Validation of a commercially available inertial measurement unit for recording jump load in youth basketball players

ABSTRACT

A high incidence of overuse knee injuries among youth basketball players may be attributed to number of jumps. Wearable technology may be an effective tool for measuring jump load compared to traditional counting methods. The purpose of this study was to validate a commercially available jump counter (VERT® Classic) in youth basketball practices and games, and to identify the characteristics (i.e., height, direction, takeoff) of jumps recorded by the VERT® Classic. 46 (19F, 27M) youth basketball players wore a VERT® Classic and were recorded on video during games and practices. The number of jumps recorded by the VERT® Classic and evaluated by video raters were compared for each jump characteristic using intraclass correlation coefficient (ICC(3,k)), mean offset, and limits of agreement. The number and percent of VERT® Classic jumps and corresponding video jumps according to timestamp were reported. VERT® Classic jumps had excellent reliability with video-counted jumps over 15 cm (ICC(3,k) = 0.958), with a mean offset of ?2.4 jumps (fewer VERT® Classic) and limits of agreement ?12.6 to 7.8 jumps. Pairs of corresponding jumps represented 68.0% of total video jumps and 92.0% of VERT® Classic jumps. The VERT® Classic can provide an estimate of jump load in youth basketball.     

Participatory evaluation: implications for improving electronic learning and teaching approaches

This paper examines the participatory approach used by a group of academic support staff in evaluating an academic professional development resource designed to support e‐learning and teaching. The resource, titled Designing Electronic Learning and Teaching Approaches (DELTA), showcases examples of electronic learning and teaching approaches developed at Monash University, Australia. The evaluation included individual and collective reflection, dialogue and action, drawing on the features of participatory action research. This paper explores the value of this critically reflective, participatory approach for evaluation to improve the use of new learning technologies, demonstrating how it provided a clear decision‐making framework for iterative improvement of the DELTA site by identifying consensus items for action and recording other items for later consideration, while also contributing to team members’ own professional development.     

Effect of Mouthguard Use on Metabolic and Cardiorespiratory Responses to Aerobic Exercise in Males

Purpose: This study investigated the physiological effects of wearing a mouthguard during submaximal treadmill exercise. Method: Twenty-four recreationally active males (M_age = 21.3 ± 2.4 years, M_height = 1.78 ± 0.06 m, M_weight = 81.9 ± 10.6 kg, M_{body mass index} = 25.8 ± 3.4 kg·m^?2) performed incremental, continuous exercise at 2, 4, 6, and 8 mph (3.2, 6.4, 9.7, 12.9 kph) for 5 min at each speed on a motor-driven treadmill on 2 separate occasions in a randomized, crossover, counterbalanced design while wearing or not wearing a self-adaptable “boil and bite” mouthguard. Respiratory rate (RR), tidal volume (V_T), ventilation (V_E), oxygen consumption (VO₂), respiratory exchange ratio (RER), and heart rate (HR) data were averaged during the last 60 s of each exercise stage; blood lactate (LA) was measured before exercise and 3 min and 10 min following exercise. Results: Repeated-measures analysis of variance revealed that mouthguard use failed to alter the response of RR, V_T, V_E, VO₂, RER, and HR to treadmill exercise (p > .05), although each variable did increase in magnitude as a result of increasing treadmill speed (p < .001). Although increasing to above resting values at both 3 min and 10 min (p < .001) after cessation of exercise, LA levels also displayed no differences with mouthguard use (p > .05). Conclusion: Despite predictable increases in respiratory, metabolic, and cardiovascular variables in response to incremental exercise, the presence of a mouthguard failed to affect the magnitude or nature of these physiological responses.     

Generalizability of diagnostic-prescriptive teaching strategies across student locus of control and multiple instructional units

The influence of locus of control and diagnostic testing with prescribed remediation on immediate and retained science achievement was the focus of the study. To test the generalizability of the results across instructional units and to check on the existence of a treatment warm-up period, the experiment was conducted across three biology units. The results supported the existence of the warm-up period with no significant effects of diagnosis and remediation during the first unit. On later units and on the retention measure, the experimental subjects achieved significantly more than the control. No locus of control X treatment interactions were found; although, in one unit, the internal locus of control subjects achieved significantly higher than externals.     

The role of state humanities program in reaching nontraditional learners

Humanities programs that involve citizens in discovering the relevance of the humanities to contemporary American experience are supported by the National Endowment for the Humanities through its state affiliates. Potential benefits are enhanced through the incorporation of intended learners in the planning and evaluation stages. For a decade, state humanities agencies have been catalysts in the design and delivery of programs that reach adults who have not traditionally been students of the humanities.Ronald Benson is Executive Director of the Georgia Endowment for the Humanities. Before coming to Georgia, Ron was Professor of Philosophy at Ohio Northern University.     

Body image perception, satisfaction and somatotype in male and female athletes and non-athletes: results using a novel morphing technique

Thirty-six adults (24 males, 12 females) were assessed for anthropometric somatotype and body image (perception and satisfaction) by a novel technique using quantitative distortion of a digital still image. Software produced random distortions in nine body regions. The participants manipulated interactive slider controls to adjust each body feature in turn, recreate their perceived image and indicate their desired image. There were no differences in perception between the sexes. However, the ideal-actual differences (i.e. satisfaction) indicated that males desired larger and females smaller features, respectively, in the chest and thighs (P < 0.001) and arms and calves (P < 0.01). When the male-derived data were partitioned by sport (strength, endurance, team-sport and controls), differences were found in the perceived image size in the chest and rib regions (P < 0.01 and P < 0.05, respectively). Strength athletes perceived these areas to be smaller and the control group perceived these areas to be larger than the true values. Somatotype analysis indicated that the physique associated with minimal dissatisfaction was 2.0-5.0-3.0 for males and 3.0-2.5-3.0 for females. Cluster analysis, combining anthropometric and satisfaction data, revealed seven distinct subgroups distinguished by particular attributes of physical appearance. We conclude that the method is reliable and that body image includes sex-specific, anthropometric, perceptual and personality-related components.     

Reliability and validity of a GPS-enabled iPhoneTM “app” to measure physical activity

This study assessed the validity and reliability of an iPhone^TM “app” and two sport-specific global positioning system (GPS) units to monitor distance, intensity and contextual physical activity. Forty (23 female, 17 male) 18–55-year-olds completed two trials of six laps around a 400-m athletics track wearing GPSports Pro^TM and WiSpi^TM units (5 and 1 Hz) and an iPhone^TM with a Motion X GPS^TM “app” that used the inbuilt iPhone^TM location services application programming interface to obtain its sampling rate (which is likely to be ≤1 Hz). Overall, the statistical agreement, assessed using t-tests and Bland–Altman plots, indicated an underestimation of the known track distance (2.400 km) and average speed by the Motion X GPS^TM “app” and GPSports Pro^TM while the GPSports WiSpi^TM device overestimated these outcomes. There was a ≤3% variation between trials for distance and average speed when measured by any of the GPS devices. Thus, the smartphone “app” trialled could be considered as an accessible alternative to provide high-quality contextualised data to enable ubiquitous monitoring and modification of programmes to ensure appropriate intensity and type of physical activity is prescribed and more importantly adhered to.