Murat Çilli

ACUTE EFFECTS OF A RESISTED DYNAMIC WARM-UP PROTOCOL ON JUMPING PERFORMANCE

This study aimed to investigate the kinematic and kinetic changes when resistance is applied in horizontal and vertical directions, produced by using different percentages of body weight, caused by jumping movements during a dynamic warm-up. The group of subjects consisted of 35 voluntary male athletes (19 basketball and 16 volleyball players; age: 23.4 ± 1.4 years, training experience: 9.6 ± 2.7 years; height: 177.2 ± 5.7 cm, body weight: 69.9 ± 6.9 kg) studying Physical Education, who had a jump training background and who were training for 2 hours, on 4 days in a week. A dynamic warm-up protocol containing seven specific resistance movements with specific resistance corresponding to different percentages of body weight (2%, 4%, 6%, 8%, 10%) was applied randomly on non consecutive days. Effects of different warm-up protocols were assessed by pre-/post- exercise changes in jump height in the countermovement jump (CMJ) and the squat jump (SJ) measured using a force platform and changes in hip and knee joint angles at the end of the eccentric phase measured using a video camera. A significant increase in jump height was observed in the dynamic resistance warm-up conducted with different percentages of body weight (p < 0.05). On the other hand, no significant difference in different percentages of body weight states was observed (p > 0.05). In jump movements before and after the warm-up, while no significant difference between the vertical ground reaction forces applied by athletes was observed (p > 0.05), in some cases of resistance, a significant reduction was observed in hip and knee joint angles (p < 0.05). The dynamic resistance warm-up method was found to cause changes in the kinematics of jumping movements, as well as an increase in jump height values. As a result, dynamic warm-up exercises could be applicable in cases of resistance corresponding to 6-10% of body weight applied in horizontal and vertical directions in order to increase the jump performance acutely.

Biomechanical effects of daily physical activities on the lower limb

OBJECTIVE The aim of this study was to determine the joint torques on the lower extremity during the daily physical activity movements of sit-to-stand, crouch down-stand up, and stair climbing without using an external device. METHODS The study subject was a healthy 26-year-old male without any physical problems. A link-segment model was prepared according to the subjects individual anthropometric characteristics and transferred to the MATLAB(®) program. Joint torques were calculated using SimMechanics™ software. Motions were recorded by one digital video camera as the subject performed the movements (sit-to-stand from 20 cm and 40 cm height, crouch down-stand up, and climbing 10 cm and 20 cm high step) and the joints position data was obtained using a digitization process. In addition, the vertical ground reaction forces were measured using a force plate in order to test the accuracy of the link-segment model. Lower extremity joint torques were calculated. RESULTS Maximum joint torques occurred in the knee joint. The knee and the ankle joints were the most loaded joint during the high step movement. The highest torques of the knee and ankle joint were 157.2 Nm and 146 Nm, respectively, during the movements. Knee joint torque and the ankle joint torque increased when the sitting height increased. The hip joint experienced the least amount of load during the movements. CONCLUSION The knee joint has enough strength against high torques during extension and flexion movement. Joint torques can be successfully calculated using a simulation process involving an inverse dynamics method without an external device mounted on the limbs. The obtained data can be used in the design of prosthetics and orthotics and for structural analysis of the bones.

Development of a human hand model for estimating joint torque using MATLAB tools

Determining the joint torques of the hand is a useful design parameter for humanoid mechanism, rehabilitation robots and orthotic and prosthetic devices. In previous studies, different methods have been suggested for estimating joint torques of the hand such as mathematical models and simulation models. This paper presents a 16 DOF hand kinematic model and its simulation. Kinematic structure of an average human hand was created by SimMechanics and Simulink on MATLAB. The model was simulated by inverse dynamics method using the video record of a healthy subject (male, 29 years, 71 kg and 174 cm) and the joint torques of the index finger and wrist were calculated. The maximum torque at index finger with 0.015 Nm occurs at the MCP joint during the cylindrical grip. The maximum wrist torque was calculated as 0.225 Nm during movement of flexion/extension. Flexion/extension and abduction/adduction movements of the fingers and the wrist can be analyzed with this model changing joint rotation axis easily. This MATLAB model can be used in order to calculate the joint torques at different movements of the hand without complex equations and external devices.

