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Parker, J., Ivarsson, A., Johnson, U., Svetoft, I., Andersen, M., Schough, C., . . . Warpman, S. (2019). Is self-determined motivation associated with the effects of an intervention aimed to increase physical activity and exercise levels? An 80-day follow-up. In: Abstract book for the ISBNPA 2019 Annual Meeting in Prague: . Paper presented at International Society of Behavior Nutrition and Physical Activity 2019 Annual Meeting, Prague, Czech Republic, 4-7 June, 2019 (pp. 488-488). International Society of Behavioral Nutrition and Physical Activity
Open this publication in new window or tab >>Is self-determined motivation associated with the effects of an intervention aimed to increase physical activity and exercise levels? An 80-day follow-up
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2019 (English)In: Abstract book for the ISBNPA 2019 Annual Meeting in Prague, International Society of Behavioral Nutrition and Physical Activity , 2019, p. 488-488Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Objective: State-of-the-art technologies, for instance smart watches and smartphones, have the potential to positively influence physical activity and exercise in sedentary populations. Psychological factors, such as self-determined (SD) motivation, might influence the impact state-of-the-art technologies have on level of physical activity and exercise. The aim of this study was to investigate if self-determined motivation influences an intervention on both physical activity (PA) and exercise in a sedentary population.

Methods: 16 participants (men = 5, women = 11) with a self-reported low level of PA over the last year and predominantly sedentary jobs volunteered to participate in the study. PA data (steps and exercise time) were collected over an 80-day period using a wrist-worn accelerometer (Apple-watch and iPhone). Motivation was measured with the Behavioral Regulation in Exercise Questionnaire-2. At the start of the study, each participant completed the questionnaire and received their Apple-watches. Data analysis: All PA and exercise data were recorded through the Apple-watch and via Health App. Data for PA (steps) and exercise time were then extracted and aggregated to daily totals. Statistical analysis: Group means and standard deviations were calculated. A linear regression analysis was used to analyze the relationship between exercise time, PA, and SD, the R2 value effect size (ES) was used to estimate the magnitude of the differences. All data analyses were performed in MatLab (software, R2016b).

Results/findings: SD motivation (3.9±0.9) had a medium (R2 = 0.09) but not statistically significant (p = .26) effect on the amount of moderate to high-intensity exercise time (33.3±39.6 minutes) during the 80-day period. There was no statistically significant effect (R2 = 0.003, p = .84) of SD on PA (12953±7717 steps).

Conclusions: Given the small sample size, achieving a medium effect size has meaningful significance despite not achieving statistical significance. This result suggests that self-determined motivation effects the amount of daily exercise but not PA in a sedentary population. Combining technology and other strategies (e.g., motivational interviewing, coaching) to promote behavior change is promising, and these interventions should include theoretically derived behavior change techniques and take level of SD motivation into account.

Place, publisher, year, edition, pages
International Society of Behavioral Nutrition and Physical Activity, 2019
Keywords
Self-determined motivation, Physical activity
National Category
Public Health, Global Health, Social Medicine and Epidemiology
Identifiers
urn:nbn:se:hh:diva-39689 (URN)978-1-7324011-1-2 (ISBN)
Conference
International Society of Behavior Nutrition and Physical Activity 2019 Annual Meeting, Prague, Czech Republic, 4-7 June, 2019
Funder
Knowledge Foundation
Available from: 2019-06-11 Created: 2019-06-11 Last updated: 2019-08-02Bibliographically approved
Parker, J. (2018). A multi-disciplinary approach to studying performance among high-level golfers: physiological and biomechanical aspects. (Licentiate dissertation). Halmstad: Halmstad University Press
Open this publication in new window or tab >>A multi-disciplinary approach to studying performance among high-level golfers: physiological and biomechanical aspects
2018 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

In competitive golf, the player’s ability to hit the ball a long distance affects the score in a positive way. Swing kinematics is considered an important factor in driver performance; one way of improving swing kinematics is through strength and power training. Subsequently, high-level golfers and their coaches often explore novel ways of increasing the distance of a shot, in particular driver carry distance (CD). This licentiate thesis presents two studies with the overall aim of studying how swing kinematic and physical characteristics are associated with driver performance among intercollegiate golf players. The studies report swing kinematics associated with driver performance (study 1) and the impact of isokinetic rotational training on driver performance and swing kinematic variables (study 2).

