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Your search keyword '"McNair, Peter J."' showing total 347 results
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347 results on '"McNair, Peter J."'

29. Reliability and validity of a linear position transducer for measuring jump performance

Author

Cronin, John B., Hing, Raewyn D., and McNair, Peter J.

Subjects
Transducers -- Usage, Muscle strength -- Measurement, Measuring instruments -- Testing, Health, Sports and fitness
Abstract

This study determined the reliability and validity of a linear position transducer to measure jump performance by comparing the mean force, peak force, and time-to-peak force measurements with data obtained simultaneously with a force platform. Twenty-five men performed squat, countermovement, and drop jumps with the linear transducer connected from a waist belt and base, which were placed upon a force platform. The Pearson correlation coefficients across the 3 jumps for the mean force (r = 0.952-0.962), peak force (r = 0.861-0.934), and time-to-peak force (r = 0.924-0.995) were high, providing evidence that the linear-transducer and force-platform measurements were similar. The trial-to-trial reliability of the jumps measured by the linear position transducer gave an intraclass correlation coefficient of 0.924-0.975 for mean force, 0.977-0.982 for peak force, and 0.721-0.964 for time-to-peak force. The coefficients of variation were 2.1-4.5% for mean force, 2.5-8.4% for peak force, and 4.1-11.8% for time-to-peak force. Our findings showed that the calculations derived from the linear transducer were very similar to those of the force platform and hence provided evidence of the validity of this method. The data from the linear transducer were also shown to be reliable. Therefore, this method of calculating force may provide a cost-effective alternative to the force platform for measuring this variable. KEY WORDS. force platform, validity, assessment, stretch-shorten cycle

Published
2004

31. Force-velocity analysis of strength-training techniques and load: implications for training strategy and research

Author

Cronin, John B., McNair, Peter J., and Marshall, Robert N.

Subjects
Strengthening exercises -- Research, Health, Sports and fitness
Abstract

The purpose of this study was to investigate the force-velocity response of the neuromuscular system to a variety of concentric only, stretch-shorten cycle, and ballistic bench press movements. Twenty-seven men of an athletic background (21.9 [+ or -] 3.1 years, 89.0 [+ or -] 12.5 kg, 86.3 [+ or -] 13.6 kg 1 repetition maximum [1RM]) performed 4 types of bench presses, concentric only, concentric throw, rebound, and rebound throw, across loads of 30-80% 1RM. Average force output was unaffected by the technique used across all loads. Greater force output was recorded using higher loading intensities. The use of rebound was found to produce greater average velocities (12.3% higher mean across loads) and peak forces (14.1% higher mean across loads). Throw or ballistic training generated greater velocities across all loads (4.4% higher average velocity and 6.7% higher peak velocity), and acceleration-deceleration profiles provided greater movement pattern specificity. However, the movement velocities (0.69-1.68 m*[s.sup.-1]) associated with the loads used in this study did not approach actual movement velocities associated with functional performance. Suggestions were made as to how these findings may be applied to improve strength, power, and functional performance. Key Words: bench press, stretch-shorten cycle, contractile component, elastic component

Published
2003

47. Management of symphysis pubis dysfunction during pregnancy using exercise and pelvic support belts

Author

Depledge, Jill, McNair, Peter J., Keal-Smith, Cheryl, and Williams, Maynard

Subjects
Women -- Health aspects, Pelvic pain -- Care and treatment -- Risk factors, Pregnancy, Complications of -- Risk factors -- Care and treatment, Health
Abstract

Background and Purpose. Symphysis pubis pain is a significant problem for some pregnant women. The purpose of this study was to investigate the effects of exercise, advice, and pelvic support belts on the management of symphysis pubis dysfunction during pregnancy. Subjects. Ninety pregnant women with symphysis pubis dysfunction were randomly assigned to 3 treatment groups. Methods. A randomized masked prospective experimental clinical trial was conducted. Specific muscle strengthening exercises and advice concerning appropriate methods for performing activities of daily living were given to the 3 groups, and 2 of the groups were given either a rigid pelvic support belt or a nonrigid pelvic support belt. The dependent variables, which were measured before and after the intervention, were a Roland-Morris Questionnaire score, a Patient-Specific Functional Scale score, and a pain score (101-point numerical rating score). Results. After the intervention, there was a significant reduction in the Roland-Morris Questionnaire score, the Patient-Specific Functional Scale score, and the average and worst pain scores in all groups. With the exception of average pain, there were no significant differences between groups for the other measures. Discussion and Conclusion. The findings indicate that the use of either a rigid or a nonrigid pelvic support belt did not add to the effects provided by exercise and advice. Key Words: Belts, Exercise, Pain, Pregnancy, Symphysis pubis, Women's health., Women with symphysis pubis dysfunction during pregnancy often face major functional difficulties resulting in a considerable decrease in quality of life. Fry (1) described the types of symptoms that women [...]

Published
2005

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