scholarly journals Validity and reliability of a novel monitoring sensor for the quantification of the hitting load in tennis

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255339
Author(s):  
Vedran Hadžić ◽  
Aleš Germič ◽  
Aleš Filipčič
Keyword(s):  
Intraclass Correlation ◽  
Video Camera ◽  
Measurement Unit ◽  
Validity And Reliability ◽  
Small Magnitude ◽  
Tennis Players ◽  
Video Footage ◽  
Digital Video Camera ◽  
Junior Tennis ◽  
Gyroscope Sensor

Wearable sensor systems are a emerging tools for the evaluation of the sport’s activity and can be used to quantify the external workload of the athlete. The main goal of this paper was to evaluate the validity and reliability of the “Armbeep inertial measurement unit” (IMU) sensor both in a closed tennis exercise and in open matchplay. Twentyfour junior tennis players performed a baseline drill and played matches, during which they wore a combined accelerometer and gyroscope sensor. Video footage was concomitantly recorded using a digital video camera. The agreement between the measurements was assessed with the intraclass correlation coefficient (ICC) and the standard error of measurement (SEM). A simple linear regression was used to predict the number of shots registered from the video and from the Armbeep IMU sensor’s data. The number of total forehand and backhand shots during the drill repetitions showed an excellent test and re-test reproducibility (ICC≥0.90). There was a significant relationship between the Armbeep IMU sensor’s number of contacts and the total number of shots (R2 = 0.938) which indicated the excellent reliability of the tested Armbeep IMU sensor for those parameters. Considering the accuracy of the total tennis shots and the small magnitude of error for wrist speed and acceleration, the Armbeep IMU sensor appears to be an appropriate on-court tool that can be used to monitor the hitting load during tennis practice and matches.

scholarly journals Valid and Reliable Barbell Velocity Estimation Using an Inertial Measurement Unit

2021 ◽  
Vol 18 (17) ◽  
pp. 9170
Author(s):  
Steffen Held ◽  
Ludwig Rappelt ◽  
Jan-Philip Deutsch ◽  
Lars Donath
Keyword(s):  
Inertial Measurement Unit ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Velocity Estimation ◽  
Measurement Unit ◽  
Systematic Bias ◽  
Validity And Reliability ◽  
Inertial Measurement ◽  
Intraclass Correlation Coefficients ◽  
Reliability Indicators

The accurate assessment of the mean concentric barbell velocity (MCV) and its displacement are crucial aspects of resistance training. Therefore, the validity and reliability indicators of an easy-to-use inertial measurement unit (VmaxPro®) were examined. Nineteen trained males (23.1 ± 3.2 years, 1.78 ± 0.08 m, 75.8 ± 9.8 kg; Squat 1-Repetition maximum (1RM): 114.8 ± 24.5 kg) performed squats and hip thrusts (3–5 sets, 30 repetitions total, 75% 1RM) on two separate days. The MCV and displacement were simultaneously measured using VmaxPro® and a linear position transducer (Speed4Lift®). Good to excellent intraclass correlation coefficients (0.91 < ICC < 0.96) with a small systematic bias (p < 0.001; ηp2 < 0.50) for squats (0.01 ± 0.04 m·s−1) and hip thrusts (0.01 ± 0.05 m·s−1) and a low limit of agreement (LoA < 0.12 m·s−1) indicated an acceptable validity. The within- and between-day reliability of the MCV revealed good ICCs (0.55 < ICC < 0.91) and a low LoA (<0.16 m·s−1). Although the displacement revealed a systematic bias during squats (p < 0.001; ηp2 < 0.10; 3.4 ± 3.4 cm), no bias was detectable during hip thrusts (p = 0.784; ηp2 < 0.001; 0.3 ± 3.3 cm). The displacement showed moderate to good ICCs (0.43 to 0.95) but a high LoA (7.8 to 10.7 cm) for the validity and (within- and between-day) reliability of squats and hip thrusts. The VmaxPro® is considered to be a valid and reliable tool for the MCV assessment.

