Why "Fire the Lats" in a Kettlebell swing?

When swinging a kettlebell in the RKC Hardstyle, you will regularly hear an RKC instructor say "fire the lats" as an aid to "pack the shoulder" or to keep the shoulder from flying out of its socket

(is Lance, pictured left, firing those lats?? aren't those shoulders a bit high?)

When i saw my first RKC and heard this, i had no idea what the above instruction meant or to feel whether or not i was achiving it. Much tough love was administered in an effort to trigger the phenomena.

At the RKC cert, lat firing was realized, along with many other refinements to the swing, such that i understood Pavel's idea of the swing firing down and INTO THE GROUND rather than out. The nirvana moment happened for me when i felt/got that with "lats fired" the kettlebell swing could barely reach chest height - the arms just did not go higher.

Didn't really think about the causes of that effect, but have tried since then to instill it as a heuristic in the folks i coach: when that big side muscle is working, the shoulders stay in the sockets and the arms just will not go more than chest height - individual variation will be a bit below (like me) or maybe a bit above (haven't seen that as much).

So why, you might ask, would the lats being ON have what i've called a "braking effect" on the apogee or top point of a swing?

We can go back to the pull up as a lat exercise to put this picture. As i wrote there:

. .. [the Lats] enable the trunk to be pulled up via shoulder (or glenohumeral joint) extension. How does that work? The lat is like a big triangle of tough stretchy stuff that is nailed down along the spine from the middle of the back, just under the shoulder blade, right down into the butt at the sacrum. That's a lot of back. So the mid (or thoracic) spine is one point on the triangle; the sacrum (at the butt) is the second, and the third is in the arm, on the "medial side of the intertubercular groove of the humerus"

The lat connected in this way supports four movements of the shoulder joint: extension (movement of the humerus straight, posteriorly), bringing it across and in front of the body (adduction); internal rotation (putting your lower arm behind your back); bringing your arm up and around so that you can grab the opposite shoulder to the upraised arm (horizontal abduction).

So, the lat works on the shoulder, or in particular the shoulder joint, by its connection on the upper arm. Firing it will therefore brake the top arc of the swing, and maintain the shoulder control when the arm adducts or crosses slightly in front of the body to do two handed or one handed swings.

You can try this out yourself without a kettlebell. Lock your elbow and first start with your arm at your side, relaxed, and just try raising your arm by moving your arm in front of you and all the way up so your upper arm is close to your ear (if you can't get it to your ear we have another thing to talk about). Look at how great the arc is of that arm. from your side all the way up, like 180 degrees.

Now get your arm by your side and try flexing the muscles you feel along your sides. When you have that "grr" tight feel, now see how high you can raise your arm comfortably. Somewhere around 90 degrees, give or take?

In other words, and here's what at least to me seems so amazing, the muscle is not working within the shoulder to hold it back in its socket, but is actually using this mass of back muscle tied into the inside of the upper arm, to put a brake the arm action forward when it's flexed, and THAT the main action keeping the shoulder "packed" in the swing.

One more visualization: imagine someone tied a thick jump band to the inside of your arm, and held it going under your armpit and across your back. Initially when the band is relaxed, you can move your arm up in a full arc. If that person tightens that elastic up, that's going to limit the degree of the arc the arm can now be raised (this may also help reinforce why the lats are so big in pull ups: that lat muscle wants to get that arm down and back, in the direction of the muscle fiber).

SO the arm is kept from flying up (or out) of the socket with the help of the lats that both hold it back and limit its arc / range of motion when the muscle is flexed.

What is the shoulder socket or glenohumeral joint? If we talk about "packing the shoulder" in the swing, therefore, we are talking about a joint - the shoulder joint. A joint is where two bones come together to act as a lever. In the shoulder joint, the top of the upper arm bone or humerous, connects with the scapula, or shoulder blade.





The way the lat is connected to the upper arm, therefore, pretty literally, helps keep the arm in its socket.

It's not the only muscle acting on the shoulder joint. There are a bunch of muscles stabilizing the shoulder like the rotator cuff set, but beyond these stabilizers, there are three main actors on the shoulder: the delts, which take the arm to the sides, the pecs which helps bring the arm up (think bench press) or forward (baseball throw) and the lats.

In the swing, while the deltoids and pecs do some work, the major action on the shoulder is the lat. Remeber, the swing is not a pull (from the pec). The swing is carried forward on momentum from the hips. The lat acts first like a brace and then a brake, as said, to keep that momentum from throwing the arm out. This effect is reminiscent of the action of the hamstrings when sprinting: the hamstring acts as a brake so that the leg doesn't go flying out from all that quad power: it wants to pull that leg back down into extension.

The second action is bringing the bell down, keeping the shoulders packed with lats fired, lets one accelerate it beyond what gravity/momentum allows if the arms just come down with the descent of the swing. Pavel demonstrated this powerful pull down into the ground rather than way out in front at the cert using a super light (8K) bell, saying with the right form/muscle work, you should be able to get that power drive acting on any size bell you can swing - even tiny ones. The difference in feel is that the energy of the bell is coming down into the ground. As we practiced this over the cert weekend, many of us started to find ourselves being propelled backwards in our swings just at the end of the swing, showing heel skid marks in the sand.

Note: as RKC Randy Hauer points out, the down phase of the swing is initiated with the hips flexing (hinge at the hips). My point is that in the upper body part of this move, the flexed lats keep that move solid. Thanks for the clarification, Randy.

Putting the muscle together with the movement
By seeing how the lat is connected to the arm, and knowing that a flexed muscle means a muscle that is being shortened in the contraction, you can probably see how that muscle - again with all that muscle mass along the back of the lat working - is going to be able to support the transfer of power from the hips and out through the arms without the arms projectiling out of the shoulder. Likewise, keeping those lats fired and the arms stable while coming down with the bell insures the same protection coming down again, whether with gravity alone at 32m/s/s or overspeeding down.

Summary
By considering both how/where the lat is connected to the arm and how it operates on the shoulder joint has helped me understand why "firing the lats" supports excellent form in the swing, as doing so:

• holds the arm into the shoulder joint socket (packs it in) and thus protects the shoulder during the momentum up of the swing
• acts to brake the upper motion of the swing for optimal moment of the down stroke
• supports that big in front of the body DOWN pull on the arms during that hip hinge down stroke of the swing

Update: then there's the spine.
Bonus benefit to lat firing? Spine stabilization. Look at that lat images above: the lat's knit through so much of the spine, right into the butt, you get that working both sides, that spine is gonna be solid through the swing. ya ya, there are all the erectors and stuff in the lumbar spine too, and good thing, but look at that lat go! Thanks to Dev Chengkalath for reminding me that the lats connet to and affect the spine as well as the shoulder in the swing.