With the ongoing development of microtechnology, player tracking has become one of the most important components of load monitoring in team sports. The 3 main objectives of player tracking are better understanding of practice (provide an objective, a posteriori evaluation of external load and locomotor demands of any given session or match), optimization of training-load patterns at the team level, and decision making on individual players’ training programs to improve performance and prevent injuries (eg, top-up training vs unloading sequences, return to play progression). This paper discusses the basics of a simple tracking approach and the need to integrate multiple systems. The limitations of some of the most used variables in the field (including metabolic-power measures) are debated, and innovative and potentially new powerful variables are presented. The foundations of a successful player-monitoring system are probably laid on the pitch first, in the way practitioners collect their own tracking data, given the limitations of each variable, and how they report and use all this information, rather than in the technology and the variables per se. Overall, the decision to use any tracking technology or new variable should always be considered with a cost/benefit approach (ie, cost, ease of use, portability, manpower/ability to affect the training program).
Martin Buchheit and Ben Michael Simpson
Peggy M. Roswal, Claudine Sherrill and Glenn M. Roswal
This study compared the effectiveness of data based and creative dance pedagogies in relation to motor skill performance and self-concept of mentally retarded students. Subjects (N=35) were moderately mentally retarded males and females, ages 11 to 16 years, in special education classes. Their mean age was 12.88 years in the data based group and 13.47 years in the creative dance group. Excluding testing, the study lasted 8 weeks. Each group received 40 lessons of 30 minutes each. Data based pedagogy was based on the work of Dunn, Morehouse, and Dalke (1979), and creative dance pedagogy was based primarily on the work of Riordan (Fitt & Riordan, 1980). Pretest and posttest data were collected through administration of the Data Based Dance Skills Placement Test, selected subtests of the Cratty Six-Category Gross Motor Test, and the Martinek-Zaichkowsky Self-Concept Scale. Multivariate analysis of covariance revealed no difference between pedagogies. The group means indicated improvement in dance skill performance but not in self-concept or body perception, balance, and gross and locomotor agility.
Viviene A. Temple and John T. Foley
The development of motor skill proficiency during childhood is cumulative and influenced by physical growth and maturation, genetic potential, affordances in the physical and social environment, and the interactions between these factors. Therefore, typically during childhood, the trajectory of change in motor proficiency is positive. To lend developmental validity to the revision of the Test of Gross Motor Development—3rd edition (TGMD-3), this longitudinal study examined whether the skills and subtests of the TGMD-3 changed as might be expected from grade 3 to grade 4 among 277 children. The findings of this study lend support to the developmental validity of the TGMD-3 in that (1) there was within-individual change in the expected direction for both locomotor and ball skills, (2) consistent with the majority of research, boys had significantly higher ball skills scores than girls in both grade 3 and grade 4, and (3) the mean percent of maximum possible scores were in the range of approximately 60–75, which demonstrates that the majority of 8- and 9-year-old children had not reached a ceiling on this test.
Joseph F. Seay, Jeffery M. Haddad, Richard E.A. van Emmerik and Joseph Hamill
Increases in movement variability have previously been observed to be a hallmark property of cooraination changes between coupled oscillators that occur as movement frequency is scaled. Prior research on the walk-run transition in human locomotion has also demonstrated increases in variability around the transition region, supporting predictions of nonequilibrium phase transitions (Diedrich & Warren, 1995). The current study examined the coordinative patterns of both intra- and inter-limb couplings around the walk-run transition using two different temporal manipulations of locomotor velocity as a control parameter in healthy young participants (N = 11). Coordination variability did not increase before the transition. The nature of the change in continuous relative phase variability between gait modes was coupling-specific, and varying the time spent at each velocity did not have an overall effect on gait transition dynamics. Lower extremity inter-limb coordination dynamics were more sensitive to changes in treadmill velocity than intra-limb coordination. The results demonstrate the complexity of segmental coordination change in human locomotion, and question the applicability of dynamical bimanual coordination models to human gait transitions.
