What are the optimal biomechanical
techniques of a rugby lineout throw, lift and jump?
The
Answer:
The lineout in rugby union is one of the
most iconic dynamic contests, along with the scrum. A lineout takes place when
the ball touches or passes the line of touch, either while being carried by a
player or not (World Rugby, 2016a). The lineouts purpose is to restart play by
throwing the ball between two lines of competing players. The image below shows the standard set-up for a lineout, including offside rules.
There are three individual biomechanical components that make up a lineout: the thrower, the jumper and the lifters. If one component doesn’t function effectively, the team in possession will likely turn over the ball.
The lifter at the back has a different approach because they are in a position where they might have to move or switch with other players. Just before the jumper takes off, the back lifter will move their outside leg and step to the outside of the jumper, facing their back to the opposition. This position prevents the opposition team from interfering with the jumper. The back lifter will squat down with an upright back and grip the jumper’s glutes in a “bucket seat” grip. This grip is optimum for the back lifter because it provides a secure grip at the highest possible point on the leg. If the lifter grabbed the jumper’s shorts, they might not have a secure hold and drop the jumper, and they lose a few inches of possible height as shown in Video 2 and 3. The bucket seat grip allows the jumper to sit in the lifter’s hands so they can comfortably catch the ball.
The back lifter goes through the same process, however they will step forward on an angle and are not required to squat as low because of the higher grip position, as shown in the image to the left. Both lifters step towards each other almost nose-to-nose with their legs and arms fully extended. By moving closer together, the lifters move the jumper’s centre of mass over their head, allowing them to hold the jumper efficiently for long periods of time if necessary (Blazevich 2010e; Blazevich 2010f). This position provides optimum height and stability for the jumper.
Attacking lineouts are able to win collisions
after getting pushed back because more players will join the maul and add their
mass, momentum and velocity to overpower the opposition (Blazevich, 2010g). Not
every player from the opposition forward pack can join the maul because they
have to be ready to tackle the player with the ball, who can break
away from the maul. This is shown clearly in the image of the entire Springbok pack pushing back a smaller number of Samoan players. The aim of the lifters is to get their height lower than
the opposition and then drive upwards. This will reduce the friction force that
the opposition player can maintain on the ground and their boots may slide
(Blazevich, 2010h). If the opposition player’s boots cannot maintain full
contact with the ground, they will not be able to sustain an optimum ground
reaction force to resist the momentum of the attacking maul (Blazevich, 2010d).
(Talking Rugby Union, 2015)
Video 5: Demonstrating a lineout throw, and the catch and throw phase of a lineout jumper from the player's perspective (Global Rugby, 2014a).
Essentially the main difference between the two sports is the load that is being lifted; in weightlifting the load is a barbell of varying weight that rests on the ground, while the load in rugby is a human that is lifted while in the air.
(Bishop, 2014)
Additionally, the jumping/catching stage is similar to what is commonly seen is the sport of AFL, in order to take a mark above an opponent. The main similarly between these two sports results from both players being required to watch the ball in the air and catch it with thumbs touching and fingers spread out.
The jumping phase from a rugby lineout occurs in restricted space, which can happen in AFL when marking the ball in a pack. Through an understanding of the forces at play regarding a lineout in rugby, coaches and athletes from a wide range of sports are able to pursue a more efficient and effective technique model.
Demonstration:
Sayers, M. G. L. (2011). Kinematic Analysis of Line-Out Throwing in Elite International Rugby Union. Journal of Sports Science & Medicine, 10(3), 553-558.
There are three individual biomechanical components that make up a lineout: the thrower, the jumper and the lifters. If one component doesn’t function effectively, the team in possession will likely turn over the ball.
Set-up
phase of lineout thrower:
The lineout throw is specifically
delivered by the hooker in the team, who will move to where the linesman is
standing. The hooker will stand on the sideline with their feet shoulder width
apart for balance. The images below show that the hooker will grip the ball with their dominant hand at the
bottom, with their fingers on the seam, and the other hand at the top.
