According to a google’s web service “Google trend”, the term “Joint hurts (関節が痛い)” is searched increasingly frequently in Japan since 2011 as shown in the graph below.
The statistic starts from 2006. It was stable until the early 2011, but it came into the increasing trend.
The latest result is over 4 times much as before 2011.
The reason is not identified.
However, as one of the possibilities, Strontium-90 has similarity to calcium in human body. It is known to accumulate in bone and cause bone related disease such as Leukemia.
Personally speaking, both of my parents suffered from severe joint pain from the summer of 2011, and the reason is not verified.
See also.. Google trends shows Japanese searching the word “Losing hair” increasingly since 2011 [URL]Iori Mochizuki You read this now because we’ve been surviving until today.