İnme Rehabilitasyonunda Kullanılabilecek Kablo ve Yay Tahrikli Giyilebilir Bir El Bileği Egzersiz Cihazı Tasarımı

Inme, her yil milyonlarca kisiyi etkilemektedir. Bu kisilerin cogu, hareket kabiliyetlerini geri kazanabilmek icin rehabilitasyona ihtiyac duymaktadirlar. El kaslarinin robotik temelli rehabilitasyonuna yonelik cok sayida cihaz onerilmis olmasina ragmen bu cihazlarin hala gelistirilmesi gereken yonleri vardir. Onceki cihazlarda kuvvet ve hareket aktarimi icin kullanilan yontemlerin bir takim olumsuz yonleri bulunmaktadir. Bunlardan biri, cihazlarda kullanilan mafsallar ile el ve el bilegi eklemlerinin donme merkezlerinin tam olarak hizalanamamasidir. Bu durum, vucut eklemleri uzerinde kesme kuvvetleri olusturmaktadir. Donme merkezlerini hizalamak icin uygulanan yontemlerin bazi dezavantajlari bulundugundan yeni uygulamalara ihtiyac vardir. Bu calismada, el bilegi egzersizlerini gerceklestirmek amaciyla yeni bir cihaz onerilmektedir. Cihaz, hareket ve kuvvet aktarimini kablo ve yay tahriki ile yapmaktadir. Boylece donme merkezlerinin hizalanmasi sorunu yasanmamaktadir. Cihaz, pasif ve aktif egzersizlere olanak saglamaktadir. Cihazin ev ortaminda kullanima uygun, tasinabilir ve dusuk maliyetli olmasi amaclanmistir. Gelistirilen cihazin, rehabilitasyon maliyetlerini azaltmasi ve tedavi surecini kisaltmasi beklenmektedir. Cihaz, inme rehabilitasyonun yani sira sinir yaralanmasi, sinir sikismasi, tendon yaralanmasi, kiriklar ve spor yaralanmalari gibi durumlarda da kullanilabilir. Dusuk maliyetli olmasi beklenen cihazin, ticarilestirilmesi durumunda tibbi cihazlar alaninda dis pazarlara bagimli ulkemizin rekabet gucune katki yapmasi beklenmektedir .

Development of a wearable exercise device for rehabilitation of hemiplegic hand

Millions of people suffer a stroke each year. One of the problems after stroke is hemiplegic hand. In previous studies a lot of robotic based devices has been suggested for rehabilitation of hemiplegic hand. Actuators using for force transmitting in previous devices have some disadvantages. One of them is misalignment on the centre of rotation between joints used in devices and joints of the hand. In this study a novel device is suggested to perform the finger exercises. The device has a cable and spring driven mechanism with an electrical linear actuator. The device allows both passive and active exercises. It is aimed that the device is suitable for at home use, wearable, portable and low cost. It is expected from the new device that it will reduces the rehabilitation cost and therapy period. The device can be used for other rehabilitation treatments such as nerve injury, nerve compression, tendon injury, fracture and sport injury besides stroke rehabilitation.

Development of a biomechanical model for the analysis of the wrist extension and flexion movement

The wrist links hand and forearm to each other and it allows movements in two different planes. Thus it has an important role in the mobility of the hand. In previous studies, researchers have analysed the movement of the wrist joint using different mathematical models and methods. In this study, the hand and the wrist have been modelled as a simple pendulum in the sagittal plane. MATLAB&Simulink-based SimMechanics software was used for this process. The joint torque of the wrist during extension and flexion movement of the hand was calculated using motion analysis data. It has been found that the SimMechanics model given useful results.