The methods used were (1) a cross-sectional correlation study (n=15) and (2) an open trial intervention study (n=20). The studies investigated (1) the relationship between golf swing kinematics and driver performance, and (2) the impact of strength training on swing kinematics and driver performance variable.

The results show variables that were distinctive for the club head speed (CHS) were mainly during the downswing: greater X-factor stretch; and higher pelvis peak speed. Whilst, factors distinctive to the regression model for CD were mainly at impact: reduced thorax rotation; and greater thorax lateral bend. Nine weeks of isokinetic training increased seated rotational force and power, peak arm speed and arm acceleration, ball speed, and CD more compared to isotonic training. Even though isokinetic training did not increase CHS, it did result in greater CD.

This licentiate thesis contributes to the understanding of which variables influence driver performance, in particular CD, among high-level golfers. Segmental interactions (pelvis-thorax), lead arm speed and acceleration, isokinetic and isotonic training. These results may guide training interventions aiming to improve driver and golf performance among high-level golfers, particularly those with a background of strength training. Future studies could investigate how the interaction between swing kinematics, clubhead trajectory, and driver performance variables differ between male and female golfers.

Place, publisher, year, edition, pages
Halmstad: Halmstad University Press, 2018. p. 73
Series
Halmstad University Dissertations ; 49
Keywords
Carry distance, clubhead speed, driver performance, golf kinematics, sports performance, strength training, isokinetic training
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:hh:diva-37792 (URN)978-91-88749-02-4 (ISBN)978-91-88749-03-1 (ISBN)
Presentation
2018-09-18, O125, Högskolan i Halmstad, Halmstad, 09:00 (English)
Opponent
Supervisors
Funder
Knowledge Foundation, 2012/0319
Available from: 2018-09-20 Created: 2018-08-27 Last updated: 2018-09-20Bibliographically approved
Hertting, K., Holmquist, M., Parker, J., Karlsson, M. & Sandéhn, A. (2018). Ping pong health!: A table tennis intervention for improved health at the workplace. In: Urban Johnson, Lars Kristén, Miran Kondrič (Ed.), The Science and Practice of Racket Sport for Improved Performance and Health: Special Focus on Table Tennis: Book of Abstracts. Paper presented at The Science and Practice of Racket Sports for Improved Performance and Health, Halmstad University, Halmstad, Sweden, April 25-27, 2018 (pp. 22-23). Halmstad: Halmstad University
Open this publication in new window or tab >>Ping pong health!: A table tennis intervention for improved health at the workplace
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2018 (English)In: The Science and Practice of Racket Sport for Improved Performance and Health: Special Focus on Table Tennis: Book of Abstracts / [ed] Urban Johnson, Lars Kristén, Miran Kondrič, Halmstad: Halmstad University , 2018, p. 22-23Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Introduction: Physical activity has a positive impact on physical and psychological well-being (Delisle, Werch, Wong, Bian, & Weiler, 2010), as well as social relations and skills development (Lamu & Olsen, 2016; Perkins & Williamon, 2014). Adopting a “healthy organization” culture through health programs, with strong senior and middle management support, and using interventions can promote health at workplaces (Rajaratnam et. al., 2014). We, therefore, consider it relevant to have physical activity, social relations and skill development as the starting point in a tabletennis intervention at the workplace.

Aim: The aim was to develop, implement, and evaluate an intervention for improving health and wellbeing in the workplace by introducing table tennis.

Methods and results: The intervention design consisted of two workshops and five table tennis sessions. Thirteen employees from a warehouse within the retail sector participated in the intervention. The participants had various backgrounds in table tennis and sport in general, different motives to participate, and came from different groups of employees (management and stock). After an introductory workshop, two table tennis coaches held one training session a week over the fiveweek intervention period. The employees were divided in to two groups and each group had a 45-minute session. The evaluation is in progress at present. Pre- and post-measurement has been conducted using health questionnaires Short Form 36 Health Survey (SF-36) and International Physical Activity Questionnaire (IPAQ). These will be analysed using a Bayesian paired t-test analysis. Based on the results of the questionnaire focus group interviews will be conducted with participants. Three focus groups of 4-5 participants in each group. The questions will focus on 24 experiences of the intervention and reflections on future directions for table-tennis and wellbeing activities at the workplace. Finally, there will be a workshop pointing out future directions for sport-based health activities at the workplace.

