Helmet are essential at construction sites and other work sites, but precisely because they’re worn every day,Gives me a headache, slips out of place easily, fitsThere are quite a few people who struggle with this kind of worry.
Actually, have you ever thought about why your helmet doesn't fit your head?
It is not simply a matter of size; there is a fundamental difference in the shape of the skulls of Japanese (Asians) and Westerners.
In this article, we’ll explain some tips for choosing a safe and comfortable helmet based on differences in head shape.
1. The key difference is the “cross-sectional shape”
A look at CT scans of the head, for example, reveals that there are undeniable differences in the shape of the skulls of Japanese and Western people.
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Head Shapes of Japanese (Asians)
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Looking at the cross-section of the sliced head, its shape isClose to the yenThis is a major characteristic. The protrusion of the forehead (frontal bone) and the back of the head (occipital bone) tends to be less pronounced than in Westerners.
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Head Shapes of Westerners
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The shape of the cross-section isQuite tall and narrowThat's right. The forehead (frontal bone) and the back of the head protrude prominently, and the smooth forehead creates a sense of depth.
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The difference in the basic shape—between a "nearly circular shape" and a "fairly elongated shape"—directly affects how the helmet fits when worn.
2. Common Problems with Helmets from Overseas
Recently, there has been an increase in the number of helmets manufactured overseas. However, most of these are designed primarily with the elongated skulls of Westerners in mind.
If you force yourself to wear a helmet that doesn't fit your head properly, you're more likely to experience the following problems.
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I get a headache on the side of my head (the temple area)
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When Japanese people, whose heads are roughly round in shape, wear a narrow, tall helmet, they experience a tight, constricting pain on both sides of their temples.
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It's loose at both ends and wobbles.
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If you choose a larger size in an attempt to fit the width of your head, you’ll end up with excess space at the front and back of your forehead and the back of your head, causing the helmet to wobble back and forth. This means the helmet won’t be able to provide its intended protection in the event of an impact.
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3. Tips for Choosing the Right Construction Helmet for You
Based on the structure of the skull, here are some specific tips for choosing a helmet that fits correctly and safely.
① Choose "Asian Fit" or "Made by a Japanese Manufacturer"
When choosing products from overseas manufacturers, be sure to check whether they are “Asian-fit models,” which have been redesigned to accommodate the rounder head shapes typical of Asians.
In addition, helmets from long-established Japanese manufacturers (such as Tanizawa and Midori Safety) are designed from the outset to fit the shape of Japanese heads (which have a cross-section closer to a circle), so you can expect a superior fit.
② Be mindful of not only “head circumference” but also “width”
Generally, helmet sizes are indicated by the circumference of the head (head circumference: cm), but even with the same head circumference, the required width differs between “elongated” and “round” head shapes. When trying on a helmet, check not only the top of your head but alsoIs there any tight, constricting sensation in the temporal region (around the temples)?Please check this first and foremost.
③ Fine-tune the internal “adjusters (shock-absorbing liners and interior)”
The headband and adjusters inside the helmet are essential components for filling the gaps at the front and back. Make minor adjustments as needed based on your hairstyle, any swelling in your head, and whether you’re wearing an inner cap (hat), and position the helmet so that it fits snugly and evenly around your entire head.
④ Align the "V-shape" formed by the chin strap and ear straps correctly
Due to differences in skeletal structure, there may be slight variations in the position of the ears and chin from person to person. While wearing the helmet, adjust the ear straps so that they form a neat V-shape, and make sure the chin strap fits snugly against your throat. This will significantly prevent the helmet from shifting forward, backward, or side to side.
Summary: A Good Fit Is the First Step Toward Safety
Construction helmets are safety equipment designed to save lives.
Understanding the unique Japanese head shape—which is “close to a circle”—and choosing a helmet that fits your head evenly and comfortably is the key to ensuring maximum safety and improving work efficiency.
The next time you buy a new helmet, be sure to keep the shape of your head in mind so you can find the perfect fit!
Dojima River Occupational Safety Consulting Office
