Emre Ak - Academia.edu (original) (raw)

Papers by Emre Ak

Despite extensive preventive efforts, falls continue to be a major source of morbidity and mortal... more Despite extensive preventive efforts, falls continue to be a major source of morbidity and mortality Understanding the methods used to recover from falling is important to develop necessary prevention techniques. Arm movements play an important role in recovering from postural perturbations. This study aimed to understand the effects of arm rotations in three different levels of perturbation. The participants leaned forward in 5.5, 6.5 and 7.5 degrees and suddenly released by switching off the electromagnet attached on their back. A six camera motion analysis system and a force plate were used to record the kinetic and kinematic variables. Visual 3d software was used to create subject specific models. The angular momentum of the arms about the shoulder and MTP joints were calculated. The differences between 5.5 and 6.5 degrees were compared in terms of the angular momentum and the angular velocity of the arms. None of the participants were able to recover from 7.5 degrees. Significa...

Türkiye Fiziksel Tıp ve Rehabilitasyon Dergisi, 2013

Journal of Human Kinetics, 2010

The Effect of Fatigue on the Kinematics of Free Throw Shooting in Basketball Fatigue is an indisp... more The Effect of Fatigue on the Kinematics of Free Throw Shooting in Basketball Fatigue is an indispensible part of a basketball game which may affect an athlete's shooting kinematics. Although kinematic analyses of various sports related movements were extensively done, this study is the first to consider the effects of fatigue on the kinematics of free throw shooting. After measuring the resting heart rate, ten collegiate level, male basketball players (21.8±1.6 y; 192.8±3.6 cm; 84.1±8.5 kg) were asked to perform free throws. Two successful and two unsuccessful free throws were selected. Thereafter, participants were asked to complete the fatigue protocol, which included 30m sprints and 5 vertical jumps at each end, until they reached volitional exhaustion. Additional two successful and two unsuccessful free throws were collected. All shots were recorded by using two digital cameras operating at 60 Hz and placed in a stereoscopic view. The elbow, trunk, knee and ankle joint angle...

BMJ Open Sport & Exercise Medicine

The IOC recently published its framework on fairness, inclusion and non-discrimination based on g... more The IOC recently published its framework on fairness, inclusion and non-discrimination based on gender identity and sex variations. This framework is drafted mainly from a human rights perspective, with less consideration for medical/scientific issues. The framework places the onus for gender eligibility and classification entirely on the International Federations (IFs), even though most will not have the capacity to implement the framework. The position of no presumption of advantage is contrary to the 2015 IOC consensus. Implementation of the 2021 framework will be a major challenge for IFs that have already recognised the inclusion of trans and women athletes with differences of sexual development (DSD) using a scientific/medical solution. The potential consequences for sports that need to prioritise fairness or safety could be one of two extremes (1) exclusion of all transgender or DSD athletes on the grounds of advantage or (2) self-identification that essentially equates to no...

Amaç: Bu çalışmada genç tenisçilerin başarılı ve başa-rısız tenis servisi atışları arasındaki ekl... more Amaç: Bu çalışmada genç tenisçilerin başarılı ve başa-rısız tenis servisi atışları arasındaki eklem açı farkları incelendi. Hastalar ve yöntemler: Dokuz sağlıklı tenisçi (5 kız, 4 erkek; ort. yaş 11.8±0.8 yıl; boy 153.6±7.2 cm; vücut kütle indeksi 42.3±4.1 kg; oyunculuk deneyimleri 6.2±1.5 yıl) çalışmaya katılmak için gönüllü oldu ve gerçek tenis maçında olduklarını varsayarak atabilecekleri kadar hızlı servis atışı yaptı. Başarılı ve başarısız servis atışları saniyede 60 resim kaydedebilen iki adet kamera ile kaydedildi ve daha sonra Pictran yazılımı ile analiz edildi. Topa vuruş öncesi, vuruş anı ve vuruş sonrasındaki eklem açıları karşılaştırıldı. Bulgular: Bağımlı değişkenler t-testi ile analizi yapılan bu üç vuruş safhasında başarılı ve başarısız servisler arasında anlamlı bir fark görülmedi. Sonuç: Çalışmanın bulguları servis atışının vuruş önce-si, vuruş anı ve vuruş sonrası safhalarında başarılı ve başarısız denemeler arasında bir fark olmadığını ortaya koydu. Servis atışı s...

