Medline Plus. Aging Changes in the Bones-Muscles-Joints 2023.
https://medlineplus.gov/ency/article/004015.htm#:~:text=Muscles%20may%
20become%20rigid%20with,tone%2C%20even%20with%20regular%20exercise.&text=Bones%20become%20more%20brittle%20and,pain%2C%20stiffness%2C%20and%20deformity

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