THE 2D TROCHANTER TRACKING METHOD: A LOW COST ALTERNATIVE WHEN ASSESSINGVERTICAL POWER-FORCE-VELOCITY PROFILES?

Power force velocity profiles of ballistic push offs are increasingly more used for the purpose of performance assessment. The main input parameter for such profiles is jump height. This study aims to propose and validate a simple low cost method for calculating jump heights based on 2D tracking of the trochanter. Furthermore a comparison with the existing low cost time in air method was carried out. Twelve athletes performed squat jumps on a force platform and were simultaneously filmed with a high speed camera. The error analysis depicted increased accuracy and precision as well as slightly stronger relation to the criterion for the 2D trochanter tracking compared to the time in air method. The result can be explained by the fact that the landing position of the athlete has no influence on the jump height calculation when using the trochanter tracking method

VERTICAL POWER-FORCE-VELOCITY PROFILING: RELIABILITY COMPARISON OF MULITPLE- AND TWO-POINT METHODS

Power-Force-velocity (P-F-v) profiling is an approach used for performance diagnostics to assess an athlete’s anaerobic performance level. The aim of the study was to determine and compare the test-retest reliability of the 5p-method and the 2p-method for a group of sport students. With respect to the 2p-method this was the first study to determine the reliability using an independent data-set for vertical jumps. Acceptable reliability (ICC \u3e 0.78, CV \u3c 7.6%, no significant differences) was obtained for the variables F0, v0 and Pmax obtained through the 5p-method. Using the 2p-method acceptable reliability was just found for the variables F0 and Pmax. Therefore, the use of the 5p-method is recommended for performance diagnostics and derived individualized training regimes based on these P-F-v profiling results, as well as for research on this topic involving populations similar to sport students

BIOMECHANICAL PERFORMANCE DIAGNOSTICS: CONCEPTS AND APPLICATIONS IN SKI-JUMPING

This paper presents an overview regarding the evaluation of existing biomechanical measurement methods regarding their feasibility of application in biomechanical performance diagnostics (BPD) in ski-jumping. Depending on the purpose of the BPD different biomechanical measurement systems have been developed and applied. Force plates as well as pressure insoles are used to assess the kinetics during hill jumps and dry land exercises. Using an inverse dynamics approach, ground reaction forces can be calculated during take-off (hill jumps and imitation jumps) based on the kinematic information. Inertial measurement units provide the opportunity to determine the orientation of the skis during flight. In order to select adequate measurement systems based on the purpose of the BPD advantages and disadvantages have to be considered

EFFECT OF LANDING STRATEGIES ON LOWER LIMB JOINT KINETICS DURING LOADED JUMPS

The purpose of this study was to analyze the effect of landing strategies on the landing kinetics during loaded jumps. Ten male participants performed counter movement jumps with 50% body weight (BW) additional load using four different landing strategies. Landing strategy referred to peak knee joint flexion during landing. Peak vertical force increased up to 50% with decreasing knee joint flexion during landing. No changes were found regarding peak joint moments and powers. Total lower limb joint work increased up to 83% with increasing knee joint flexion during landing. The results suggest that energy dissipation during loaded landing is shifted from active (muscle-tendon system) to passive (skeletal system) as peak knee flexion decreases during landing, resulting in mechanical stress on different body tissues depending on the landing strategy

CONSISTENCY AND VALIDITY OF ACUTE FOOT-STRIKE PATTERN ALTERATIONS DURING LABORATORY-BASED RUNNING

Due to the limited learning time allotted in most foot strike pattern modification studies, the reliability of pattern alterations may be jeopardized. The purpose of the current study was to investigate the reliability and validity of requested acute alteration of foot strike patterns performed by participants in a laboratory environment. Participants employed a high degree of consistency within foot strike pattern conditions and across the steps within a condition (average within subjects 95% confidence interval = 0.5° - 4°). On a group level, participants accurately performed all foot strike conditions with the exception of the midfoot strike pattern. Thus, even with the alteration of foot strike pattern, a generally reliable and valid foot strike angle performance is evidenced

What are the facilitating conditions that support teaching as inquiry (TaI) for secondary technology teachers who are middle leaders in greater Christchurch?

This study aims to propose ideal conditions for Technology teachers to develop effective philosophies enabling them to focus on activities that promote successful learning. This research examines how selected secondary Technology educators, exemplify aspects of Teaching as Inquiry (TaI) effective pedagogies, that support the generation and development of successful philosophies. By identifying five common traits or characteristics, this study enquires what it is they do that supports successful teacher philosophy, generating positive outcomes for learners. It explores how and why Technology teachers have developed this approach, how these traits are connected and inter-related to attitudes and the resulting dispositions they hold, and the philosophies they have developed. In the quest for sustainable conditions, enabling and inhibiting influences are also investigated. To be fully inclusive of all aspects influencing TaI practice, aspects outside the location of individual inquiry are explored: How individual TaI exists within school culture, faculty, senior administrative and management philosophies within systems where the teacher is employed, and how TaI practice exists within wider national policy. It explains how TaI in New Zealand, appears to flourish within a foundation of Culturally Responsive Pedagogies. It also suggests a simple re-consideration around the nature of individual learners, and how their needs to develop responsive and effective pedagogies, seeing a different ‘new construct, end-goal’ of future focussed schooling, could conflict with immediate current assessment, and compliance needs. This study concludes by suggesting a set of ideal facilitating conditions that together could enable the development of philosophies supporting the effective pedagogies of Teaching as Inquiry