Fear & Loading: Triggers And Fingers

by
posted on June 2, 2015
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
trigger.jpg
Sometimes I research a little too much on subjects, but I ran across something last week I think you’ll find interesting. The paper, titled “Quantifying the Independence of Human Finger Movements: Comparisons of Digits, Hands, and Movement Frequencies,” appeared in The Journal of Neuroscience on Nov. 15, 2000. Charlotte Hager-Ross and Marc H. Schieber conducted the research and composed the article.

Their experiments attempted to determine how well humans could move one digit on their hand without moving the others. It didn’t focus on shooting, but when we move the trigger, our thumb—accustomed to years of working in tweezer-like concert with the index finger—often inadvertently applies point-of-impact-altering pressure to the pistol grip or rifle stock.

The scientists determined the ability to avoid the problem varies considerably and, “To some extent such intersubject variability may reflect differences in the long-term motor experiences of each subject,” they wrote. Those “long-term motor experiences” are what we call practice, range time, tickling the trigger.

As for the wisdom of slowing down and really squeezing, “Negative correlations—lower individuation indexes at higher movement frequencies—were found for all digits except the thumb.” So the faster you pull the trigger, the greater the accuracy-robbing pressure applied by the rest of your hand (with the exception of the thumb).

For the average test subject, the thumb was not immune to movement, however. “We found that even when asked specifically to move one digit without moving any other digits, normal human subjects produced low-amplitude motion in noninstructed digits simultaneous with the large-amplitude motion of the instructed digit.”

Why does it happen? Adjoining and shared muscles, tendons and tissue are part of the explanation, but there’s more at play according to the pair. “…[T]he motoneuron pools innervating different finger muscles receive considerable shared central input.”

None of this is earth-shattering news, and it should come as no surprise they found, “…the thumb and index finger showed the highest degrees of individuation and stationarity, i.e., the greatest independence.” It is, however, nice when science verifies the sage advice to practice and slow down your shots.

And, if you haven’t been practicing with your off-hand regularly, you’re officially out of excuses. “In strongly right-handed subjects, however, we found no evidence of a systematic difference in finger movement independence between the right and left hands in terms of either individuation or stationarity,” the researchers wrote. In fact, there may be a slight advantage in using the weak side for long-distance shooting. “Performing a separate paired comparison of the individuation indexes for each digit of the right versus left hand revealed a significant difference only for the thumb, where the individuation index was higher for the left, nondominant thumb than for the right.”

Latest

Gun Locker: TriStar APOC Pro

If you like Gen3 G19s and can’t resist a bargain, you’ll love TriStar’s take on this ubiquitous concealed-carry pistol.

Building an X-Card Gun for Turkey Shoots

Unofficially known as a “turkey shoot,” X-Card competition challenges shotgunners to place shot pellets as closely as possible to the center of a target. And some makers have perfected a way to fine-tune shotguns for this purpose.

Spanish National Police Adopt Springfield Armory Echelon 4.0FC

The Spanish National Police (Policia Nacional) has officially adopted the Springfield Armory Echelon 4.0FC 9mm pistol as the issue pistol for its uniformed officers.

NRA Launches New NRA.org Platform and Official App to Modernize and Enhance the Member Experience

The National Rifle Association today launched its new NRA.org website and continued enhancements to the official NRA App, marking a major step and significant investment to modernize the organization and better serve members.

Political Report | Federal Firearms Rights Restoration is Officially Back

Criminal-justice reform has been distorted to mean counterproductive policies like eliminating cash bail or politicized district attorneys exhibiting a determined indifference to violence, but there is a place for sensible reforms that allow genuinely rehabilitated offenders to reintegrate into the community of law-abiding citizens.

Stable Fun: The Taurus Brace-Ready TX22

Taurus USA first adopted the ideal of a brace-ready format for a traditional handgun in its GX4 Strike Bravo, and now, the company is extending that concept to its TX22 rimfire handgun.

Interests



Get the best of American Rifleman delivered to your inbox.