Place, publisher, year, edition, pages
Halmstad: Halmstad University, 2018
Keywords
Health, well-being, workplace intervention
National Category
Other Health Sciences
Identifiers
urn:nbn:se:hh:diva-38405 (URN)978-91-639-7129-7 (ISBN)
Conference
The Science and Practice of Racket Sports for Improved Performance and Health, Halmstad University, Halmstad, Sweden, April 25-27, 2018
Available from: 2018-11-22 Created: 2018-11-22 Last updated: 2018-12-13Bibliographically approved
Parker, J. & Lundgren, L. (2018). Surfing the Waves of the CMJ: Are There between-Sport Differences in the Waveform Data?. Sports, 6(4), 1-12, Article ID 168.
Open this publication in new window or tab >>Surfing the Waves of the CMJ: Are There between-Sport Differences in the Waveform Data?
2018 (English)In: Sports, E-ISSN 2075-4663, Vol. 6, no 4, p. 1-12, article id 168Article in journal (Refereed) Published
Abstract [en]

The ability to analyse countermovement jump (CMJ) waveform data using statistical methods, like principal component analysis, can provide additional information regarding the different phases of the CMJ, compared to jump height or peak power alone. The aim of this study was to investigate the between-sport force-time curve differences in the CMJ. Eighteen high level golfers (male = 10, female = 8) and eighteen high level surfers (male = 10, female = 8) performed three separate countermovement jumps on a force platform. Time series of data from the force platform was normalized to body weight and each repetition was then normalized to 0–100 percent. Principal component analyses (PCA) were performed on force waveforms and the first six PCs explained 35% of the variance in force parameters. The main features of the movement cycles were characterized by magnitude (PC1 and PC5), waveform (PC2 and PC4), and phase shift features (PC3). Surf athletes differ in their CMJ technique and show a greater negative centre of mass displacement when compared to golfers (PC1), although these differences are not necessarily associated with greater jump height. Principal component 5 demonstrated the largest correlation with jump height (R2  = 0.52). Further studies are recommended in this area, to reveal which features of the CMJ thatrelate to jumping performance, and sport specific adaptations. © 2018 by the authors.

Place, publisher, year, edition, pages
Basel: MDPI, 2018
Keywords
force-time, jump testing, kinetic assessment, principal component analysis, vertical jump
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:hh:diva-38530 (URN)10.3390/sports6040168 (DOI)
Funder
Knowledge Foundation, 2012/0319
Available from: 2018-12-10 Created: 2018-12-10 Last updated: 2018-12-10Bibliographically approved
Parker, J. (2017). Construct validity and test-retest reliability of the force-velocity profile in a golf specific rotation movement. In: Ferrauti, A., Platen, P., Grimminger-Seidensticker, E., Jitner, T., Bartmus, U., Becher, L., De MArées, M., Muhlbauer, T., Schauterte, A., Wiewelhove, T., Tsolakidis, E. (Ed.), Book of Abstracts of the 22nd Annual Congress of the European College of Sport Science – 5th - 8th July 2017, MetropolisRuhr – Germany: . Paper presented at 22nd Annual Congress of the European College of Sport Science, Essen, Germany, 5th-8th July, 2017 (pp. 294-294). Cologne: European College of Sport Science
Open this publication in new window or tab >>Construct validity and test-retest reliability of the force-velocity profile in a golf specific rotation movement
2017 (English)In: Book of Abstracts of the 22nd Annual Congress of the European College of Sport Science – 5th - 8th July 2017, MetropolisRuhr – Germany / [ed] Ferrauti, A., Platen, P., Grimminger-Seidensticker, E., Jitner, T., Bartmus, U., Becher, L., De MArées, M., Muhlbauer, T., Schauterte, A., Wiewelhove, T., Tsolakidis, E., Cologne: European College of Sport Science , 2017, p. 294-294Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