(Global Rugby, 2014a)
The thrower will flex their elbows so
that the ball is hovering over their head. The angle of flexion in the elbows
and how close the elbows are to the head will both change the amount of
potential energy (Blazevich, 2010f). Some players may rely on a greater range
of motion in the extension of their arms in order to generate more power, while
others will focus more on explosive plantar flexion and the transfer of energy
though the legs to the arms.
Video 1: English test forwards Tom Youngs, Dan Cole and Tom Wood explain the various techniques of the lineout (QBERugby, 2012).
Video 1: English test forwards Tom Youngs, Dan Cole and Tom Wood explain the various techniques of the lineout (QBERugby, 2012).
Release
phase of lineout thrower:
The lineout throw is a whole body
movement where energy is transferred from the feet all the way to the hands to
produce a powerful whip-like motion as demonstrated by Video 1 and the stills below. The thrower will begin by moving the ball
behind their head and arching their lower back. They will then rock forward by
exploding off the balls of their feet using their calves and gluteal muscles, while flexing their
abdominal muscles to straighten their back. This increases the impulse-momentum
relationship on the ball due to the propulsive impulse of plantar flexion
(Blazevich, 2010d). When the thrower rocks forward, they will extend their
elbows and wrists sequentially at the peak of the motion in a throw-like
movement pattern (Blazevich, 2010i). They will violently slide the fingers of
the dominant hand down the ball in a “ripping” motion to produce rotation and
make the ball spiral through the air to reduce wind resistance. The violent movement of the fingers
produces significant torque on the ball which is optimal to produce a high
number of revolutions (Blazevich, 2010e). The thrower will follow through with
their hands and fingers outstretched to assist guiding the ball in a straight
line. Once the ball is released by the thrower, the kinetic energy of the throw
can be calculated by measuring the mass of the ball and the velocity of which
it travels to its target (Blazevich, 2010f). There isn’t an optimal projection
angle for the lineout throw like other sports, as the height of the target
changes along with the height of the thrower. Projection speed is very
important to reduce flight time and also increase distance if the ball needs to
travel to the back of the lineout (Blazevich, 2010b).
Set-up
phase of lineout lifter:
There are two lifters in a lineout,
therefore there are two different set-ups. The lifter at the front of the
jumper stands with their back towards the thrower, while the lifter at the back
stands behind the jumper with a hand on their backside, facing the opposing
team. This is not the optimum starting position to lift a human off the ground,
however this is required due to the complex dynamics of the lineout contest.
Video 2: Former All Black hooker and current Sunwolves head coach Mark Hammett instructs players on lifting positions and techniques for both lifters, as well as jumping techniques (Coblentz, 2011).
The “pod” of the two lifters and jumper may have to move backwards or forwards depending on where the ball will be thrown. When the front lifter is just about to lift, they will get into a crouched position with a flat back, similar to the starting position of a deadlift. The lifter will grip the jumper’s legs on the outside, squeezing the legs together. Video 2 discusses how this grip is very functional because it prevents the lifter’s arms being slapped down, as well as keeping the jumper’s legs from splaying apart. When the player jumps, the force of pushing off the ground will cause an opposite reaction moving the legs apart; the vice grip nullifies the effects of Newton’s Third Law on the legs (Blazevich, 2010c).
Video 2: Former All Black hooker and current Sunwolves head coach Mark Hammett instructs players on lifting positions and techniques for both lifters, as well as jumping techniques (Coblentz, 2011).
The “pod” of the two lifters and jumper may have to move backwards or forwards depending on where the ball will be thrown. When the front lifter is just about to lift, they will get into a crouched position with a flat back, similar to the starting position of a deadlift. The lifter will grip the jumper’s legs on the outside, squeezing the legs together. Video 2 discusses how this grip is very functional because it prevents the lifter’s arms being slapped down, as well as keeping the jumper’s legs from splaying apart. When the player jumps, the force of pushing off the ground will cause an opposite reaction moving the legs apart; the vice grip nullifies the effects of Newton’s Third Law on the legs (Blazevich, 2010c).
