The purpose of this study was to identify the difference in technique required to execute the Dipping Free Kick in soccer from the Instep Kick. Subjects were six experienced soccer players ranging from college varsity to third division professional levels. Each subject performed three successful free kicks and three maximal velocity instep kicks. Video data were analyzed for angular acceleration and angular velocity of the hip, knee and ankle of the kicking leg at the moment of ball contact. The joint angles of the trunk and hip, knee and ankle of the kicking leg at the moment of ball contact were also compared between the two types of kick. Calculated data was analyzed using a One Way Repeated Measures ANOVA and follow-up Student-Newman-Keuls tests. The statistical analysis of the angular accelerations of the hip, knee and ankle of the kicking leg at the moment of ball contact of the free kick were not significantly different from the instep kick. The statistical analysis of the angular velocity of the hip of the kicking leg at the moment of ball contact revealed no significant difference of the free kick from the instep kick. The statistical analysis of the angular velocity of the knee and ankle of the kicking leg at the moment of ball contact revealed a significant difference (p<.05) for the free kick from the instep kick. The statistical analysis of the trunk angle and hip, knee and ankle angles of the kicking leg at the moment of ball contact revealed no significant difference of the free kick from the instep kick. The results indicate no consistent difference in the technique employed to complete the free kick when compared to the instep kick. Each individual used different combinations of changes from the technique used to complete the instep to complete the dipping free kick. / School of Physical Education

Dissertation submitted in partial compliance with the requirements for the MTech: Chiropractic, Durban University of Technology, 2011. / Background: In terms of kicking speed the instep kicking technique is the most effective and commonly used method. Immobilization or restricted motion within a joint segment, results in adverse changes in the surrounding ligaments, tendons and muscular tissue. To improve joint mobility and thus improving flexibility, this study focused on spinal manipulation. Objectives: The main purpose of this study was to determine the immediate effectiveness of lumbar spine and sacroiliac manipulation on the range of motion (ROM) of the lumbar spine and sacroiliac joints as well as the kicking speed of the subjects. Methods: Forty asymptomatic soccer players, playing for the regional Premier League team or higher, were divided into four groups of 10 each. Group 1 received lumbar spine manipulation, Group 2 received sacroiliac (SI) joint manipulation, Group 3 received combined lumbar spine and SI joint manipulation and Group 4 received the sham laser intervention (placebo/control). Pre and post warm-up and post intervention lumbar and SI joint ROM were measured using a digital inclinometer. Kicking speed was measured post warm-up and post intervention with a Speed Trac™ Speed Sport Radar. The subjects’ perception of a change in kicking speed post intervention was also recorded. SPSS version 15.0 was used to analyse the data. Results: Pre and post outcome measurements were compared using a p value of < 0.05 to indicate statistical significance. Statistically significant ROM increases were noticed in left and right lumbar rotation motions post lumbar manipulative intervention. Lumbar extension, left and right lumbar rotation and SI joint extension ROM increased post combination of lumbar spine and SI joint manipulation. There VI was a significant increase in kicking speed post intervention for all three manipulative intervention groups. A significant correlation was seen between subjects’ perception of change in kicking speed post intervention and the objective results obtained. Conclusions: Lumbar spine and SI joint manipulation is an effective intervention for short-term increase in kicking speed.

Soccer experts (N = 18), novices (N = 16), and children who are physically awkward (N = 18), were studied for differences in self-regulatory forethought and self-reflection processes during a soccer kicking task. The participants (age range 12--14 years) were questioned regarding goals, strategy choice, and self-efficacy, as well as self-reflection attributions and feelings of self-satisfaction as they practiced the task. Among the significant results, children who are physically awkward possessed less soccer kicking knowledge and displayed lower self-efficacy after success than experts and novices. They also set less specific goals, selected less rhythm/timing strategies following failure, and attributed less to rhythm/timing and practice following success than experts. In comparison to novices, children who are physically awkward showed no differences in goals and strategy prior to the task but in terms of strategy after failure and attributions after success they had less "I don't know" strategy answers and practice attributions. There was no significant difference among the three groups in self-satisfaction.

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Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: The RoboCup offers a research platform to advance robotics and multi-robot cooperation in dynamic environments. This project builds on work previously done to develop a research platform for multi-robot cooperation at Stellenbosch University. This thesis describes the development of an active ball handling system for a robot in the RoboCup Small Size League (SSL). This was achieved by building on the work done in the previous projects. The hardware for the kicker and dribbler mechanisms on the robot were implemented and tested to characterise their capabilities. The kicker was characterised to control the speed at which a ball is kicked and the dribbler for optimal control over a ball. More accurate movement was required and the Proportional Integral and Derivative (PID) controllers for translational and rotational movement on the robot were improved. The test results show an improvement in straight line trajectory tracking when compared to those of the previous controllers. Dribble control sensors were implemented on the robot for successful dribbling by the robot. This resulted in a significant improvement to the dribbling ability of the robot when these sensors are used. This dribbling ability was compared to the dribbling ability of the robot when no feedback was received from the sensors. Lastly a proposed curved trajectory tracking algorithm was tested by combining translational and rotational movement of the robot. This algorithm showed the capabilities of the robot to follow a curved trajectory with the improved translational and rotational controllers. / AFRIKAANSE OPSOMMING: Die RoboCup bied ’n navorsingsplatvorm om robotika en multi-robot samewerking in ’n dinamiese omgewing te bevorder. Hierdie projek bou voort op werk wat reeds gedoen is om ’n navorsingsplatvorm vir multi-robot samewerking aan die Universiteit van Stellenbosch te ontwikkel. Hierdie tesis beskryf die ontwikkeling van ’n aktiewe balhanteringsstelsel vir ’n robot in die RoboCup Klein Liga (KL). Dit is bereik deur voort te bou op die werk wat in vorige projekte gedoen is. Die hardeware vir die skopper- en dribbelmeganismes is geïmplementeer en getoets om hulle vermoëns te karakteriseer. Die skopper is gekenmerk deur die spoed waarteen ’n bal geskop word en die dribbler vir optimale beheer oor ’n bal. Meer akkurate beweging was nodig en die PID-beheerders vir translasie- en rotasiebeweging in die robot is verbeter. Die resultate van die toetse toon ’n verbetering in reguitlynbeweging in vergelyking met dié van die vorige beheerders. Dribbelbeheersensors is in die robot geïmplementeer vir suksesvolle dribbelbeweging deur die robot. Gevolglik is daar ’n aansienlike verbetering in die dribbelvermoë van die robot wanneer hierdie sensors gebruik word. Hierdie dribbelvermoë is vergelyk met die dribbelvermoë wanneer die robot geen terugvoer van die sensors ontvang nie. Laastens is ’n voorgestelde algoritme vir die robot om ’n geboë trajek te volg, getoets. Dit is bereik deur die translasie- en die rotasiebeweging van die robot te kombineer. Hierdie algoritme het die vermoë van die robot om ’n geboë baan te laat volg deur gebruik te maak van die verbeterde translasie- en rotasiebeheerders.