Movement of the knee is not simple. It is not a hinge like a door, but a complicated system of rotating and sliding at the same time. There are a number of important considerations to ensuring it moves correctly and is not damaged.
During the Spring of 2019 I spent several days at a biomechanics institute in Ulm, Germany, where engineers have developed an advanced system to simulate knee movement using muscles they way that we do, and do it dynamically. In other words, they can simulate walking or jumping off a table or bounce up and down. To do this takes a testing machine that can pull on the right muscles at the right time as well as simulate body weight. Cables are attached to simulate the quadriceps, hamstrings, and calf muscles. The muscles are controlled by a computer.
Movement of the knee is tracked using a combination of 8 cameras at different angles to the knee. These can track very small movements of the joint and bones. This is all recorded by the computer and can be analyzed to better understand how the joint moves.
We hope to return to the lab in the coming months to design new experiments. This setup is one-of-a-kind in the world. Engineers at the Institute can put this information into models which allow us to quantify what is normal and what is not.
With this we can study and better understand how the normal knee moves, as well as the damaged knee. It becomes more exciting when we try to improve the damaged knee by repairing structures and seeing if we can restore the knee to a normal state. We can better understand which activities are impaired with no meniscus for example, and how repairing it or replacing it corrects the joint.
Again this set up is one of a kind. Ask me questions to learn more about it all and I’ll post them here.