Introduction: Assessing the isoinertial force-velocity (F-V) and power relationships has previously been found valuable to assist the understanding of the underlying mechanisms responsible for maximal power output. Multiple studies have investigated the F-V profile in the lower body, however, few studies have investigated F-V profiling in rotational movements, in particular, the golf swing. There is a need for isoinertial strength assessment protocols which can relate to final swing performance. The specific objective of the study was to investigate if measurements of force, velocity, and power using five different loads in a golf specific rotational movement are valid and reliable. Methods: 12 elite golfers (handicap -1.5±1.2) 8 men and 4 women performed a golf relevant rotational movement using five different loads (2, 6, 10, 14, and18 kg) in a motorised cable machine (1080 Motion AB, Sweden), measuring exercise peak force (PF), peak velocity (PV), and peak power (PP). In addition, normal-swing driver clubhead speed (CHSnor), and maximum clubhead speed (CHSmax) was measured using radar (Trackman, Denmark). The best of three trials for CHSnor, CHSmax, and the golf rotation was used for further analysis. Test-retest occasions were separated by 7-14 days. Statistical analysis: Change in mean (CIM) individual inter-session coefficient of variation (CV) and intraclass correlation coefficient (ICC) was used to analyze test-retest reliability, a Spearman's correlation between the rotation output variables and the CHS was used to assess construct validity.For reliability, an ICC of >0.70 was considered acceptable and results for correlation was considered excellent (≥0.90), good (0.75–0.89), moderate (0.50–0.74), poor (<0.50).was considered to be acceptable. Results: PF, PV, and PP for all of the five loads, apart from PP with 2 kg (CIM=12.2%, CV=14.1%, &ICC= 0.29) and PP with 18kg (CIM=8.6%, CV=19.1%, & ICC= 0.93), showed good reliability (CIM= 0.05-3.6%, CV=1.4-8.5%, & ICC= 0.84-0.97). PF (r=0.780-0.89 & 0.75-0.88), PV (r=0.76-0.86 & 0.78-0.85), and PP (r=0.75-0.84 & 0.76-0.85) for all loads had statistically significant strong correlations with both CHSnor and CHSmax respectively, apart from PF at 2kg (r=0.33). The average day to day variation among all loads for PF, PV and PP were 17.9 ±13.7 N, 0.30 ± 0.23 m/s, and 135.9 ± 128.1 W respectively. Greatest PP was achieved with the 14 kg load, although PP at 6, 10, and 14kg only differed by 90 W (8%) between these loads. Discussion: Isoinertial force-velocity-power profiling in high-level golfers can be assessed after a familiarization session. The strongest correlation among the rotational tests and CHS was between PF at 10 kg and CHSnor (r=0.89) and in general, the PF, PV, and PP variables had a strong relationship with both CHSnor and CHSmax. Such profiling may provide valuable information insight into the neuromuscular capabilities of high-level golfers and may be used to monitor specific training adaptions.

Place, publisher, year, edition, pages
Cologne: European College of Sport Science, 2017
Keywords
Golf performance, force velocity power
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:hh:diva-35129 (URN)978-3-9818414-0-4 (ISBN)
Conference
22nd Annual Congress of the European College of Sport Science, Essen, Germany, 5th-8th July, 2017
Funder
Knowledge Foundation
Available from: 2017-10-03 Created: 2017-10-03 Last updated: 2017-10-06Bibliographically approved
Parker, J., Lagerhem, C., Hellström, J. & Olsson, C. M. (2017). Effects of nine weeks isokinetic training on power, golf kinematics, and driver performance in pre-elite golfers. BMC Sports Science, Medicine and Rehabilitation, 9, Article ID 21.
Open this publication in new window or tab >>Effects of nine weeks isokinetic training on power, golf kinematics, and driver performance in pre-elite golfers
2017 (English)In: BMC Sports Science, Medicine and Rehabilitation, ISSN 2052-1847, Vol. 9, article id 21Article in journal (Refereed) Published
Abstract [en]

Background

It has previously been shown that isotonic strength training can improve driver performance among golfers, though few studies have investigated effects of strength training on swing kinematics together with driver performance. In this study we investigated whether isokinetic rotational training could improve driver performance and swing kinematic variables amongst elite golfers.