The lifter at the back has a different approach because they are in a position where they might have to move or switch with other players. Just before the jumper takes off, the back lifter will move their outside leg and step to the outside of the jumper, facing their back to the opposition. This position prevents the opposition team from interfering with the jumper. The back lifter will squat down with an upright back and grip the jumper’s glutes in a “bucket seat” grip. This grip is optimum for the back lifter because it provides a secure grip at the highest possible point on the leg. If the lifter grabbed the jumper’s shorts, they might not have a secure hold and drop the jumper, and they lose a few inches of possible height as shown in Video 2 and 3. The bucket seat grip allows the jumper to sit in the lifter’s hands so they can comfortably catch the ball.
Lift
phase of lineout lifter:
When the lineout is called, both lifters
will step towards the jumper so the jumper can jump vertically instead of
forwards or backwards. It is very important that the lifters explosively push
upwards when the jumper is off the ground to reduce the effects of inertia and
gravity as the jumper has momentum moving vertically (Blazevich, 2010c;
Blazevich, 2010d).
The front lifter will squat down, grip
the jumper’s legs and explode upwards using the gluteal muscles and quadriceps.
The squat movement is a push-like movement that produces a large cumulative
force due to the torque on the hip, knee and ankle joints (Blazevich, 2010i).
At the same time, they will push the jumper’s legs upwards using the deltoids
and triceps, locking out the elbows at the top of the lift.
Video 3: Springbok and Durban Sharks prop Tendai Mtawarira performs a one-man lift on Anton Bresler. This demonstrates both the power of locking out the push-like movements, and the disadvantage of gripping a player by the shorts (Theh Mageza Ndlovu, 2012).
Video 3: Springbok and Durban Sharks prop Tendai Mtawarira performs a one-man lift on Anton Bresler. This demonstrates both the power of locking out the push-like movements, and the disadvantage of gripping a player by the shorts (Theh Mageza Ndlovu, 2012).
The back lifter goes through the same process, however they will step forward on an angle and are not required to squat as low because of the higher grip position, as shown in the image to the left. Both lifters step towards each other almost nose-to-nose with their legs and arms fully extended. By moving closer together, the lifters move the jumper’s centre of mass over their head, allowing them to hold the jumper efficiently for long periods of time if necessary (Blazevich 2010e; Blazevich 2010f). This position provides optimum height and stability for the jumper.
The set-up of the lineout lift is not very
conducive to harnessing potential energy for a lifting motion as it is designed
for the lifters to change position and react quickly. If the jumper had to move
towards the lifter, then gathering potential energy would be more important.
However, kinetic energy plays a big part in a successful lift because the
lifters have to be fast and explosive when moving to the jumper, squatting
down, and exploding up with the legs. The faster a player moves; the more
kinetic energy they can transfer into the lineout jumper (Blazevich 2010f). Lifters who are able to rapidly accelerate through their ankles, knees, hips, shoulders and elbows will likely get their jumper in the air before the opposition and therefore win the ball (Blazevich, 2010a)
Catch
phase of lineout lifter:
The catch phase is the reverse of the
lift phase in a standard lineout jump. Therefore, the lifters will flex the
elbow joint and squat down until the jumper has safely made it to the ground as seen below.
Video 4: Demonstrating a complete lineout lift and jump with slow-motion footage, and explanations of technique phases (Global Rugby, 2014b).
Video 4: Demonstrating a complete lineout lift and jump with slow-motion footage, and explanations of technique phases (Global Rugby, 2014b).
