Showing 11 results for Land
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Volume 0, Issue 0 (11-2019)
Abstract
Introduction and Objective: One of the strategies that athletes can use to temporarily increase strength and muscle power is post-activation potentiation (PAP) during warm-up. However, the effect of this phenomenon on kinematics of special movement has not been determined. Therefore, the aim of this study is to investigate the acute effect of PAP during warm-up on lower extremity kinematic characteristics during heading in soccer players.
Methodology: The study sample consisted of 24 semi-professional youth soccer players with an average age of 18.67±1.11 years, height 182.32±7.12 cm, mass 74.17±7.46 kg. who performed four different warm-up methods, including PAP-take-off, PAP-landing, combined-PAP, and general warm-up, derived from the stages of soccer heading. Knee and hip angular velocities during the take-off phase, maximum knee flexion angle, and duration of knee joint pause during the landing phase were recorded using a three-dimensional motion analysis device (vicon peak ltd, oxford, vicon UK) with four T20 cameras with a frequency of 1000 Hz. Finally, analysis of variance with repeated measurements and post hoc Bonferroni test were used at a significance level of P<0.05.
Results: There was a significant increase in knee and hip angular velocities following combined-PAP and then PAP-take-off compared to other warm-up programs. Moreover, there was a significant increase in knee flexion angle after PAP-landing compared to other warm-up programs. Additionally, there was a significant increase in the duration of knee joint pause after general warm-up compared to other warm-up programs.
Discussion and Conclusion: PAP-take-off improves jumping performance, while PAP-landing improves landing performance. The combination of these two methods, i.e., combined-PAP, will yield better results overall.
Mr Hamidreza Zanguie, Dr Mohammad Yousefi, Dr Abbas Farjadpezeshk, Khorshid Bijari,
Volume 0, Issue 0 (11-2019)
Abstract
Understanding the correct biomechanics of the knee joint during single-leg landing and correcting Incorrect movement patterns can be one of the ways to prevent the recurrence of anterior cruciate ligament injury. Therefore, the purpose of this study is to review the researches that investigated the biomechanics of the coronal plane of the lower limb during multidirectional single leg landing. The relevant articles from valid databases with the keywords Single Leg Landing, Landing, Kinematic, Biomechanics, Return to Sport, Performance Test, Functional Test, Hop Test, Kinetic thematic search methods from 1995 to 2023 were examined. A total of 1022 articles were identified then duplicate studies were eliminated in the next stage, the titles and abstracts of the studies were reviewed and 439 studies were excluded due to inconsistency with the research question. Finally, only 19 articles that met the inclusion criteria were examined. This review showed that only SLL in the forward direction has been investigated in most of the literature using a 3D motion analysis system. There is also no evidence on the biomechanics of other directions of SLL and on the use of 2D motion analysis to evaluate the biomechanics of multidirectional SLL.
Maliheh Ardakanizadeh, Leila Vesaliakbarpour,
Volume 0, Issue 0 (11-2019)
Abstract
Background: It seems that aerobic exercise in water is more effective in promoting motor fitness factors due to its greater resistance force compared to the dry environment. Accordingly, the aim of this study was to compare the effect of aerobic exercise in water and land on the physical fitness of inactive girls.
Methodology: Thirty non-athletic girls (18-25 years old) were randomly divided into two groups of 15 people: water and drought. The subjects performed aerobic activity for six weeks, 3 sessions per week, and 45 to 60 minutes per session with 60 to 70% of maximum heart rate. Before and after aerobic activity, their explosive power using the vertical jump (Sargent), agility by 4×9 test, reaction by reaction time test, and the balance by static balance test was calculated. For compare pre- and post-test, and to compare post-test results in water and land, One-way ANOVA with p<0.05 was used. Statistical testing was performed by SPSS version 20, and the graph were drawn by Excel 2013.
Results: After six weeks of aerobic activity (in water and land) compared to before the activity, significant improvement was found in the values of explosive power (p=0.001), agility (p=0.001) and static balance (p=0.003), while the comparison of training groups in water and land did not show a significant difference (p>0.05).
