Wednesday, 18 June 2014

What is a layup?
“In basketball, the layup is the highest percentage shot in the game. Many players know how to correctly execute only one or two of the six variations. The overhand layup is the one most commonly taught. The overhand layup is the easiest in-motion layup to learn and is shot like a regular shot” (Palazzo & Zimmerman, 2005.)
If you are still unsure about what a layup is/looks like please watch this video: https://www.youtube.com/watch?v=6TgFAQooBho
What does a text book method of teaching the layup look like?

STACK provides learning sequences on how to learn/teach particular skills as well as drills that coaches can use when introducing these techniques to students. The instructions they provide for learning/teaching a standard layup can be seen below and it is very evident that they use a fairly standard text book technique.


After reading through the points there are many sections where people could get lost or confused. Personally I have played basketball since the age of ten, I am by no means a professional player but with eleven years of basketball behind me I am unaware of where ‘the first hash mark from the block’ is or even what it looks like. I also do not see why it is necessary in the third point to ‘slap the ball hard.’ While this textbook teaching method may be efficient for certain teachers or coaches there is no evidence of it being informed by research. There is no biomechanical reference in any of the steps to tell the students why they need to do a particular part of the skill in a certain way or the benefits that come with it.

So what are the biomechanical principals surrounding a basketball layup?

Angular Velocity – Angular velocity is “the rate of change in the angle of the thrower” (Blazevich, 2010, p16.) Changing the angular velocity will change how fast the basketball will be moving and will affect how far it can be thrown (Blazevich, 2010, p20.) This is important as where the arms are bent and the angle at which they're bent will need to be decided on in relation to how far away the ring is. Blazevich states that changing angular velocity can affect the release velocity by 40% a number which is similar for both long and short armed throwers (2010, p21.) Angular velocity is the reason having ones arms bent at the elbow is biomechanically beneficial and it is important to note that changing the angle can greatly affect the outcome of the shot.

Projectile Motion - Projectile motion is “the motion of an object projected at an angle into the air” (Blazevich, 2010, p25.) This projectile motion is influenced by projectile speed, the projectile angle and the relative height of projection. The projection speed relates to how far an object will go, this is decided upon when the angular velocity is created by bending the arms at the elbow before shooting and will determine whether the ball makes the ring or falls back to earth before reaching it. Projection angle relates to the angle at which the ball travels and again will determine if the ball makes the ring or not. The relative height of projection is “the vertical distance between the projection point and the point at which it lands” (Blazevich, 2010, p 26.) When throwing a basketball at a ring the relative height of projection is negative as the ball needs to land somewhere higher than it started. This tells us that the optimum projection angle should be greater than 45° as it gives the ball a greater curve and means it will be falling straight down into the ring. The projectile motion helps to reiterate why the angular velocity is so important and how bending the arms at just the right angle in the preparation phase can determine the outcome of the shot. This is particularly important in basketball as “the ball is much more likely to fall through the ring/basket if it falls vertically than when it skims across the ring/basket” (Blazevich, 2010, p 38.)


Newton’s Laws/Reaction Force – Newton’s first law relates to a state called inertia. The law is that “an object will remain at rest or continue to move with constant velocity as long as the net force equals zero” (Blazevich, 2010, p 44.)  Inertia is the term used to describe that and object will remain in its present state, unless it is acted upon by a force, but the larger the mass of an object the greater the force needed to change its state. The second law is that “the acceleration of an object is proportional to the net force acting on it and inversely proportional to the mass of the object” (Blazevich, 2010, p 45.) Newton’s third law states that “for every action there is an equal and opposite reaction” (Blazevich, 2010, p 45.) All of these laws and biomechanical principals relate to the run up and jump in a basketball layup. To get moving and build up speed in the run up, inertia needs to be overcome, this is done by using our own mass and pushing it forwards. When we push our foot against the ground and away from the position we are in, the earth creates an equal and opposite reaction which essentially ‘kicks’ us forward. This is a reaction force which relates to everything having an equal and opposite reaction (Blazevich, 2010, p46.) This also explains why bending our knees before jumping means that we can jump much higher because it helps us to overcome inertia. By bending at the knees we create more potential energy, meaning that the distance in which to accelerate is greater. By creating more time/space to accelerate one is able to create a larger reaction meaning they can jump higher propelling them away from defenders and closer to the ring. An important factor is to recognise that the gravitational force is less when were lighter so by safely minimising body fat (within healthy limitations) we are able to great a greater net force accelerating us upwards when jumping.

