Prediction of Jumping Distance Using Run-Up Velocity and Age for Female Long Jumpers

It is the flight distance which is approximately ninety percent of jump distance in long jump. On the other hand, there are many biomechanical factors that determine the flight distance and horizontal velocity is considered to be the most effective factor. The aim of this study was to create a jump distance estimation model based on run-up velocity that can practically be used by trainers. The research data was included 858 valid trials of 156 female Turkish long jumpers (ages: 17.8±3.4 years). According to the correlation results of the current study; a nonlinear regression model was used between the variables found to have the highest correlation (age, last 10 meter run-up velocity, jump distance). According to this model, 79.10% of the jump distance can be estimated with the variables of age and run-up velocity in the last ten meters. Developed to be used for female long jumpers at a broad performance level, this model may make it possible to make technical evaluations about whether the velocity, technique and strength of a female long jumper are stable. Keywords: long jump, velocity, age, prediction model

Acquisition of the Long Jump Skill Using Varying Feedback / Usvajanje tehnike skoka u dalj korištenjem povratnih informacija različitih vrsta i frekvencija

The aim of this study was to examine the acquisition of the long jump skill in elementary school children using augmented feedback of varying type and frequency. Eighty-eight boys and girls aged (mean ± SD) 11 ± 0.5 years, without any prior experience in the long jump skill acquisition, were assigned to one of the four study groups: (1) the group receiving only verbal feedback on key errors, (2) the group receiving both verbal and video feedback on key errors, (3) the group receiving both verbal and video feedback on all errors, and (4) the group receiving no feedback. Before and after an 8-week training intervention, long jump distance and relevant kinematic variables were recorded. The results indicated that the group receiving both verbal and video feedback on all errors improved the most in terms of the long jump distance. Varying feedback influenced kinematic parameters differently, as there was no consistent change in the monitored kinematic variables across groups. It was concluded that, when learning a complex motor skill in a typical Physical Education setting, elementary school children are likely to benefit the most when receiving frequent feedback (both verbal and using video analysis, focusing on all errors) in comparison with the situation in which they receive feedback reduced in the type (only verbal) and the frequency (focusing only on key errors).Keywords: bandwidth feedback; kinematics; knowledge of performance; motor learning. --- Cilj ovoga rada bio je ispitati utjecaj različitih količina i vrsta povratnih informacija (PI) u procesu usvajanja tehnike skoka u dalj kod učenika osnovne škole. Osamdeset i osam učenika i učenica, starosti 11 (±0,5) godina, bez prethodnoga iskustva u treningu skoka u dalj, raspodijeljeno je u jednu od četiriju skupina ispitanika koje su dobivale PI: (1) verbalno samo na ključne greške, (2) verbalno i vizualno samo na ključne greške, (3) verbalno i vizualno na sve greške ili (4) nisu primale PI. Duljina skoka i relevantni kinematički parametri skoka u dalj izmjereni su prije i nakon 8-tjednog eksperimentalnoga tretmana. Rezultati istraživanja pokazali su kako je grupa koja je primala PI, na svaku grešku verbalnim i vizualnim putem najviše napredovala u smislu duljine skoka u dalj. Različite količine i vrste PI različito djelovale su na promatrane kinematičke parametre te nisu uočene konzistentne promjene između grupa. Zaključeno je kako djeca osnovnoškolske dobi prilikom usvajanja kompleksne motoričke vještine imaju više koristi od većih frekvencija PI (verbalnih i vizualnih na sve greške) u usporedbi s reduciranim PI prema vrsti (samo verbalne) ili frekvenciji (samo na ključne greške).Ključne riječi: kinematika; motoričko učenje; poznavanje izvedbe; reducirane povratne informacije.

Invasive Cuban Treefrogs (Osteopilus septentrionalis) Have More Robust Locomotor Performance Than Two Native Treefrogs (Hyla spp.) in Florida, USA, in Response to Temperature and Parasitic Infections

Introduced species pose a threat to biodiversity, and ecological and physiological factors are important in determining whether an introduced species becomes successfully established in a new region. Locomotor performance is one such factor that can influence the abundance and distribution of an introduced species. We investigated the effects of temperature and parasitism by the intestinal nematode Aplectana hamatospicula on the maximum jump distance and endurance in one invasive and two native treefrogs in Florida, USA. We collected frogs from the wild, estimated their parasite loads, and tested their locomotor performance at three temperatures. Contrary to expectations, invasive Cuban treefrogs (Osteopilus septentrionalis), which are adapted to a warmer climate in the Caribbean, outperformed pinewoods treefrogs (Hyla femoralis) and squirrel treefrogs (H. squirella) at each temperature, even when controlling for body size differences. In all three species, maximum jump distance was positively related to temperature, and this relationship was stronger for larger frogs. Parasites influenced both the maximum jump distance and endurance of frogs. In all three species, larger frogs jumped farther maximum distances than smaller frogs, but this relationship was stronger when frogs had lower, rather than higher, parasite loads. Parasitism had little effect on endurance in invasive frogs, but it tended to decrease the endurance of native frogs at high temperatures. Furthermore, at low temperatures, the lengths of consecutive jumps of infected native frogs tended to increase, suggesting that parasites limited the distances of initial jumps. Effects of temperature and parasites on the locomotor performance of frogs could influence their abilities to forage, escape predators, and disperse. The tremendous locomotor performance of O. septentrionalis, which is maintained across temperatures and parasite loads, likely contributes to the invasion success of this species.

