Unfortunately there is not any research to be found that I know of for crossfit exercise and injury. Luckily crossfit has pretty much stolen their exercises from other sports where some solid research has been done.
When it comes to the kipping pull-up I’m just going to take my best guess as to why these injuries occur based on some of the gymnastics injury research, my own experience and some common sense. If anyone has some other insight to add please share!
NOTE: I’ve since added some additional ideas as to why kipping pullups might be causing injury, you can find an updated article HERE:
There is some research in the field of gymnastics and the forces on the shoulder during some of the swinging motions that are commonly seen in the sport. When comparing these movements to the kipping pull-up we need to look with a grain of salt because we’re comparing different but similar motions and the studies are using athletes from varying populations(age, performance level, gender etc). I’m sure the general membership at your crossfit gym isn’t quite the same as the gymnasts in these studies.
Niu and colleagues found that in the long swing movement in the still rings as the athletes swing past the bottom (lowest point) in the swing, peak forces reached 4.27 to 4.66 times bodyweight. Cheetham and Sreden found forces at 5.1 to 7.9 times bodyweight. A study by Caine looking at female gymnasts found that in the low swing forces were 8.5 times bodyweight. Obviously this is a tremendous amount of force for your body to handle, especially by a joint that is known for tremendous mobility and not necessarily stability (shoulder).
Cerulli and colleagues in an article entitled, “A biomechanical study of shoulder pain in elite gymnasts” speculated that poor technique (improper timing of muscle activation during a giant swing) could lead to a SLAP lesion in the shoulder (Fairly common crossfit injury huh?). The authors reported a critical phase when muscle activity was very low and thus stress on the shoulder joint was very high. (ie: shoulder muscles relax and the labrum/ligaments take the brunt of the load) The authors hypothesized that this coupled with large tension from the biceps tendon could be causing SLAP tears (tear of the labrum that may include the long head of the biceps tendon if the damage is great enough). The authors went on to recommend proprioceptive training as a prophylactic treatment for these athletes, teaching the gymnasts to recognize the position of the humeral head into the glenoid fossa (ball into socket) during these movements.
Side Note: In watching videos of elite gymnasts doing giants, it does appear as if their shoulders rise up by their ears in a shrug position at times. This is definitely not what people like Gray Cook describe as a safe packed position. Possibly this is a form thing for the judges? I can’t really explain this. Possibly this is a variable in the high incidence of labral tears in gymnasts? If anyone has more information about gymnastics please feel free to chime in.
Obviously we aren’t elite athletes doing giants and intense ring work but I really think a lot of things could be learned from these studies and applied to making the kipping pull-up safer.
- Kipping pull-ups like these other gymnastic movements place a large amount of stress on the shoulder joint and it’s surrounding musculature
- Firing the musculature at the right time is important in minimizing stresses on the shoulder (Proprioceptive training)
- Technique becomes critical
- Learning how to position the humeral head properly into the glenoid is critical. (Sounds a lot like shoulder packing)
Why else might crossfit athletes get injured doing kipping pullups.
- Poor flexibility – If you don’t have the mobility to put your arms fully overhead, kipping pullups end up being an end range stretching exercise under a lot of load(your bodyweight)
- Poor Technique and No Shoulder Packing – These studies emphasize the importance of technique and putting the humeral head into a healthy position
- Fatigue – It’s natural to lose form when you get tired. Crossfit is notorious for fatiguing people. Once the musculature that surrounds the shoulder fatigues, you won’t be able to maintain a shoulder packed, healthy shoulder position. Now you’re hanging on the labrum and ligaments within the shoulder joint and those articular(joint) forces go up just as in the study above.
So what the hell can we do about it?
- If you aren’t flexible enough to put your arms overhead normally, avoid this movement until your mobility improves. HERE is a link to a screen to assess your overhead flexibility. Here is a link to a video demonstration of my favorite stretches to achieve overhead mobility.
- Learn how to pack your shoulder properly. Once you learn that position, its time to learn how to shoulder pack while hanging and kipping. This could be described as proprioceptive training for the shoulder. We’re learning how to keep the humeral head properly centered into the glenoid fossa (ball into socket).
Shoulders Back and Down (Photo Left: Poor position – Photo Right: Shoulder Packed and war ready)
- Learn how to kip properly – Here is an excellent progression from Jason Khalipa and his lovely wife Ashley. Just make sure to keep the shoulders down and back during the progression. Let’s keep those shoulders away from that shrugged, high risk position as best as we can.
- Stop with technical breakdown. If you fall out of the shoulder packed position the stress on the joint goes up. When this happens, take a breather and get back to it when you can do the exercise with proper technique. Rest or use some bands to assist you. Whatever it takes to do it properly every time.
- Learn the motor program – I probably didn’t need to put in this point because it goes hand in hand with technique. Learn how to kip properly and reinforce this a few times per week. I like putting kipping (just the kip, not the whole pull-up) into the warm-ups of the clients at Crossfit Tribe. They learn how to shoulder pack and when workouts come up with kipping pull-ups, they’ve built the strength and the motor program to perform this movement properly. More importantly they will be able to tell when they’ve sunken into a poor position and how to correct it. (People need to know what to do in a group training environment)
Hopefully this helps us get a better idea of why the kipping pull-up gets a bad name. Like most other movements and with crossfit in general I feel like we can take the necessary steps to ensure our athletes and clients make the best progress in the safest manner possible.
Let me know your own thoughts about the kipping pull-up guys. I for one really enjoy them because they’re fun and challenging. How about you?
Lats for days brah,
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P.S. I’ve updated my thoughts on the kipping pullup. To see the new information click HERE:
Wilk, K. E., Reinold, M. M., & Andrews, J. R. (2009). The Athlete’s Shoulder . (2 ed., pp. 491-495). Philadelphia, PA: Churchhill Livingstone.
Niu J, Lu X, Xu G, et al: Study on gymnastic rings movements using force measuring system. In Hong Y, Johns DP (eds): Proceedings of XVIII International SYmposium on Biomechanics in Sports, 2000, pp 72-109
Cheetham PJ, Sreden HI, Mizoguchi H: Preliminary investigation of forces produced by junior male gymnasts on the rings. In Hoshizaki TB, Salmela JH, Petiot B, (eds): Diagnostics Treatment and Analysis of Gymnastic Talent. Montreal, Sports Psyche Editions, 1987, pp 99-106
Caine DJ: Injury Epidemiology. In sand WA, Caines DJ, Borms J (eds): Scientific Aspects of women’s gymnastics. Basel, Karger, 2002, pp 72-109
Cerulli G, Caraffa A, Ragusa F, et al: A biomechanical study of shoulder pain in elite gymnasts. In Riehle HJ, Veiten MM (eds): ISBS ’98 XVI Internationa Symposium on Biomechanics in Sports. Konstanz, Germany, university of Konstanz, 1998, pp 308-310