Showing 8 results for Jump
Mr Saeid Eimani Zadeh, Dr Mansoor Sahebzamani, Dr Mohamad Taghi Amiri Khorasani,
Volume 13, Issue 10 (10-2015)
Abstract
The purpose of this study was to investigate the effect of soccer specific functional fatigue on hip and knee
joints angles during landing in professional players.15 soccer players with at least 2 years experience in
Kerman soccer clubs were selected randomly. To evaluate the lower extremity kinematics following
jumping and soccer specific- heading, three cameras (with50Hz) were used. To cause fatigue in subjects,
specific functional protocol similar to specific bangsbo soccer was used and Quantic sport v21 soft ware
was administrated for kinematic analysis of the recorded films. To statistical analyzing of data, descriptive
statistical methods, and paired-t test were administrated at α=0.05.Finding revealed that hip and knee
angles in sagittal and frontal plane in landing is influenced by functional fatigue. This results has been
reducing knee and hip flexion angles and increased varus in knee joint. Results demonstrated a more
erect landing posture due to a decrease in hip and knee flexion angles in the post fatigue condition.
However, functional fatigue significantly decrease lower extremity control ability in male soccer player
during landing.
Mr Mojtaba Ashrostaghi, Dr Elham Shirzad,
Volume 13, Issue 10 (10-2015)
Abstract
Take-off is the critical phase of the long jump event. The aim of this study was to explore the relationships
between different variables and success in take-off. 37 trials performed by 8 long jumper, participants in
fourth indoor Asian senior athletics championships held in Tehran, with personal best average of 7.68±0.28
meter were recorded at 300 Hz. Five speed-related, five technical and four strength-related variables as well
as an anthropometric variable were measured using motion analysis software. More gain in vertical velocity
and less loss of horizontal velocity are considered as two criteria of take-off success and their relationships
with other variables were determined through correlation and regression analysis. Significant level of 0.05
was set. Some variables of all four groups were significantly correlated with success criteria. These variables
along with some others were entered in regression equations. The results emphasized on dominant role of
the technique and approach velocity and represented the effect of anthropometric characteristics on success
in takeoff. Furthermore eccentric strength of knee extensors was shown as the main strength factor in this
performance.
Dr Ali Yalfani, Mrs Farzaneh Gandomi,
Volume 14, Issue 11 (4-2016)
Abstract
Chronic ankle instability has defined as recurrent ankle sprain, so that 40% of injured athletes after acute injury despite of receiving of adequate rehabilitation, suffering from this instability. The purpose of this study is investigate of postural sway’s risk factors proportion in jump-landing and lateral hopping tasks, in prediction of chronic ankle sprain occurrence. 25 ankle sprain injured athletes and 25 healthy athletes participated in this descriptive-analytic study. Six variables (area of sways, path length and velocity of sways in jump-landing and lateral hoping tasks) were measured as predictor variables, and we used to Logistic Regression test for predicting. The results of study showed that path length and velocity of sways in jump-landing, area and path length of sways in lateral hopping had statistical significant proportion in classification of injured and healthy groups, and the model classified about 77% cases correctly. Therefore, athletes with ankle sprain history have less control of posture than healthy subjects in jump-landing and hopping tasks and have higher risk to getting recurrent ankle sprain. Also subjects with chronic ankle sprain have less control of posture in frontal plan
Mehdi Soltani Ichi, Pezhman Motamedi, Hamid Rajabi,
Volume 17, Issue 17 (4-2019)
Abstract
The purpose of this research was to determine the acute effects of plyometric training with changing of height landing on the electromyographic activity during preparatory phase land-jump in male students. The population of this research were 10 physical education male students of Kharazmi University, which selected as sample. (21/10±1/286yrs, 173±6/467 height, 68/2±7/42 weight). In four different days subjects Performed as single leg one of four protocols plyometric training and land - jump from a height of 40 and 60 cm. EMG activity of the quadriceps and hamstring muscle group 150 milliseconds before foot contact with the ground was recorded. Analysis of variance with repeated measures and Bonferroni post hoc test was used. The results of this study showed that muscle activity after changing of height landing in preparatory phase (from 40 to 60 cm) has increased significantly (P=0/002, P=0/001, P=0/001) respectively. Activity of muscles (rectus femoris, vastus lateralis, biceps femoris) during landing after performing plyometric and changing of height landing in preparatory phase has increased significantly (P=0/039, P=0/001) (P=0/006, P=0/000) (P=0/001, P=0/014) respectively. Jump height has increased significantly (P=0/007, P=0/002) respectively. The results showed that acute perform plyometric training with changing of height landing result in significant changes in the electrical activity of muscles and also the height of the jump in the preparatory phase.
