Where to put my thumb
The correct grip on the pull bar is an eternal subject to discussion. In its center: the optimal position of the thumb. While the Hookgrip - a type of grip in which the index finger and middle finger are placed over the thumb - is the standard, the preferences for pull-ups vary from athlete to athlete.
Many athletes prefer the so-called "gorilla grip", where the thumb is placed above the pull bar next to the fingers. It corresponds to the technique by which our ancestors picked up small, unwieldy objects from the ground.
At the pull-up bar, however, the thumb turns around the bar as the better solution. Here are some of the reasons for the "pronated grip"
Shoulder stability from the thumb
If you wrap your thumb around the pull-up bar, you increase the shoulder stability in the free hang at the lowest point of the pull-up. The pronated thumb grip forces an external rotation of the shoulder, a stable and strong position from which a lot of pulling force can be generated.
The gorilla grip pulls the shoulder joint apart. You fall, so to say, "deeper into the hang". This increases the range of movement. Particularly in the first part of a kipping-pull ups, which starts with an "arch posture" in which the athlete takes a swing with a hollow back, the thumb-over grip often feels more powerful. In fact, a larger kip can be generated in the upper grip - but the tension completely lost in the free hang has now to be built up again, so that the advantage of the larger rom is lost again.
More grip strength and relief for the forearm
When opening a bottle, we always put our fingers on one, the thumb on the other side of the cap. This creates more friction and torque. This is similar to the grip on the pull bar: Wrapping the thumb around is more powerful and, above all, more persistent. We relieve our forearms and leave more work to the hands, which because of their constant use in everyday life show an impressive stamina, and that without any specific training. Especially in workouts with high repetition numbers the pronated thumb grip is therefore advantageous.
When pull-ups and their faster variants - butterfly-pull ups, kipping-pull ups – appeal in WODs under time pressure, the thumb-under grip is a must. This has security reasons: the thumb acts as a safety hook, which holds the athlete securely on the bar even during a swinging exercise. Also, our during CrossFit workouts often sweaty hands and pre-tired forearms benefit from an indestructible hold.
More transfer to other exercises
Nobody would come up with the idea of utting the thumb over the barbells when lifting weights. It makes sense, of course, to choose the same grip on the pull bar as we would at barbell. After all, pull-ups are just as much a "pull-exercise" as deadlifts, cleans and snatches. If we simulate the thumb position of the barbell exercises in our pull ups, we develop the crucial muscles in the forearm, biceps, shoulder and back. In other words, the thumb wrapped around the bar has the greatest transfer effect on weight lifting.
Thumbs over the bar: An exception
There is an exception: Unusual thick pull-up bars often leave no other option than the gorilla grip. Especially persons with small hands should place their thumbs next to the fingers in order to create the best lever.