The body has some pretty unique ways of telling us things about ourselves. For example, there are various areas of research that have made suggestions about our motor abilities, cognitive function, and skill acquisition associated with our left and right-handedness. And now, we’re seeing more research on the hand making its way back in the news, but this time, it comes in the form of fingers.
The Newly Published 2D:4D Research
A recent study published from the University of North Dakota analyzed the relationship between an adolescent boy’s second and fourth digit length (2D:4D) and their relationship to the balance between prenatal testosterone and estrogen. It’s been suggested that our fingers, specifically the fourth (ring finger) has more receptors for androgens (compounds that often come in the form of steroid hormones). A longer fourth finger would suggest higher amount of prenatal testosterone, which would suggest higher levels of physical development.
Researchers had 57 adolescent aged boys (13-18) volunteer, then recorded their age, height, and BMI. They they had the boys in the study perform a grip test with a hand grip dynamometer similar to the testing protocol in the video below. They recorded the best of two maximal contractions.
Digit lengths were blindly recorded prior to the grip test, and were measured with digital photographs of the participant’s right hand’s palmer surface and outstretched fingers.
As for the results, researchers adjusted individual’s strength levels dependent on their height and BMI. They found and suggested that regardless of an adolescent boy’s height and BMI participants with a shorter second digit, comparatively to the fourth, had better grip strength.
What Other 2D:4D Research Has Suggested
Going off of this study, the ratio between one’s second and fourth digit has been previously suggested (with inconsistent results) to be a predictor of development and athletic abilities. For example, this 2008 study suggested that men with a smaller second digit compared to the fourth digit had higher levels of grip strength.
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#TrainingTuesday 💛 minor progress on the #pegboard, and a new #campusboard technique that I think will actually pay off after a few sessions. It's called "pulling harder" 👍 Plus a #handstand #photobomb 😋 I forgave him because right after I came down out of the handstand he asked if I was a professional #rockclimber 💪 You, sir, are my new favorite 😜 #pullupsfordays #handstandpress #vsit #thisactuallycuredtheheadacheivehadallday
Yet this research from 2006 suggested the opposite, or null findings, when it came to second and fourth digit ratios in women. From the limited research at hand, it’s hard to definitively say how accurate the 2D:4D ratio truly is when determining strength and athletic capabilities. But it’s an interesting concept.
All of these finger studies had me wondering; what else can the hand tell us? Apparently, there are a few things that a hand’s anthropometrics and strength can indicate.
Grip Strength Determining Maximal Strength, and Other Factors
How strongly we can grip something can also be an indicator of maximal strength, along with other characteristics. In a lot of cases, we don’t need science to understand that a stronger grip is often associated with better in-gym performance. A good grip will support pulling, pressing, and other grip dominated movements, as well as in-sport performance.
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In 2013, one pilot study hypothesized that grip strength can be a useful indicator of predicting maximal upper body strength. Researchers of this pilot study compared 15 healthy individuals, and how one’s maximal grip strength related to a maximal bench press. They found there was a linear relationship between grip strength and maximal pressing strength. Yet, this study was only a pilot with very small population, and further research needs to be done on this topic.
[Need to improve your grip? Check out these 9 grip strengthening exercises.]
Another study from 2007, analyzed how grip strength predicted body morphology (waist-to-hip/shoulder-to-hip ratios, and 2D:4D), sexual behavior/history, and aggression in men and women. What they found and suggested was fairly interesting. The study included 61 females and 82 males, then compared their maximal grip strength using a dynamometer to the above mentioned attributes.
To analyze body morphology, researchers recorded measurements of the participants hands, second/fourth digits, hips, waist (women), shoulders (men). Then, to record sexual behavior, history, and aggression, participants filled out anonymous surveys. Researchers found that men with higher grip strength tended to have larger shoulder-to-hip ratios (V-taper shape), more sexual encounters, and tended to be more aggressive, compared to those with less grip strength. Women’s maximal grip didn’t have the same relationships as the men in the above factors.
[Borrow movements from some of the strongest grip-based athletes on the earth. Check out these four rock climbing approved grip exercises.]
But how does grip strength relate to things like sexual behavior? Well, researchers suggest and discussed briefly how evolutionary aspects may be at play, and how a stronger grip could indirectly relate to primitive activities such as hunting, mating, etc. This suggests that a stronger grip could have ties to one’s natural predisposed characteristics, such as prenatal testosterone, and so forth.
Hand Size and its Relation to Athleticism
Looking outside finger length and grip strength, the size of your hand may also be an indication of your athleticism. And this makes sense when you consider how the best athletes are often those with anthropometrics that are usually described as outliers. Consider Odell Beckham’s hands: they’re a whopping 10″ long, while the average male’s hand is around 7.4″.
There was a study published in 2011 that looked at hand dimensions, hand shape, and various anthropometrics, and how they related to grip strength in athletes and non-athletes. Researchers took multiple measurements of the hands/arm including: finger length, finger span, finger perimeters, palm length, hand length, forearm length, and many more. To no one’s real surprise, researchers found a higher relationship between grip strength in athletes and their hand dimensions, compared to non-athletes.
From their analysis, researchers found that there were three hand anthropometric that indicators were better at predicting an athlete’s abilities in grip-based sports. These measurements include the total span of the fingers, index finger length, and full finger perimeter length.
The newly published research provides a little more insight into the ways our body’s natural anthropometrics suggest abilities we possess. Keep in mind, this research is only making suggestions due to what they observed, and there will always be outliers and anthropometric anomalies.
Don’t get discouraged by the research. Grip strength is one of the more innate attributes that come with strength training and sport, but can be improved in various ways.
Feature image screenshot from @obj Instagram page.