Journal of Human Movement Studies

Online ISSN: 0306-7297
Publications
Article
70 university students attempted to catch, single-handed, tennis balls delivered by a projection machine. Groups of Ss operated under conditions in which the time from sight of the ball to contact (total-time) remained constant but in which the period of illumination varied. Catching success was a discontinuous function of total-time, while conditions within groups yielded equivalent levels of performance. The discontinuity is discussed in terms of motion perception and a transition in processing from the image-retinal system to the eye-head motion detecting system. A 2nd experiment (R. H. Sharp, 1975), with 10 Ss, which employed the electro-oculographic technique of recording eye movements, provides some support for this hypothesis. In addition, it highlights the importance of eye and head movement in ball-catching skills. (19 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
 
Article
Presents results from 3 experiments with 11 19-60 yr old Ss. Ss attempted to perform a standard movement of the upper limb under loading conditions that were changed without notice just prior to the voluntary response. Results suggest that the height of the initial volley is preprogrammed centrally but that the silent period and size of the 2nd volley depend on feedback from the periphery. (17 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
 
Article
The purpose of the present study was to investigate if virtual reality technology might enhance the psychological benefits of aerobic exercise in a laboratory setting. In this study, 121 college students (72 females, 49 males) were randomly assigned to one of four 30-minute bicycle experimental or control conditions (i.e. exercise alone, exercise with virtual reality technology, virtual reality without exercise, and a control videotape condition watching someone bicycle). The Activation- Deactivation Adjective Check List (AD-ACL) measuring energy, tiredness, tension and calmness was administered immediately before and after each experimental or control condition as well as administered prior to bedtime. Our results suggest that virtual reality may enhance the energy and tiredness levels of females hours after the completion of the exercise and virtual reality experience, but that this is not the case for males. Our results found no enhanced virtual reality effect immediately following exercise participation but did find that exercise participants had more energy (with or without virtual reality) relative to control subjects. Exercise and virtual reality both resulted in less tiredness compared with controls. To our knowledge, this is the first empirical study investigating virtual reality and the psychological benefits of exercise. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
 
Article
Investigated the responses of a 31-yr-old male athlete to continuous paced work at moderate intensity for 100 hrs under conditions of controlled liquid and energy intake. Heart rate (HR) increased at first, then gradually declined to reach a steady state after 44 hrs. Lung function (vital capacity and forced expiratory volume) and reaction time showed a significant deteriorating trend over the experimental period. HR, lung function, and reaction time were significantly intercorrelated. Subjective time perception was correlated with reaction time and HR. Blood glucose levels were not related to any of the other variables. None of the variables exhibited a circadian rhythm. Periodicities over 8, 48, and 96 hr cycles were observed in lung function. Scores in 2 mental performance tests were not greatly affected over the duration of the experiment. (31 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
 
Article
16 male university students either interacted with or observed 4 performers, each programmed to exhibit all 4 combinations of 2 facial expressions (frowning and smiling) and 2 gaze patterns (10% and 90% looking). Ss then rated the performers on 20 rating scales. Judgments along "evaluative" dimensions were affected only by the facial expression, judgments of "potency" only by the gaze pattern and "activity" by both (additively). Observing, rather than interacting, did not affect these judgments, except that stooges were rated "more difficult to understand' when observing. In no case did gaze and facial expression interact to affect judgments. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
 
Article
Conducted 2 experiments with 4 university students who served as encoders and 36 who served as decoders. English, Northern Italian, and Southern Italian encoders were videotaped while role-playing specific emotions and degrees of 2 dimensions of emotion (sleep-tension and pleasant-unpleasant). Decoders from the same cultures as the encoders identified the emotions expressed from silent videotape recordings presented in 1 of 3 conditions of visibility--all of screen visible, face only, or rest of body visible. Results show that for discrete emotions and the pleasantness dimension the face is the best source of such information and that the rest of the body does not provide any additional information. For the intensity dimension, judgments based on bodily cues were of the same degree of accuracy as those based on facial cues. In no case was information from facial and bodily cues cumulative. The data suggest that for neither the English nor the Italians do hand gestures and other bodily cues function as a major source of information in the communication of emotions. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
 
Article
A review of classical concepts of time perception makes it necessary to acknowledge a distinction between the reduction of temporal uncertainty through mediation on the basis of some train of input information (input timing) and that which arises only as a by-product of the execution of a planned motor act which is being designated operational timing. Experimental support based on cine analysis of complex skilled movements in novice, intermediate, and expert human performers is provided, and attention is drawn to the misconception that attributes temporal efficiency in movements to an active process of time perception. (15 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
 
Article
Conducted 2 experiments with 24 undergraduates and 30 15-29 yr olds. Results show that vision functions proprioceptively as an integral component of the control system for maintaining a stance. In several stances, Ss' body sway could be controlled by moving their surroundings (i.e., by manipulating their visual proprioceptive information about body sway). A previous experiment had shown the same for toddlers. Results also show that visual proprioceptive information is generally more sensitive than mechanical proprioceptive information from the vestibular system and the ankles and feet and is yet more sensitive if the person is facing a nearby object. Consequently, vision normally improves balance in normal standing and especially in less practiced stances where ankle-foot proprioception is impoverished; indeed, if it is too impoverished, balance is dependent on visual proprioception. This suggests that, in learning a new stance, visual proprioception normally plays a lead role in tuning up ankle-foot proprioception and muscular control. (18 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
 
