noun
frozen shoulder in one's 40s; shoulder pain around age 40
Commonly used to describe shoulder pain or stiffness that appears around the age of 40, often due to aging or overuse. Similar to 五十肩 (frozen shoulder in one's 50s).
四十肩で腕が上がらなくなった。
I can't lift my arm because of frozen shoulder in my 40s.
四十肩の痛みがひどくて、夜も眠れない。
The pain from my shoulder condition is so bad I can't even sleep at night.