Shoulder, hip and knee pain - looking to evolution for answersCreated by:
In an attempt to uncover the reason behind the common occurrence of shoulder, hip and knee pain in humans, scientists at the University of Oxford studied 300 specimens from different species spanning 400 millions years to see how bones changed subtly over millennia. Using CT scans of these 300 ancient specimens housed at the Natural History Museum in London and the Smithsonian Institution in Washington, scientists were able to create a library of 3D models to pick out variations to the shapes of single bones over millions of years. They found that as species evolved from moving around on 4 legs to standing up on 2 legs, the anatomical necks of the femur grew broader to support the extra weight. With the thickening of the neck, the risk of arthritis developing increases. Similarly in the shoulder, thickening of the bone led to narrower grooves and lesser space for tendons passing through to move, leading to pain in some people when they reach overhead.