The Effects of Target Length on the Visual Control of Step Length for Hard and Soft Impacts

2002 ◽  
Vol 18 (1) ◽  
pp. 57-73 ◽  
Author(s):  
Elizabeth J. Bradshaw ◽  
W.A. Sparrow
Keyword(s):  
Video Camera ◽  
Step Length ◽  
Visual Control ◽  
Whole Body ◽  
Black And White ◽  
Video Footage ◽  
Digital Video Camera ◽  
Control Time ◽  
Approach Velocity ◽  
Speed Accuracy

Adjustments to gait were examined when positioning the foot within a narrow target at the end of an approach for two impact conditions, hard and soft. Participants (6 M, 6 F) ran toward a target of three lengths along a 10-m walkway consisting of two marker strips with alternating black and white 0.5-m markings. Five trials were conducted for each target length and impact task, with trials block randomized between the 6 participants of each gender. A 50Hz digital video camera panned and filmed each trial from an elevated position adjacent to the walkway. Video footage was digitized to deduce the gait characteristics. A linear speed/accuracy tradeoff between target length and approach time was found for both impact tasks (hard, r = 0.99, p < 0.01; soft, r = 0.96, p < 0.05). For the hard-impact task, visual control time increased linearly (r = 0.99, p < 0.05) when whole-body approach velocity decreased. Visual control time was unaffected by whole-body approach velocity in the soft-impact task. A constant tau-margin of 1.08 describes the onset of visual control when approaching a target while running, with the control of braking during visual control described by a tau-dot of –0.85. Further research is needed to examine the control of braking in different targeting tasks.

Validation and Reliability of the New Lifestyles NL-1000 Accelerometer in New Zealand Preschoolers

2012 ◽  
Vol 9 (2) ◽  
pp. 295-299 ◽  
Author(s):  
Leanne Liggett ◽  
Andrew Gray ◽  
Winsome Parnell ◽  
Rob McGee ◽  
Yvette McKenzie
Keyword(s):  
Physical Activity ◽  
Rating Scale ◽  
Vigorous Physical Activity ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Activity Level ◽  
Activity Levels ◽  
Validity And Reliability ◽  
Video Footage ◽  
Activity Rating

Background:Objective measures, such as accelerometers, are increasingly being used to measure physical activity (PA) levels in children, and the use of validated and reliable instruments is desirable when measuring the effectiveness of programs. The purpose of this study was to determine the validity and reliability of the New Lifestyles NL-1000 accelerometer among preschoolers using a modified version of the Children’s Activity Rating Scale (CARS).Methods:Fourteen preschoolers wore the NL-1000 at their waist while the device measured activity levels [in seconds of moderate-to-vigorous physical activity (MVPA)]. They were also videoed for approximately 12 minutes while participating in normal activities at an early childhood center. At approximately 2-minute intervals, activity level readings derived from the NL-1000 were recorded. The video footage was analyzed using a modified CARS technique and the CARS scores compared with data obtained from the accelerometer.Results:Within subject reliability was measured using intraclass correlation coefficients (0.58 for CARS and 0.59 for NL-1000). Furthermore, 95% of the variation in CARS could be explained by variation in the accelerometer counts, with 2.4% of the variation being participant-specific.Conclusion:The NL-1000 is a sufficiently reliable and valid tool for assessing MVPA in preschoolers.

Monitoring Hitting Load in Tennis Using Inertial Sensors and Machine Learning

2017 ◽  
Vol 12 (9) ◽  
pp. 1212-1217 ◽  
Author(s):  
David Whiteside ◽  
Olivia Cant ◽  
Molly Connolly ◽  
Machar Reid
Keyword(s):  
Machine Learning ◽  
Support Vector Machine ◽  
Inertial Sensors ◽  
Measurement Unit ◽  
Support Vector ◽  
Tennis Players ◽  
Video Footage ◽  
Automated Method ◽  
Kernel Support Vector Machine ◽  
Shot Type

Context:Quantifying external workload is fundamental to training prescription in sport. In tennis, global positioning data are imprecise and fail to capture hitting loads. The current gold standard (manual notation) is time intensive and often not possible given players’ heavy travel schedules. Purpose:To develop an automated stroke-classification system to help quantify hitting load in tennis. Methods:Nineteen athletes wore an inertial measurement unit (IMU) on their wrist during 66 video-recorded training sessions. Video footage was manually notated such that known shot type (serve, rally forehand, slice forehand, forehand volley, rally backhand, slice backhand, backhand volley, smash, or false positive) was associated with the corresponding IMU data for 28,582 shots. Six types of machine-learning models were then constructed to classify true shot type from the IMU signals. Results:Across 10-fold cross-validation, a cubic-kernel support vector machine classified binned shots (overhead, forehand, or backhand) with an accuracy of 97.4%. A second cubic-kernel support vector machine achieved 93.2% accuracy when classifying all 9 shot types. Conclusions:With a view to monitoring external load, the combination of miniature inertial sensors and machine learning offers a practical and automated method of quantifying shot counts and discriminating shot types in elite tennis players.