The goal is to bring the jumper’s centre
of mass as close to the lifter’s body as possible so the pressure is placed on
the lifter’s more powerful quadriceps instead of the weaker deltoids
(Blazevich, 2010e). The catch phase becomes more complicated if the jumper is
thrown into the air, meaning the lifters are no longer gripping the jumper’s
legs. This technique will allow the jumper to achieve maximum height to catch
the ball, however there is potential for the jumper’s legs to splay or they
might fall forwards or backwards as their centre of gravity changes (Blazevich,
2010c). It is imperative that the lifters secure a grip in the jumper as soon
as possible to prevent accident or injury.
Drive
phase of lineout lifter:
The drive phase is a continuation of the
catch phase, but only if the lineout is progressing into a maul. A maul is
called by the referee when at least one player from the defending team and one
player from the attacking team binds onto the player carrying the ball (World
Rugby, 2016b). This tactic can be very effective as a player can be driven
towards the opposing goal line without the risk of getting tackled by the
opposition. The attacking team will commonly use the lineout maul tactic when a
lineout is called within the 22 metre line. The maul is completed if the ball
is released from the maul, it is collapsed by legal or illegal means, or a try
is scored by the attacking team.
All the jumper has to do once they
secure possession is land safely on the ground with their back towards the
opposition and transfer the ball to a teammate approaching from behind, who will then bind onto the jumper.
The lifters must immediately bind onto the shorts of the jumper with their most
medial arm crossing in front of the jumper’s legs, like in the image below. This position will prevent
an opponent from tackling the legs of the jumper and disrupting the maul before
it can be formed. The lifters will then lower their body height and therefore
their centre of mass, by getting into a position similar to a scrum (Blazevich,
2010e). They will explode into the opposition defenders with a flat back, using
the calves, quadriceps and gluteal muscles to push off while the legs are bent
at a 90-degree angle.
This initial collision with the
opposition will result in the lifters or the opposition being pushed back, this
depends on the mass of the players involved and the velocity they move forward
with. It is common for the opposition to win this first collision by not
competing in the air and waiting for the jumper to return to the ground before
driving into the stationary lifters who have no momentum (Blazevich, 2010g).
The lifters will bind onto the opposition with their free hand during the
initial collision and continue to drive with the legs.
(Talking Rugby Union, 2015)
Low body-height and a flat back in the
lineout drive will increase the potential energy of the lifters as they will be
able to transfer the power from pushing with their legs directly into the
opposition without losing kinetic energy from rounding their back or getting
forced upright (Blazevich, 2010f).
Jump
phase of lineout jumper:
The lineout jumper stays as vertical as
possible before initiating the jump to take up the least amount of space in the
line. The push-like motion begins with violent plantar flexion using the calve
muscles and simultaneous extension of the hips and knees (Blazevich, 2010i).
Although this is not the optimal
technique for achieving height in a vertical jump, the lineout is a dynamic
system where the opposition reacts to jumping cues (such as swinging the arms
or hip flexion) in order to jump for and spoil the ball as explained in Video 2. The powerful
extension of the legs produces a high-cumulative force to push the player off
the ground quickly so that the lifters do not have to move the full weight of
someone in a stationary position. The high velocity that the player leaves the
ground is due to the high propulsive impulse from this push-like movement
(Blazevich 2010d; Blazevich, 2010i). By exploding off the balls of the feet,
the jumper is able to keep their legs straight and conserve vertical momentum
(Blazevich, 2010d). Straight legs are also beneficial for the lifters
maintaining a secure, vice-like grip during the duration of the lift. The force
of gravity that normally returns the jumper to the ground is negated by the
push of the lifters in an equal and opposite reaction (Blazevich, 2010c).
The mass of a jumper and the velocity of
their jump will determine the kinetic energy that the jumper produces
(Blazevich, 2010f). A heavier jumper will produce more kinetic energy, however
it has to be taken into account that the lineout requires a player to be lifted
beyond the height they can naturally jump, meaning increased mass would result
in an overall slower lineout jump. The standard set-up for a lineout is not
optimum for harnessing maximum potential energy because the angle of hip
flexion is too small to build up full power in the legs (Blazevich, 2010f).
