The four main elements are depicted here very clearly;
1. They are both striking the ball at the "equator" or midline of the ball;
2. They are striking the BALL, with the inside of their foot;
3. They are keeping their ankles locked and firm;
4. Lastly, they are concentrating on the ball.
Ideally they would be leaning into the ball a little more and as a result getting their center of gravity and mass a little more behind the ball, but this is a very good example of a block tackle.
The key elements are the ones listed above, but I stress items 1 and 3. Strike the ball at the "equator" and keep your ankle locked. It will result in more successful challenges and less injury.
Bring on Manchester United, the FA Cup is for the taking!!!
Walk On
Hal White
YNWA