Kinematics of the instep penalty kick to four different targets (50cm2) placed at the upper left ... more Kinematics of the instep penalty kick to four different targets (50cm2) placed at the upper left (UL), lower left (LL), upper right (UR), and lower right (LR) corners in the goal. Five colligate male soccer players were examined for their knee flexion and ankle extension strategies. The swing, ball contact and follow through phases were analyzed by using a dual camera and Pictran software system. Results revealed that participants had significantly higher ankle extension while hitting the target at the UR ( m=77.6 deg, sd=10.5) and LR ( m=84.4 degree, sd=10.1) corners. In conclusion players presented similar knee flexion but not ankle extension kinematic strategies at the contact and follow through phases of the instep penalty kick to different corners in the goal.

OBJECTIVES Penalty kick has always been the most exciting moment of the soccer game. Many cups ha... more OBJECTIVES Penalty kick has always been the most exciting moment of the soccer game. Many cups have been won and lost with the penalties. Some players choose focusing on goal keepers movements; some however decide at the shooting point while waiting for the referees whistle. However, the most important factor is the technique of the player. A perfect technique should be executed in order to put the ball in the goal. Thus, the aim of this study was to investigate the kinetic and kinematic features of the penalty kicking technique of professional soccer players.

B u çalışmanın amacı 8-10 yaş grubu elit tenis oyuncularında yaşın ve cinsiyetin sezinleme zamanı... more B u çalışmanın amacı 8-10 yaş grubu elit tenis oyuncularında yaşın ve cinsiyetin sezinleme zamanı performansı üzerindeki etkilerinin incelenmesidir. Araştırma grubunun (n=228) sezinleme zamanı performanslarının ölçümünde Bassin Anticipation Timer ölçüm aracı kullanılmıştır. Yaşın ve cinsiyetin sezinleme zamanı performansı üzerindeki etkilerinin incelenmesinde 3x2 Varyans Analizi yöntemi kullanılmıştır. Araştırma sonuçları 10 yaş grubundaki oyuncuların 8 yaş grubundakilere oranla ve erkek oyuncularının kız oyunculara oranla sezinleme zamanı performanslarının daha başarılı olduğunu göstermiştir. Elde edilen bu bulgular, yaşın ve cinsiyetin, sezinleme zamanı üzerinde etkileri olduğunu göstermektedir.

Hareketin bilimsel olarak kaydedilmesi ve degerlendirilerek geri donus verilmesi sporun vazgecilm... more Hareketin bilimsel olarak kaydedilmesi ve degerlendirilerek geri donus verilmesi sporun vazgecilmez unsurudur. Sporda hareket analizi gunumuzde sadece laboratuar ortaminda gerceklestirilebilmektedir. Bu durumda spora ozgun ince farkliliklar ortadan kaybolmakta ve basariyi beraberinde getiren unsurlarla ilgili sinirli bilgi edinilebilmektedir. Sporda hareket analizinin dogal ortamda dijital video kameralara kaydedilerek fotogrametrik yontemlerle degerlendirilmesi gerek ulkemizde gerekse yurt disinda ozgun bir fikir olup orijinallik arz etmektedir. Bu calismada futbol sporunda penalti atis hareketinin, digital video kameralarla cekimi gerceklestirilerek hareket adimlarinin analizleri fotogrametrik yontemler kullanilarak yapilmistir.

Kinematics of the instep penalty kick to four different targets (50cm 2 ) placed at the upper lef... more Kinematics of the instep penalty kick to four different targets (50cm 2 ) placed at the upper left (UL), lower left (LL), upper right (UR), and lower right (LR) corners in the goal. Five colligate male soccer players were examined for their knee flexion and ankle extension strategies. The swing, ball contact and follow through phases were analyzed by using a dual camera and Pictran software system. Results revealed that participants had significantly higher ankle extension while hitting the target at the UR ( m =77.6 deg, sd =10.5) and LR ( m =84.4 degree, sd =10.1) corners. In conclusion players presented similar knee flexion but not ankle extension kinematic strategies at the contact and follow through phases of the instep penalty kick to different corners in the goal.