Mean values of VO 2max , compared to upper and lower limits, according to FITNESSGRAM.
Means and SD of selected risk factors by
Article
The purpose of this study was to examine the relationship between levels of cardiorespiratory fitness (CRF) and selected cardiovascular disease risk factors in a group of schoolgirls. The sample included 268 Caucasian schoolgirls (8-15yrs). Cardiorespiratory fitness (VO2max) was assessed by 20m shuttle-run test. Total cholesterol (TC) level and triglycerides (TG) were assessed by Reflotron Analyser (Boehringer Mannheim). Systolic (SBP) and diastolic (DBP) blood pressures were evaluated using a Dinamap Monitor (model 8800). Body fat was estimated from skinfold measurement (subscapular and triceps). Associations between cardiorespiratory fitness and body fat (%fat) [r=-36, p≤0.01] and triglycerides (r= -0.18, p≤0.01) were found. However when adjusted for age and %fat those correlations disappeared. Analysing the data by quartiles of VO2max, it was found, that as the level of VO2max increased, the values of cardiovascular disease risk factors (SBP, DBP, BMI %Fat, TC, TG) decreased. However only the %fat and BMI showed consistent significant differences (p≤0.05) between fitness groups. Our data showed a weak association between CRF with lipids and blood pressure. The data also enhanced the role of body fat on the girls' CRF level. Our findings pointed out that the values of the VO2max would appear to agree with suggested minimal health fitness standard levels incorporated in the Fitnessgram test related to girls.
 
Article
Small groups of athletes (maximum size 8) were taught to voluntarily control their finger temperature, in a test of the feasibility of thermal biofeedback as a tool for coaches. The objective was to decrease precompetitive anxiety among the 140 young, competitive athletes (track and field, N=61; swimming, N=79), 66 females and 74 males, mean age 14.8 years, age range 8.9-20.5 years, from local high schools and swimming clubs. The biofeedback (visual and auditory) was provided by small, battery-powered devices that were connected to thermistors attached to the middle finger of the dominant hand. An easily readable digital LCD display, in 0.01 degrees C increments, provided visual feedback, while a musical tone, which descended in pitch with increased finger temperature, provided the audio component via small headphones. Eight twenty minute sessions were scheduled, with 48 hours between sessions. The measures employed in this prestest-posttest study were Levenson's locus of control scale (IPC), and the Competitive Sport Anxiety Inventory (CSAI-2). The results indicated that, while significant control of finger temperature was achieved, F(1, 160)=5.30, p<.05 and internality was significantly correlated with the ability to control finger temperature (p<.01), the decrease in precompetitive anxiety was non-significant.
 
Article
This study sought to identify personality variables associated with elite (springboard and platform) diving. It was hypothesised that elite divers would show distinct differences on a set of selected personality scales from a sample of elite athletes fi-om other sports. An exploratory analysis was also conducted on the diving sample to examine the potential relationship between the personality scales and a standardised performance index of diving ability.. One-way analyses of variance revealed that divers (n = 18) reported higher levels of thrill and adventure seeking, experience seeking and disinhibition than the non-divers (n = 18). Divers also tended to be more, confident in their physical ability and appearance than non-diving athletes. Within the diving sample a standardised performance index was calculated. Multiple regression analysis indicated that specific personality variables did not predict elite diving ability. Selected personality variables appear to distinguish elite divers from elite non-diving athletes, but did not appear to be predictive of actual performance. Further research is needed to clarify to what extent the characteristics identified are present prior to participation in diving or are the result of participation in diving. These findings are discussed with reference to the prediction of sports performance and the potential role of personality assessment.
 
Article
Understanding the components of the physique and body of basketball players is important for better monitoring of training and diet programs. Therefore the purpose of this study was to examine the body composition characteristics of elite European basketball players. Sixty-four players of the Greek National Teams participated in this study. The players were divided into three age groups: juniors (n=6), under 22 (n=30) and men (n=18). The percentage body fat and fat free mass were measured using bioelectrical impedance. Two-way analysis of variance was used to determine the interaction of age group and player position with respect to percentage body fat, fat free mass and body mass index. The percentage body fat was 11.7%. The percentage body fat of juniors (11.1%) and under-22 (10.9%) team was significantly lower as compared to men (13.5%). Guards had significantly lower percentage body fat (10.5%) compared to centres (13.1%). These results can assist in the development of a normative database on body composition characteristics of basketball players as the players move from the juniors to the professional men's level and among different player positions.
 
