Should one incorporate rotation exercises into strength training to get strong hips?

Question

Consider a right punch (cross) from boxing (1):

hip extension at the rear leg causes a forward momentum of the body that has to be countered by an extension moment at the front knee. This hip extension is the source of much of the power of the punch, especially in the start of the punch.

However a punch is not a forward motion, as much as a rotation both of the pelvis and the thoracic spine:

If we compare the foot position in the final position of the punch with the starting foot position:

we notice that the rear leg has moved from external rotation into internal rotation. This is performed as a pivot on the ball of the rear foot. During this phase of the punch the hip extensors and the internal hip rotators of the rear leg work together to produce the hip rotation. This phase (which precedes the images) is called "hip drive".

The phase when the punch is being delivered is called the "brake". During this phase the boxer has to counter forces trying to push him out of his stance. The pelvic rotation wants to rotate his front foot counter clockwise. He has to counter this by applying an internal hip rotator momentum (isometric) on the front leg. Likewise the pivoting of the rear leg causes a rotational momentum that wants to rotate his rear foot even further counter clockwise. He has to counter this with an external hip rotator momentum (isometric) on the rear leg:

The biomechanics of a javelin throw (2) is quite similar to those of a boxing punch:

"The right hip acts as the “accelerator”, and the left side acts as the “brakes.”"

"The acceleration of the right hip comes from acetabular/femoral internal rotation (AFIR) and extension."

"The brakes of the hip drive are left side AFIR, abduction, and extension."

This therefore seems like a fundamental human movement pattern. Typically this movement is not trained in common strength training programs. Most other fundamental human movement patterns like the hinge and squat are. Following the philosophy of "use it or loose it" I think this may be a bad thing.

I am thinking that this maybe causes weak hips which in turn causes tight hips?

Should one incorporate rotation exercises into strength training? If so, how?

Further during running hip rotation also play an important role. However when running the thoracic rotation is in the opposite direction of the pelvic rotation (3):

"Rotation of the hips (pelvis) in the transverse plane (think: spinning around in circles) is the key to running faster and more efficiently."

"If there is minimal transverse hip rotation, the role of the glute max is minimized."

(1) The Biomechanics of a Knockout Punch

(2) Dynamics and Demands of the Hip Drive and Block in Javelin Throw

(3) It’s All in the Hips

Answer 1

[A boxing straight punch,] like in the gait it seems that when one leg is internal rotation the other one is in external rotation.

This photograph actually shows the rear leg in internal rotation. His knee is pointed forwards, whereas external rotation would have it pointing outwards. If the rear foot was planted with the heel down, then the movement of the hips would cause external rotation of the femur, but it's much more common in boxing to pivot on the ball of the rear foot, effectively internally rotating the rear leg in compensation for the movement of the hips.

It's also worth noting that during the strike, the internal rotation of the front (left) leg does not come from the left hip internal rotator, it comes from extension of the right hip. You can experiment with this yourself by trying to throw a straight right with your rear foot lifted off the ground, causing the rotation of the torso to come entirely from the left hip internal rotator. This is a very different feeling, and a much weaker movement.

It therefore seems to me that the a right punch from boxing is closely related to the gait?

No, because they only appear related if you ignore all the other hip movements occurring at the same time that differ completely between these two movements, and focussing only one one particular articulation within a three degree of freedom joint. In gait, you have the pelvis in a mostly stable movement (i.e. not undergoing acceleration), with the legs moving through unloaded hip flexion followed by loaded hip extension, with a barely perceivable. In a punch, you have the balls of the feet fixed in position extension of the rear hip is used to drive a powerful rotation in the torso.

I would also think that shotputting, throwing a baseball, hitting a baseball etc. would biomechanically be the same movement as a right punch?

Shotputting is a very different movement, involving spinning of the whole body while hopping from foot to foot. Throwing a baseball and swinging a bat are different because they don't have the requirement to withdraw the punch and return the the starting, stable position, so a pitcher or batter can let the swing take them off balance and shift their weight entirely onto one leg.

This therefore seems like a fundamental human movement pattern.

To reiterate, not if you've isolated hip rotation from the other movements which it is occurring in concert with. Then it's just an isolated articulation.

Typically this movement is not trained in common strength training programs. Most other fundamental human movement patterns like the hinge and squat are. Following the philosophy of "use it or loose it" I think this may be a bad thing.

It's pretty rare for any sport to actually require loading of the hip rotators (recalling that the hip rotation in boxing is performed by the much stronger hip extensors, not the hip rotators), so hip rotator strength is not a concern for most athletes. In those that do require rotation, which is pretty much only those that require rotation with one leg off the ground, they'll generally get far better training from just performing their sport than they would from deliberate resistance training of the rotators. E.g. a kickboxer would use their internal rotators in throwing a roundhouse kick, but they wouldn't get a good training effect from swinging a kettlebell, because the speed of contraction would be so different. They'd get a far better training effect just from kicking a heavy bag.

I am thinking that this maybe causes weak hips which in turn causes tight hips?

Weak muscles do not cause tight muscles.

Should one incorporate rotation exercises into strength training?

No. In the words of Anthony Kiedis, that would be a waste of time.