions of large and small muscle groups of the upper extremity. Systolic blood pressure was measured at approximately 20 sec intervals during sustained isometric contractions of the index finger adductors and handgrip muscles contracting at 40% of maximal voluntary contraction (MVC). Contractions were terminated when EMG activity exceeded 10% of maximal activity of selected accessory muscles or when the 40% MVC Tension could no longer be held constant (±10%). The slopes of the regression lines representing systolic blood pressure responses to sustained isometric contraction of a small and large muscle group of the upper extremity were significantly different (p<.001). Older theories that pressor responses are determined only by the % MVC and not by the mass of contracting muscle need to be reexamined.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

OYSTER, NANCY. Changes in plasma eosinophils and cortisol of women in competition.Med. Sci. Sports Exercise, Vol. 12, No. 3, pp. 148–152, 1980. This study investigated degrees of stress in ten advanced and high intermediate college women tennis players when competing against other women and when competing against men. Evidence of stress was determined through fluctuations in the plasma eosinophil and cortisol levels. Blood samples were drawn three times (prior to exercises, after a five minute warm-up and after 15 minutes of competition) on each of the four days of testing. Each sample was analyzed for eosinophil counts and cortisol. Changes in eosinophil counts of 30 percent or more were considered significant. There appeared to be a trend toward eosinopenia during competitions as compared with warm-up None of the chi-squares comparing competition against men with competition against women was significant. Cortisol changes were analyzed using ANOVA. Again none of the competitive cortisol differences was significant among male or female competitors. When the cortisol data was pooled, significant differences in response to stress were found between the individual players. Individual responses were examined separately in the text of this article.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

HYMES, EMILY M. and ARTHUR L. DICKINSON. Characteristics of elite male and female ski racers.Med. Sci. Sports Exercise, Vol. 12, No, 3, pp. 153–158, 1980. Fifty-four members of the U.S. Ski Team who competed in the alpine, cross-country, or Nordic combined events were studied to learn more about the characteristics of elite ski racers in each of the events. Variables examined were percent body fatness, maximal oxygen uptake, maximal ventilation, isometric knee extension strength, power, agility, balance, and response time. In addition, isokinetic knee extension strength and endurance were measured on the alpine skiers. Cross-country skiers had higher VO2maxadjusted for weight or lean body weight than alpine skiers of the same sex. Male skiers had larger VO2maxwith or without adjustments for weight or learn body weight than female skiers in the same events. Alpine skiers had significantly more isometric knee extension strength (males = 3078 N, females = 2194 N) and power during the Margaria-Kalamen stair run (males = 1791 W, females = 1131 W) than cross-country skiers of the same sex. Differences in isokinetic knee extension strength at slow rates of contraction (30°/s) between male and female alpine skiers were not significant when strength was expressed as strength × kg LBW-1. Male alpine skiers produced more power and had more isokinetic leg strength x kg LBW-1at high contraction rates (180°/s) than female alpine skiers.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

VODAK, PAUL A., WILLIAM M. SAVIN, WILLIAM L. HASKELL, and PETER D. WOOD. Physiological profile of middleaged male and female tennis players.Med. sci. Sports Exercise, Vol. 12, No. 3, pp. 159–163, 1980. Cardiorespiratory characteristics, relative body fat, grip strength and selected skinfolds, circumferences and bone diameters were determined in 25 males and 25 females 9 (31–55 yr) whose exclusive mode of regular exercise was tennis (9.7–11.1 hr/wk). Mean resting heart rates were 54 beats/min for the males and 61 beats/min for the females. Mean resting blood pressures were 117/75 and 107/68 mmHg for the males and females, respectively. Compared to normally active populations of the same age and sex, the tennis players displayed an above average maximal oxygen uptake (mean values equal 50.2 ml/kg·min-1for the females), below average relative body fat (mean values equal 16.3% and 20.3% for the males and females, respectively), greater dominant grip strengths, and similar non-dominant grip strengths. The results indicate that either physically superior individuals choose to play tennis, or that regular tennis participation produces above average levels of fitness, or both.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

KNOWLTON, RONALD G., KENNETH J. ACKERMAN, PATRICIA I. FITZGERALD, STEPHEN W. WILDE, and MARIA V. TAHAMONT. Physiological and performance characteristics of United States championship class orienteers.Med. Sci. Sports Exercise.Vol 12, No. 3, pp. 164–169,1980. The purpose of this investigation was to study the anaerobic and aerobic power of female and male United States championship orienteers and relate these data to competitive performance. In addition, it was considered valuable to obtain a general physical description of the athletes. Anthropometrically, neither the females (n=5) nor the males (n=13) conformed to a somatotype classification typical of endurance athletes. Although the mean anaerobic power values for the females (76.6 kg·m·sec-1) and the males (106.6 kg·m·sec-1) were consistent with what is known for distance runners, the respective aerobic powers of 46.1 and 61.6 ml·kg-1·min-1were considerably below expectations for national class competitors. The explanation for this latter finding was attributed to their reported training programs. Partial residual plots and multiple regression procedures were used to determine the relationship between aerobic power and gender, respectively, with speed of competitive performance. The final equation to predict performance was P = −13.10 + 0.62(Vo2max) + 0.26 (Experience, years) - 0.03 (Anaerobic power) + 1.21 (gender) −0.01 (Vo2max)2with an R-square of 0.73 and P<0.01.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