Article
The aim of this study was to analyse, in swimming-pool conditions, the behaviour of the kinematic parameters – stroke rate (SR), stroke length (SL) and stroke index (SI) - during a time to exhaustion test performed at the minimum velocity that elicits maximal oxygen uptake (TLim-v O2max) in elite freestyle swimmers. Eleven swimmers from the National Portuguese Swimming Team (5 male and 6 female) performed an intermittent incremental test for v O2max assessment and an all-out swim at v O2max to determine TLim-v O2max and to analyse the evolution of the kinematic parameters throughout the test. SR increased and SL (and SI) decreased during the TLim-v O2max test, as a general tendency. When the differences in SR, SL and SI between each 12.5% section of the test were tested, a significant increase in SR and a decrease in SL and SI was verified at 25% [(74.00 (25.83 m)], 50% [(148.10 (51.66 m)] and 87.5% [(259.15 (90.41 m)] of the TLim-v O2max duration. These data showed a reduction of the propelling efficiency throughout such a test. These findings could be useful when designing training programmes, namely of middle distance swimmers, taking into consideration maximum aerobic speed, time to exhaustion and propelling efficiency.
 
Article
A study was designed to determine the effects of various ball sizes on children's catching ability and to examine the results as a between- and within-group factor. It was believed that the use of the two-test design would help to establish the validity of past and future tests of this nature. The between-subjects design group consisted of 48 first grade children who were required to make a series of catches using one ball size (6 inch, 8.5 inch, or 10 inch diameter). Each of the children on the within-subjects group received a total of 12 trials, catching all three ball sizes in random order. Since the initial analysis showed a significant trials effect as the subjects adapted to the task, data were modified to reduce this effect. Subsequent analyses showed that the only significant interactions in the between-subject design situation was between the size of the ball and the gender of the subject. For the within-subjects design group, only the main effect of the ball size was significant. The 10 inch diameter ball resulted in more successful catching than the 6 inch ball. The two design types appeared to be interchangeable in the paradigm. (FG)
 
Article
Summary This study examines the impact of a teaching volleyball approach proposing a step-by step game forms development on students' play performance. An entire 7th grade class composed of 12 girls and 13 boys (aged 12-15) from a northern Portugal public junior high school participated in a teaching experiment implemented during a 12-lesson unit. Program sought after technical efficiency and efficacy, as well as tactical adjustment and decision-making within simplified game play contexts. The results indicated that the class as a whole made significant improvements in several measures of play performance either in technical or tactical domains. Girls and low skill level students seemed to take more benefit from the program than boys or high skill level students. The transition from a cooperative-oriented to a more competitive-oriented game play is likely to need much more time to attain significant effects.
 
Article
A wide range of electromechanical delay (EMD) values have been reported in the literature which attributed to either the biological characteristics of the subjects or the experimental methods adopted. The purpose of the present study was to investigate the normal range of EMD in different age and gender groups in normal healthy population under a consistent experimental condition. The subject sample consisted of 176 volunteers (91 males and 85 females) in an age range from 8 to 78 years. During testing the subject sat in a testing chair equipped with a force transducer connected to the lower leg. Surface electromyograms were recorded from the rectus femoris, vastus lateralis and vastus medialis muscles. Upon seeing a visual stimulus, the subject performed a maximal isometric knee extension. The findings in this study included: (1) the range of EMD values in the maximal isometric knee extension was from 20 to 100 ms; (2) the longest EMD value was found in the 8-12 year age group (p<0.05), there were no significant EMD variations found in the 13-16, 18-24 and 25-42 year groups, and EMD elongated in the 56-78 year group (p<0.05); (3) there was no gender difference in EMD in the overall subject population, however, in the 18-24 year group, the EMD of men was shorter than women (p<0.05); (4) significant correlation coefficients were found between EMD and maximal contraction force, the rate of force development, body height and mass (p<0.05); (5) there were no significant differences found between the mean EMD values of the vastus lateralis, rectus femoris and vastus medialis, however, EMDmax, ie. the longest EMD among the three muscles in each contraction, was significantly longer than the mean EMD values of the three muscles (p<0.05).
 
Article
The purpose of this study was to examine the effect of gender in the relationship between time limit at the minimum velocity that elicits maximal oxygen consumption (TLim-v O2max) and three swimming economy (SE) related parameters: the energy cost corresponding to v O2max (Cv O2max), the slope of the regression line obtained from the relationship between energy expenditure ( ) and corresponding velocities in a incremental test (Cslope) and the ratio obtained by the mean value and the velocity mean value of the incremental test (Cinc). Each subject of two gender groups – 11 male and 12 female swimmers - performed an incremental test for v O2max assessment and an all-out TLim-v O2max test. TLim-v O2max, v O2max, Cv O2max, Cslope and Cinc averaged, respectively, 244.6±56.5s, 1.45±0.04m.s-1, 15.9±2.2J.kg-1.m-1, 35.0±4.8J.kg-1.m-1 and 14.3±2.4J.kg-1.m-1 in the male group and 248.0±60.5s, 1.33±0.04m.s-1, 14.3±1.8J.kg-1.m-1, 35.7±6.4J.kg-1.m-1 and 11.5±1.5J.kg-1.m-1 in the female group. An inverse correlation was found between TLim-v O2max and Cslope for the entire group (r=-0.78, p<0.001) and for each gender group (r=-0.90, p<0.001 and r=-0.61, p<0.05, for female and male respectively), confirming that SE is a very important performance-influencing factor. Complementarily, despite the relationship between energy cost and TLim-v O2max efforts is evident in each gender, the TLim-v O2max tests performed by the female swimmers seem to depend more on their own SE than on male swimmers.
 
