Torque, Levers and Angular Momentum
Torque has specific effects that can be related to levers. Torque and levers both share the same importance in the tennis serve which is the power output that is created within the serves components. Torque is known to be the force in which allows rotation in specific objects. This is presented around an objects axis (McGinnis, 2005), (McLeste & Pierre, 2008). This can be related into the tennis serve as the tennis racquet arm, hips and legs as all these variables rotate in some way. Torque displays significance in the tennis as it is used to the swing in the serve.
Torque is greater when the size of the moment arm (the distance from the muscle to the joint) is larger. This works with the extension of the arm in the serve. The more the arm is extended, the greater the length of the moment arm and the lever, which in turn puts more acceleration on the racquet head and more power on the ball (see diagram below).
Torque is greater when the size of the moment arm (the distance from the muscle to the joint) is larger. This works with the extension of the arm in the serve. The more the arm is extended, the greater the length of the moment arm and the lever, which in turn puts more acceleration on the racquet head and more power on the ball (see diagram below).
The video above shows the connection phase of the follow through.
Third Class Lever
Source: Pill, 2013
In a third class lever which favours speed, the angular velocity is greater when the further the resistance is from the force. This works similar to the moment arm principle as more displacement from the force which in this case is the wrist, allows the racquet to accelerate faster as it has a greater swinging distance. This is why the ball is struck at close to its highest point.
Torque also contributes to angular impulse. Angular impulse is the product of torque and time (Blazevich, 2012). In the tennis serve the rotation of the arm, the racquet, the torso and the legs, create torque. This torque contributes to the angular velocity of the racquet, which creates the acceleration on the ball and has a dramatic effect on the force emitted on the ball.
Torque also contributes to angular impulse. Angular impulse is the product of torque and time (Blazevich, 2012). In the tennis serve the rotation of the arm, the racquet, the torso and the legs, create torque. This torque contributes to the angular velocity of the racquet, which creates the acceleration on the ball and has a dramatic effect on the force emitted on the ball.