Methods

Twenty competitive pre-elite golfers (handicap better than −3.0), 13 men and 7 women, were split into two groups, one group received the isokinetic power training (IK) alongside their normal isotonic pre-season strength-training and the other group continued with their normal isotonic pre-season strength-training regime (IT). The IK group completed 12 sessions of isokinetic power training on a standing rotation exercise (10% body weight at 1 m/s) and barbell squat (25 kg plus 10% body weight at 0.5 m/s). The IT group continued with their normal isotonic pre-season strength-training regime. Participants were tested for rotational power, lower body power, golf swing kinematics, and driver performance before and after a nine-week training period.

Results

After the nine-week training period both the IK and the IT groups increased their dominant side rotational force and power (effect sizes between 0.50–0.96) and magnitude based inference indicated that IK had a likely (> 80%) more beneficial increase in dominant side rotational force and power. For swing kinematics, IK had a likely (> 80%) more beneficial improvement in lead arm speed and acceleration compared to the IT group. For driver performance, IK had a possible (65%) beneficial effect on ball speed and likely (78%) beneficial effect on carry distance when compared to IT, whereas neither of the groups improved club head speed.

Conclusion

In the present study on pre-elite golfers we found that 9 weeks of isokinetic training increased seated rotational force and power, peak arm speed and arm acceleration, ball speed, and carry distance more compared to isotonic training. Even though isokinetic training did not increase CHS, it did result in greater carry distance. © The Author(s). 2017

Place, publisher, year, edition, pages
London: BioMed Central, 2017
Keywords
Golf biomechanics, Isokinetic training, PowerDriver performance, Kinematics, Performance gains
National Category
Other Natural Sciences Sport and Fitness Sciences
Identifiers
urn:nbn:se:hh:diva-35843 (URN)10.1186/s13102-017-0086-9 (DOI)000417565100002 ()29238597 (PubMedID)2-s2.0-85037710214 (Scopus ID)
Projects
KK-HÖG projekt successful injury-free golf
Funder
Knowledge Foundation, 2012/0319
Available from: 2017-12-13 Created: 2017-12-13 Last updated: 2018-10-29Bibliographically approved
Verikas, A., Parker, J., Bacauskiene, M. & Olsson, M. C. (2017). Exploring relations between EMG and biomechanical data recorded during a golf swing. Expert systems with applications, 88, 109-117
Open this publication in new window or tab >>Exploring relations between EMG and biomechanical data recorded during a golf swing
2017 (English)In: Expert systems with applications, ISSN 0957-4174, E-ISSN 1873-6793, Vol. 88, p. 109-117Article in journal (Refereed) Published
Abstract [en]

Exploring relations between patterns of peak rotational speed of thorax, pelvis and arm, and patterns of EMG signals recorded from eight muscle regions of forearms and shoulders during the golf swing is the main objective of this article. The linear canonical correlation analysis, allowing studying relations between sets of variables, was the main technique applied. To get deeper insights, linear and nonlinear random forests-based prediction models relating a single output variable, e.g. a thorax peak rotational speed, with a set of input variables, e.g. an average intensity of EMG signals were used. The experimental investigations using data from 16 golfers revealed statistically significant relations between sets of input and output variables. A strong direct linear relation was observed between lin- ear combinations of EMG averages and peak rotational speeds. The coefficient of determination values R2 = 0 . 958 and R2 = 0 . 943 obtained on unseen data by the random forest models designed to predict peak rotational speed of thorax and pelvis , indicate high modelling accuracy. However, predictions of peak rotational speed of arm were less accurate. This was expected, since peak rotational speed of arm played a minor role in the linear combination of peak speeds. The most important muscles to predict peak rotational speed of the body parts were identified. The investigations have shown that the canon- ical correlation analysis is a promising tool for studying relations between sets of biomechanical and EMG data. Better understanding of these relations will lead to guidelines concerning muscle engagement and coordination of thorax, pelvis and arms during a golf swing and will help golf coaches in providing substantiated advices. ©2017 Elsevier Ltd. All rights reserved.

