Just because you can’t see it in the mirror, doesn’t mean it’s not important. The poor old Latissimus
Dorsi doesn’t get much respect, but it does an awful pile of work. This is because it is part of a myofascial chain referred to in the work of Thomas Myers as the Back Functional Line. This sling of connective tissue and muscle drapes its way across the back of the body from the top of the arm all the way down to the opposite knee. In actuality, the fascial connections stretch even further in both directions depending on the situation.
And you don’t need to be involved in elite sport to experience the work of the BFL! Something as
innocuous as shoveling snow places significant demands on this line of tension. In this picture you can at least envision the line of tension running from the gluteus maximus of the left leg (your right in this mirror image) to the contra-lateral shoulder, including the latissimus dorsi. Next time you are shoveling snow, pay attention to the feeling in your back on the side of the hand which is lower down towards the bottom of the shovel. You will be able to feel the activation, especially of the lower fibers of the muscle.
Obviously, any movements involving pulling with the arms will also involve the lats, especially anything from overhead like a pull-up. This is because a major job of the lats is extension of the humerus. But you don’t need to be using the lats as prime movers in order to put great load on them. They are also a powerful s
tabilizer of the shoulder architecture. I have been working a lot lately with exercises designed to build up towards being able to do a planche. This requires great strength of the pectoralis major and especially of the anterior deltoids. But if those muscles are pulling towards the
front, the lats have to be stabilizing to keep the joint locked down and back. And they are working dang hard at it too. The day after my strength day, which contains absolutely no targeted work for the lats, they are probably the most sore of all my muscle groups, just from the isometric effort of stabilization.
Because I am putting the lats under such load, I want to make sure that I am compensating for that work. I don’t want them to become chronically shortened and leathery, so I have to release the tension, open the muscle so that it can recover properly. One of the best ways I have found to do so is an exercise I was introduced to by Coach Scott Sonnon. It is a screwing Downward Dog movement which needs to be seen to be understood. And it just so happens that I found some footage of the master himself performing the exercise:
You can see that from the Downward Dog position, Coach Sonnon alternately rotates one arm externally while lowering the same side elbow towards the mat. At the same time he keeps the back neutral and the contralateral heel on the mat. So how does this release the lat? To answer that question you need to understand a couple of points. The first is the sling of muscle and connective tissue referred to earlier. This Back Functional Line is a fundamental factor in the movement. By keeping the heel down and the back neutral, you are putting the entire line on stretch as you move the elbow down towards the mat. This is because the line stretches right from the contralateral foot, up the tibialis anterior, into the vastus lateralis and the gluteus maximus, across the sacral fascia into the lubodorsal fascia, up into the latissimus dorsi and then carries on into the triceps via a connection with the Deep Back Arm Line.
But why the external rotation of the arm? For that you have to understand a bit about the functional
anatomy of the Lat. As you can see in the accompanying photo, the insertion of the muscle is on the
anterior side of the humerus. This means that it is both an extensor and an internal rotator (it also has the capacity to aid in spinal extension - but that is beyond the scope of this discussion). So by externally rotating the humerus at the same time as you lengthen the functional chain of muscle and connective tissue you stretch and release the latissimus dorsi even more.

So don’t be scared to screw up your Downward Dog if you want to keep your lats happy and healthy. They are big muscles that get little respect. Treat them well!