The coracobrachialis muscle is able to give you pain at the front of your shoulder and the back of your upper arm and forearm.
People that suffer from tightness, tender or trigger points in this muscle, usually also have problems with muscles that act with it synergistically/together.
Those are the pectoralis major, the front part of the deltoid and the short head of the biceps brachii.
When your coracobrachialis contains trigger points, it can give you pain right at their location and send it to other, seemingly unrelated areas of your body.
In the pictures you can see that trigger points in the coracobrachialis can create pain that radiates down the backside of your arm to the back of your hand.
It might also be possible that you feel an ache at the side of your shoulder.
Less often the back of your shoulder will be painful.
It can be involved in the following symptoms.
Scratching your back – the muscle has to contract to lift the arm – can be painful .
Also reaching back to get into your jacket might be painful as the muscle has to stretch in order not to inhibit the motion.
The coracobrachialis originates from the processus coracoideus – the bony and peaky landmark at the front of your shoulder – and runs to the inner side of your humerus.
The X in the picture displays the area that is commonly afflicted with trigger points.
It is known that the coracobrachialis is overloaded especially with actions that also overwork the synergistic muscles that are listed above.
Trigger and tender points develop first in those muscles and then in the coracobrachialis.
Thus excessive chest workouts or activities where you have to press your arm very tight towards your body – e.g. work on the rings in gymnastics – are a common source of trouble.
If you find it, place your thumb on it and search along its way for tender spots and massage them with care.
Be aware that you are working in area with lots of nerves. So make sure to stay on the muscle and be gentle, that in case you hit a nerve it is not that “harmful”.