Presentation on theme: "Isokinetic Assessments of Muscle Function"— Presentation transcript:
1 Isokinetic Assessments of Muscle Function Lab 5Isokinetic Assessments of Muscle Function
2 Three most common forms of strength testing IsometricDynamic constant external resistance (DCER)Isokinetic
3 Isometric testingIt involves the use of a device that measures force output resulting from muscle actions with the body segment in a fixed position.No movement is involved.No mechanical work is performed.Results are specific to the joint angle and are not reflective of force production capabilities for normal movements.
4 DCER testingUtilizes resistances that are moved through a range of motion by a body segmentIndicates only the amount of resistance that can be overcome at the weakest point in the range of motionDoes not assess force production capabilities at controlled velocities of movement
5 Isokinetic testingInvolves the use of special equipment that continuously measures and records torques and joint angles as a body segment moves through a range of motion at a preselected velocity controlled by an isokinetic dynamometerProvides force output values for every point throughout the movement and allows for control of velocity for such movementsCan be used to estimate fiber type in the exercise muscle group.
6 Peak torque vs. velocity of movement As velocity of movement increases, peak torque levels tend to decrease during concentric muscle actions due to increased dependency on fast twitch fibersThose who excel in activities requiring high-velocity movements do so, in part, because of an ability to develop high levels of torque during rapid movements.
8 Peak torque and range of motion Force production capabilities are diminished at the extremes of a full range of motion.This response pattern underscores the inability to apply maximal overload throughout a DCER-type movement.
10 Peak torque vs. repetitions With repeated maximal effort muscle actions, torque production declines.Fast twitch fibers tend to become fatigued sooner than slow twitch fibers.Rate at which torque declines during repeated muscle actions reflects, to some degree, the fiber type composition in the exercised muscle group.