The QL (Quadratus Lumborum)

Comments; This is a primary target on the back when fighting,
It is easy to hit and can be hit even from the front of the opponent if you are close enough, the muscle is a deep muscle and so you have to hit it quite hard for a spasm effect to occur, hit towards the centre of the person, the direction is important, Watch Pressure points of the back 1 video on you tube

The Infraspinatus

COMMENTS: This muscle can also refer pain into the vertebral border of the scapula. This muscle has a large attachment and is fairly thin. Because of this, it is normal for it to be a little tender when compressed against the scapula
For a pressure point strike hit where the circle is on the illustration as you can see there is a nerve plexus at this point, the Whole arm will become numb.

Watch Pressure points of the back 3 Video on youtube

The Supraspinatus

COMMENTS: This muscle runs under the clavicle, attaching to the top of the humerus. It pulls the arm out to the side. The supraspinatus and deltoid are the only two muscles that lift the arm to the side (the trapezius helps to stabilize and helps after 90 degrees). If strained,so if hit hard this can Spasm and immobilise the lifting of the arm, there is also a lot of pain associated with this hit.

Watch pressure points of the back 2 Video on youtube