時尚雙語:什麼姿勢用筆記本電腦最健康

Sales of laptop computers passed desktops in the U.S. for the first time ever this fall, according to market-research firm IDC.

That's bad news for backs, necks and shoulders.

'Laptops are inherently unergonomic -- unless you're 2 feet tall,' says physician Norman J. Marcus, a muscle-pain specialist in New York City.

When you work at a computer, the keyboard should be at elbow height, so your upper and lower arms form an angle of 90 degrees or more and your forearms are supported by armrests. The monitor should be roughly at eye level so you can lean back in a chair with back support.

But most users simply set their laptops on a desk or table. The keyboard is too high, which makes your arms reach up, your shoulders hunch and your wrists bend down. The monitor is too low, which pulls your head and neck forward and down and puts a strain on your back.

That's OK if you use your laptop occasionally, for short periods. But if you use one for hours at a stretch -- as do millions of college students, business travelers, telecommuters, video-gamers and growing numbers of office workers -- you're setting yourself up for muscle problems that can make your entire upper body hurt.

Ergonomics experts have warned about laptop problems for years -- mostly in vain. People continue to abandon bulky desktops in favor of the ever-sleeker, lighter portables. And WiFi connections let us use laptops anywhere -- in bed, on the floor -- in all kinds of contorted positions.

據市場研究公司國際數據公司(IDC)的數據，今年秋季美國筆記本電腦銷量有史以來首次超過臺式電腦銷量。

但對人的頸、肩、背來說，這是個壞消息。

紐約市肌肉疼痛科醫生諾爾曼·馬庫斯(Norman J. Marcus)說，筆記本電腦本質上是不符合人體工程學的，除非你身高只有兩英尺。

當你在電腦前工作時，鍵盤應該和肘部齊高，這樣你的大臂與小臂成90度角或更大的角度，小臂可以放在椅子扶手上。顯示器應該大概和眼睛處於同一水平線，這樣你就能往後靠在椅背上。

但是，大部分使用者都只是把筆記本電腦放在書桌或是普通桌子上。鍵盤放得太高，你必須把胳膊伸得老高，聳起肩膀彎着手腕。顯示器太低，你的腦袋和脖子都必須往前下方伸，使你的背部緊張。

如果你只是偶爾、短時間地用一下筆記本電腦，這樣做不會有太大問題。但是，如果你一坐就是幾個鐘頭（就像好幾百萬大學生、商務旅客、網絡上班族、遊戲玩家，以及越來越多的辦公室白領一樣），那你就是在和自己的肌肉過不去，這可能會讓你的整個上身疼痛。

人體工學專家多年來一直在提醒筆記本電腦的問題，但是往往是徒勞無功。人們繼續丟掉笨重的臺式電腦，轉向更加輕薄的筆記本電腦。而且無線上網技術還讓我們可以在任何地方使用筆記本電腦──牀上、地板上──姿勢也可以千奇百怪。