However, because take-off speed is paramount in a lineout jump it is not
necessary to have maximum potential energy in the set-up.
Catching
phase of the lineout jumper:
Once the jumper leaves the ground they
begin the second push-like motion which is the raising of their hands from their
chest to catch the ball being thrown above their head. The jumper
simultaneously flexes their shoulders and extends their elbows and fingers
quickly to reach for the ball (Blaevich, 2010i).
Video 5: Demonstrating a lineout throw, and the catch and throw phase of a lineout jumper from the player's perspective (Global Rugby, 2014a).
Throwing
phase of the lineout jumper:
Once
the jumper has possession of the ball, they proceed to a throw-like motion to
deliver the ball to the waiting scrum-half standing five metres to the side of
the lineout as shown in Video 5. The jumper’s torso rotates to face the scrum-half before flicking
their wrists to propel the ball downwards (Blazevich, 2010i). Rotating the
torso is important for generating momentum in the throw, as well as denying the
opposition a chance to directly hit the ball out of the jumper’s hands
(Blazevich, 2010d).
How else can we use this information?
The information contained in this blog can be applied to a range of different sports where similar movement patterns occur. The throw stage of the rugby lineout is very similar to the soccer throw-in that brings the ball back into play.
(Soccer Training Central, 2016)
The movement that occurs in a soccer throw-in has an almost identical motion and requires the same muscle groups (including the calves, gluteals, abdominals and triceps), in order to quickly whip the ball to a teammate.
(Olympic Weight Set Review, 2015)
The lifting stage of the lineout has a strong similarity to Olympic weightlifting. This is due to the fact that both lifts focus on explosive movements in the posterior chain and arms to get a heavy load above their heads.
(Bishop, 2014)
Additionally, the jumping/catching stage is similar to what is commonly seen is the sport of AFL, in order to take a mark above an opponent. The main similarly between these two sports results from both players being required to watch the ball in the air and catch it with thumbs touching and fingers spread out.
(Lienert, 2011)
The jumping phase from a rugby lineout occurs in restricted space, which can happen in AFL when marking the ball in a pack. Through an understanding of the forces at play regarding a lineout in rugby, coaches and athletes from a wide range of sports are able to pursue a more efficient and effective technique model.
Coaching Drills to develop optimum technique:
Now that we have explained the
biomechanical principals necessary to complete a successful rugby lineout
consisting of a throw, lift, jump and catch, we can begin to explore some
drills that are essential in order bring about technical improvement in this
skill. A coach can use the biomechanical principals highlighted in this blog in
order to determine the aspects of a rugby lineout that need specific attention. Below is a list
of basic drills that focus on the various components involved in a standard
rugby lineout.
Bungie
Throw - Aim: This is a stationary drill aimed
at increasing the accuracy and motion of the throw. This is achieved through
increasing tricep strength by the use of a bungie strap that adds resistance to
the extension of the arms above the players head.
Description: The throwing player will
sit on their knees with their elbows flexed so that they are holding the bungie
strap just behind their head. A second player will stand behind holding the
strap. The player will aim to throw/pull the bungie strap with pace and power
and maintain their body shape (Sportsplan, 2016).
Demonstration:
Swiss
Ball – Aim: A stationary drill aimed at
increasing the motion of the throw by developing core activation and
facilitating an effective release phase of the lineout throw.
Description: The player will lie with
their back on an exercise ball, with legs firmly planted and knees bent at a
90-degree angle. From this position the player is unable to make a whip-like
motion, as they are unable to generate energy all the way from their feet to
their body as a result of the exercise ball. The player will pull in their core
that will allow them to flatten out their back before extending their arms in a
throw-like motion and squeezing their gluteal muscles (Sportsplan, 2016).
Demonstration:
Piston
Jumping – Aim: A stationary drill that focuses on
the motion of the jump, the timing and motion of the lift and the timing of the
catch.
