I previously profiled a client in Examples of posture indicating movement. That client was having some upper back issues.
They had some good lower back extension going on, as well as an upper back rounding forward.
This was prevalent during other activities, like a plank exercise:
Being younger helps, but this client also picks things up quickly. As they were feeling good, we progressed pretty fast into some exercises making it even tougher to control the spine. In this person’s case, preventing the hips from falling in front of or below the shoulders. In other words, we wanted to prevent the hips and shoulders looking like they do above.
They started doing what’s below. Notice the hips never falling below the shoulders. In effect, we have a dynamic plank going on:
We didn’t do much pulling the first month (more rationale behind that here), but then we started and within a few months were doing this:
The reason behind the knees being forward is not only to save space. When the feet go behind the torso it’s common for the lower back to significantly extend:
First, we know this person already extends their lower back too much. We don’t want more of that movement.
Second, the latissimus dorsi is a commonly overactive and stiff muscle. Especially if the lower back is in extension and or shoulder mobility is limited.
The lats connect from the shoulder all the way down to the lower back:
Muscles pull their attachments closer to one another. The lats pull the arms down, and the back of the hips up. That is, they extend the lower back.
Therefore, when the arms are overhead -when the lats are attempted to be stretched at their shoulder connection- if the lower back extends, the lats don’t stretch as much, if at all.
Think a rubber band. Hold one side in each hand. Pull both ends apart and obviously it stretches.
Pull your right hand away from your left with the left stationary. The band also stretches.
But pull your right hand away from your left, bringing your left hand to the right at the same time, and the band loses any stretch.
With chin ups or pull ups, we end up with a double whammy when this happens.
At the bottom here we want the lats to be fully stretched. This way we stretch the lats a good deal even in a movement which significantly works them. However, with the arms overhead, the shoulder connection is being stretched, but with the lower back extended, the lat isn’t fully stretched. This is happening:
Then at the top here, the lats are being tightened more than needed. The arms are being pulled down and the lower back is extending.
By bringing the knees forward the lower back flattens, we don’t tighten the likely already stiff lats, we avoid a motion many already do too much (lumbar extension), and we get a solid abdominal (and hip flexor) workout.