Hello! Shorty here to give you some #necksupport. Today's topic is a group of muscles called the scalenes. There are three--anterior, medium and posterior OR front, middle and back. They attach to the transverse processes of your vertebrae (the little arms that stick out to the sides) and run down along your neck, connecting to your first and second ribs.
This is looking straight on like you were looking in the mirror. The bright red muscles are the scalenes. Image from Wikipedia
Why are these things important? Well, because they attach to both your neck and your ribcage. If they get tight they can cause compression in your neck and do nasty things like shift, tilt or rotate your head. They can also inhibit breathing in the upper part of your chest if they are very tight and always engaged (they should slightly assist your upper ribs moving up and down with your breathing).
There are little places in each vertebral (spinal) segment where nerves emerge and continue into part of your body. Some of the nerves that feed into your shoulders, arms and hands move through and intertwine with the scalenes. If they are tight, they can inhibit or irritate these nerves from moving smoothly. Nobody wants a cramped nerve, know what I mean?
This image is looking at someone's right shoulder. Look closely at the text. The yellow part is the brachial plexus, a bundle of nerves. It is sandwiched between the anterior and medial scalene muscles and continues underneath the collar bone. Image from Gray's Anatomy.