back pain

I've been writing my diary in English to improve my skill.
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For the past 2 weeks, I had been suffering from back pain and I couldn’t concentrate on my work.
Even though I wasn't able to think of a cause at first, I realized that it began ever since I got a new desk which was a centimeter higher than the old one.
I couldn’t believe that such a little difference caused this problem, however I finally got better after adjusting my desk height.