SLAUGHTER, M.H. and T.G. LOHMAN. An objective method for measurement of musculo-skeletal size to characterize body physique with application to the athletic population.Med. Sci. Sports Exercise.Vol. 12, No. 3, pp. 170–174, 1980. The purpose of this paper is to present an objective method for estimating the musculo-skeletal size in relation to height for use in the study of body physique in athletes. The method can be applied to various male and female athletic groups and indicates the relative musculo-skeletal size by the extent to which each group falls above or below the regression of FFB on height as derived from the non-athletic male and female populations. Athletes within both sexes are found to differ greatly among performance events in this aspect of physique with track runners having the least amount of FFB related to height (within 1 standard error of the non-athletic population regression line) and professional football players having the most (2 to 3 standard errors above the non-athletic population line). Measurement of FFB can be obtained by underwater weighing or anthropometric dimensions and thus this approach offers application to the study and assessment of relative musculo-skeletal size in a variety of laboratory and field settings.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

JACKSON, ANDREW S., MICHAEL L. POLLOCK and ANN WARD. Generalized equations for predicting body density of women.Med. Sci. Sports Exercise.Vol. 12, No. 3 pp. 175–182, 1980. Previous research with women has shown that body composition regression equations derived from anthropometric variables were population specific. This study sought to derive generalized equations for women differing in age and body composition. The hydrostatic method was used to determine body density (BD) and percent fat (%F) on 249 women 18 to 55 years (X = 31.4 ± 10.8 yrs) and 4 to 4 %F (X = 24.1 ± 7.2%F). Skinfold fat (S), gluteal circumference (C) and age were independent variables. The quadratic from of the sum of three, four and seven S in combination with age and gluteal C produced multiple correlations that ranged from 0.842 to 0.867 with standard errors of 3.6 to 3.8 %F. The equations were cross-validated on a different sample of 82 women with similar age and %F characteristics. The correlations between predicted and hydrostatically determined %F ranged from 0.815 to 0.820 with standard errors of 3.7 to 4.0 %F. This study showed that valid generalized body composition equations could be derived for women varying in age and body composition, but care need to be exercised with women over an age of forty.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

MANN, RALPH V. and JAY T. KEARNEY. A biomechanical analysis of the Olympic-style flatwater kayak stroke.Med. Sci. Sports Exercise.Vol. 12, No. 3, pp. 183–188, 1980. To investigate the biomechanics of flatwater kayaking, the technique of nine Olympic caliber K-1 paddlers was analyzed using cinematographic and computer procedures. Results indicated that, during paddle-water contact, the horizontal arm action was one of push-then-pull with the push coming from the arm farthest from the water (thrust segments) followed by the pull coming from the ann closest to the water (draw segments). During this action, the center of paddle rotation shifted up the paddle shaft as the stroke progressed, which increased the time the paddle was in the power phase of the stroke. The horizontal movement patterns of the individual segments indicated that the push was accomplished by an integrated movement of the thrust wrist and elbow, with minimal shoulder involvement. Subsequently, the pull was accomplished by an integrated movement of the draw wrist, elbow, shoulder, as well as the thrust shoulder. During the latter stages of water contact, since the performers were unable to generate additional useful power, the paddle was rapidly withdrawn to avoid-dragging. Subject stability in the frontal plane was maintained by shifting the body mass toward the water contact side at paddle entry and away from it at exit. This action opposed the vertical forces produced as a by-product of the stroke. The final outcome of this stroke technique was the maintenance of the body center of gravity velocity while the boat oscillated under the performer.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

MARSHALL, JOHN L., NORMAN JOHANSON, THOMAS L. WICKIEWICZ, HENRY M. TISCHLER, BERTRAM L. KOSLIN, SUSAN ZENO, and AL MYERS. Joint looseness: a function of the person and the joint.Med. Sci. Sports Exercise.Vol. 12, No. 3, pp. 189–194, 1980. In order to evaluate whether joint-looseness is a function of a particular joint and/or a characteristic of the person (a trait), 124 male and female subjects varying in age from 6 to 18 were tested. Evidence was found that joint-looseness is a trait. The validity of the trait measure was enhanced by finding significant negative correlations with age and performance. Although females were significantly looser on some joint-looseness tests, they were not looser on the trait indicator.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID

摘要:

OSTERNIG, LOUIS R., BARRY T. BATES, and STANLEY L. JAMES. Patterns of tibial rotary torque in knees of healthy subjects.Med. Sci. Sports Exercise.Vol. 12, No. 3, pp. 195–199, 1980. Discrepancies in measures of active tibial rotation have been attributed to methodological variability and failure to adequately control accompanying foot and thigh motion. The purpose of this study was to assess maximum active tibial rotation on twenty-eight males utilizing a technique designed to stabilize the foot and thigh. Eversion and inversion motions of the talocalcaneal joint were controlled by means of a special boot connected to an isokinetic dynamometer modified with a position potentiometer. The results revealed symmetry between contralateral limbs with mean total ranges of motion of 57° and 59° for the right and left legs, respectively when tested and 90° of knee flexion and 50° at 45° of flexion. Converting these data to internal and external rotary components disclosed significant discrepancies (21–38%) between two methods applied to determine rotary neutral position. No significant differences were found between contralateral limbs for maximum torque development at all positions measured. Both range of motion and torque were found to be less at 45° of knee flexion when compared to the 90° position. Force data showed that all subjects consistently generated 90–100% of their peak torque within the initial 5–10° of active rotation and sustained relatively high torque values throughout an additional 15–20° before sharply reducing force magnitudes. These data support the concept of “wind up” effect of the medial and lateral hamstring muscles contributing to the rapid development of torque. Symmetrical patterns of contralateral limbs in torque and range of motion indicate that post-surgical comparisons with the unoperated limb to assess certain functional states of the knee may be reasonably accurate.

ISSN:0195-9131    

出版商:OVID    

年代:1980

数据来源: OVID