Canadian journal of applied sport sciences. Journal canadien des sciences appliquees au sport最新文献

The purpose of this study was to provide an assessment tool to judge coaching performance that was appropriate for completion by athletes. The questionnaire underwent a variety of developmental stages. In its final form, it contained 36 items. The tool was shown to be a valid, reliable, and standardized questionnaire. It demonstrated discriminability and provoked honest, accurate responding in subjects. The test was capable of providing immediate feedback to coaches seeking information about athletes' perceptions of their coaching performance. Responses on the developed scale were weighted to reflect the desirability of the coaching characteristics of a good coach. The questionnaire provides a total score which can be interpreted by the coach as a measure of how much of an "ideal" coach exists in him/her.

One thousand and one disorders of the ear, nose and sinuses in 650 SCUBA divers were analysed for anatomical distribution and causation. The outer, middle and inner ears made up 64.6% with a surprising 23.9% being related to the lower jaw, its teeth, attached muscles and the temporo-mandibular joint. Of the remaining, 3.1% were related to the nose, 6.6% to the sinuses and there was a miscellaneous group of 1.8%. Most outer ear infections seemed to be self-inflicted whilst the middle ear conditions were due to dysfunction of the Eustachian tube. The middle ear conditions were prevented by reducing nasal congestion as by cauterising the inferior turbinates of the nose, or by giving counselling in the technique of clearing the ears. Apart from Eustachian tube dysfunction in some, there is no clear lead as to causation of the inner ear complaints. Nasal treatment also relieves blockage of the ostia of the sinuses and thus sinus barotrauma. Overall the commonest preventable cause appears to be nasal congestion due to a variable mixture of infective or vasomotor rhinitis, allergic rhinitis, unilateral hypertrophy and a deviated nasal septum.

A method of comparing the performances of athletes of disparate bodyweights in Olympic weightlifting is developed that is able to accommodate the fact that, of the ten bodyweight classes contested, the lighter nine have upper limits assigned to them while the heaviest has only a lower limit. The results are presented so as to answer the question "What would a given athlete weighing x kilograms total if he were a +110 kg. athlete of the same level of ability?"

The effect of a hockey helmet and face shield on the head and neck during inertial loading was studied. A Hybrid III Anthropometric Test Dummy (ATD) was struck from both the front and rear by a spring-loaded, instrumented striker moving at 2.9 ms-1. Data were collected from a triaxial force transducer mounted at the atlanto-occipital (a-o) junction of the ATD, a load cell in the striker, and by cinematography (250 fps). Angular kinematics of the head and moments of force about the a-o junction were determined along with impact force levels. When compared to a bare-head condition, the addition of a helmet and face shield caused an increase in head angular displacement (20-40%) but did not affect head angular acceleration. Axial and shear forces at the a-o junction did not change appreciably with the addition of a helmet and face shield. A triphasic pattern was evident for the neck moments including a small phase which represented a seating of the headform on the nodding blocks of the uppermost ATD neck segment, and two larger phases of opposite polarity which represented the motion of the head relative to the trunk during the first 350 ms after impact. No substantial differences were apparent between the helmeted and non-helmeted trials. The magnitudes of forces and moments found in the present study were well within tolerance levels reported by others (Melvin, 1979; Cheng et al., 1982). It was concluded that the increase in angular displacement of the head, with the addition of a helmet and face shield, does not place the wearer in a position of increased risk of cervical spine trauma.

Maximal oxygen uptake was determined in 62 boys each year from age 11 to 15 years. Multiple regression analyses were used to predict treadmill VO2 max at yearly age intervals from size measures and submaximal cycle heart rates. Derived equations were validated in an independent sample of 98 boys of the same age range. In boys aged 12 to 15 years approximately 80% or more of the variance in VO2 max was accounted for by age specific equations employing mass, height and skinfolds as explanatory variables. Prediction of VO2max was not as strong for 10 and 11 year olds, with less than 70% of the variance explained. Measures of VO2 or work rate and heart rate were not useful in predicting VO2max either by themselves or in conjunction with the size measures. The findings clearly demonstrated that submaximal exercise testing to predict VO2max, or cardiorespiratory fitness, in boys was of questionable value. The prediction of VO2max in boys aged 12 to 15 by in the independent sample was shown to have a mean absolute error of 6 to 8% while the value for age 11 y was 10%. The error is similar in magnitude to that of predicting VO2max with an exercise test in adults. The present age specific equations resulted in smaller errors of estimation than found in previous studies of VO2max estimation in children.

