Share
5th February 2015
03:10pm GMT
Rather than stepping back and keeping the scrum stable, Castro locks his legs, causing him to stand.
By photo three, he's practically upright, while we can see that Healy has maintained a perfect body position from start to finish; body straight, and power coming from his legs.
The scrum results in Johnny Sexton running in under the posts off the first phase, and Castro is subbed moments later.
In November, Italy came up against Argentina, Samoa and South Africa, with Castrogiovanni having a difficult afternoon against his former Leicester team-mate, Marcos Ayerza of the Pumas.
After conceding a free-kick for early engagement in the opening scrum of the day, Castro was lucky not to concede two penalties just after the break for collapsing.
In the first instance, similar to his destruction by Healy, his technique is exactly what you want, with a straight back and a good angle in his legs, with his heels off the ground.
But once Ayerza starts to get the nudge on, Castro can't deal with the pressure, and drops his knees. With Ayerza's technique still perfect, Castro is now scrummaging on his knees, and is really fortunate it's not spotted by Craig Joubert.
Minutes later, this time on an Italian put-in, it's an identical situation, as he collapses under Ayerza pressure.
As usual, he's in a good initial position, but once the drive comes on, he goes down to his knees before causing the collapse, which Joubert inexplicably misses.
Castro starts this Saturday for the Italians, and Ireland should be looking to target him, with a younger, powerful loosehead in Jack McGrath well capable of turning his legendary opponent inside out.
Dario Chistolini (Tighthead)
Castrogiovanni may be the first choice tight-head, but Dario Chistolini is a much more awkward opponent.
The 26-year-old made his debut during last summer's tests and featured in all three of Italy's autumn internationals. He replaced Castrogiovanni against Argentina, when his carelessness resulted in an Pumas try within seconds of entering the pitch.
Warned by Joubert about his binding as he packed down for his opening scrum, Chistolini tried to pull down Ayerza by the arm and conceded a penalty, which was taken quickly and turned into seven points for Argentina.
In the previous game against Samoa, however, Chistolini proves his strength.
In this scrum, the Zebre prop shows great power and skill to remain perfectly straight, despite the attempts of Samoa's Zak Taulafo to drive in at an angle on him.
In the opening still, we can see that while Taulafo is attempting to drive in at an angle and force Chistolini to pop up, the Italian's technique, combined with his excellent power, keeps his side stable.
And when Taulafo exaggerates his angle further, Chistolini doesn't budge, causing the Samoan to drop the scrum and handing the Italians a penalty.
Matias Aguero (Loosehead)
Another Zebre prop, and this one is set to start at loose head.
Aguero wasn't part of the side that was hammered at the Aviva 11 months ago, but started all three games in the autumn. He is a player Ireland should be targeting, with a fondness for the less legal aspects of scrummaging.
In Italy's defeat of Samoa, he started well, winning this excellent penalty from Anthony Perenise, keeping a straight, upright body when Perenise started to drive in at an illegal angle.
In the second picture, keep an eye on the differences in angle between Perenise and his front-row team-mates, while Aguero keeps an ideal body position to win the penalty.
However, as the game progresses, Aguero's good start goes out the window.
As Perenise displays a strong stance, Aguero tries to come up and under his opponent's chest, driving at an angle.
And as the scrum develops further, the angle only becomes more pronounced, to the point that when the scrum collapses, Aguero is almost parallel to his opponent, with his backside pointing to the heavens.
Steve Walsh didn't give a penalty, but he did a few minutes later, when Aguero pushed the limit too far.
As we can see in the initial photo, Perenise and Aguero are lined up perfectly, and there should be no reason for this scrum not to be solid.
But as we can see in picture two, while Perenise's body position has remained as it was, Aguero's has changed dramatically, as he bores across his opponent.
This time it's spotted by Walsh, and a Samoan penalty arrives.
He had a less eventful game the following week against Argentina, however, displaying some decent technique that could trouble Ross in particular, who struggles against opponents who can get as low as this.
In this first half scrum, he keeps his body incredibly low to the ground, using some excellent footwork to keep his hips in line with his head. Italy eventually win a penalty on the far side after Marcos Ayerza collapses in at an angle.
As we can see, he does brilliantly to stay upright, despite the attempts of his opponent to pull down his bind.
Aguero starts this Sunday, and Mike Ross will get the better of him if he keeps his driving straight and legal, allowing McGrath to attack on the opposite side.
But if they follow Aguero and attack too much, the Italian could cause them problems.
Alberto De Marchi (Loose and Tighthead)
Italy head-coach Jacques Brunel has only named four props in his squad, with the versatile De Marchi able to pack down at loose and tighthead (although loose is his preferred position).
The Sale Sharks prop started against Ireland in last season's Six Nations, and had very little impact, appearing on both sides of the scrum. He started at loosehead and struggled against Ross as Ireland's scrum, then under the tutelage of John Plumtree, won all eight of their own put-ins and caused trouble for the Italians on their ball.
In this first-half drive, we can see how Ireland's pack are all driving in the same direction, causing Italy, with De Marchi at loosehead, to move backwards, and cough up possession.
As they attempted to counter the strong Irish drive later in the game, De Marchi began bending the rules to give himself a chance in the scrum battle, but again, Ross's technique is far too good.
In this opening photo, we can see how Ross is under a lot of pressure due to De Marchi's efforts to drive him in at an angle, something Nigel Owens should really be spotting.
But as the scrum develops, Ross pushes the weight back at De Marchi, correcting things.
As he drives forward, we can see how Ross's body position has remained perfect, and the attempt to con the referee backfires on De Marchi.
After being replaced in the second half, De Marchi comes back onto the field for the final 10 minutes, this time at tighthead, and things don't go any better for him on that side of the scrum, as he gets driven back several feet before his side concede a penalty.
While a lot of scrumwork comes down to individual errors, this penalty is a result of a team push from the Irish, leaving the Italians no option but to break up and relieve the pressure.
The initial photo shows the sides just as Eoin Reddan feeds, with both sides of the scrum looking steady.
But once the Irish begin to drive, the Italians completely break up and, as we can see in the second photo, when the penalty does arrive for the Italian second row leaving the scrum (circled in yellow), Jack McGrath has driven back De Marchi (red) by about three or four yards.
The Irish scrum may have lost Plumtree since that hammering of Italy last March, but if they remain disciplined against a side that likes to test the referee's limits, it can be just as effective a weapon as it was last season.Explore more on these topics:
