American Ninja Warrior is an obstacle course game show where people tackle ridiculously
impossible challenges.
Obviously, you have to be fit to make it through the course, but there’s one aspect of fitness
where the competitors usually fail.
The weakest link, the reason that many of these athletes get eliminated is grip strength.
Of course, that’s not the only reason — I mean the whole point of the show is that completing
it is nearly impossible — but a large portion of the obstacles are dependent on a strong
grip.
What's up everyone, my name is Patrick, I was curious about the
mechanics behind these challenges.
Specifically the hand and wrist. Like what makes this such a weak link in the kinetic chain?
And what does the science says about how to make it potentially stronger?
Before we get into the research, we need to know the structures we’re working with.
There are a lot of muscles involved in grip, and even those depend on which form of grip
you’re using - like all of these.
Either way, the primary muscles responsible for grip strength are in your forearm as you’re
painfully aware of if you’ve been rock climbing.
On the anterior side, you have a bulk of muscles called the wrist flexor group since they flex
your hand, and on the backside, your wrist extensors.
They both have origins close to the elbow joint at the medial and lateral epicondyles
— both of which you can feel pretty easily.
They thin out into long, slender tendons and cross the wrist where they move the hand.
Unfortunately, those names are a little misleading because within that muscle mass are some muscles
that exclusively flex or extend the wrist and some that cross the wrist to curl your
fingers, resulting in a gripping motion.
And if you’re just hanging on with just your fingertips, you use even fewer, even
tinier muscles — again, climbers know this very well.
What’s counterintuitive though is /which/ forearm muscles are the most important.
It totally makes sense to think your wrist flexors would be the best area to focus on,
what with the way they curl your fingers downward and everything, but it’s actually the wrist
extensors that make the biggest difference.
This is going to come up later on, but the wrist extensors act synergistically with the
wrist flexors — EMG recordings show that as the force from your wrist flexors increases,
so does the force from extensors.
That’s what makes grip strength so unique — it’s less brute force like a bicep curl
and more of a balancing act.
So yeah, wrist and finger flexion is how you wrap your hand around the bar, but the wrist
extensors are how you hold on tight.
What makes Ninja Warrior even more interesting is how your grip has to change along with
a changing body position.
And decades of experiments show that the position of other body parts impacts your grip strength.
We’ll start with the easiest to understand: hand spread.
Bigger objects are harder to grip.
Like, compare a basketball - which I keep under my desk at all times...
...to this vase. I can't even wrap my hand around half of either, but I can at least hold the vase
I can't do the basketball.
Part of that is because bigger hands let you cover more of the surface area of the ball,
yes, but it also impacts something called the length-tension curve — there’s a just-right
length that each muscle provides the strongest contraction.
If your hand is stretched out over a big object, it won’t grip as strongly as it would when
the muscle is in a shorter position.
Many of the Ninja obstacles are so challenging because you’re grabbing an oversized hold
or bar.
And a study from 2007 shows that when you increase the diameter of the bar, you decrease
your ability to do the lift itself.
Take the salmon ladder for example, which uses a larger diameter bar, even though the
large muscles on your back and shoulders haven’t gotten weaker, your ability to do the move
is worsened by the weaker grip point.
But it’s not just your hand.
Literally every joint up the kinetic chain can tweak your grip strength — unfortunately,
it seems like every review I read had conflicting results.
One of the only consistent aspects was that grip strength is greater when you’re standing
compared to lying down.
And of course, these studies are done in super calm situations with a standard hand ergometer,
so a little different than the cameras and crowds of Ninja Warrior.
One aspect that deserves a bit of a deeper dive in this video is wrist position.
Greatest grip strength comes from about 20o-45o wrist extension with every so slight ulnar
deviation — the hand moves
towards the pinky.
You can try this at home.
If you move into wrist flexion, you won’t be able to make a fist.
But extend your wrist as much as you can and you’ll still be able to clench shut.
Basically, you can drastically weaken grip strength with just a few mechanical tweaks,
and with the chaos of the Ninja course, you can forgive the athletes for not worrying
about ergonomics.
So if you can’t necessarily optimize for grip strength in the competition, your next
best option is to train and strengthen your grip, but even /that’s/ hard to do.
Now, most of the research in this field is conducted on elderly folks.
A weak grip is a good predictor of mortality, so physical therapists have their older patients
work on exercises like what you might’ve seen in Doctor Strange — squeezing resistance
Researchers have compared these functional exercises against targeted weightlifting in
the forearm muscles and find that, again, in /older/ adults, they get pretty comparable
results as long as they do /something/.
But for these studies, lots of researchers admit that they really don’t know what mechanism
is responsible for improvements in grip strength.
It could be neural adaptations, increased dexterity, but it’s still a mystery.
Now, these rehab exercises are gonna be too easy for the younger, athletic type, so coaches
have naturally looked into the best weightlifting routine.
One study published in 2004 in the Journal of Strength and Conditioning Research took
a high school baseball team and put them into 2 groups of about 20 kids each: both got a
traditional, preseason weight lifting program, but half of them got additional forearm exercises.
This was a pretty challenging extra credit workout: wrist curls, extensions, ulnar and
radial deviation, and plate grips.
Unfortunately, after those 12 weeks of training, the only thing group 2 did was get stronger
at those particular lifts.
BUT when it came to actual grip strength, both groups improved by the same amount.
3 months of dedicated forearm exercise made /no difference/ in grip strength compared
to the group that did deadlifts and bicep curls but no dedicated forearm work.
Both improved by about 5%, so it made a difference compared to if they did no exercise, but there
was no difference between the groups.
Just like the older adults, as long as they did /something/ they improved grip strength.
But like I said earlier, grip strength is more about muscular balance and less about
bulk.
Remember the synergistic effect of the wrist extensors?
Some studies that look into improved grip strength in young people say that strengthening
exclusively the extensors can improve grip strength.
One study published in the European Journal of Applied Physiology in 2011 looked into
training the wrist extensors isometrically, that is, without the wrist moving.
The team measured the 13 subjects’ grip strength with a dynamometer before and after,
but they also did an EMG — they measured the electrical activity of the motor neurons
controlling certain muscles.
Remember how there are over 30 muscles involved in grip?
EMG data can give us an idea of which muscles are most active that lead to that reading
on the dynamometer.
So the group took their initial measurements, then for 8 weeks they had subjects do 30 reps
of this exercise for 5 days a week.
This was plenty of time to see both neural adaptations and some hypertrophy.
At the end of the trial, the subjects saw less dominance in their wrist /flexors/ and
more from their extensors and significantly increased gripping force.
The researchers think that the rebalancing of forces, as well as the added muscle mass,
was responsible for the hashtag gains.
As far as documented science goes, there’s still no clear winner in how to best improve
grip strength.
Keep in mind that a lot of the research out there on this topic is inconsistent.
Both in how the testing and exercises are conducted but also with small sample sizes.
If you’re planning out your strategy for grip strength domination, it might be worth
playing with a few different routines to see what works for you.
Thanks for watching this video.
I was inspired to make this video after watching a few videos on Mike Boyd’s channel, so
if you want to check those out, I put those links in the description.
Otherwise you can check out some of my other videos here and here, or subscribe up here.
Have fun, be good.
Thanks for watching.