|Reprinted from Coleman et al 2012, yes with permission. It cost me $20 just to use it!|
You can see the cartilage of a healthy human joint outlined in yellow (from an MRI).
I recently came across a great little paper on knee joint thickness by Coleman et al. It confirms what we may have already known or guessed.... but it does it beautifully and in a highly quantified manner. The data is from humans, but I would expect that similar would be seen with doggies! Very sophisticated experimental techniques, and modelling with some lovely beautiful pictures (!) and well controlled data.
Read the paper here Coleman et al 2012
The paper shows that there is a physical squeezing and compressing of cartilage when you stand up. This has all kinds of ramifications to scientists who work in the area (like us!!).
The difference in thickness is quite small between day and night, but certainly significant in the knees.
Snippets of the data are that men's cartilage is much much thicker than womens'... and of course, there is a significant correlation between cartilage strain and body mass index (BMI).
...So if you want nice thick knee cartilage; be a chap, spend the day in bed*... but don't eat too much!!!
*...but seriously: it is generally accepted that moderate exercise is good for healthy joints, but excessive weight is an absolute no no......
Other blogs pertaining to osteoarthritis and exercise:
What Gives People and Animals Arthritis
Is Running Good for Your Health
Exercise and osteoarthritis