Conclusion: It seems that performing six weeks of aerobic activity in water and land can affect Explosive power, agility and static balance, but no effect on reaction, also there is no difference between the two environments.
Behnam Moradi, Ebrahim Mohammad Ali Nasab Firouzjah, Sajad Roshani, Narmin Ghani Zadeh Hesar,
Volume 0, Issue 0 (11-2019)
Abstract
Introduction and purpose: The landing error scoring system is a valid and reliable tool for functional assessment of jump-landing movement. The aim of the present study was to investigate the effectiveness of sports training on the landing error scoring system in athletes.
Methodology: Searching between 2014 and 2024 from IranDoc, Magiran, PubMed, Google Scholar, SPORTDiscus, Scopus, PEDro and (ISI) Institute for Scientific Information databases using the combination of jump-landing keywords. Landing mechanics, landing kinetics and kinematics, injury prevention, training, rehabilitation and landing error scoring system were done. A total of 88 articles related to this field were found, after reviewing and screening through the inclusion criteria, 8 articles were reviewed in full text.
Results: Various exercises, including neuromuscular, suspension, knee injury prevention, fatigue and kinesiotype, have been used to be effective on the landing error scoring system test. As a result of corrective exercises and fatigue, the experimental groups showed an improvement and a decrease in the jump-landing movement performance in the landing error scoring system, respectively.
Discussion and conclusion: It seems that in order to prevent jump-landing movement errors and possible injuries caused by it, exercises should be done that, in addition to increasing concentration and coordination in movement, make athletes resistant to factors such as danger.
Rasool Mohamadi, Dr Heidar Sadeghi, Dr Amir Hossein Barati,
Volume 13, Issue 9 (4-2015)
Abstract
Introduction and Purpose: The swimming start is very important for achieving better results in
competitions. The Purpose of this study was to compare the effects of two plyometric training techniques
both in aquatic and on land in two start techniques (grab and track) of butterfly swimming in Elite male
adolescent Swimmers.Methodology: 20 elite male swimmers divided into two groups of plyometric
exercises in water and land-based. Swimming performance variables including; anaerobic power of hands
and legs, 25 meter swimming record, The time of contact of head with water and the time of keeping
movement in water, Flying distance from the starting point to the end point of contact with water and the
distance of continuing movement after entering the water using both start techniques, the number of
movements of hands and legs in 13 meters butterfly swimming without start and glide. Data analysis was
performed with MANOVA test. Results: Significant difference was seen in the mean time of contact of head
with water in both start techniques (grab and track) of Butterfly swimming; in addition, there is significant
difference in mean number of hand movement and leg movement in butterfly swimming and the number of
hand and leg movement in full 13 meter butterfly swimming after polymeric exercise in two
groups.Discussion and conclusion: According to the findings of this study, using plyometric training
program led to an increase and improvement in the measured parameters, and use these exercises to
improve start swimming recommended
Seyed Hossein Mirkarimpour, Mohammad Falah Mohamaddi, Dr Mohammad Hossein Alizadeh,
Volume 13, Issue 9 (4-2015)
Abstract
One of the factors affecting jump-landing patterns is fatigue. Fatigue is an inevitable component of physical
activity, hence the aim of the present study was to investigate the effect of functional fatigue on landing
mechanics through Landing Error Scoring System (LESS).Fourteen male college students with a mean age of
22±2 years, weight of 68.3±7.2 kg and height of 174±4 were randomly divided into two groups: experimental and
control. Effect of independent variable, fatigue, due to activities resembling athletic training or competition (6-
stations functional fatigue protocol) on dependent variable, landing mechanics, through pre test-post test was
investigated. The independent t-tests and non-parametric U-Mann Whitney test was used for statistical analysis
of data (P < 0.05). The results of the present study indicated the relationship between fatigue and attenuation of
landing mechanics (P=0.02), and therefore an increase in injury risk. Also it was shown that the effect of fatigue
on decreasing knee flexion angle at initial contact was significant (P=0.022). With regard to the results, it can be
concluded that functional fatigue induced by physical activities can alter landing mechanics, and increase loading
of lower extremity joints, particularly the knee. So the risk of injury in these joints may be increased.
