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Biomedical subjects

G Tenenbaum

Publications and source records attributed to G Tenenbaum.

At least 37 records · Page 2Linked to original sources
PubMed1994

Effect of vibratory stimulation training on maximal force and flexibility.

In this study, we investigated a new method of training for maximal strength and flexibility, which included exertion with superimposed vibration (vibratory stimulation, VS) on target muscles. Twenty-eight male athletes were divided into three groups, and trained three times a week for 3 weeks in one of the following conditions: (A) conventional exercises for strength of the arms and VS stretching exercises for the legs; (B) VS strength exercises for the arms and conventional stretching exercises for the legs; (C) irrelevant training (control group). The vibration was applied at 44 Hz while its amplitude was 3 mm. The effect of training was evaluated by means of isotonic maximal force, heel-to-heel length in the two-leg split across, and flex-and-reach test for body flexion. The VS strength training yielded an average increase in isotonic maximal strength of 49.8%, compared with an average gain of 16% with conventional training, while no gain was observed for the control group. The VS flexibility training resulted in an average gain in the legs split of 14.5 cm compared with 4.1 cm for the conventional training and 2 cm for the control groups, respectively. The ANOVA revealed significant pre-post training effects and an interaction between pre-post training and 'treatment' effects (P < 0.001) for the isotonic maximal force and both flexibility tests. It was concluded that superimposed vibrations applied for short periods allow for increased gains in maximal strength and flexibility.

Adult↗
PubMed1993

Breast-feeding habits among Jewish and Arab mothers in Hadera County, Israel.

A survey of breast-feeding habits of Jewish and Arab mothers was carried out in Hadera county in Israel. Jewish mothers breast-fed their babies approximately 3 months, while Arab mothers did so for 5 months. The rate of breast-feeding among Jewish and Arab mothers was 84% and 94.4%, respectively. The results indicated that education, previous experience, enjoyment, husband's encouragement, previous information about the importance of breast-feeding, belief that breast-feeding strengthens the mother-child relationship, and the convenience of breast- over bottle-feeding were all factors that had an impact on breast-feeding habits among Jewish but not Arab mothers. Breast-feeding as a means of birth control, religion, and impairment of the breast's shape were factors that had no effect on either Arab or Jewish mothers. Complications during pregnancy and cesarean delivery decrease the probability of breast-feeding in Arab and Jewish mothers. Jewish mothers stopped breast-feeding because of insufficient milk, fatigue, work obligations, and physician's recommendation. Among Arab mothers the main reasons were insufficient milk, physician's recommendation, baby's refusal, and nipple problems. Jewish mothers who decided not to breast-feed stated that the reasons were previous experience with insufficient milk, nipple problems, and unpleasant feelings. The few Arab mothers who did not breast-feed cited medical or nipple problems.

Breast Feeding↗
PubMed1993

The relationship between cognitive characteristics and decision making.

Team handball players (N = 118) underwent a number of cognitive tests to examine how much of their decision making (DM) ability, as measured through responses to game slides projected to them for 2 seconds under low and high exertion levels (i.e., walking and running), was accounted for by cognitive components. A stepwise multiple linear regression indicated that experience was the most pronounced predictor of DM capacity in both exertion conditions. In the walking condition, concentrational consistency, avoidance of concentrational mistakes, and short-term memory, together with experience, produced a multiple R of 0.48 with decision making. In the running condition, choice reaction time (CRT), intelligence, and short-term memory, together with experience, correlated 0.46 with DM. These differences in cognitive abilities, as predictors of DM under walking and running conditions, are discussed in terms of information processing models and other cognitive processes.

Attention↗
PubMed1992

Effect of iron on serum 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D concentrations.

In 13 of 17 infants (aged 10.5 +/- 4.3; mean +/- SD mo) with iron-deficiency anemia, the serum 24,25-dihydroxyvitamin D concentration was below the normal range and in 9 of these 13 the serum 25-hydroxyvitamin D concentration was below the normal range despite the fact that these infants received 10 micrograms vitamin D/d from the age of 1 mo. The infants were treated with intramuscular iron dextran (Imferon). The iron-dextran treatment increased the hemoglobin and serum iron concentrations as well as 25-hydroxyvitamin D and 24,25-dihydroxyvitamin D concentrations. It is known that iron deficiency impairs fat and vitamin A intestinal absorption. Therefore, it is suggested that absorption of vitamin D may also be impaired. This may contribute to the development of vitamin D deficiency. Iron supplementation may have improved the absorption of vitamin D in the small intestine and hence increased the vitamin D concentration in the plasma.

25-Hydroxyvitamin D 2↗
PubMed1992

A crisis related analysis of perceived spectators' behavior in competition.

Spectator behavior in competition is analyzed in terms of spectators' response (positive or negative), or lack of response in reaction to a player's action, or which is independent of a player's action, in a home or away game. This study investigated the perceived contribution of these variables to extreme psychological arousal states (crisis, noncrisis). Forty-eight elite ball-game players responded to a questionnaire asking them to estimate the occurrence probability of the Bayesian combinations among these variables under crisis and noncrisis conditions. An RM-ANOVA procedure revealed that under the crisis condition a negative response, an unsuccessful action, and a home game were rated as more probable, whereas under the noncrisis condition the reverse would be true. The athlete's psychological state was more strongly related to spectator response than to game location or athlete's action. Results are discussed theoretically in reference to the crisis construct.

