User Friendly Upper Body Muscle Guide for Pain Part 2

 This is a continuation of breaking down the muscles and their actions. As in the first part (read it here), it's a good idea to identify the motion giving you trouble and from there looking deeper to the muscles involved in that motion.

 These muscles are primarily the assisting muscles. They also stabilize your bones while the primary muscles do the major action. They are commonly injured when the primary (bigger) muscles become dysfunctional, which can happen because of bad form or posture, injuries, or a primary muscle being too short (tight) or too weak. It is unusual for these small muscles to be used as the primary action creator. I will keep this as simple and user friendly as possible. Hopefully you find it useful.

This first group of muscles commonly referred to as SITS (Supraspinatus, Infraspinatus, Teres Minor and Subscapularis), assist each other as well as the larger muscles.

Supraspinatus
Goes from upper portion of the shoulder blades closest to the spine to the top outer edge of the upper arm bone.

Common Actions
Assist the Posterior Deltoids and the Upper and Middle Trapezius to swing the arms backwards as if getting ready to bear hug a bear. It also assist Posterior Deltoid in rotating the arm back through the shoulder joint, like a baseball pitcher "winding up" for the pitch. It also stabilizes the shoulder joint keeping the ball in the socket.

Infraspinatus
Goes from lower edges of your shoulder blades closest to spine. It spans across the flat side of the shoulder blade to  the back side of the upper arm bone below the Supraspinatus .

Common Actions
Does about the same as the Supraspinatus. It can be argued most of the contribution is the rotating action.

Teres minor
Goes from top half of the shoulder blades right on the edge closest to your arms. Connects to the upper arm directly below the Infraspinatus.

Common Actions
Once again helps with the same action.

Subscapularis
Goes from face of the shoulder blades facing inwards to the area in front of your Infraspinatus at your armpit.

Common action:
Well known for stabilizing the shoulder, and rotating the arm through the shoulder. You see this in action if you give a straight armed thumbs down like a Caesar.

 Now for the rest of the assisting muscles.

Teres major
Goes from the lowest part of your shoulder blade to near the top of the upper arm bone.

Common Action:
Assist the big Latissimus muscle in swinging the arms back and can assist to rotate the shoulder so  thumbs turn downward (like above). Action is like you want to slap something behind you with straight arms and palms facing back.

Serratus Anterior
Goes from the first eight ribs to the inside edge of your shoulder blades (facing your body and closer to your spine)

Common Actions:
 Squeezes the shoulder blades and rotates them upward WHILE keeping them close to your ribs. Confused? Think when your arms are in a handstand. Swinging weights above your head with straight arms and "downward facing dog" for the yogis out there.

Pectoralis Minor

 Goes from the upper and outer surface of ribs 3,4 and 5, while including corner area on the side of the abdominals (tummy muscles). It comes together and meets on the upper shoulder blade close to your spine.

 Common Actions
 It assist the Pectoralis Major, Latissimus Dorsi, and Lower Trapezius by pulling your shoulders downward and back, while bringing the chest out. Also helps with inhaling. Feel this in motion when you take a deep breath through your nose.


Rhomboid Major
Goes from the spine to the shoulder blade ( facing your ribs on the edge near your upper arm).

Common Actions
 Assist the Posterior Deltoid, Latissimus Dorsi, and Trapezius in squeezing your shoulder blades together.


Rhomboid Minor
Goes from the base of your skull to the thoracic spine  and top edge of your shoulder blades.

Common Actions
Just about the same as Rhomboid Major

Levator Scapula
Goes from neck to the edge of your shoulder blades closest to your spine.

Common Actions
 Assist the Trapezius for shrug, but also can act alone tilting your neck and rotating your head in that same direction.


Coracobracialis
Goes from the shoulder blade inside tip (closest to your upper arm) to the middle of the upper arm bone.

 Common Action
 Assist the Anterior Deltoids, Pectoralis Major, and of course Bicep Brachii. Mainly assist when it comes to swinging your arms upward or swinging the arms across the front of your body. Swing your arms like Conan.