Orthopaedic Sports Medicine Center of Ioannina

The Biodex System 3 ( Biodex Corp ., Shirley , NY ) is a state of the art isokinetic dynamometer which fully accommodates a wide variety of positions and exercises. Various aspects of muscle performance can be tested such as strength, power and resistance to fatigue, in all major peripheral joints of the human body. It consists of the dynamometer motor which can shift and rotate in order to fit the testing position of each joint, a positioning chair with 360 degrees of rotation motorized seat height adjustment and superior stabilization and a number of shafts specifically designed to adapt to each joint. Muscle performance is monitored and recorded on a computer and it is expressed as torque since it is actually the force which causes joint rotation as it is applied on a distance from the axis of joint rotation. All types of muscle action can be performed on the Biodex System-3 isokinetic dynamometer: isometric, isotonic and isokinetic, with the last being a key for testing and rehabilitation. During isokinetic exercise the joint rotates with constant velocity apart from periods of acceleration and deceleration from and to zero and this happens because the dynamometer instantly detects any changes from a pre-selected speed and accommodates the resistance in order to eliminate deviations from steady velocity. In this way, along with the full control of the range of motion, the two fundamental aspects of muscle performance (velocity and length) are under the best possible control and reliability of testing is enhanced. Apart from the concentric mode of contraction, eccentric tests and exercise can also be performed, this being important considering that this mode reflects the efficiency for force dissipation during breaking actions. Protection from injuries is also achieved since the dynamometer literally reacts to the applied external force and stops to operate when the force ceases.