Biomechanics Blog - The Biomechanics of Cricket

Dylan Phillips  HLPE 3531 Skill Acquisition and Biomechanics 

 

What are the key components to perform a successful front foot drive in cricket?

Background information on cricket batting

Cricket batting is a dynamic interceptive action where the batsmen can be hit the ball to any part of the ground. They have to deal with many different task constraints to hit the ball. Fast bowlers can swing the ball through the air, move it off the pitch or sometimes do both. Spin bowlers can make the spin of the pitch, these actions make it hard for the batter to hit the ball because in a very short period of time the batter has to determine where the ball will land and if it will move off its line, all while deciding what shot to play. The biomechanics of cricket batting is a kinetic chain that can be described through six kinematic sequences these are the;

Stance and initial movement

It is important that the batter has a stable base, for a base to be stable the centre of mass is evenly distributed across both feet. This is important for the initial movement because if your weight is on spread between both feet it enables the batter to move forward onto the front foot for a drive or move onto their back foot to play a cut or pull shot (Stuelcken, Portus & Mason 2005).

Back-lift

The back lift is important in the cricket front foot drive because the it enables batter to correctly orientate the bat at the impact. The traditional back lift for an off drive is a loop like motion see figure 1, the reason for this is it allows the batter to generate greater velocity (bat speed) (Penn & Spratford 2012). Decent developments in batting have seen changes in the back lift; this development has seen players use their bottom hand wrist to elevate the bat during the backswing see figure 2. The reasons for this are it enables the bat to stay close to the centre of mass which makes the bat feel lighter. Another reason for this action is will decrease the rotational inertia of the movement which means the movement is quicker than the traditional approach, allowing them to hit the ball later (Hurrion 2009).

Figure 1                                                                                   Figure 2

       The loop motion in the                                                 the new short back lift batters

        traditional back-swing                                                 are adopting to give the more 

                                                                                                time to hit the ball.      

                               

Forward stride

A good forward stride is significant part of the front foot drive because this enables the batter to move the centre of mass to the front foot which helps with transferring the summation of forces in the front foot drive, the heavy body parts move first, then the light ones move after, which helps with transferring body energy forward and into the bat (Hurrion 2009). A study of experienced batsmen showed that they all take a short to medium stride to execute the drive because this enables them to play the ball later. Transformation from the stable base to the front foot is achieved through the stride forward with flexion of the front knee and raising the heel of the back foot (Sarpeshkar & Mann 2011).

Down-swing

The downing swing should consist of a pendulum movement with the bat and hands following the line of the ball. The hands and arm initiate the downward swing of the bat (Penn & Spratford 2012). As was discussed earlier the back swing plays an important role in the down swing because if the back lift is short, obviously the down-swing is going to be short in comparison with a big back lift has a bigger down swing. During the down swing the body position should keep a stable base and a high elbow as is seen in figure 3, then front arm should then straighten from this position.

Figure 3

                                                  shows the correct body position for the drive

Bat –Ball Impact

When a batter is about to makes contact with the ball during the front foot drive it is important they have a stable base throughout the shot. This stable base enables the batter to produce enough force behind the ball to score runs. The head of the batter should be over the top of the ball when the shot is played. When the bat hits the ball this is known as the coefficient of restitution, this is the proportion of total energy that remains with the colliding objects after the collision (Blazevich 2013 p. 117). In the process when the ball hits the bat it compresses against the bat, comes to a complete stop, expands back to its original shape and then leaves the bat to the position it was hit. To hit a perfect ball it has to come out of the ‘sweet spot’ this is about 150 mm from the bottom of the bat  (see figure 4) where the bat is its thickest point. ‘The sweet spot’ is actually known as the fundamental vibration node and the centre of percussion. When the ball hits the node spot it causes no vibrations and it feels good when you hit the ball, the closer the ball hits to the node spot the less vibration happens, hitting the node spot make the ball go further. Most points on the bat have spots that will cause the bat to vibrate. The higher up the bat near the splice the ball hits causes more vibrations, the vibrations persist well after the ball has left the bat (Physics of Cricket 2005). One interesting point when discussing the bat – ball impact is that when a bat is not knocked in the coefficient of restitution is affected, increasing the bat stiffness decreased the coefficient of restitution. Knocking in a bat is helps squeeze the wood fibres together which hardens the bat and helps lessen the vibration of the bat.

                                                                            Figure 4

                                                              Demonstrates the 'sweet spot' fundamental 

                                                           vibration node and the centre

                                                                of percussionon the bat 

The follow-through

A full follow through is important in getting maximum velocity from the bat. The follow through is also important because after the ball is hit the bat retains 95% of its speed so it is important that the bat has time to slow down naturally in the motion, this also helps with injury prevention (Stretch, Bartlett, & Davids 2000).

Correct technique and the kinetic chain.

The kinetic chain of a cricket drive is shown below (figure 5) Dr Paul Hurrion is the England Cricket Biomechanics Tutor he explains that ‘to apply power in the shot, the individual must set the base of support, so that he / she can step into position, stop (no further movement) then stabilise the specific joint, working from the ground up, looking at; ankle, knee, hip, pelvis, torso, shoulders, arms, then finally bat. This I refer to as the five S’s’ (Dr Paul Hurrion 2009).

STEP / STABILISE / SHOULDERS / SWING / STRAIGHT

                                                                                   

Figure 5

The Kinetic chain of the front foot drive

English Cricket Ian Bell playing a front foot drive

What is the best back-lift to use when playing the front foot drive?

There are two types of backswing the short back-lift (using the wrists and a fulcrum) and a long back lift (traditional loop motion back lift). This blog will look at each back-lift and determine which one will be more effective form of back-lift for the front foot drive.

Short back -lift

A study on the different back swings found the a short back swing will cause a short downswing and therefore the down swing to impact time is 0.16 seconds, comparatively a study of traditional loop like motion  found the downswing to impact was 0.21 seconds showing it is considerably longer. What is important about this is the short backswing enables the batter to have a slightly longer time to perceive the ball flight and decide on the shot. The short back-lift has the toe of the bat high and close to the body; this helps with the mass of the bat because it is close to the axis of rotation which aids with the angular acceleration of the bat. The short back-lift uses the bottom hand wrist to assist the bat into a good angle of incidence which helps when hitting the ball because more of the face is in line with the ball and therefore the batter is likely to make contact with the ball (Stuelcken, Portus & Mason 2005). Although there are many positives to hitting the ball with a short back swing they do not get the same amount of power and the traditional loop like motion. There are certain things a person can do to improve the speed of the bat and hit the ball further these are;

·         Increasing the mass of the bat, this helps with gaining the momentum behind the stroke, but it is important that the bats weight does not affect the batsmen ability to swing it quickly (Blazevich 2013 p. 122).

·         A player can increase the speed of the bat by increasing the axis of rotation, this can be done by holding the bat closer to the top of the bat, the causes the bat(lever) to be longer which in turn means the bat has more distance to travel causing more speed (Blazevich 2013 p. 2).

Long back lift

The Traditional back lift in cricket in a loop like motion see in figure 1. In this back lift the player takes the bat back on an angle pointing to second lift and they then whip it round in a loop motion and play a shot. This motion allows plenty of bat speed and velocity. One of the main problem found with this action is there can be some variation in the swing of the bat in the loop which can cause the bat to come through at varied angles which can cause some difference from the same shot(Paul Hurrion 2009).

The recent research into cricket indicates that a using a short back-lift with the bottom hand wrist assisting to elevate the bat during the backswing is the most effective form to use. It enables the batter to still generate enough velocity behind the bat along and the speed of the ball from the bowler allows the batter to effectively hit the ball with enough force to score runs. Using a short backswing in cricket also lets the batter to play the ball later which is important in cricket because they then have more time to determine the swing, movement off the pitch and spin which is important information to know before the batsmen decides on the shot selection and plays the shot. The short back lift also follows a straighter line than that of the loop like motion, which enables then to use a more of the face of the bat which increases the contact zone the ball can hit.