Description: The drill is arranged with
four groups of lifters and jumpers standing around a large square. The drill
starts with one jumper who is lifted and held in the air until the next jumper
in a clockwise direction is lifted. When the next pod’s jumper reaches their
highest point, the ball is lobbed from the first jumper to the jumper from the
second pod. Once the ball has been caught they can return to ground, before
being lifted repeating the drill (Sportsplan, 2016).
Demonstration:
Full
Lifts Process – Aim: A moving drill focusing on the
motion of the jump, the timing and motion of the lift and the timing of the
catch. Additionally aimed at developing unit cohesion and communication.
Description: The players will lineup
along a line standing between coloured cones. The coach will then call out a cone colour, making the player between that colour act as the jumping
player. The players on either side are required react quickly to go
through the lifting process. This replicates a game-like scenario where players
have to perform lineouts where the opposing teams player is throwing in. As a
result they have limited time to perform the lineout and must react quickly and
accordingly (Sportsplan 2016).
Demonstration:
Photos: Sportsplan (2016)
Resources
for Biomechanical Analysis and Technical Improvement:
Website: Sportsplan
Website: Sportsplan
Sportsplan is a website that aims to
make coaching easier and more user friendly. You can search for over thousands
of ideas and drills, build and share training plans with other coaches and gain
expert advice from those in the profession.
Price: $6 a month for premium content
Available from:
Available from:
App on Iphone and Android: Coaches Eye
Coaches eye is an app that’s allows capturing of an athletes performance via
video footage. This footage can be analysed and is the most effective way to
provide feedback, allowing technical improvements to occur. This app is very
useful for coaches trying to improve the quality of their sides lineout, as it
is able to record all aspects of the lineout for side by side comparison using
biomechanical markers.
Price: $7.99
Available from: Itunes App store and Google Play store.
Available from: Itunes App store and Google Play store.
Reference
list:
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Blazevich, A. (2010a). Position,
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biomechanics, the basics: Optimising human performance. London: A&C
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Coblentz, B. (2011, November 12). Intro to Rugby: Part 2 - Lifting Skills [Video file]. Retrieved
from https://www.youtube.com/watch?v=yqdVNl3FUyM
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Lienert, S. (2011). Hawthorn surges home to down Fremantle Dockers [Image]. Retrieved from http://www.perthnow.com.au/sport/afl/hawthorn-surges-home-to-down-fremantle-dockers/story-e6frg1xu-1226069613937
Olympic Weight Set Review. (2015). Olympic Weightlifting: Breaking Down the “Clean and Jerk” Step by Step [Image]. Retrieved from http://www.olympicweightsetreview.com/olympic-weightlifting-breaking-clean-and-jerk-step-step/
QBERugby. (2012, November 23). QBErugby 'How To': Lineouts [Video file]. Retrieved from https://www.youtube.com/watch?v=gD5cZ1OPccs
Sayers, M. G. L. (2011). Kinematic Analysis of Line-Out Throwing in Elite International Rugby Union. Journal of Sports Science & Medicine, 10(3), 553-558.
Soccer Training Central. (2016). Learn How to Play Soccer: Master the Soccer Throw In [Image]. Retrieved from http://soccertrainingcentral.com/learn-how-to-play-soccer-master-the-soccer-throw-in/
Sportplan. (2016). Rugby Lineout Drills. Retrieved from http://www.sportplan.net/drills/Rugby/Lineout/practiceIndex.jsp
Talking Rugby Union. (2015). Springboks lay their demons to rest [Image]. Retrieved from http://www.talkingrugbyunion.co.uk/media/img/c/Screen_Shot_2015-09-28_at_12.07.45.png
Theh Mageza Ndlovu. (2012, May 28). Tendai Mtawarira - Rugby Player's Crazy
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World Rugby. (2016b). Maul. Retrieved from http://laws.worldrugby.org/?law=17