The Relationship of Training Load to Physical-Capacity Changes During International Tours in High-Performance Junior Tennis Players

2015 ◽  
Vol 10 (2) ◽  
pp. 253-260 ◽  
Author(s):  
Alistair P. Murphy ◽  
Rob Duffield ◽  
Aaron Kellett ◽  
Machar Reid
Keyword(s):  
Repeated Measures ◽  
High Performance ◽  
Physical Capacity ◽  
Size Analysis ◽  
Small Magnitude ◽  
Tennis Players ◽  
Capacity Change ◽  
Before And After ◽  
Junior Tennis ◽  
Physical Capacities

Purpose:Given the travel that punctuates junior tennis development, an understanding of the changes in fitness owing to touring and the association between training loads (TLs) and fitness on return is vital. The authors investigated physical-capacity changes from pretour to posttour, determining if those changes were related to the TL of athletes on tour.Methods:Thirty junior athletes completed fitness testing before and after 4-wk tours. Testing included double-leg countermovement jump (CMJ), dominant single-leg and nondominant single-leg CMJ, speed (5, 10, 20 m), modified 5-0-5 agility (left and right), 10 × 20-m repeated-sprint ability (RSA), and multistage fitness tests. Repeated-measures ANOVAs determined physical-capacity change, with effect-size analysis establishing the magnitude of change. To avoid regression toward the mean, a 1/3-split technique was implemented for comparative analysis (high to low TLs).Results:Moderate effects (d = 0.50–0.70) for reductions of up to 3.6% in 5-, 10-, and 20-m speeds were observed. However, all remaining changes were only of trivial to small magnitude (d < 0.40). Closer analysis of the interaction between TL and physical capacities (1/3-split) revealed that subjects who completed the greatest amount of total and tennis TL returned with a greater decline in speed and aerobic capacities (d > 0.80). Furthermore, it was observed that match load dictates on- and off-court TL, with an increase in matches won understandably stunting exposure to off-court TL.Conclusions:Specific training should be prescribed on tour to maintain speed characteristics over a 4-wk international tour. On-tour training schedules should be carefully monitored to maximize specific TL exposure after losses on tour.

Validity and Reliability of a New Device to Measure Type of Actions in Indoor Sports

2020 ◽  
Author(s):  
Carlos Lago-Fuentes ◽  
Paolo Aiello ◽  
Mauro Testa ◽  
Iker Muñoz ◽  
Marcos Mecías Calvo
Keyword(s):  
Coefficient Of Variation ◽  
Inertial Measurement Unit ◽  
High Reliability ◽  
Intraclass Correlation ◽  
Measurement Unit ◽  
Validity And Reliability ◽  
Inertial Measurement ◽  
New Device ◽  
Standing Up ◽  
Indoor Sports

AbstractThe purpose of this study was to analyze the validity and the reliability of the intensity ranges, number of actions and changes of direction measured by a commercial inertial measurement unit. Eleven elite youth futsal players performed a circuit with different type of displacements as sprinting, running at low-medium intensity, standing up and changes of direction. Data recorded by the Overtraq system were compared with video-analyzer during the six trials of each player. Standard error mean, Intraclass Correlation Coeficient and Coefficient of variation, were calculated to analyze the reliability of the device, as well as the Root Mean Square Error and Confidence Interval with correlation of Pearson for its validity. The results reported good validity for three intensity ranges (R2>0.7) with high reliability (Intraclass Correlation Coeficient: 0.8–0.9), especially for high intensity actions (Intraclass Correlation Coeficient: 0.95, Coefficient of Variation: 3.06%). Furthermore, the validity for the number of different actions was almost perfect (96.3–100%), with only small differences regarding changes of activity (mean error: 2.0%). The Overtraq system can be considered as a valid and reliable technology for measuring and monitoring actions at different intensities and changes of direction in futsal, likewise common actions for other indoor sports.

