The biomechanics of a basketball free throw

The development of the basketball shoe

As basketball began to grow as a sport the main shoes worn was the canvas converses. It wasn’t until the 1970’s and 1980’s that Nike began to make shoes made with science. Creating shoes that are lighter and more flexible. The development of the basketball shoe effects a basketball free throw based on how light the shoes are compared to the heavy converses that used to be worn.

The most effective foul shot is taken using the whole body. The shot begins with the legs pushing down into the ground this motion will generate force. This force is then passed into the shoulders, down through the forearm and is then passed through to the ball propelling it towards the ring. Correct timing throughout this process will create more momentum and therefore a more effective shot. This process is also known as a kinetic chain where all joints are extended applying force to the object.

The following diagram shows the difference in force between a well timed basketball shot, a basketball shot taken too early and basketball shot taken too late.

Force summation

As shown in the diagram by perfectly timing the movements more force is generated. It is also pivotal that the next movement starts at the peak of the movement beforehand.

Technology

The development of the basketball

Basketball was initially played with a soccer ball. The soccer ball would be heavier and therefore require more force to propel upwards towards the basket, tiring players quicker and effecting their shooting style. It was not until 1929 that the balls had stopped being made out of leather and instead had become bigger, lighter and easier to bounce. This would affect the foul shot in term of the mass and inertia of the ball.

Technique

linear motion

There are two types of linear motion, curvilinear motion and straight line motion. When completing a basketball shot the ball travels under a parabolic flight path, this is classed as a curvilinear motion known as projectile motion.

When correctly completing a basketball free throw, the starting position of the player should be bent knees, elbows and wrist. When completing the skill the motion will begin in the toes and develop to the fingertips.

Beginning the movement in the knees will also reduce the amount of stress placed on the arms and shoulders. The same amount of force is needed for the shot to be successful only it has to come from the top half of the body creating more stress and increases the likelihood of an injury.

There is a number of factors that affect the projectile motion of a free throw. These include speed of release, angle of release and height of release. The parabolic path occurs for a number of reasons, those reasons being gravity and air resistance.

Bibliography

For a 6 foot 4 player the optimum angle of release is approximately 50.1 degrees. However this does not take into account the speed of release. By increasing the height of the parabolic arc the target size becomes larger. An increase in the release angle would increase the amount of force required for the ball to get to the hoop which may reduce the accuracy of the shot.

Motion

1. What are the Biomechanical Principles of a Free Throw? . Blogspot. [Online] April 20, 2013. [Cited: October 10, 2016.] http://biomechanicsoffreethrow.blogspot.com.au/.

2. What are the biomechanical principles involved in shooting a basketball free throw? . Blog Spot. [Online] June 19, 2014. [Cited: October 10, 2016.] http://kjbrooksby.blogspot.com.au/2014/06/what-are-biomechanical-principles.html.

3. What is the most effective way to shoot a free throw in basketball? Word Press. [Online] April 23, 2013. [Cited: October 10, 2016.] https://jackkowalick.wordpress.com/2013/04/23/what-is-the-most-effective-way-to-shoot-a-free-throw-in-basketball/.

4. Anatomical Analysis of Free Throw Shot in Basketball. Blog Spot. [Online] September 22, 2013. [Cited: October 11, 2016.] http://bobdimplesc24.blogspot.com.au/2013/09/anatomical-analysis-of-free-throw-shot.html?view=snapshot.

5. the evolution of the game. hooptactics. [Online] 2016. [Cited: October 11, 2016.] http://hooptactics.com/Basketball_Basics_History.

6. Hodgson, Chris, McNaughton, Neil and Wilson, Andrew. Physical Education. Adelaide : Adelaide Tuition Centre, 2014. ISBN-978-1-921548-94-9.

The biomechanics of a basketball free throw

Rotational motion

Rotational motion occurs at each of the bent flexors within the body. For example for an effective shot the knee should be bent at approximately 90 degrees, therefore as the shot begins and passes from the toes to the knee the bones will rotate around the knee flexor creating rotational motion.

Rotational motion will also occur for the ball once it has left the players hand. If the shot is completed successfully the ball will undergo back spin. When this is happening the ball is rotating around its axis which is known as rotational motion.

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Distribution of mass

Levers

When taking a free throw in basketball the player would increase their stability by lowering their centre of gravity and widening their base of support slightly. The line of gravity will also be in the centre of the body in order to ensure stableness. When the shot is being undertaken the line of gravity will remain in the centre, the base of support will remain the same and the centre of gravity will shift upwards. However the centre of gravity will not fall out of the base of support unless the shooter moves forward during their shot.

Both a second class lever and third class lever are present in a basketball free throw. The first third class lever is found in the elbow and forearm as the shot is being taken. A third class lever is classified as the force being in between the axis and resistance. As shown in figure 1. Another example of a third class lever is the wrist as shown in figure 2. A person with longer arms or limbs have more speed in their shot. However longer limbs require more force to move.

Newton's three laws

figure 2

figure 1

1st law

3rd law

'An object will remain at rest unless acted upon by an unbalanced force. Alternatively a body in motion will remain in motion unless acted on by an unequal force.’

The basketball has inertia and the greater the mass of the ball the larger the inertia. When shooting a free throw the athletes needs to change their position from rest to vertical motion in order to propel the ball .

‘Whenever on object exerts a force on the second object, the second object exerts an equal and opposite force on the first object.’

During the action of a free throw the foot pushes down on the ground, the ground creates an equal and opposite force pushing the athlete upwards.

2nd law

‘the acceleration of a body is directly proportional to the net force acting on it, but inversely proportional to the mass of the body.’

Otherwise expressed as F=M x A. When shooting a free throw force needs to be applied by the athlete to accelerate the ball.