Arousal↗
PubMed1992

Evaluation of anaerobic performance capacity by the isokinetic Ariel computerized exercise system-reliability and validity.

The present study examines the reproducibility and validity of computerized muscle strength and endurance evaluation protocols using the Ariel Computerized Exercise System (ACE). Since the ACE has only recently become commercially available, there are no published normative data for various exercises, nor are the measurements' accuracy and validity for the various exercise protocols documented. Twenty males (17 to 30 years old) performed a set of isokinetic maximal leg and arm exercises on the ACE Multi Function Unit twice on 2 separate days. Test-retest correlation coefficient ranged from 0.44 (bench press) to 0.91 (bench pull and leg extension flexion). Thirty additional male subjects (16 to 31 years old) performed, on 2 separate days, the Wingate Anaerobic Test (WAnT) (leg), and various force and endurance leg exercises (squat) on the ACE. Correlation coefficients of the various performance indices between the 2 test systems ranged from -0.02 to 0.23. The results obtained on the ACE indicate moderate to high reproducibility and low concurrent validity with WAnT.

Adolescent↗
PubMed1990

Anxiety, self-control and shooting performance.

55 rifle shooters were administered state-trait anxiety and self-control questionnaires. Shooting performance was recorded on 7 competitive occasions. Analysis indicated shooting performance is dependent more on anxiety state than on anxiety trait and self-control. Highly skilled shooters were less anxious and performed better across all competitions than moderately skilled shooters but did not differ on self-control and anxiety trait. The assumption that increased anxiety negatively affects performance through the mediation of self-control should be further studied.

Adaptation, Psychological↗
PubMed1990

Effect of handlebar gripping on blood pressure during cycle ergometry.

The effects on SBP, DBP and HR of gripping the cycle ergometer handlebar during dynamic cycle ergometry were evaluated in 39 healthy males. Heart rate, SBP and DBP were measured at 150 Watt power load while gripping and not gripping the handlebar of a cycle ergometer. The sequence of gripping first or second was randomized. No differences in SBP, DBP or HR were shown under the two treatments. For submaximal cycle ergometry the influence of static handgrip on the handlebar does not seem to have a significant influence on SBP, DBP or HR response to dynamic exercise.

Adult↗
PubMed1989

Game standings and psychological crisis in sport: theory and research.

Individual psychological crisis in competitive situations negatively affects motor performance. Psychological crisis development is probabilistically defined for every moment of the competition. This study estimates the effect of game standings defined interactively by three components: direction of lead, tendency, and event's expectancy, upon crisis vulnerability of a basketball player. Twenty-eight top basketball experts responded to a 'Game Standing Questionnaire' in which they were asked to assess probabilistically the relevance of game standings to crisis development. The Bayesian likelihood ratio was applied to these estimates. Results revealed that game standings have a considerable diagnostic relevance with regard to the development of an individual competitive psychological crisis. Furthermore, a negative tendency, a lead by the opposing team, and an unexpected event are more likely to occur under crisis conditions than under non-crisis conditions. Various aspects related to the validation and the practical applicability of the study are discussed.

Arousal↗
PubMed1988

Type A personality components and the blood pressure response to dynamic exercise.

One hundred and eleven healthy male subjects underwent cycle ergometry testing and completed a Jenkins type A personality survey. The subjects were divided into three equal groups with respect to their distribution on the Jenkins scales. The groups were compared for heart rate (HR), systolic blood pressure (SBP), the ratio of SBP/HR, and VO2 max/kg during rest and at exercise. Repeated measures MANOVA indicated that high scoring type A had lower HR values during exercise with no differences in SBP. However, the SBP/HR ratio was higher in the high type A group. The same was true for the component of hard-driving and competitiveness. Those scoring highest in this component also had higher VO2 max/kg body weight. From the description it could be conjectured that those with higher scores on type A components push themselves harder and thus achieve improvement in fitness. No clear explanation exists for the relative differences in SBP response.

Adult↗
PubMed1988

Time phases and the individual psychological crisis in sports competition: theory and research findings.

A conceptual model of the development of an athlete's individual psychological crisis during competition has recently been proposed and applied to basketball. In this article the diagnostic value of the time dimension with regard to such a process of crisis development is investigated. The relevance of six time phases for the diagnosis of individual psychological crisis during the competition is discussed in detail. The present study was conducted on 28 basketball experts who completed a 'phases of competition' questionnaire using the components of the Bayesian likelihood ratio (diagnostic value) for each phase. Results revealed that time limits can be determined unanimously and that the proposed phases do have a considerable diagnostic relevance as predicted on theoretical grounds. Various aspects related to the validation and the practical applicability of the present research are briefly discussed.

Basketball↗
PubMed1988

The interaction of individual psychological crisis and time phases in basketball.

