One of the main things we test when onboarding the wrestlers and grapplers (primarily Jiu-Jitsu) athletes I train is grip strength. We warmup, go through a few hip, spine, and shoulder mobility screens, and then we start our performance based assessments with three trials of max effort squeezes on a hand dynamometer. These numbers than can be used to track long term progress and address certain weak links in their ability to perform on the mat.
Grip strength is a crucial aspect of combat sports when it comes to scoring points or creating submissions (for the BJJ crowd). In order to move an opponent and create an opportunity to score, you have to be able to hold on tightly. Add in sweat, movement, varying grip widths, and sometimes someone else actively counter-gripping your hand, then grip strength becomes a competitive advantage in controlling your opponent.
To add on to this, these athletes need to be able to squeeze and have high grip strength without the use of their thumbs. A collar tie in wrestling is a great example, where the hands go on the back of the neck and you're latching onto whatever grip points you can with the tips of your fingers. You then have to move the person with this grip point, which is kind of like trying to cup a small log and pick it up off the ground. Having really strong forearms and solid finger flexion available allows us to be more efficient in this on the mat.
Another aspect, is gripping a wet surface under fatigue. Wrestlers and grapplers, especially at the heavier weights, are known for being incredibly sweaty human beings. And at the tail end of a 6-minute match, they're bound to be drenched. Then, if trying to work from a wrist tie up, you're grabbing wet surface with a sweaty hand trying to move it. If you can imagine trying to grab a fish underwater with a palm covered in Vaseline, this is kind of close to what the tail end of a long match can feel like.
This is where grip strength, and grip strength endurance becomes key. It's also why we test three attempts at a max grip in each hand with the combat sport athletes I work with. For starters, we need to see how much grip strength we can produce maximally. I don't have standard norms for this, but of the wrestlers I've tested the higher level athletes tend to grip close to (if not greater than) bodyweight on the dynamometer. However, the other key factor here is repeatability. It's great to grip bodyweight or close to it, but it means little if this can't be replicated more than once in a few minute time frame. We need grip strength to be repeatable for it to truly transfer back to sport.
Now, if you're wondering how we train this, there's a few different ways to attack this.
You can use Fat-Gripz if you have them on some key movements like rows, pullups, curls, and carries. This is a great option for implementing grip strength work within your already defined program.
Thumbless/Monkey Grip style carries, Trap Bar Deadlifts, Pullups, Chinups, and Rows. Don't do this with Pressing Variations because the risk too high, but for things which require a high level of grip work already, we can work on some of the grip strength needed without having the added benefit of the thumb.
Sand/Rice Buckets and "finding the penny." This is one we're starting to test and create a protocol for right now with my current set of wrestlers. All you're doing is filling a 3-5 gallon bucket with play-sand or rice (a 25lb of rice at a Sam's Club or Costco is usually $10-15), and burying a penny at the bottom. The goal is to spend a few minutes at the end of a session trying to dig your hand through the bucket to find the penny. If you find it, you then have to hide it for the next person.
Now, there are a plethora of other ways to train grip as well. This is just a brief outline of some methods we use and things we're experimenting with currently. But, as a whole, it's one of the things which needs to be trained in the wrestling and grappling population (again, looking at the BJJ crowd). The greater the grip strength, the better the scoring opportunities will come. Especially late in matches when fatigue sets in and the sweat starts pouring.