The velocity of the rowing boat appears to depend on the force which the athlete applies at the handle of the oar. Although force is generated by legs, upper body, and arms, the latter are the only limbs which actually transmit and apply the force against the oar. The force output of the arms seem to be a function of the forearm position used by the athlete while gripping the oar. The traditional gripping technique is with the forearms in pronation. This technique was never challenged or scientifically researched to see whatever a modified one might lead to better efficiency. Consequently, the purpose of this investigation was to analyze whether athletes' force output differed if the gripping technique was changed from pronation to a semiprone grip (one arm prone, the other semiprone). Under the specific conditions of this investigation it was demonstrated that the semiprone position was generating greater force output, thus being superior to the classical prone grip.

The accuracy of predicting residual volume (RV) and the effect of employing such predictions in the assessment of body composition by hydrostatic weighing was examined. Prediction equations derived by Wilmore (Med. Sci. Sports, 1969) and Boren et al. (Am. J. Med., 1966) were cross-validated on 400 male subjects with varying degrees of pulmonary dysfunction. Statistical analysis included comparison of predicted vs measured RV and regression analysis of measured on predicted values. Neither equation met acceptable statistical criteria (p greater than .05). Underwater weights were calculated based upon the measured RV and an assumed standard body weight, body density, and percent body fat (i.e., 70 kg, 1.0647 g/cc and 15.0%). Predicted RV was then substituted in the calculation and the effect on standardized values examined, between the calculated and standardized percent fat value with both equations. Results suggest in the present subjects, RV cannot be accurately predicted and the use of such prediction equations introduces sizable errors in body composition estimation.

Past research has used either individual or mean data to illustrate the determination of the ventilation thresholds. Although an individual's data may represent the best rather than the typical response, the accuracy and validity of threshold determinations can be assessed. In contrast, the presentation of mean data may not allow the reader to evaluate the internal validity of the results.

This study was undertaken to compare the variance in time to fatigue (TF) at intensities expressed relative to VO2max, ventilation threshold 1 (VT1) or 2 (VT2). Two 3-min, 30 Watt incremental tests on the cycle ergometer were used to determine VO2max (50.7 +/- 7.2 ml X kg-1 X min-1), VT1 (51.7 +/- 3.7% VO2max) and VT2 (79.0 +/- 3.7% VO2max) for 16 subjects. At weekly intervals, subjects worked to volitional fatigue at 3 randomly-ordered power outputs that represented 73.1 +/- 2.8, 85.4 +/- 2.8 and 95.0 +/- 3.4% VO2max. A significant quadratic interaction was observed for TF values between VO2max and intensity, suggesting a different magnitude of response related to VO2max. Subject data were then grouped according to VO2max into a low (N = 5, 40-44 ml X kg-1 X min-1), medium (N = 5, 48-52 ml X kg-1 X min-1) or high (N = 6, 56-61 ml X kg-1 X min-1) category. For all groups, a decaying exponential function best described the relationship between TF and intensity. The method of expressing intensity appeared to have only a small effect on the proportion of variance explained by this logarithmic relationship (0.85 less than or equal to r2 less than or equal to 0.93). In contrast, however, a 30% reduction in the standard error of estimate for TF was observed when intensity was expressed relative to both ventilation thresholds as compared to the traditional expression of intensity relative to VO2max.(ABSTRACT TRUNCATED AT 250 WORDS)

The purpose of this study was to determine the action of the thumb, index, and middle fingers in releasing fastballs and curveballs for nine right-handed college pitchers. Micro-switches for the fingers were created by using two strips of electroconductive tape and a ball covered with electroconductive paint. Time data, accurate to 10(-4)s, were initiated by the stride foot onto a floor mat switch. When each digit left the ball, a corresponding timer was triggered with the final channel tripped by a contact switch in the catcher's glove. A total of 103 fastball and 88 curveball trials had complete data for each of the variables studied. Results showed that for the fastball, in 91.1% of the cases, the thumb preceded the middle and index fingers by approximately 6 ms. (p less than .001) but there was no significant difference between the middle and index fingers. The curveball data indicated that five of the nine pitchers had a definite release sequence of thumb first followed by middle then index finger (p less than .001). In total, 72.7% of the curveballs thrown had a release sequence of thumb, middle, and index fingers and 24.0% had a middle, thumb, index finger release sequence. The remaining 2.3% of the pitches had either similar times or odd combinations of release sequence.