See the little ball on the end of the tibia. How well it fits into the hollow on the end of the femur.
In order to see this hollow or groove, you must look on the under side of the leg.
Yes, John, it reminds us of the ball-and-socket joint, only this is a hinge joint, and does not move in so many directions.
The tibia can move towards the femur and away from it on this hinge.
When our little friend gets ready to jump, he draws the tibia close up to the femur. When he jumps, he pushes the femur quickly away from the tibia.
If you watch the grasshoppers, you will soon understand just how they use their hind legs in jumping.
The tarsus bends easily.
It has three joints.
The last segment is a cunning little foot.