Rotational training often gets overlooked as a very effective means to build injury prevention to the knee, but I think it is crucial to see such training in that way. Especially in light of the fact that when many people employ rotational training they often do so with flat feet on the ground the entire time.
Not creating a deliberate pivot into the ground that allows rotation to occur at the hips (the joint with WAY more rotation to it than the low back ) not only makes our rotational training less effective, but places way more stress upon the knee in very unnatural ways. The knee typically doesn’t handle large rotational forces acting upon it, that is why patterning good rotational training will enhance our movement, mobility, power, and keep us healthy at the same time.
A 2012 paper in the Journal Of Strength & Conditioning gives some important explanations..”Creating rotational power in the torso is problematic for enhancing performing while improving injury prevention. Power is the product of force multiplied by velocity, or in a rotational sense, twist velocity multiplied by twisting torque. One of these must be low if the other is high. For example, in the golf swing, the twist velocity is high, but the rotational force is low resulting in low power, and low risk. If the twist force is high, then the speed must be low. This same concept holds true for pitching in baseball—observe the motion at the hips and shoulders as there is very little torso twisting. How- ever, if the rotational force is high, then the twisting velocity must be low to keep the torso power low. The implications for training are to stiffen the torso and focus the twist motion about the hips and shoulders.”
These progressions of teaching rotational training are key because each tool and drill trains rotation at a different level with various challenges and working on various aspects. The first drill is to teach how to keep the core stable as we rotate through the foot and hip while keeping the torso relatively “quiet”. The rotational kb press increases the challenge because of the greater lever arm. Then the Ultimate Sandbag teaches more reflex stability and power.