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Corrado Lupo, Alexandru Nicolae Ungureanu, Riccardo Frati, Matteo Panichi, Simone Grillo and Paolo Riccardo Brustio

, among team sports, basketball is characterized by progressive rule changes, which contribute to make interpretation of the ITL difficult without a valid method. In fact, basketball is characterized by intermittent high-intensity actions, 5 especially after rule modifications (offense from 30 to 24 s

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Benjamin W. Infantolino, Daniel J. Gales, Samantha L. Winter and John H. Challis

The purpose of this study was to validate ultrasound muscle volume estimation in vivo. To examine validity, vastus lateralis ultrasound images were collected from cadavers before muscle dissection; after dissection, the volumes were determined by hydrostatic weighing. Seven thighs from cadaver specimens were scanned using a 7.5-MHz ultrasound probe (SSD-1000, Aloka, Japan). The perimeter of the vastus lateralis was identified in the ultrasound images and manually digitized. Volumes were then estimated using the Cavalieri principle, by measuring the image areas of sets of parallel two-dimensional slices through the muscles. The muscles were then dissected from the cadavers, and muscle volume was determined via hydrostatic weighing. There was no statistically significant difference between the ultrasound estimation of muscle volume and that estimated using hydrostatic weighing (p > 0.05). The mean percentage error between the two volume estimates was 0.4% ± 6.9. Three operators all performed four digitizations of all images from one randomly selected muscle; there was no statistical difference between operators or trials and the intraclass correlation was high (>0.8). The results of this study indicate that ultrasound is an accurate method for estimating muscle volumes in vivo.

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Stacy A. Clemes, Beverley M. David, Yi Zhao, Xu Han and Wendy Brown

Background:

In light of evidence linking sedentary behaviors to health outcomes, there have been calls for the measurement of sedentary behavior in surveillance studies. This study examined the convergent validity of 2 self-report measures of sitting time and accelerometer-determined sedentary time (minutes/day of <100 counts/minute).

Methods:

44 adults wore an ActiGraph accelerometer for 7 days, during which they also recorded daily sitting time in a diary, in response to a single-item question. After 7 days, participants completed a new domain-specific questionnaire to assess usual weekday and weekend-day sitting time. Total sitting times recorded from the self-report measures were compared with accelerometer-determined sedentary time.

Results:

Total sitting time calculated from the domain-specific questionnaire did not differ significantly from accelerometer-determined sedentary time on weekdays (mean difference [±SE] = –14 ± 28 mins/day) and weekend days (–4 ± 45 mins/day, both P > .05). Sitting time was significantly underestimated using the single-item specific-day question on weekdays (–173 ± 18 mins/day) and weekend days (–219 ± 23 mins/day, both P < .001).

Conclusions:

When assessed via self-report, the estimation of total sitting time is improved by summing sitting times reported across different domains. The continued improvement of self-report measures of sitting time will be important if we are to further our understanding of the links between sedentary behavior and health.

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Tiago V. Barreira, John P. Bennett and Minsoo Kang

Purpose:

To obtain validity evidence for the measurement of step counts by spring-levered and piezoelectric pedometers during dance.

Methods:

Thirty-five adults in a college dance class participated in this study. Participants completed trials of 3- and 5-min of different styles of dance wearing Walk4life MVP and Omron HJ-303 pedometers, while their steps were visually counted. Pearson correlation, paired t-test, mean absolute percent error (MAPE), and mean bias were calculated between actual step and pedometer step counts for the 3- and 5-min dances separately.

Results:

For the Walk4life trials the correlations were .92 and .77 for the 3- and 5-min dances. No significant differences were shown by t-test for the 3- (P = .16) and 5-min dances (P = .60). However, MAPE was high, 17.7 ± 17.7% and 19.4 ± 18.3% for the 2 dance durations, respectively. For the Omron, the correlations were .44 and .58 for the 3- and 5-min dances, respectively. No significant differences were shown by t-test for the 3-min (P = .38) and for the 5-min (P = .88) dances. However, MAPE was high, 19.3 ± 16.4% and 26.6 ± 15.2% for the 2 dance durations, respectively.

Conclusions:

This study demonstrated that pedometers can be used to estimate the number of steps taken by a group of college students while dancing, however caution is necessary with individual values.

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Emma K. Zadow, Cecilia M. Kitic, Sam S.X. Wu, Stuart T. Smith and James W. Fell

Purpose:

To assess the validity of power output settings of the Wahoo KICKR Power Trainer (KICKR) using a dynamic calibration rig (CALRIG) over a range of power outputs and cadences.