B u calismanin amaci 8-10 yas grubu elit tenis oyuncularinda yasin ve cinsiyetin sezinleme zamani... more B u calismanin amaci 8-10 yas grubu elit tenis oyuncularinda yasin ve cinsiyetin sezinleme zamani performansi uzerindeki etkilerinin incelenmesidir. Arastirma grubunun (n=228) sezinleme zamani performanslarinin olcumunde Bassin Anticipation Timer olcum araci kullanilmistir. Yasin ve cinsiyetin sezinleme zamani performansi uzerindeki etkilerinin incelenmesinde 3x2 Varyans Analizi yontemi kullanilmistir. Arastirma sonuclari 10 yas grubundaki oyuncularin 8 yas grubundakilere oranla ve erkek oyuncularinin kiz oyunculara oranla sezinleme zamani performanslarinin daha basarili oldugunu gostermistir. Elde edilen bu bulgular, yasin ve cinsiyetin, sezinleme zamani uzerinde etkileri oldugunu gostermektedir

Аннотация: авторы рассматривают нормы об уголовной ответственности за терроризм и преступления те... more Аннотация: авторы рассматривают нормы об уголовной ответственности за терроризм и преступления террористической направленности на примере Уголовного Кодекса Китайской Народной Республики, а также обращают внимание на ряд специфических черт национального законодательства.

Although there are many studies demonstrating increased trunk activation under unstable condition... more Although there are many studies demonstrating increased trunk activation under unstable conditions, it is not known whether this increased activation would translate into meaningful trunk strength with a prolonged training program. Additionally, while balance-training programs have been shown to improve stability, their effect on specific joint proprioception is not clear. Thus the objective of this study was to examine training adaptations associated with a 10-week instability-training program. Participants were tested pre- and post-training for trunk extension and flexion strength and knee proprioception. Forty-three participants participated in either a 10-week (3 days per week) instability-training program using Swiss balls and body weight as resistance or a control group (n = 17). The trained group increased (p < 0. 05) trunk extension peak torque/body weight (23.6%) and total work output (20.1%) from pre- to post-training while the control group decreased by 6.8% and 6.7% r...

TOTBID Dergisi

Şekil 10. Voleybolda smaç vuruşunun kaydedilerek değerlendirilmesi. [32] Teşekkür Sporda hareket ... more Şekil 10. Voleybolda smaç vuruşunun kaydedilerek değerlendirilmesi. [32] Teşekkür Sporda hareket analizi çalışmalarımızın bir bölümünü gerçekleştirdiğimiz TSK-ODTÜ MODSİMER'e ve Prof. Dr. İbrahim Yıldıran'ın danışmanlığında Gazi Üniversitesi, Sağlık Bilimleri Enstitüsü'nde "Voleybolda Smaç Kolunun Açısal Kinematik Analizi" başlıklı Yüksek Lisans Tezini gerçekleştiren Elif Öz'e teşekkürü borç biliriz.

The purpose of the study was to investigate the effects of age and gender on coincidence timing a... more The purpose of the study was to investigate the effects of age and gender on coincidence timing accuracy (CTA) of junior tennis players (ages of 8-9-10). The Bassin Anticipation Timer Device was administered to measure CTA of participants (n=228). A 3x2 ANOVA was conducted to analyze age groups and gender differences on CTA. Results revealed that 10 year-old players had significantly lower CTA scores than eight year-old players and male players performed more precisely on CTA than their female counterparts. These results suggest that both age and gender have effects on CTA.

The Knee, 2013

Acute effects of physical exercise on the deformational behaviour of articular cartilage and chan... more Acute effects of physical exercise on the deformational behaviour of articular cartilage and changes in cartilage oligomeric matrix protein (COMP) are definite. However, conclusive positive effects of fitness exercise on functional adaptation of articular cartilage have not been proved. Therefore, in this parallel-group randomised controlled trial, we tested the hypothesis that adequate amount of physical exercise with enough impact would be able to stimulate the functional behaviour of articular cartilage. We evaluated 44 healthy males for their physical-fitness levels and their blood samples were obtained before, immediately after and 0.5h after a 30-min walking exercise. Thereafter, participants were assigned to the running, the cycling, the swimming and the control groups. At the end of 12weeks of intervention, the same measurement procedures were applied. Mixed repeated-measures analysis of variance (ANOVA) design was used for statistics. ( 2). Pre-test measurements showed that 30min of walking significantly increased serum-COMP levels in all groups. The post-tests revealed that the COMP level of all groups, except running, showed an increase after a 30-min walking activity. Overall, it was concluded that, 12weeks of regular, weight-bearing, high-impact physical exercise (i.e., running) decreases the deformational effect of walking activity. This finding is an evidence of functional adaptation of articular cartilage to specific environmental requirements.