Place, publisher, year, edition, pages
Kidlington, Oxford: Pergamon Press, 2017
Keywords
Canonical correlation, Random forest, Prediction, EMG, Golf
National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:hh:diva-34611 (URN)10.1016/j.eswa.2017.06.041 (DOI)000408789300008 ()2-s2.0-85021670724 (Scopus ID)
Funder
Knowledge Foundation, 2012/0319
Available from: 2017-07-12 Created: 2017-07-12 Last updated: 2018-03-23Bibliographically approved
Parker, J., Johnson, U. & Ivarsson, A. (2017). Is perceived autonomy support provided by a coach related to the frequency of injury preventative behavior among elite golfers?. In: : . Paper presented at The International Society of Sport Psychology 14th World Congress, Sevilla, Spain, 10-14 July, 2017.
Open this publication in new window or tab >>Is perceived autonomy support provided by a coach related to the frequency of injury preventative behavior among elite golfers?
2017 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Research has shown that perceived autonomy support can have an indirect effect on behaviors via autonomous motivation (Hagger & Chatzisarantis, 2015). This indirect effect has, for example, been found in relation to injury preventive behaviors within sport (Chan & Hagger, 2012). Overuse and acute injuries are a common problem among golfers (McHardy & Pollard, 2005) and exploring factors that might increase the frequency of preventive behaviors is warranted. The aim of the study was to investigate if perceived autonomy support from the coach has an indirect effect on the self-reported frequency of injury preventive behaviors via the level of autonomous motivation. A total of 59 elite golfers, (handicap M=-1.2, SD=4.9, age M=21, SD=5.5), completed a questionnaire with questions related to autonomy support from the coach, autonomous motivation for injury prevention, and the frequency of five injury preventive behaviors (e.g., how often do you ask for advice about injury preventive exercises, how often to you train to improve your physiological status). A mediation analysis, using Hayes (2012) process macro in SPSS 20.0, was performed. The results showed that perceived autonomy support and autonomous motivation could explain 45% of the variance in the frequency of preventive behaviors, F (1,56) = 22.71, p < .001. The result showed that perceived autonomy support had a statistically significant positive indirect effect on the frequency of preventive behaviors via autonomous motivation (ab = .16, 95% CI = 0.05-0.34, p<.05). Based on the results, coaches should consider giving feedback that supports autonomous motivation among golfers when aiming to encourage injury preventative behavior. Injury prevention programs should include strategies to improve the athlete’s autonomous motivation to carry out preventive activities. Future research should investigate the relationship between estimated and the objective frequency of injury prevention behavior. 

National Category
Sport and Fitness Sciences
Identifiers
urn:nbn:se:hh:diva-35130 (URN)10.13140/RG.2.2.23857.68962 (DOI)
Conference
The International Society of Sport Psychology 14th World Congress, Sevilla, Spain, 10-14 July, 2017
Funder
Knowledge Foundation
Available from: 2017-10-03 Created: 2017-10-03 Last updated: 2018-07-05Bibliographically approved
Linnér, L., Stambulova, N., Parker, J. & Ekengren, J. (2016). Dual Career Balance in Student-Athletes University Transition. In: : . Paper presented at 31st Annual Conference of the Association for Applied Sport Psychology (AASP), September 28 - October 1, 2016, Phoenix, Arizona, USA.
Open this publication in new window or tab >>Dual Career Balance in Student-Athletes University Transition
2016 (English)Conference paper, Poster (with or without abstract) (Refereed)
Abstract [en]

Balancing studies, a personal life and sports, that is, having a dual career, is considered as a challenge associated with transitional demands in athletic and non-athletic (psychological, psychosocial, academic/vocational, financial) domains (Wylleman, Reints, & De Knop, 2013). The aim of this study was to investigate student-athletes’ university transition with a specific focus on how student-athletes balance different domains of their lives. Twenty-three Swedish university student-athletes (mean age= 21.52; 16 males and 7 females) representing six sports (equestrianism, golf, handball, ice hockey, soccer, table tennis) partook in the study. Participants completed the Dual Career Monitoring Survey (DCMS), weekly, over the first twelve weeks of their university education. The DCMS is developed by the authors and measures student-athletes perceptions of balance, time investments, demands, coping, satisfaction, resources and barriers in relation to sport, studies, private life, social life and financial situation. In exploring student-athletes’ perception of dual career balance throughout the twelve weeks, an intra-class correlation analysis revealed a between-person variance of 0.14 (14%). That is, with regards to balance in their dual careers 86% was due to within-person variance, suggesting that balance is idiosyncratic and that further analysis should investigate within-person change. Encouraged by these findings we continued with a person-centered analysis using the Dynamic P-technique for modeling patterns of data (Nelson, Aylward, & Rausch, 2011). The relationships between changes in balance (i.e., prioritizing sport, studies or other domains of life), demands, coping and satisfaction throughout the twelve weeks will be presented. Our findings contribute to the understanding of balance as a central tenet of athletes’ dual careers (Second author et al., 2015). From our findings we suggest practitioners to take into account the individual dynamics in dual career balance from a whole-person perspective.