Article
The aim of this study was to determine the relationship between the interval shuttle run test (ISRT) and maximal oxygen uptake (VO2max) in soccer players. The ISRT was developed to measure interval endurance capacity. During the ISRT, subjects alternately run for 30sec and walk for 15sec with increasing speed until exhaustion. Within a two week period, 15 male soccer players performed the ISRT and a maximal treadmill test to measure VO2max. The number of runs on the Isrt correlated moderately with VO2max (r=0.77, 95% CI=0.43-0.92). We conclude that aerobic energy production, as indicated by the VO2max contributes for approximately 60% of the total energy requirement during the ISRT
 
Article
The effects of type of KR and KR frequency on the learning of a sequential timing task were examined. Subjects practiced three task versions that all had the same relative timing among movement segments, but differed with regard to the overall movement time (MT). KR was either presented in terms of the relative segment MTs or in terms of the absolute segment MTs, in addition to the overall duration. The type of KR was crossed with KR frequency in a 2 & 2 design. That is, subjects under both relative-timing KR and absolute-timing KR conditions were given KR either after every practice trial (100% KR) or after every other trial (50% KR). In a delayed retention test on the practiced task versions, type of KR and KR frequency produced additive effects, with relative-timing KR and a reduced KR frequency leading to more effective learning of the relative-timing structure than absolute-timing KR and KR after every trial. Transfer to task versions with the same relative timing but novel overall durations was facilitated by relative-timing KR, compared to absolute-timing KR, whereas the effect of the reduced KR frequency did not reach significance. When transfer to tasks with a new relative timing was required, however, the reduced KR frequency generally produced better relative timing performance than frequent KR. Overall, the results suggest that both reducing the relative frequency of KR and providing subjects with KR about relative timing can enhance the learning of the relative timing structure, or GMP learning. In addition, the present results demonstrate that a reduced KR frequency not only enhances learning of the practiced relative timing structure but also transfer to a new relative timing, compared to frequent KR.
 
Article
Thesis (P.E.D.)--Indiana University, 1973. Vita. Bibliography: leaves 100-108. Microfiche. s "UO-75 382--UO-75 383."
 
Article
Time motion analysis is extensively used to assess the demands of team sports. At present there is only limited information on the reliability of measurements using this analysis tool. The aim of this study was to establish the reliability of an individual observer's time motion analysis of rugby union. Ten elite level rugby players were individually tracked in Southern Hemisphere Super 12 matches using a digital video camera. The video footage was subsequently analysed by a single researcher on two occasions one month apart. The test-retest reliability was quantified as the typical error of measurement (TEM) and rated as either good (<5% TEM), moderate (5-10% TEM) or poor (>10% TEM). The total time spent in the individual movements of walking, jogging, striding, sprinting, static exertion and being stationary had moderate to poor reliability (5.8-11.1% TEM). The frequency of individual movements had good to poor reliability (4.3-13.6% TEM), while the mean duration of individual movements had moderate reliability (7.1-9.3% TEM). For the individual observer in the present investigation, time motion analysis was shown to be moderately reliable as an evaluation tool for examining the movement patterns of players in competitive rugby. These reliability values should be considered when assessing the movement patterns of rugby players within competition.
 
Article
The aim of the present study was to identify, from multiple regression equations, the relative importance of selected kinematic variables with regard to finishing time (FT) for elite male and female 100m and 200m breaststroke swimmers. Competitive performances were collected and analysed (using digitising technology) for A and B finalists in 100m events (male: n = 159, FT = 65.07 ± 2.62 s; female: n = 157, FT = 74.06 ± 3.66 s) and 200m events (male: n = 172, FT = 142.71 ± 7.41 s; female: n = 172, FT = 159.92 ± 8.73 s) from 12 world, international and national championships. Swimming velocity was identified as the primary determinant of FT in all events, while turning time was a secondary determinant in all events except in the men's 100m, where start time was observed to be relatively more important. End time was of only limited importance in the women's 100m and men's 200m, while stroke rate and stroke length were poorly related to FT and so were excluded from the regression equations. Data from cross validation groups (men's 100m, n = 29; women's 100m, n = 28; men's 200m, n = 56; women's 200m, n = 56) demonstrated that predictions of FT would be acceptable to coaches of competitive swimmers.
 