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
P Zalbeik, A Letafatkar, Sh Rezvan Nobahar,
Volume 18, Issue 19 (7-2020)
Abstract
Feedback instruction is a proven modality for the alteration of motion patterns. There are no existing data on the contribution of strength training, when combined with feedback instruction, to the altering of lower extremity biomechanics. Thus the purpose of the current study was comparison of strength training program with external and internal focus of attention strategies on kinetic and functional factors in athletes with plyometric pattern. 36 athlete females (handball, Basketball and vollyball) voluntarily with avarage age 22.3±2.27 years were randomly assigned to strength training with external focus, strength training with internal focus and strength training groups. Participants completed these training for 8 weeks. Kinetic factors were measured using force plate during landing, as well as functional movement and movement pattern respectively were measured by single leg triple hop test (SLTH) and landing error scoring system. One-way analysis of variance (ANOVA) showed that the effect of strength training with external focus group training significantly was better than two others groups in Peak vertical ground reaction (p=0.039), posterior ground reaction force (p=0.046), mediolateral time to stability (p=0.032), single leg triple hop test (p=0.041) and landing error scoring system scores (p=0.030). But there was no significant between-group difference in anteroposterior time to stability (p=0.312). Subjects in strength training with external focus group showed significantly within-group changes in all variables except anteroposterior time to stability from posttest to pretest. Programs that include both strength training and movement education through external focus of attention may be necessary in order to prevent ACL injuries and increase athletic performance.
Mahboubeh Alemzadeh, Seyed Abdolali Hosseini, Mehrdad Anbarian, Safoura Ghasemi,
Volume 19, Issue 22 (12-2021)
Abstract
Nowadays, light and minimal shoes have been used by athletes in various types of sports activities in order to be in a position close to barefoot position. But its effect on the electrical activity of the shank muscles is not well understood. Therefore, the aim of this study was to investigate the electrical activity of selected shank muscles when using minimalist shoes, normal shoes and barefoot during single-leg landing. For this purpose, 15 healthy boys with a mean age of 23.53± 2.64 years who had no history of any abnormalities participated in this study. Electromyographic variables of tibialis anterior, peroneus longus, peroneus brevis, gastrocnemius medialis, gastrocnemius lateralis and soleus muscles of subjects' superior legs were examined in two phases; pre-activity and eccentric. Analysis of Variance (ANOVA) with repeated measures tests were used for data analysis. The significance level was set at α=0.05. The results showed that in both phases, the activity of selected muscles in the shank of individuals during the one-legged landing movement in the barefoot position was more than the minimalist shoes and when using the minimalist shoes was more than normal shoes (P<0.05); Since minimalist shoes have been shown to have moderate muscle activation patterns, between barefoot and casual shoes, it is recommended to use it to prevent sports injuries and also to strengthen the shank and leg muscles in environments where it is not possible to move barefoot.
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.
Zahra Ghahremani, Hassan Daneshmandi, Mehrdad Anbarian,
Volume 21, Issue 26 (12-2023)
Abstract
The purpose of this study was to assess the acute effect of warm-up protocols (general and post-activation potentiation) on vertical jump performance and jump-landing technique in female handball players with trunk dysfunction. Twelve trained female handball players with trunk dysfunction participated voluntarily in this study. Subjects randomly performed three different warm-up protocols on separate days: 1- general warm-up protocol, 2- general warm-up with 2 repetitions of dynamic half-squat at %90 of one repetition maximum, 3- general warm-up with 2 repetitions of static half-squat at %90 of one repetition maximum. In the fifth minutes of recovery period after 3 protocols, subjects performed vertical jump and the Landing Error Scoring System tests, and Landing Error Scoring System scores, valgus and flexion angles, and vertical jump height was assessed. ANOVA with repeated measures was used for statistical data analysis. The jump height increased significantly after performing the second and third protocols related to general warm-up (p=0.039, p=0.047 respectively), but there weren’t a significant difference in Landing Error Scoring System score, valgus and flexion angles for three protocols. It seems that the special warm-up method by post-activation potentiation can improve vertical jump performance without influencing Anterior cruciate ligament injury risk.