National Category
Psychology (excluding Applied Psychology)
Identifiers
urn:nbn:se:hh:diva-31948 (URN)
Conference
31st Annual Conference of the Association for Applied Sport Psychology (AASP), September 28 - October 1, 2016, Phoenix, Arizona, USA
Available from: 2016-09-07 Created: 2016-09-07 Last updated: 2016-10-04Bibliographically approved
Verikas, A., Vaiciukynas, E., Gelzinis, A., Parker, J. & Olsson, M. C. (2016). Electromyographic Patterns during Golf Swing: Activation Sequence Profiling and Prediction of Shot Effectiveness. Sensors, 16(4), Article ID 592.
Open this publication in new window or tab >>Electromyographic Patterns during Golf Swing: Activation Sequence Profiling and Prediction of Shot Effectiveness
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2016 (English)In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 16, no 4, article id 592Article in journal (Refereed) Published
Abstract [en]

This study analyzes muscle activity, recorded in an eight-channel electromyographic (EMG) signal stream, during the golf swing using a 7-iron club and exploits information extracted from EMG dynamics to predict the success of the resulting shot. Muscles of the arm and shoulder on both the left and right sides, namely flexor carpi radialis, extensor digitorum communis, rhomboideus and trapezius, are considered for 15 golf players (∼5 shots each). The method using Gaussian filtering is outlined for EMG onset time estimation in each channel and activation sequence profiling. Shots of each player revealed a persistent pattern of muscle activation. Profiles were plotted and insights with respect to player effectiveness were provided. Inspection of EMG dynamics revealed a pair of highest peaks in each channel as the hallmark of golf swing, and a custom application of peak detection for automatic extraction of swing segment was introduced. Various EMG features, encompassing 22 feature sets, were constructed. Feature sets were used individually and also in decision-level fusion for the prediction of shot effectiveness. The prediction of the target attribute, such as club head speed or ball carry distance, was investigated using random forest as the learner in detection and regression tasks. Detection evaluates the personal effectiveness of a shot with respect to the player-specific average, whereas regression estimates the value of target attribute, using EMG features as predictors. Fusion after decision optimization provided the best results: the equal error rate in detection was 24.3% for the speed and 31.7% for the distance; the mean absolute percentage error in regression was 3.2% for the speed and 6.4% for the distance. Proposed EMG feature sets were found to be useful, especially when used in combination. Rankings of feature sets indicated statistics for muscle activity in both the left and right body sides, correlation-based analysis of EMG dynamics and features derived from the properties of two highest peaks as important predictors of personal shot effectiveness. Activation sequence profiles helped in analyzing muscle orchestration during golf shot, exposing a specific avalanche pattern, but data from more players are needed for stronger conclusions. Results demonstrate that information arising from an EMG signal stream is useful for predicting golf shot success, in terms of club head speed and ball carry distance, with acceptable accuracy. Surface EMG data, collected with a goal to automatically evaluate golf player’s performance, enables wearable computing in the field of ambient intelligence and has potential to enhance exercising of a long carry distance drive.

Place, publisher, year, edition, pages
Basel: MDPI AG, 2016
Keywords
EMG, muscle activity onset, peak detection, random forest, decision fusion
National Category
Sport and Fitness Sciences Bioinformatics (Computational Biology)
Identifiers
urn:nbn:se:hh:diva-31870 (URN)10.3390/s16040592 (DOI)000375153700171 ()27120604 (PubMedID)2-s2.0-84964308572 (Scopus ID)
Funder
Knowledge Foundation, 2012/0319
Available from: 2016-08-27 Created: 2016-08-27 Last updated: 2018-10-22Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1184-5036

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