Article
The relations between swimming velocity (V), stroke rate (SR) and stroke length (SL) are regularly investigated according to changes in regulations or improvements in technique. In this study, 377 male and 369 female elite swimmers were assessed on 100m and 200m competitive events in freestyle, butterfly, backstroke and breaststroke. For each swimming style and for both sexes, V and SR were higher (P < 0.01) on 100m events than on 200m ones. For males and females, SL was not significantly different between 100m and 200m events in freestyle and backstroke. In butterfly, SL values observed on 100m events were significantly higher (P < 0.01) than those noticed on 200m for both sexes. On the contrary, SL values observed on 100m breast event were significantly lower (P < 0.01) than those observed on 200m breaststroke . In all events, V and SL were higher (P < 0.01) in males than in females. On the contrary, SR values were never significantly different between male and female swimmers in each style and distance events. When the evolutions of V, SR and SL were compared between the 100m and 200m events, three stroke categories may be distinguished: alternating strokes (freestyle and backstroke), butterfly and breaststroke.
 
Article
Research on talent identification and development among young sportsmen and women is relatively limited. The greatest need is in team sports. Many studies have been carried out involving individual sports because it is easier to control the different variables (Salmela and Régnier, 1983). This is the reason that this study focuses on rugby, a well known team sport. The aim of the study is firstly to compare the game-specific, physical, motor and anthropometric variables of English and South African 12yr old rugby players and secondly, to compare these same variables between English 12yr old competitive and social rugby players. The comparison of the data between English and South African children (Pienaar and Spamer, 1998), indicated that the English children possessed a higher level of subcutaneous fat; a finding which is probably best explained by differences in lifestyle and socio-economic factors between the two countries. Their higher fat level may indeed explain the poorer performance of the English children during the physical and motor ability tests.
 
Article
The aim of this research was to investigate possible relationships between physical activity (PA) and physical fitness (PF) of girls (13-15yrs) in the North-West Province in South Africa. A singular cross-section research design was used. 13-15 year old girls (n=290) who were part of a bigger survey (N=1257) between the ages of 10-15yrs were randomly selected out of 44 schools in the North-West Province. The girls were classified as low, moderate or high active by means of the PDPAR (previous day physical activity recall; Trost et al, 1999). Physical fitness was tested by means of a physical fitness battery test (Docherty, 1996; Wood, 1997) consisting of abdominal strength, handgrip strength, bent arm hang, flexibility and VO2 max tests. 73.3% girls were classified as low active with the Statistica for Windows (Statsoft, 1999) computer package. No significant relationships could be found between physical activity and physical fitness of 13-15 year old girls, although a regression analysis showed that physical fitness contributed to VO2 max. A high level of physical activity, strength endurance and a low fat percentage showed a positive relationship with cardiovascular fitness.
 
Article
The aim of this study was to investigate the possible relationships between anthropometrical parameters (skinfolds, girths, lengths and breadths/lengths), somatotype components, motor abilities and physical activity in prepubertal, pubertal and postpubertal children. The subjects of this study were 525 pupils, aged 10-17 years, divided into groups two years apart. Their body height, weight, BMI, 9 skinfolds, 13 girths, 8 lengths and 8 breadths/lengths were measured. Somatotype components (endomorphy, mesomorphy, ectomorphy) were estimated according to Carter and Heath (1990). The following EUROFIT tests were used: 20m endurance shuttle-run, handgrip strength, standing broad jump, flexed arm hang, sit-ups, 10x5m shuttle-run, plate tapping, sit-and-reach and Flamingo balance. Physical activity was assessed using the questionnaire of Telama et al (1996). The relationships between anthropometry and EUROFIT tests results were moderate. In some weight-bearing tests especially in the pubertal age, the relationships were significant. The subjects' physical activity did not depend on the anthropometrical parameters. Endurance shuttle-run tests results in all age and sex groups correlated significantly with physical activity.
 
Article
The purpose of this study was to compare the defensive actions of the four finalists of the 18th World Champion Soccer Games in France in 1998. The research sample consisted of the four national teams that qualified for the semi-finals and the final (France, Brazil, Croatia and Holland) of the 18th World Champion Soccer Games (France 1998). Twenty-eight videotaped soccer games (seven games for each team) were observed with one video and computer. Data were inserted into a computer with the database system Access and transformed into asci form for further statistical analysis concerning the defensive actions of the teams studied. Three parameters were evaluated: a. temporary possession of the ball in the defensive and middle area b. possession of the ball in the defensive and middle area c. inhibitory actions in the defensive, middle and offensive area. Multivariate analysis of variance (MANOVA) showed that the winning team of the World Champion Soccer Games (France) applied defensive actions in the offensive area more often than the other three teams which used their defensive actions in the defensive and middle areas. It is possible that the above defensive behavior of the French team was one of the important factors which contributed to its superiority in the 18th World Champion Soccer Games conducted in France.
 
Article
Profiling athletes is of importance for discerning anthropometric, physiological and other characteristics that distinguish the studied group from other subject populations. Despite the outstanding popularity of soccer, there is a lack of the data related to the player profiles, particularly those that compare elite junior competitors of different age. Within the present study the members of the national male junior soccer teams of 13 (N = 27), 15(N = 18), 16(N = 19), 17 (N = 20) and 18 years of age (N = 18) were tested. In addition to some standard anthropometric and physiological tests, several predominantly sport-specific tests were also applied. A number of the tested variables proved to discriminate between the tested players and other athletes of similar age. However, the recorded physiological and sport-specific performance demonstrated no differences within the 16 and 18-years of age, being also close to the results observed on elite senior soccer players. We conclude that the obtained profiles predominantly based on standard tests are more likely to be valid for earlier age of junior soccer players, while the more advanced age could require involving predominantly sport-specific tests, particularly those assessing technical and tactical skills.
 