How important is grip in the front foot cricket drive?

Many studies on cricket batting have looked at the kinematics and the kinetic chain involved when playing the shot, but little attention is paid to the grip. This blog will use the research done on the grip and determine how important the grip is when playing a front foot drive? The grip is important in cricket because players can improvise the grip to control the rebound velocity, this enables them to manipulate the ball into free areas on the ground and score runs (Glazier, Davids & Bartlett 2002). Studies into cricket determine that the top hand grip is the dominate hand in cricket, with the bottom hand helping with the execution of the shot.  Research found that the grip force is different between the top hand and bottom hand, the top hand grip is tighter than the bottom hand. It was found that grip force was tighter just before bat-ball contact and decreased during and after impact (Penn & Spratford 2012).

Who else can use this information?

This information could be used by a both golfers and baseball players alike, both of these sports like cricket use a kinetic chain to hit the ball. Golfers have similar swings to the loop like back swing. Often golfers will over complicate the back swing and have unnecessary movements with the club head that can cause a varying swing of the golf club which leads to an inconsistent performance. So if a golfer is having trouble with the golf swing it may help to record their back swing to see if they are getting a consistent loop like swing. One of the major differences between golf and cricket, is in golf the ball is hit from a stationary position, although the swing speed plays an important role in golf it is not as important compared to cricket, therefore they can take a little longer to hit the ball. The baseball batter like the cricket batter has to have an effective and quick batting action to make good contact and effective contact with the ball. The baseball bat also has a ‘sweet spot’ like in cricket if you can find the sweet spot the ball will go further. The swing and grip in baseball is also important similar to cricket the batter can shorten the swing and grip. This is often done when a pitcher is pitching so the ball so fast, the batter cannot make contact with the ball. To compensate for this the batter will often shorten the backswing and grip the bat further down the handle; this makes the swing shorter so they are not being beaten by the pace of the ball. The only problem with this is they reduce bat speed from the shorter back-lift, with the shortening of the bat length the batter shortens the lever of the bat which also reduces the velocity they can get behind the bat.   

Reference list

A. Stretch, R., Bartlett, R., & Davids, K. (2000). A review of batting in men’s cricket. Journal of Sports Sciences, 18(12), 931-949.

Blazevich, A. J. (2013). Sports biomechanics: the basics: optimising human performance. A&C Black.

Glazier, P., Davids, K., & Bartlett, R. (2002). 19 Grip force dynamics in cricket batting. Interceptive Actions in Sport: Information and Movement, 311.

Stuelcken, M. C., Portus, M. R., & Mason, B. R. (2005). Cricket: Off‐side front foot drives in men's high performance Cricket. Sports Biomechanics, 4(1), 17-35.

Paul Hurrion (2009) Cricket Batting 1 - Batting is a side-on game – or at least it used to be. retrieved from

http://www.quintic.com/education/case_studies/Cricket%201.htm

Paul Hurrion (2009) Cricket Cricket Batting 2- Balance & Stability, the key to power & consistency in batting. retrieved from

http://www.quintic.com/education/case_studies/Cricket%202.htm

Penn, M. J., & Spratford, W. (2012). Are current coaching recommendations for cricket batting technique supported by biomechanical research?. Sports Biomechanics, 11(3), 311-323.

Physics of Cricket.  Retrieved from http://www.physics.usyd.edu.au/~cross/cricket.html

Sarpeshkar, V., & Mann, D. L. (2011). Biomechanics and visual-motor control: how it has, is, and will be used to reveal the secrets of hitting a cricket ball. Sports Biomechanics, 10(4), 306-323.

Singh, H., & Smith, L. V. (2008). Describing the Performance of Cricket Bats and Balls. In Washington State University Conference.