Désirée B. Maltais, Claire Gane, Sophie-Krystale Dufour, Dominik Wyss, Laurent J. Bouyer, Bradford J. McFadyen, Karl Zabjek, Jan Andrysek and Julien I.A. Voisin
Little is known about the effects of acute exercise on the cognitive functioning of children with cerebral palsy (CP). Selected cognitive functions were thus measured using a pediatric version of the Stroop test before and after maximal, locomotor based aerobic exercise in 16 independently ambulatory children (8 children with CP), 6–15 years old. Intense exercise had: 1) a significant, large, positive effect on reaction time (RT) for the CP group (preexercise: 892 ± 56.5 ms vs. postexercise: 798 ± 45.6 ms, p < .002, d = 1.87) with a trend for a similar but smaller response for the typically developing (TD) group (preexercise: 855 ± 56.5 ms vs. postexercise: 822 ± 45.6 ms, p < .08, d = 0.59), and 2) a significant, medium, negative effect on the interference effect for the CP group (preexercise: 4.5 ± 2.5%RT vs. postexercise: 13 ± 2.9%RT, p < .04, d = 0.77) with no significant effect for the TD group (preexercise: 7.2 ± 2.5%RT vs. postexercise: 6.9 ± 2.9%RT, p > .4, d = 0.03). Response accuracy was high in both groups pre- and postexercise (>96%). In conclusion, intense exercise impacts cognitive functioning in children with CP, both by increasing processing speed and decreasing executive function.
James J. Malone, Ric Lovell, Matthew C. Varley and Aaron J. Coutts
Athlete-tracking devices that include global positioning system (GPS) and microelectrical mechanical system (MEMS) components are now commonplace in sport research and practice. These devices provide large amounts of data that are used to inform decision making on athlete training and performance. However, the data obtained from these devices are often provided without clear explanation of how these metrics are obtained. At present, there is no clear consensus regarding how these data should be handled and reported in a sport context. Therefore, the aim of this review was to examine the factors that affect the data produced by these athlete-tracking devices and to provide guidelines for collecting, processing, and reporting of data. Many factors including device sampling rate, positioning and fitting of devices, satellite signal, and data-filtering methods can affect the measures obtained from GPS and MEMS devices. Therefore researchers are encouraged to report device brand/model, sampling frequency, number of satellites, horizontal dilution of precision, and software/firmware versions in any published research. In addition, details of inclusion/exclusion criteria for data obtained from these devices are also recommended. Considerations for the application of speed zones to evaluate the magnitude and distribution of different locomotor activities recorded by GPS are also presented, alongside recommendations for both industry practice and future research directions. Through a standard approach to data collection and procedure reporting, researchers and practitioners will be able to make more confident comparisons from their data, which will improve the understanding and impact these devices can have on athlete performance.
Samuel W. Logan, E. Kipling Webster, Nancy Getchell, Karin A. Pfeiffer and Leah E. Robinson
The purpose of this review is to synthesize the evidence of the relationship between fundamental motor skills (FMS) competence and physical activity by qualitatively describing results from 13 studies that met rigorous inclusion criteria. Inclusion criteria: (a) published in a peer-review journal, (b) participants were between the ages of 3–18, (c) participants were typically developing, (d) FMS was measured by a process-oriented assessment, (e) assessed physical activity, (f) related FMS and physical activity through statistical procedures, and (g) printed in English. Databases were searched for relevant articles using key terms related to FMS and physical activity. Evidence suggested low to moderate relationships between FMS competence and physical activity in early childhood (r = .16 to .48; R 2 = 3–23%, 4 studies), low to high relationships in middle to late childhood (r = .24 to .55; R 2 = 6–30%, 7 studies), and low to moderate relationships in adolescence (r = .14 to .35; R 2 = 2–12.3%, 2 studies). Across ages, object control skills and locomotor skills were more strongly related to physical activity for boys and girls, respectively. Future research should emphasize experimental and longitudinal research designs to provide further understanding of the relationship between FMS competence and physical activity.
Mohamed Ali Nabli, Nidhal Ben Abdelkrim, Imed Jabri, Tahar Batikh, Carlo Castagna and Karim Chamari
To examine the relation between game performance, physiological responses, and field-test results in Tunisian basketball referees.