Development and validation of a questionnaire measuring knowledge, attitudes, and practices (KAP) to healthy eating and activity patterns in school children (HEAPS)

2021 ◽  
pp. 026010602098235 ◽  
Author(s):  
Panchali Moitra ◽  
Preeti Verma ◽  
Jagmeet Madan
Keyword(s):  
Correlation Coefficient ◽  
Healthy Eating ◽  
School Children ◽  
Content Validity ◽  
Activity Patterns ◽  
Intraclass Correlation ◽  
Validity And Reliability ◽  
Attitudes And Practices ◽  
Item Content ◽  
Knowledge Attitudes And Practices

Background: Development of culturally appropriate and psychometrically sound instruments that measure knowledge and health behaviors of children will help to inform appropriate interventions. Aim: To develop and test the validity and reliability of a questionnaire measuring knowledge, attitudes, and practices to healthy eating and activity patterns in school children in India. Methods: Review of literature, focus-group discussions, and theoretical constructs of the Health Belief Model guided the development of an item pool. Face and content validity were assessed by children and a panel of experts and the item content validity, item difficulty, and discrimination indices were calculated. Construct validity was determined using the principal axis method of exploratory factor analysis among a cross-sectional sample of children ( n=252). Internal consistency (Cronbach α values >0.7) and test-retest reliability (intraclass correlation coefficient values >0.75) were estimated. Results: Item content validity index for clarity and relevance were satisfactory (>0.80) and internal consistency for knowledge (Kuder-Richardson 20 = 0.832), attitude (Cronbach’s α = 0.912), and practice items (Cronbach’s α = 0.769) were good. Four factors (children’s eating habits, family dietary practices, and consumption of healthy and unhealthy foods) and two factors (moderate to vigorous activities and sedentary activities) explained 67.7% and 48.2% of the total variance in practice items. Intraclass correlation coefficient estimates ranged from good to excellent (0.72–0.99). Conclusions: The results of the validity and reliability of the 84-item knowledge, attitudes, and practices to healthy eating and activity patterns in schoolchildren questionnaire were promising. The detailed description of the methodology employed may prove useful to researchers conducting similar studies in children.

scholarly journals Validity and reliability of the lederman Prenatal Self-Evaluation Questionnaire (PSEQ) in Brazil

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Janiny Lima e Silva ◽  
Matheus de Sousa Mata ◽  
Saionara Maria Aires Câmara ◽  
Íris do Céu Clara Costa ◽  
Kleyton Santos de Medeiros ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Confirmatory Factor Analysis ◽  
Pregnant Women ◽  
Internal Consistency ◽  
Intraclass Correlation ◽  
Psychosocial Adaptation ◽  
Validity And Reliability ◽  
Evaluation Questionnaire ◽  
Self Evaluation ◽  
Confirmatory Factor

Abstract Background The Lederman Prenatal Self-Evaluation Questionnaire (PSEQ) is used to assess psychosocial adaptation to pregnancy, labor, childbirth, and maternity. The PSEQ is a tool used in various countries and has been translated into Portuguese; however, it needs to be validated in Brazil. This study aimed to analyze the validity and reliability of the PSEQ in Brazilian pregnant women. Method This methodological validity study investigated internal consistency and reliability using Cronbach’s alpha and intraclass correlation coefficients. Construct validity was assessed using Pearson’s correlation between domains and confirmatory factor analysis. To assess concurrent validity, Pearson’s correlation between the different domains of the PSEQ and Prenatal Psychosocial Profile-Portuguese Version (PPP-VP) was determined. The level of significance was set at 5%. Results This study included 399 pregnant women in the northeastern region of Brazil. The internal consistency and reliability of the total PSEQ score were high (Cronbach's alpha = 0.89; intraclass correlation coefficient = 0.95). Validity analysis showed positive and significant correlations between all PSEQ domains, ranging from 0.14 to 0.56. Confirmatory factor analysis demonstrated the following values of goodness of fit: RMSEA = 0.05, SRMR = 0.08, CFI = 0.61, χ2/df = 1.77. The discriminant and concurrent validities of the PSEQ were confirmed. Conclusions The Portuguese version of the PSEQ has adequate psychometric properties and is a valid and reliable tool to evaluate psychosocial adaptation to pregnancy in Brazilian pregnant women.