Article
International collaboration in research, especially in team sports, is needed to get more clarity on the characteristics of elite youth athletes. The aim of this study is to draw a comparison between an elite English and an elite South African 18-year-old rugby team. Components that will be tested are game-specific variables, physical and motor abilities and anthropometric data. In order to link up with modern research, aspects such as innate characteristics and date of birth will also be referred to. Results show that the South African boys were slightly leaner than their English counterparts and that slight differences in kicking and passing abilities are thought to be more attributable to environmental factors than physical characteristics.
 
Article
In 1966 Kots and Syrovegin claimed to have shown that people use just a limited number of ratios of speed of movement at the wrist and elbow joints when called upon to execute a variety of different actions; and that certain of these speed ratios represent modular units in motor programming. A number of criticisms of this paper were offered. The first experiment sought to replicate this study. It generated data which questioned Kots and Syrovegin's claims; moreover, it highlighted the problems of establishing statistically whether certain speed ratios are preferred and whether any of these can be said to be used in a modular fashion. The second experiment indicated that Kots and Syrovegin's findings may simply reflect the fact that their subjects became very stereotyped in the sizes of wrist and elbow arcs that they used. It showed that a limited number of speed ratios will reliably emerge if subjects utilise just a few sizes of wrist and elbow components and execute the resultant actions smoothly and economically. Finally, some of the limitations of this general approach were discussed.
 
Article
The old adage "with time comes change" is certainly true with respect to developments in Africa in physical education (PE) and sports science (SS) in the last decade. The fields have emerged from mere pockets of isolated practices to a more cohesive global academically respectable profession. Of particular interest is the emergence and growth of sub-regional and continent-wide professional bodies with direct or indirect association with government departments of education, health, sports and private organisations. This article reviews professional milestones in the evolution of PE and SS in Africa and analyses prospects for future development.
 
Article
The purpose of this study was to measure a wide range of body composition, physical performance and mood state parameters in order to determine which parameters could be used to monitor training and are more indicative of specific sculling performance. Ten Estonian male elite rowers (20.7±3.3yrs; 192.7±4.9cm; 91.6±5.8kg) volunteered to participate. The study was conducted at the beginning of the preparatory period. The rowers performed 2000m competition for single sculling. This was followed by two testing sessions on consecutive days under similar conditions one week later. At the first measurement session, each subject completed a body composition assessment, filled in the Recovery-Stress Questionnaire for Athletes (RESTQ-Sport) and competed on 500m rowing ergometer distance. The second measurement session consisted of maximal strength tests followed by a performance test on a 6000m rowing ergometer distance. Significant relationships were observed between the 2000m maximal sculling time and body mass, arm muscle mass, arm pull, leg press, 6000m ergometer time, Standardised Stress and Standardised Recovery values. Multiple regression equations demonstrated that the prediction model using physical performance variables predicted performance time of 2000m distance on single sculls best (R=0.86), followed by the equations comprising body composition (R=0.71) and mood state (R=0.56) variables. In summary, the results of the present study indicate that arm muscle mass and maximal arm muscle strength in addition to maximal aerobic capacity are the most important characteristics in the studied group. In addition to specific anthropometric and physiologic characteristics, the evaluation of mood state in athletes has an important implication in training monitoring and crew selection.
 
Article
The effects of a solo cross-country ski trek on the performance and skeletal muscle characteristics of a 22 year old male were examined. The subject cross-country skied 300km over 15 days while pulling an 80kg sled. All measurements were made before and after the trek. The expedition produced little change in body composition, pulmonary function, flexibility, grip strength or muscle fiber area. There were increases in ventilation threshold (12%) and VO2max (11.6%). Relative peak 5sec and mean 30sec anaerobic power declined 8.9% and 6.0%, respectively. There was a 19.4% increase in knee extension and 6.2% increase in knee flexion peak torque in the left leg but there was little change in either measure for the right leg. Increases in right and left shoulder extension (17.3% and 31.3%) and flexion (3.7% and 12.5%) peak torque were observed. Biopsy samples from the vastus lateralis indicated increases in capillary to fiber ratio (5.3% left leg; 15% right leg), citrate synthase activity (65.8% left leg; 17.6% right leg) and lactate dehydrogenase activity (21% left leg; 2.7% right leg). These results indicate that short-term, long duration cross-country skiing while pulling an 80kg sled resulted in substantial increases in aerobic fitness, isokinetic peak torque, skeletal muscle capillarization and metabolic enzyme activity but had negative effects on anaerobic power.
 
