Why I like to teach Kipping Pullups to my CrossFit Athletes Part-2.

 

Correlation vs Causality

I decided to start this post with this piece from the last one, because I think this is worth repeating.   Correlation is not causality is a basic principle of statistics. Simply because someone who "kips" has a shoulder injury does not necessarily prove that kipping is the cause of the injury.

Tarzan Knows Best

When I was younger we would watch Tarzan movies and try to emulate Johnny Weissmuller, who with his sidekick Cheeta was swinging through the jungles, jumping from vine to vine and tree limb to tree limb, bringing jungle justice to nasty white hunters and other bad guys.

Back in the day these costumes were pretty racey.

At this time I was growing up in Rockaway, New York, a peninsula with the Atlantic ocean on one side and Jamaica bay on the other. We had a base ball field by our house--actually we lived in the projects, but that's another story--that had two diamonds. The ball field diamonds had a huge chain link fence backstop that we hung a rope off of. We would climb in the inside of the backstop, pushing our fingers and Converse Chuck Taylors--high tops, thank you--through the chain link. One of our friends would hold a rope that we had hung from the front of the back stop for us to jump on to and swing out and then back into the stop, all the while doing our best Tarzan yell.
 

The rope hung from the outer edge of the back stop.

I'm not recalling this to take you on a trip down memory lane, but to highlight that hanging from our arms is a natural movement for primates, which we are. We're primates

As primates we are completely adapted to hanging from our arms, and it doesn't depend on rotator cuff strength.

Adapted to Hanging Out

 

Hanging out in the Hood.

 Animals that hang or climb trees as well as those that dig, have developed a "bone spur" within the Subclavian muscle that we call a Clavicle. The subclavian muscle runs from the acromian process to the sternum, the clavicle sits within this muscle's facial sheath. The acromian process acts like a roof or a stop over the top of the glenoid fossa--the "socket" on the scapula that the humerus sits in--which allows us primates to hang our body weight from our arms without dis-locating it.
(Unfortunately there is no such shelf on the under side of the glenoid fossa preventing our arm from slipping out when we bear weigh overhead. This is the job of the rotator cuff. More on that in a later
post.)

 There are three main muscles that we use to hang from our arms: the Lattisimus Dorsi (lat), aka the "swimmers muscle", the Pectoralis Major (pec) and the Middle Trapezius (trap).  (For a fascinating view into the body's fascial connections my friend and fellow Rolfer Tom Myer's book Anatomy Trains is a must read.)

The pec attaches from the sternum to the clavicle and the humerus, effectively suspending the front of the body from the upper arm.

The pec attaches to the clavicle and humerus.

(In this photo you can see the massive latissimus dorsi between the upper arm and the rib cage. It makes a lot more sense to use this muscle for a pullup than it does to use the smaller muscle around the arm's attachment to the scapula.)

The middle traps attach the scapula to the thorax.

The middle trapezius--diamond shaped--attaches the scapulae to the spine. When this powerful muscle contracts it stabilizes the spine and the scapula. This prevents the scapula from rotating or pivoting at the humeral head.

The lats attach the humerus to the pelvis.

The lat attaches the humerus to the pelvis through the Lumbar Aponeurosis a thick fascial sheet in the lower back--it looks white in this image--which effectively moves the pelvis towards the hand when the hand is fixed.
(In many people who are sedentary or don't do pullups correctly the lat is "turned off" in the sense of having actual conscious control over its activation.)
Pullups are initiated at the lat not the biceps. 

This combination of the lat, pec, traps and the acromion shelf allow us primates to hang out with little energy expenditure.

This is all great stuff, but what about the angular momentum that's generated by the kipping pullup and damage that can occur to the rotator cuff and labrum? Isn't this the problem of kipping? Or, is it the sign of something else?

That's the subject of  part 3.

The Dangers of Kipping Pullups in CrossFit

Correlation vs Causality

There seems to be a lot of speculation on the benefit of the "Kipping" pullup to athletic performance. I've read blogs from medical professionals that suggest that there is an increase in the number of shoulder injuries associated with the Kipping pullup--note there is a rarely a precise definition of the mechanics of this pullup so any swinging with a pull is considered in the data set--without consideration for other possible causes. Correlation is not causality is a basic principle of statistics, simple because someone who "kips" has a shoulder injury does not necessarily prove that kipping is the cause of the injury.

This potential error in cause-effect analyis then furthered with a suggestion of a cure for the kipping pullup injury rate--get stronger by doing dead hang or "strict" pullups. This will supposedly strengthen the rotator cuff muscles. Again there is a suspect link between the rotator cuff muscle strength increase being caused by pullups...

What is a Kipping Pullup?

I'm sort of biased in my opinion and teaching of a kipping pullup. I have a CrossFit Gymnastics Certification--I trained with Jeff Tucker, who's great and an advocate of the strict pullups before kipping solution--and I use his definition of a gymnastic kip . I have also trained with Carl Paoli and use his Kipping Pullup Progression in my teaching the kip.

Suffice it to say that my definition of a kip is not what we see on the majority of Youtube videos, CrossFit or not.

When CrossFit athletes started using the kip there was a lot of criticism suggesting that it was a "cheat" over the normal Dead hang pullup. The logic is that the kip was easier and the athlete could perform more kipping pullups because of this. Ok. So what? The supinated hand "chin up"is easier than the pronated hand pullup, they're two different versions of a pullup.

After the furor over the potential cheating of the kipping pullup died down--probably about the time the nay sayers learned to kip--the next suggested issue with it was that the kipping pullup was creating injuries in the newer not as strong athlete--wait a minute I thought it was easier. The argument suggests that a new athlete should not be taught how to do kipping pullups until they have some minimum number of dead hang pullups. The belief is that this magic number of dead hang pullups, anywhere from 5 to infinity, would strengthen the rotator cuff musculature and protect the shoulder -especially the labrum--from injury. Really? How? No one seems to know how this would work or cite a double blind study into the effects of kipping--that was a joke, you can't do a blind study on a movement.
The kip adds more momentum and makes the pullup easier--this is why we teach it, it's easier, it requires less energy and is faster than a dead hang. If it's easier and more energetically efficient then why do I need to be stronger to do it? Does the gymnastic kip if taught correctly increase the chance of injury? Are rotator cuff, lambrum problems inherent in the kipping pullup?

I'll present my thoughts on this over the next few posts.

Back Again

After a rather long hiatus from a short blogging stint, I've decided to return.
The reason is pretty simple, I think I have something to add to the collective knowledge and I wanted to provide that to my clients and athlete's.
I hope you agree or disagree in a manner that promotes the dialog.