The Impulse-Momentum Relationship – This biomechanical principle helps us to realise the best ways to accelerate our body. It links in with Newton’s third law and states that “when we hit the ground with our foot, we need to apply the largest force possible for the longest time possible, as the greater the impulse, the greater the change in momentum” (Blazevich, 2010, p53.) When running we create breaking and propulsive impulses as our foot strikes the ground. When it first lands on the heel it creates a breaking impulse which means the force created in our leg slows our speed slightly. The propulsive impulse occurs when our weight moves forward and we begin to push ourselves forward off our toes, accelerating ourselves. So to speed up our run up we need to reduce the braking and increase the propulsive forces (Blazevich, 2010, p55.) This can be done by keeping the feet closer to the body when running as “the breaking impulse is usually greater when the foot lands further in front of the body” (Blazevich, 2010, p57.)

Centre of Mass – Knowing about centre of mass and how it affects us can help propel a basketballer higher during the jump stage of a layup. When jumping bring your legs up under the body, then when gravity begins to pull you back toward the ground the legs can be rapidly extended downwards, conserving momentum and pushing the upper body higher. It is very slight and is often called being able to ‘hang.’ It is possible as our body’s centre of mass is moving downwards but then our upper body is going up creating a moment of stationary hang in the air (Blazevich, 2010, p 67.)



Angular Kinetics – Similarly to Newton’s laws and reaction force, angular kinetics notices that we are able to run forward because the force we apply against the ground is moving backwards. Our speed is decided upon in relation to the amount of force we can produce and how frequently it can be applied (Blazevich, 2010, p 73.) So to be able to run faster we need to move the leg forward and swing the leg backward at a quicker pace, this is done by increasing “the torque (moment of force) developed by the hip muscles, decreasing the mass of the leg and ensuring that the remaining mass is located as close to the hip joint as practically possible” (Blazevich, 2010, p 79.) The moment of inertia can be reduced by flexing the leg during recovery meaning that the leg swings forwards at a faster pace, one closer to the pace that the leg is swung backwards (Blazevich, 2010, p 86.)

The Kinetic Chain – The kinetic chain effectively relates to our body having “a moving chain of parts” (Blazevich, 2010, p 196) and this is then broken into two movement patterns, push-like and throw-like. Push-like movement patterns “tend to extend all the joins in our kinetic chain simultaneously in a single movement” (Blazevich, 2010, p 196) like a leg press or a basketball free throw. They are very efficient and help to produce a greater amount of force. Throw-like movement patterns alternatively move “the joints of the kinetic chain sequentially, one after another” (Blazevich, 2010, p 198) like throwing a dart or kicking a football. This type of movement pattern makes good use of fast shortening tendons creating a high release velocity, meaning we are able to throw a ball faster than if we used a push-like movement pattern. A basketball shot can incorporate both aspects of the kinetic chain moving from a push-like to a throw-like movement. The throw like stage is introduced at the end through the flick of the wrist or the follow through as it is sometimes referred to. Flicking the “wrist and fingers at the end of an over-arm throw contributes a great deal to the overall release speed of a ball” (Blazevich, 2010, p 202) and the quicker the basketball is thrown the less time there is for interference from the defence.