Computerized time–motion analysis, heart rate (HR), and blood lactate concentration [La–] were measured in 15 referees during 8 competitive games (under-19-y-old Tunisian league). Referees also performed a repeated-sprint test (RSA), Yo-Yo Intermittent Recovery Test level 1 (YYIRTL1), agility T-test, and 30-m sprint with 10-m lap time. Computerized video analysis determined the time spent in 5 locomotor activities (standing, walking, jogging, running, and sprint), then grouped in high-, moderate-, and low-intensity activities (HIAs, MIAs, and LIAs, respectively).
YYIRTL1 performance correlated with (1) total distance covered during the 4th quarter (r = .52, P = .04) and (2) distance covered in LIA during all game periods (P < .05). Both distance covered and time spent in MIA during the 1st quarter were negatively correlated with the YYIRTL1 performance (r = –.53, P = .035; r = –.67, P = .004, respectively). A negative correlation was found between distance covered at HIA during the 2nd half (3rd quarter + 4th quarter) and fatigue index of the RSA test (r = –.54, P = .029). Mean HR (expressed as %HRpeak) during all game periods was correlated with YYIRTL1 performance (.61 ≤ r < .67, P < .01).
This study showed that (1) the YYIRTL1 performance is a moderate predictor of game physical performance in U-19 basketball referees and (2) referees’ RSA correlates with the amount of HIA performed during the 2nd half, which represents the ability to keep up with play.
Jared A. Bailey, Paul B. Gastin, Luke Mackey and Dan B. Dwyer
Most previous investigations of player load in netball have used subjective methodologies, with few using objective methodologies. While all studies report differences in player activities or total load between playing positions, it is unclear how the differences in player activity explain differences in positional load.
To objectively quantify the load associated with typical activities for all positions in elite netball.
The player load of all playing positions in an elite netball team was measured during matches using wearable accelerometers. Video recordings of the matches were also analyzed to record the start time and duration of 13 commonly reported netball activities. The load associated with each activity was determined by time-aligning both data sets (load and activity).
Off-ball guarding produced the highest player load per instance, while jogging produced the greatest player load per match. Nonlocomotor activities contributed least to total match load for attacking positions (goal shooter [GS], goal attack [GA], and wing attack [WA]) and most for defending positions (goalkeeper [GK], goal defense [GD], and wing defense [WD]). Specifically, centers (Cs) produced the greatest jogging load, WA and WD accumulated the greatest running load, and GS and WA accumulated the greatest shuffling load. WD and Cs accumulated the greatest guarding load, while WD and GK accumulated the greatest off-ball guarding load.
All positions exhibited different contributions from locomotor and nonlocomotor activities toward total match load. In addition, the same activity can have different contributions toward total match load, depending on the position. This has implications for future design and implementation of position-specific training programs.
Andrew A. Dingley, David B. Pyne and Brendan Burkett
To characterize relationships between propulsion, anthropometry, and performance in Paralympic swimming.
A cross-sectional study of swimmers (13 male, 15 female) age 20.5 ± 4.4 y was conducted. Subject locomotor categorizations were no physical disability (n = 8, classes S13–S14) and low-severity (n = 11, classes S9–S10) or midseverity disability (n = 9, classes S6–S8). Full anthropometric profiles estimated muscle mass and body fat, a bilateral swim-bench ergometer quantified upper-body power production, and 100-m time trials quantified swimming performance.
Correlations between ergometer mean power and swimming performance increased with degree of physical disability (low-severity male r = .65, ±0.56, and female r = .68, ±0.64; midseverity, r = .87, ±0.41, and r = .79, ±0.75). The female midseverity group showed nearperfect (positive) relationships for taller swimmers’ (with a greater muscle mass and longer arm span) swimming faster, while for female no- and low-severity-disability groups, greater muscle mass was associated with slower velocity (r = .78, ±0.43, and r = .65, ±0.66). This was supported with lighter females (with less frontal surface area) in the low-severity group being faster (r = .94, ±0.24). In a gender contrast, low-severity males with less muscle mass (r = -.64, ±0.56), high skinfolds (r = .78, ±0.43), a longer arm span (r = .58, ±0.60) or smaller frontal surface area (r = -.93, ±0.19) were detrimental to swimming-velocity production.
Low-severity male and midseverity female Paralympic swimmers should be encouraged to develop muscle mass and upper-body power to enhance swimming performance. The generalized anthropometric measures appear to be a secondary consideration for coaches.