Validity and reliability of the Mandarin version of the Treatment Burden Questionnaire among stroke patients in Mainland China

2021 ◽  
Author(s):  
Qi Zhang ◽  
Ke Zhang ◽  
Miao Li ◽  
Jiaxin Gu ◽  
Xintong Li ◽  
...  
Keyword(s):  
Internal Consistency ◽  
Convergent Validity ◽  
Intraclass Correlation ◽  
Reliability And Validity ◽  
Therapeutic Interventions ◽  
Treatment Burden ◽  
Validity And Reliability ◽  
Stroke Patients ◽  
Retest Reliability ◽  
Test Retest Reliability

Abstract Objectives To examine the validity and reliability of the Mandarin version of the Treatment Burden Questionnaire (TBQ) among stroke patients. Background Stroke patients need long-term management of symptoms and life situation, and treatment burden has recently emerged as a new concept that can influence the health outcomes during the rehabilitation process. Methods The convenience sampling method was used to recruit 187 cases of stroke patients in a tertiary grade hospital in Tianjin for a formal investigation. Item analysis, reliability and validity tests were carried out. The reliability test included internal consistency and test–retest reliability. And as well as content, structure and convergent validity were performed for the validity test. Results Of the 187 completed questionnaires, only 180 (96.3%) were suitable for analysis. According to the experts’ evaluation, the I-CVI of each item was from 0.833 to 1.000, and the S-CVI was 0.967. The exploratory factor analysis yielded three-factor components with a cumulative variation of 53.054%. Convergent validity was demonstrated using measures of Morisky’s Medication Adherence Scale 8 (r = –0.450, P &lt; 0.01). All correlations between items and global scores ranged from 0.403 to 0.638. Internal consistency reliability and test–retest reliability were found to be acceptable, as indicated by a Cronbach’s α of 0.824 and an intraclass correlation coefficient of 0.846, respectively. Conclusions The Mandarin TBQ had acceptable validity and reliability. The use of TBQ in the assessment of treatment burden of stroke survivor may benefit health resources allocation and provide tailor therapeutic interventions to construct minimally disruptive care.

scholarly journals PETTLEP imagery and tennis service performance: an applied investigation

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Nafih Cherappurath ◽  
Masilamani Elayaraja ◽  
Dilshith A. Kabeer ◽  
Amila Anjum ◽  
Paris Vogazianos ◽  
...  
Keyword(s):  
Age Groups ◽  
Training Session ◽  
Performance Outcomes ◽  
Service Performance ◽  
Control Group ◽  
Specific Training ◽  
Tennis Players ◽  
Imagery Training ◽  
Before And After ◽  
Junior Tennis

AbstractTennis is one of the most popular and widely played sports enjoyed by players of different age groups and genders as a profession as well as a mode of recreation. A novel method, PETTLEP imagery combines both conventional and non-conventional style of training of an athlete and improves one’s performance. This study aimed to analyze the tennis service performance of junior tennis players based on PETTLEP imagery training. Forty-four junior male tennis players (Mage=13.22 years, SD=0.42) were selected for the study. The investigator handed over the MIQ-R questionnaire to all the participants in which they scored 16 and above points as per previous research. The participants were equally divided (n=11) into three experimental groups (E1, E2, and E3) and a control group. The service performance outcomes of all the players were compared before and after a training session. The three experimental groups were assigned with service-specific training, service-specific training combined with PETTLEP imagery training, and PETTLEP imagery training alone, respectively, for three days per week for 12 weeks. They were tested on their service accuracy based on the International tennis number (ITN) manual on-court assessment test. The data were assessed for normality and analyzed using non-parametric methods to reveal main effects (each training method alone) as well as to calculate the combined effect of PETTLEP and service-specific training. Certain significant improvements in tennis service were observed with service-specific training alone. Though it marginally outperformed the PETTLEP imagery method, the most improved services were observed with both PETTLEP and service-specific training utilized together. This implies an additive effect when both methods are used together.

Sign in / Sign up

Export Citation Format

Share Document