The Answer:
Students can produce consistent outcomes with a teacher or coach who does not have a biomechanical knowledge but it is likely that the outcomes being achieved are not the greatest that the individual could perform. When a teacher has a biomechanics knowledge base they are able to develop learning cues based on research and evidence. According to McGinnis (2013) “Traditional teaching and coaching methods tell you what techniques to teach or coach, whereas biomechanics tells you why those techniques are best to teach. A good knowledge of biomechanics will enable you to evaluate techniques used in unfamiliar sport skills as well as to better evaluate new techniques in sports familiar to you.” Physical educators and coaches naturally want the best for their students or athletes and this not only includes improving their performance but also reducing their risk of injury, both of which can be done with a biomechanical knowledge (Knudson, 2007.)
Qualitative analysis is one of the most important professional activities of teachers and coaches (Knudson, 2007.) Through an understanding and effective use of biomechanics it is possible to help students understand the meaning behind your skill cues. For example, instead of just telling a person to keep their centre of mass low a coach or teacher can use their knowledge to inform the student about where or how low the centre of mass should be within their base of support, how it should move and how fast in order to achieve a certain mobility or stability objective required to perform the task quickly (Knudson, 2007.) This type of qualitative analysis can not only help the student's understanding but also help the coach or teacher identify the type of training the athlete or student requires to improve (McGinnis, 2013.)

When using a text book technique teachers and coaches often give skill cues based on the aesthetics of how someone is performing a skill. The focus is placed on how the person looks when doing a layup and if it matches what is said in a text book. By having a basic biomechanical knowledge a student’s basketball layup can be improved through an understanding of what is most efficient for their body even if it may not look aesthetically appealing. Biomechanics helps students understand mentally and physically why a coach or teacher asks them to do something and with time they are able to see the benefits it creates. Using biomechanics to inform decisions and planning is very important as the most influential biomechanical flaws are able to be noticed and corrected (Blazevich, 2010, p 210.)  By using and understanding the biomechanics related to a basketball layup students or athletes should be able to improve their technique and the gained understanding can be related back into a game situation. The use of biomechanics to improve a person’s layup means that they are able to use their body to its fullest potential, while reducing the risk of injury and creating a consistent pattern to help them gain success.

How else can we use this information?

The biomechanical principles provided are relevant to use when playing a large number of sports, including anything where running, jumping or shooting is involved.  Angular velocity can be used in any sport or situation where a ball is thrown such as netball, baseball, cricket or grid iron football. By giving athletes an understanding of how the angle in their arm controls the outcome of their throw they should be able to experiment with the maths as well as trying it out in practise to give themselves a greater understanding of the effects of their own movement. An understanding of projectile motion can benefit any sport or activity where a ball or projectile object is used. Anyone who plays volleyball, basketball, tennis, shot put or javelin along with many other sports would benefit from an understanding of the things that influence projectile motion and how they can control those influences. For any teacher, athlete or coach having a basic understanding of Newton’s laws can forge beneficial changes in any sport. For any sport where running is involved understanding inertia and the best ways to overcome it can increase ones speed. Newton’s third law could biomechanically help anyone involved in a sport where jumping or shoving is involved such as diving, netball and rugby. The same goes for all of the biomechanical principles listed at the beginning of this blog, having a basic understanding of even one of them can benefit your movements or help you to improve the efficiency of other people’s movements. This information can help you to give your students or athlete’s confidence and drive. With a biomechanical knowledge you can now tell them what to work on but also why to do it and the potential benefits it can create.


References:

Blazevich, A., 2010. Sports Biomechanics The Basics Optimising Human Performance. 2nd ed. London: A&C Black Publishers.
Knudson, D. (2007). Qualitative biomechanical principles for application in coaching. Sports Biomechanics, 6(1), 109-118. DOI 10.1080/14763140601062567

LIVESTRONG.COM. (2009). How to Shoot a Layup. Retrieved from https://www.youtube.com/watch?v=6TgFAQooBho

McGinnis, P. (2013). Biomechanics of Sport and Exercise (3rd ed., pp. 1-10). USA: Human Kinetics


Palazzo, N., & Zimmerman, C. (2005). About Us and 6 Basketball Layup Variations, Part 1: Overhand Layup. Stackactive.com. Retrieved from http://www.stackactive.com/