A Knowledge-Based Smart Trainer System for Transferring Knowledge From Coaches to Long Jump Students

Background:The constructive and specific feedback in guiding long jump athletes to improve their performance in each phase is part of the critical process for achieving desired long jump distance. However, to date, the potential approach for assisting a coach in capturing long jump movement and transferring their knowledge to long jump students is not well-established.Objectives:To investigate the performance of long jump students and evaluate transferring knowledge from coaches to long jump students using a Knowledge-Based Smart Trainer (KBST) System.Methods:Twenty-two participants (fifteen males, mean age = 15.33 ± 1.95 years; seven females, mean age = 14.57 ± 2.07 years) participated in the study. All participants were recruited from eleven sports schools in Thailand. Each participant was instructed to perform the long jump movement, including running, take-off, and landing, for three attempts (Test 1,Test 2,andTest 3).Test 1was the conventional approach (coaches provided the feedback based on their experience).Test 2andTest 3were the KBST system approach (coaches provided the feedback based on the results from KBST system). Two cameras were used to record the participant movement from the starting position to the landing position. The capture data were analyzed by KBST system program. The outcome measures were starting position, maximum velocity, maximum velocity position, and take-off angle. Repeated-Measures ANOVA was conducted to compare the long jump performance across the three trials. The statistical significance was set atp-value < 0.05.Results:There was a statistically significant difference betweenTest 1andTest 3for long jump distance (mean difference = 0.292; Std. Error = 0.129; Sig. = 0.34). However, the mean of take-off angle was similar across the three trials (Test 1 =12.16°,Test 2= 12.71°, andTest 3= 12.95°, respectively).Conclusion:TheKBSTsystem was effective in improving long jump students’ performance and also transferring knowledge from the coach to long jump students.

Vertical and Horizontal Hop Performance: Contributions of the Hip, Knee, and Ankle

Background: Single-leg vertical and horizontal hop tests are commonly used to assess performance of healthy athletes and as a measure of progress during rehabilitation from knee injury. It is unclear if they measure similar aspects of leg function, as the relative joint contributions of the hip, knee, and ankle joints during propulsion and landing are unknown. Hypothesis: The proportion of work done by the hip, knee, and ankle will not be the same for these 2 jump types and will vary for propulsive and landing phases. Study Design: Cross-sectional cohort study. Level of Evidence: Level 3. Methods: Twenty physically active participants completed instrumented single-leg hop analysis in both vertical and horizontal directions. Joint peak power, work generated or absorbed, and percentage contribution of each joint during propulsive and landing phases were compared between tasks using paired t tests. Results: Vertical hop was performed with roughly similar contributions of the hip, knee, and ankle for both propulsion (31%, 34%, 35%, respectively) and landing (29%, 34%, 37%, respectively). Horizontal hop distance was mostly (87%) determined by the hip and ankle (44% and 43%), but landing was mostly (65%) performed by the knee with lesser contribution from the hip and ankle (24% and 11%). Propulsive phase showed a proximal-to-distal temporal sequence for both hop types, but landing was more complex. Conclusion: Performance during vertical and horizontal hops (jump height and jump distance, respectively) measures different aspects of hip, knee, and ankle function during the propulsive and landing phases. Clinical Relevance: Assessment of knee joint function during rehabilitation should not be done using a horizontal hop. The knee contributes about a third to vertical hop height, but only about an eighth to horizontal hop distance. Practitioners carrying out performance testing using either vertical or horizontal hops should be mindful of the relative contributions for meaningful training inferences to be derived.

Phase-Specific Force and Time Predictors of Standing Long Jump Distance

This study sought to identify potential predictors of standing long jump (SLJ) performance using force–time strategy metrics within the unloading, eccentric yielding, eccentric braking, and concentric phases. Fifteen National Collegiate Athletic Association division 1 male soccer players (19 [1] y, 1.81 [0.94] m, 80.3 [22.4] kg) performed 3 maximum-effort SLJs, while 3-dimensional ground reaction force (GRF) data were obtained. Regularized regression models were used to investigate associations between force–time strategy metrics and 2 metrics of SLJ performance (ie, jump distance and modified reactive strength index). Jump height and eccentric yielding time were the only predictors of jump distance that also demonstrated large correlations to jump distance. Anterior–posterior unloading yank, average concentric vertical force, and concentric phase duration were the only predictors of modified reactive strength index that also demonstrated large correlations to modified reactive strength index. To maximize SLJ distance in high-level soccer athletes, human performance practitioners could design interventions to drive changes in strategy to increase jump height and decrease eccentric yielding time. To improve SLJ explosiveness, interventions to drive changes in unloading and concentric force application and decrease concentric time could be emphasized. Importantly, unique variable combinations can be targeted when training for SLJ distance and explosiveness adaptations.