Article
Seven high level rowers (age 23.85±2.8yrs, height 184±7cm and weight 81.3±9.34kg) performed a test 130m long at maximal speed with a high stroke-rate (37b.p.m.) on a single scull rowing boat. The rowers were filmed with two perpendicular video camcorders. The film was digitised frame by frame using Schleihauf's Kinematic Analysis software. The x, y, z co-ordinates of the right blade and the coaming of the boat were obtained for an aquatic stroke (from the blade entry to the blade exit). The curvilinear boat displacement was characterised by a polynomial function with great amplitude (4.74m±0.72). The beginning of the stroke was characterised by a relative stability of the blade on the 3 axes followed by sinusoidal paths on the transversal and vertical axes. This stabilised portion reflected the time necessary to create a support by the blade and to overcome the inertia of the system. The 3D movements suggested that the propulsion resulted from lift and drag forces. The amplitude of the boat displacement was related to the level of performance and was greater during the beginning of the aquatic stroke for the best-studied rowers.
 
Article
We report a study designed to investigate the emergence of multi-dimensional spatial compatibility effects. Although the results supported the idea that multiple spatial codes can be generated under appropriate task conditions, the influence of depth compatibility was substantially reduced relative to the horizontal and vertical dimensions. Three-dimensional spatial coding likely proceeds hierarchically, with horizontal codes dominating in most situations. A follow-up experiment limited the task dimensions to include only vertical and depth information. By removing the dominant influence of the horizontal dimension, the influence of depth information was enhanced and sensitive to instructions pertaining to that dimension.
 
Article
The purpose of this study was to characterise differences in sprint ability and lower limb joint torque between sprints of maximal efforts vs. those performed under fatigued conditions. We also examined the relationship between differences in sprint ability and joint torque with lower limb muscular endurance and aerobic and anaerobic work capacities. Sprint motions of eleven male sprinters were analysed during a 45-55m section of an 80m running event and during a 355-365m section of a 400m running event. Muscular endurance of the lower limbs, maximal oxygen intake, and oxygen deficit were also measured. Running speed, stride length, stride frequency, knee extension torque, hip flexion torque, and hip extension torque were significantly higher in the maximal sprint than in the fatigued sprint. The ability to maintain stride frequency significantly correlated with sprint speed maintenance and the ability to maintain hip joint flexion and extension torques. The ability to maintain hip joint flexion torque significantly correlated with maximal oxygen intake, while the ability to maintain hip joint extension torque significantly correlated with muscular endurance of the knee and hip as well as with maximal oxygen intake. These results suggest that the ability to maintain joint torque during the fatigued sprint is an important determinant of performance during a 400m running event and that muscular endurance of the lower limbs influences the maintenance of joint torque.
 
Article
Relatively little is known about the effects of hypohydration and heat during 'middle distance' sporting events that place great demands on both the aerobic and anaerobic energy systems. Seven moderately trained male cyclists performed three 4000m maximal cycling trials in differing conditions and in a random order, to determine whether hydration status and heat were associated with variations in performance. Trials were paced to half distance. The conditions were i) euhydrated exercise (EUH), ii) hypohydrated exercise (HYP), involving exercise induced dehydration to 2% of total body mass, and iii) hypohydrated exercise coupled with an ambient temperature of 30°C (HYP+H). Mean resting heart rates were significantly elevated in the HYP+H condition compared with the EUH condition (p<0.01). Trial performance times were significantly shorter in the EUH and HYP conditions compared with the HYP+H condition (p<0.01), although split times were similar. This was due to the mean power output (MPO) being significantly lower during the last 1000m of the HYP+H condition (p<0.01). It appears that moderate hypohydration alone did not affect 4000m cycling time trial performance. However, when coupled with an ambient temperature of 30°C a performance decrement was observed. As anaerobic and aerobic responses were similar between trials it appears that some other factor(s) (peripheral fatigue or a reduced central drive), possibly related to elevated muscle or core temperatures, may have led to the decrement in performance.
 
Article
The purpose of this investigation was to measure heart rate response during a 55 km cross country ski race and compare the mean racing heart rate to heart rate corresponding to ventilation threshold (VT) 1 (VE/V02), VT2 (VE/VC02), maximal oxygen consumption (V02max) and maximum heart rate (HRmax). Six male subjects with a mean age, and weight of 31 ± 5.9 years and 72.6 ± 6.6 kg, respectively, wore heart rate monitors set to record heart rate every 15 seconds during the 1995 Canadian Birkebeiner 55 km cross country ski race. All subjects completed a VT and V02max test within 5 days after recovery from the race. The heart rate measured during the race varied according to changes in terrain as well as the intensity that each subject was able to maintain. The mean racing heart rate was 145 b·min-1 and corresponded to 124% of VT1, 85% of VT2 and 77% of V02max. The relationship between finishing time and VT1, VT2 and V02max was r = -0.55 (ns), r = -0.13 (ns) and r = -0.76 (p < 0.05), respectively. These results suggest that the subjects were able to maintain a heart rate equivalent to an intensity between VT1 and VT2 for the 55 km cross country ski race. Also, V02max may be a better predictor of finishing time in a 55 km cross country ski race.
 