Strain in basketball competition can be structured temporally into three psychologically meaningful phases: a beginning, main, and endphase of each half-time. The relevance of these phases for the diagnosis of an individual psychological crisis during the competition is discussed. Empirical evidence is based on the results of a study conducted on 28 basketball experts, who were asked to assess the components of the Bayesian likelihood ratio (diagnosticity) for each phase, thereby evaluating the crisis-relevance of that phase. Analysis of variance shows the significant influences of the hypothesized crisis-noncrisis character, half-time (first-second) and phase (beginning, main, end) on the (considerable) diagnostic relevance of the time-phases. The authors briefly discuss the meaning of the present results.

Adaptation, Psychological↗
PubMed1988

Pattern of psychological fitness as related to pattern of physical fitness among older adults.

The purpose of the present study was to investigate psychological fitness as well as physical fitness among late middle-aged normal men and women before, during, and after a 12-wk. physical activity program. Heart-rate of each subject was measured on a graded treadmill four times, and four psychological measures were taken: self-esteem, body-image, trait-anxiety, and well-being. Improvement of fitness was gradual and significant for both sexes, whereas no effects of time or sex were found on the first three psychological measures. Significant differences in pattern of change between women and men on well-being confirm previous findings that women report more depression and less satisfaction than men and thus are more sensitive to change.

Anxiety↗
PubMed1986

Effect of training on anaerobic threshold, maximal aerobic power and anaerobic performance of preadolescent boys.

To evaluate the effect of a 9-week interval training program on aerobic capacity, anaerobic capacity, and indices of anaerobic threshold of preadolescent boys, 28 10.2- to 11.6-year-old boys were tested. The test included laboratory evaluation of anaerobic capacity (Wingate anaerobic test) and evaluation of VO2 max and anaerobic threshold indices from a graded exercise test and measurement of blood lactate. The tests also included a 1200-m run to investigate the relationship of laboratory fitness indices, VO2 max, anaerobic threshold indices, and indices of anaerobic capacity to the performance of the run. It was found that in 10- to 11-year-old boys, a 9-week interval training increased the indices of anaerobic capacity: mean power by 10% and peak power by 14%. No change was found in percent fatigue. The training also increased VO2 max by 7% in absolute terms and by 8%/kg body weight. A significant increase was also found in the running velocity at the anaerobic threshold (running velocity at inflection point of lactate accumulation curve), but in relative terms (percent of VO2 max), the anaerobic threshold decreased by approximately 4.4%. It is concluded that proper training may improve maximal aerobic power and anaerobic capacity of preadolescent boys. It is also concluded that anaerobic threshold measures are less sensitive to the training regimen than VO2 max and that the 1200-m running performance is strongly associated with both aerobic and anaerobic capacities and less with the anaerobic threshold, which in preadolescent boys seems to be higher than in adults.

Anthropometry↗
PubMed1986

Cognitive behavioural strategies and anxiety in elite orienteers.

The primary purpose of this exploratory field study was to examine the use of cognitive behavioural strategies by highly skilled orienteers prior to and during competition. A secondary purpose of the study was to investigate whether differences in the level of qualification in orienteering is related to state anxiety. The subjects were divided into three classes with respect to their international and national records. The first two classes (A and B) were composed of international and national level athletes. The third class (C) included orienteers with unknown international records. Examination of the use of behavioural cognitive strategies during competition indicated that all orienteers reported a moderate use of mental imagery, above moderate use of inner talk and a focus of attention on present action rather than past or future. The other major findings were that prior to competition, superior orienteers reported use of higher self-efficacy, more positive outcome expectations and more task demand orientation than their less successful counterparts. Top orienteers coped more successfully with pre-competition anxiety by lowering their anxiety to a more moderate level prior to the actual performance.

Anxiety↗
PubMed1985

A statistical reevaluation of the STAI anxiety questionnaire.

This study examined the capability and efficiency of two commonly used scales, the trait and trait and state inventories (Spielberger et al., 1970), to measure anxiety construct (N = 100). The probabilistic Rasch Model (Wright & Masters, 1982) was applied to athletes' responses to trait and state anxiety items before competition (stress). The analysis indicated that several items of both scales produce misfit responses, share identical locations on the continuum, and do not produce equal units of measurement. The findings question the generalizability of the research on anxiety. Recommendations for improving the anxiety tests are made.

Adult↗
PubMed1985

Similarities between retrospective and actual anxiety states.

The purpose of the study was to examine the fit and calibration of the items in Spielberger, Gorsuch, and Lushene's (1970) State-Trait Anxiety Inventory during measurement of actual and retrospective anxiety. Subjects in the actual anxiety situation (n = 113) and in the retrospective anxiety situation (n = 55) were administered the inventory, and 20 scale items were analyzed individually by the probabilistic Rasch Model (Wright & Masters, 1982). Comparisons between the items' values in both situations revealed that 17 of the 20 items were rated similarly. In the retrospective anxiety state, 9 items (misfits) failed to discriminate between high- and low-anxious subjects, but only 6 failed to do so in the actual anxiety state. Despite the similarities, we recommend that the scales be modified to yield a more reliable measure of anxiety and to discriminate more accurately among subjects with varying levels of anxiety.

Anxiety↗