N Shaterkazemi, Sh Zandi, E Shirzad,
Volume 18, Issue 19 (7-2020)
Abstract
Regarding the effects of the kinematics of the movement on athletic performance and the Importance of promoting athlete’s performance on the sport fields, there is limited knowledge about the mechanism of the effect of different variables of volleyball spike. Therefore, the aim of this study was the prediction of jump performance in elite female volleyball players with selected kinematic variables. Thirty elite female volleyball players with mean age of 21.44±3.42 have volunteered for this study. Lower limbs kinematics have been recorded using 16 reflexive markers with Vicon motion analysis system during volleyball spike jump performance. Jump height and time of concentric phase of jump have been predicted by center of mas velocity during step, final step length and ranges of the motion of hip, knee and ankle with stepwise regression (α≤0.05). The results showed that knee range of motion center of mass velocity and step length could be the predictors for time of jump and center of mass velocity and hip range of motion could be the predictors for the jump height as well. Considering these results and the goal and situation of the volleyball match, the players should focus on different phases and affecting variables of the spike jump.
S.f Qeysari, Sh Tahmasebi Broujeni, M Shahbazi,
Volume 18, Issue 19 (7-2020)
Abstract
Various studies have shown that the external focus of attention is better than the internal focus of attention. But, so far no study has been investigated the level of electrical activity of the rectus abdominus muscle as a trunk stabilizer muscle. Therefore, the purpose of this study was to investigate the effect of focus of attention on electromyography activity of the rectus abdominus muscle during Different phases of vertical jump.Twelve male elite volleyball players from university of Tehran Participated in this research voluntary. They performed a vertical jump on the force plate in both internal and external focus of attention condition. Rectus abdominus Surface electromyography (SEMG) signals recorded by electromyography apparatus during vertical jump and The electrical activity of this muscle was calculated in the different phases of vertical jump motion. Paired t-test results showed that height of jump under the external focus was higher than the internal focus. In addition, this results showed that internal focus caused significant increasing in Rectus abdominus EMG in comparison to external focus during concentric phase. But, there was no significant difference in the eccentric phase between the external and internal focus of attention conditions. These results suggest that the external focus of attention effectively increases the efficiency of vertical jump. Therefor; we recommend using the external focus of attention instructions when executing vertical jump movement.
Mr Hamid Mahmodi, Dr Hamid Rajabi, Mr Mohsen Bapiran, Dr Pezhman Motamedi,
Volume 19, Issue 21 (9-2021)
Abstract
The purpose of this study was to compare the effect of plyometric training pre and post maturation period with soccer training on electromyographical index and soccer players performance. 30 students of soccer player's pre maturation period (weight 32.38±6.59 kg, age 10.35±0.59 years, and height 141±0.06cm) and post maturation period (weight 43.79±10.96 kg, age 15.43±0.72 years, and height 156.84±0.09 cm) were selected. Subjects in the experimental group were 15 students before and after maturity period. To evaluate the age of the indices such as height, age, dental and bone age (radiographic method) was used. Then, for homogeneous groups of index of biological age radiography was used by radiologists. Before and after 4 weeks of training,, functional tests of two 20 meter speed, agility, vertical jump and also Amplitude for vastus lateralis muscle Were taken. The result by using Paired t-test showed that in pre maturation group in the vertical jump, agility and 20 meters there was a significant difference (P=0.002,P=0.006,P=0.001) and the other variables there was no significant difference. In variations between the groups, independent t-test showed that only significant differences was found in the test 20 meter speed (P = 0.007) and in the other variables not significantly different. The results showed that plyometric training in the Pre maturation group compared to post maturation group were more effect and these results can help in the design training for premature age groups
Mohammad Alimoradi, Mansur Sahebazamini, Roya Bigtashkhani,
Volume 19, Issue 22 (12-2021)
Abstract
Background and Objective: The movement patterns play a key role in the incidence of non-contact ACL injuries. This study attempts to investigate the effect of the +11 program on the jump-landing pattern in female amateur soccer players. Methods: 30 female amateur soccer players were randomly divided into experimental and control groups (15 people in each group). The experimental group performed the +11 program 3 times per week for 16 weeks whereas the control group maintained their regular warm-up method during the study. The jump-landing pattern of the players was investigated by a Special football jump-landing task using the landing error scoring system. Results: The results of the study showed that the 16 weeks of implementation of the +11 program significantly improved the jump-landing error scores of the players in the experimental group. Also, comparison of the results between experimental and control groups showed that there is a significant difference between the two groups. Conclusion: It can be concluded that the +11 program could improve the jump-landing pattern of the female soccer players in pre_ participation evaluation (PPE). Therefore, trainers are advised to use this program as an alternative to regular warm-ups in order to prevent injury.