Methods:

Using the KICKR to set power outputs, powers of 100–999 W were assessed at cadences (controlled by the CALRIG) of 80, 90, 100, 110, and 120 rpm.

Results:

The KICKR displayed accurate measurements of power of 250–700 W at cadences of 80–120 rpm with a bias of –1.1% (95% limits of agreement [LoA] –3.6% to 1.4%). A larger mean bias in power was observed across the full range of power tested, 100–999 W (4.2%, 95% LoA –20.1% to 28.6%), due to larger biases of 100–200 and 750–999 W (4.5%, 95% LoA –2.3% to 11.3%, and 13.0%, 95% LoA –24.4% to 50.3%), respectively.

Conclusions:

Compared with a CALRIG, the KICKR has acceptable accuracy reporting a small mean bias and narrow LoA in the measurement of power output of 250–700 W at cadences of 80–120 rpm. Caution should be applied by coaches and sports scientists when using the KICKR at power outputs of <200 W and >750 W due to the greater variability in recorded power.

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Nicola Furlan, Mark Waldron, Mark Osborne and Adrian J. Gray

Purpose:

To assess the ecological validity of the Rugby Sevens Simulation Protocol (R7SP) and to evaluate its interday reliability.

Methods:

Ten male participants (20 ± 2 y, 74 ± 11 kg) completed 2 trials of the R7SP, separated by 7 d. The R7SP comprised typical running and collision activities, based on data recorded during international rugby sevens match play. Heart rate (HR) was monitored continuously during the R7SP, and the participants’ movements were recorded through a 20-Hz global positioning system unit. Blood lactate and rating of perceived exertion were collected before and immediately after the 1st and 2nd halves of the R7SP.

Results:

The average activity profile was 117 ± 5 m/min, of which 27 ± 2 m/min was covered at high speed, with a calculated energetic demand of 1037 ± 581 J/kg, of which ~40% was expended at a rate above 19 W/kg. Mean HR was 88% ± 4% of maximal HR. Participants spent ~45% ± 27% of time above 90% of maximal HR (t >90%HRmax). There were no significant differences between trials, except for lactate between the halves of the R7SP. The majority of the measured variables demonstrated a between-trials coefficient of variation (CV%) lower than 5%. Blood lactate measurements (14–20% CV) and t >90%HRmax (26% CV) were less reliable variables. In most cases, the calculated moderate worthwhile change was higher than the CV%.

Conclusions:

The R7SP replicates the activity profile and HR responses of rugby sevens match play. It is a reliable simulation protocol that can be used in a research environment to detect systematic worthwhile changes in selected performance variables.

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Moataz Eltoukhy, Christopher Kuenze, Jeonghoon Oh, Eryn Apanovitch, Lauren Butler and Joseph F. Signorile

motion capture volume, can be utilized as a cost-effective 3DMA tool. 25 Previous studies reported the validity of the Kinect v2 in multiple applications including treadmill gait, 26 over-ground gait, 27 squatting, 28 and balance. 29 To the best of our knowledge, no prior study has examined the

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Kathryn Mills, Aula Idris, Thu-An Pham, John Porte, Mark Wiggins and Manolya Kavakli

first be established. The objectives of this study were (1) to evaluate the validity of a VR game in evaluating the projected frontal plane knee angle when landing from a jump and (2) to assess the reliability of this evaluation over time. Methods A cross-sectional laboratory study was used to determine

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Stefan Altmann, Steffen Ringhof, Benedikt Becker, Alexander Woll and Rainer Neumann

with flying start . Int J Sports Physiol Perform . 2015 ; 10 : 1055 – 1057 . PubMed ID: 25803102 doi:10.1123/ijspp.2014-0415 25803102 10.1123/ijspp.2014-0415 5. Altmann S , Spielmann M , Engel FA , et al . Validity of single-beam timing lights at different heights . J Strength Cond Res

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Andrew C. Sparkes

Evaluating the quality of qualitative inquiry has begun to intrigue researchers in sport psychology. Consequently, this has raised important questions regarding the criteria for judging this emerging form of inquiry. With the intent to stimulate methodological debate, this paper explores prevailing notions of validity in qualitative sport psychology by focusing on how various scholars have framed this term. The prevailing parallel perspective of validity is discussed, as are specific problems associated with this view. In contrast, recent attempts to reconceptualize validity in relation to particular forms of qualitative inquiry are considered. The socially constructed nature of validity and the multiplicity of meanings associated with this term are presented according to a diversification perspective. More radical calls to renounce validity and seek alternative criteria for judging qualitative inquiry are also discussed. In closing, the ongoing problem of criteria and its implications for research in sport psychology are considered.