Not even one muscle can afford to take the day off!
A muscle chain is a group of muscles that work together or influence one another through movement patterns. Did you know that your body is made up of approximately 650 muscles, and each one needs to be worked every day? The toe muscle can't decide to take off for the day, because all the other muscles depend on it. No muscle stands alone. Each is part of a series of links in an invisible chain. If one muscle along the chain (no matter how small) is tight or weak or off-balance, all the other muscles are affected. This creates an unbalanced body prone to pain and injury. A balanced body, where every muscle is worked, is a healthy body.
In the picture above, I'm working through many of my muscle chains as I do windmills in front lunge position. I begin with proper foot alignment by standing on the full flatness of both feet, not allowing the back foot to turn inwards. My quads and my abs are fully engaged to prevent overloading my knees and lower back. My arms are pulling out to decompress my shoulder joints, which allows for greater range of motion, as I move my arms like the blades of a windmill. As I move, my arms are also rotating within the shoulder joints for greater mobility. And since no muscle stands alone, all the muscles in between are working as well. Don't let ANY of your muscles have the day off!