Shoulder pain can be caused by any of the muscles, tendons, and ligaments that make up the complex structure of the shoulder.
To understand your shoulder pain it is helpful to know the basic structure of the shoulder, and what part of the shoulder is causing the pain and why.
Shoulder Components Overview
There are a few bones and joints in the shoulder complex, which might prove useful to know about, before and after you are stricken with shoulder pain.
There is much more entailed in the construction and operation of the shoulder, but if the basics are known, the pain may make more sense. Because the intricate muscles, tendons and ligaments are not visible, it is hard to imagine what is causing pain. This is a very brief description of some major components that I hope you will find helpful.
Shoulder Bones and Joints
Clavicle – is also known as the collarbone, and is the only bony attachment between the trunk and upper arm (humerus). It is S-shaped, and connects with the chest bone (sternum), and acromion of the shoulder blade (scapula).
Scapula – is the shoulder blade, and is a flat, triangular bone. Along with the acromion, spine, and coracoid process, the scapula forms the back portion of the shoulder.
Humerus – is the upper arm, which extends from the shoulder to the elbow.
Cortacoid process – is a structure which projects from the scapula (shoulder blade), and is the attachment point of shoulder ligaments and muscles.
Acromion – is the outer end of the scapula (shoulder blade), to which the clavicle (collar bone) is attached, and forms the “point” of the shoulder.
Acromioclavicular Joint (AC Joint) – is the point where the clavicle (collar bone) meets the acromion of the scapula (shoulder blade).
Shoulder ligaments are soft tissue structures, which connect bones to other bones. Along with ligaments which join the bones, are muscles, which may be superficial (extrinsic muscles), or deep (intrinsic muscles). When the ligaments are stretched unnaturally, sprained, strained, inflamed, or torn, there will unfortunately be pain. Between the acromioclavicular joint (AC Joint), there are some primary ligaments to be aware of.
Glenohumeral Ligaments (GHL) – are three ligaments which maintain the stability of the shoulder, and help to keep the shoulder in place.
Coracoclavicular Ligaments (CCL) – are two extremely strong ligaments (trapezoid and conoid), which help to stabilize the AC joint, and help to keep the shoulder “square”.
Coracoacromial ligaments (CAL) – link the coracoid process (a small, hook-like structure on the scapula), to the acromion.
Shoulder Muscles and Brief Function Overview
Serratus Anterior muscle – stabilizes the scapula (shoulder blade) when the hand exerts pressure on an object.
Subclavius muscle – depresses the shoulder, draws the shoulder down and forward.
Pectoralis Minor muscle – lowers the shoulder blade (scapula).
Sternocleidomastoid muscle (SCM) – flexes and rotates the head.
Levator Scapulae – raises the shoulder blade (scapula).
Trapezius – lifts the clavicle (collarbone), elevates and rotates the shoulder blade (scapula) outward.
Deltoid – flexes, extends, and rotates the arm.
This is a long and technical list, but the shoulder is very complex and I hope this helps you to understand your shoulder pain a little better.
Do enter your details in the box on this page because I would like to send you my completely free shoulder pain report.
Tim Allardyce DO MCSP SRP