Article
The purpose of this study was to examine the reliability and convergent validity of the Godin Leisure-Time Exercise Questionnaire in fifth-grade students. Thirty-one children (average age 10.6±0.2yrs) from a rural elementary school in Wyoming completed the Godin Leisure-Time Exercise Questionnaire on two separate occasions and wore the Caltrac accelerometer for one day to determine the convergent validity of the questionnaire. The questionnaire was administered at the beginning and end of the school day. The test-retest reliabilities for females were low (r<0.20) for mild and moderate exercise categories and high (r>0.80) for the strenuous exercise category and the total leisure activity score. In males, test-retest reliabilities were moderate (r=0.30-0.45) for the mild and moderate exercise categories and moderate (r=0.50-0.60) for the strenuous exercise category and the total leisure activity score. Overall, the strength of the reliability coefficient was moderate (r=0.62) for the total leisure activity score. The relationship between the Caltrac (counts per hour) and average total leisure activity score was 0.50. The Godin Leisure-Time Exercise Questionnaire is therefore a cost-effective, easy-to-administer self-report survey that showed moderate test-retest reliability and convergent validity in fifth-grade school-children.
 
Article
The central concern in this study is the question of whether boys who were considered successful in rugby at the age of 10 will still be successful after eight years. The aim was to retest a group of players (N=34) after a period of 8 years in order to ascertain the motor and physical abilities, rugby skills and anthropometric characteristics at the age of 18 of those who had showed the most potential at the age of 10. This analysis comprises a comparison of physical and motor abilities, rugby skills and some anthropometric characteristics of successfully (n=18) and less successfully classified players (n=16). From the analysis of descriptive statistics (means, standard deviations, minimum and maximum values) and effect sizes to determine the practical significance of differences (ES), the conclusion was made that a large percentage of the more talented players at 10 years old were still successful at the age of 18. Those players classified as more successful performed better at 18 years old in some of the physical and motor abilities, all of the rugby skills and also showed more anthropometric characteristics that could benefit senior rugby players. Players in the less successful groups were, however, not much weaker than the more successful group, although anthropometric characteristics such as a smaller percentage of body fat and body mass could have hampered them.
 
Article
Although some studies have examinded the fitness profiles of senior rugby players (Hazeldine and MacNab 1991, Turnbuletal, 1995), the identification and associated development of talented rugby players at primary school level is an unexplored field. Pienaar and Spamer (1995) have developed a battery of tests for 10 year-olds for the identification of those who have a talent for rugby. A number of 10 year-old players who were initially identified as talented with this test battery were unable to achieve success two years later (inclusion into the regional primary schools team) chosen from 22 schools. The aim of this study was to draw a comparison between the group which was successful (n = 18) and the group which was not (n = 13). Results of tests to determine rugby skills, physical and motor abilities as well as anthropometric measurements were used. Apart from descriptive statistics practical significance within and between groups was also examined during the study. It became evident that as regards anthropometric measurements there were no differences between the two groups, while the successful group was significantly better as regards rugby skills and physical and motor abilities (p = < 0.05 and d - > 0.8).
 
Article
This study examined the abilities that contribute to the tennis serve in young athletes, as it is one of the most important strokes during a tennis match. If we are able to identify the abilities that are responsible for hitting a serve, then we shall be able to find children who share these abilities and have a high probability to become good tennis players. While this prediction alone is not enough, it could assist in establishing a test battery to identify future tennis players. There were 38 junior tennis athletes with at least two years experience in practicing tennis and the sample was 12.9 (± 2.7) years old. They were all active tennis players in the National Junior tennis championship. We established a test battery which consisted of a softball aiming throw, coordination of the two hands, rate control, speed of arm movement, depth perception, multi-limb coordination and tennis serve accuracy. The results were treated with the statistical method of principal components analysis. We had four factors with high loadings which were interpreting 86% of the Variance. The structure of the abilities that underlie the various tests studied were multi-limb coordination, precision of control, speed of arm movement and aiming accuracy. The findings suggest that the processes involved in determining the abilities for tennis serve will play an important role for predicting future, perhaps professional level tennis players. More research is needed to examine more subjects in a larger range of abilities through a test battery which takes into consideration the basic strokes of tennis.
 
Article
The purpose of this study was to investigate the effects of combinations of practice schedules in motor learning. The participants were randomly assigned to one of six practice groups: 1) constant-blocked; 2) constant-random; 3) blocked-constant; 4) blocked-random; 5) random-constant; 6) random-blocked. In the acquisition phase, all participants were asked to press four keys sequentially with different requirements of absolute timing in a same relative timing structure. In the transfer tests, they were tested in a novel absolute timing criterion. An overall analysis of the results points out to a superiority of the constant-random and constant-blocked combinations.
 
Top-cited authors
David Lee
  • The University of Edinburgh
Veniece Thomas
  • London Metropolitan University
Reint Geuze
  • University of Groningen
Eduardo Cervelló
  • Universidad Miguel Hernández de Elche
Karl Newell
  • University of Georgia