In this blog post from our muscle biomechanics series, we are going to discuss the Trapezius Muscle.
The trapezius muscle is one of the most important muscles of our upper back and shoulder girdle.
The trapezius has many different actions, involved in the movement of the cervical tract of the spine, scapula, and neck.
The Trapezius has the important function of the stabilizer of the scapula during many movements of our arm.
For example, during the exercise of hummer curl, which involved mainly the Biceps Brachaii Muscle, the upper part of the Trapezius contracts to stabilize the scapula preventing it from being pulled down from the weight acting on the arm.
The Trapezius Muscle is formed by twin muscles disposed on the two sides of the upper and middle spine. It connects the two scapulas with the spine and head bones.
The Trapezius has different origin points such as:
The Trapezius Muscle has three attachment points:
The innervation of the Trapezius Muscle is the accessory nerve ( XI ).
Since the Trapezius Muscle has its origin and insertion in multiple different points, it can make more movements of both the scapula and the head.
The main actions of the Trapezius Muscle are:
These six different movements are permitted with the engagement of the different muscle fibers the trapezius muscle is composed of.
The scapula adduction is permitted when the whole muscle fibers of the trapezius muscle are engaged (watch the video ).
The scapula elevation is permitted when only the upper muscle fibers of the trapezius muscle are engaged (watch the video ).
The scapula’s depression is permitted when only the lower muscle fibers of the trapezius muscle are engaged (watch the video ).
The scapula’s rotation is permitted when only the upper muscle fibers of the trapezius muscle are engaged and fixing the head in a steady position (watch the video ).
The head or vertebral column extension is permitted when only the upper muscle fibers of the trapezius muscle ( both sides ) are engaged and fixing both scapulas in a steady position (watch the video ).
The head or vertebral column lateral flexion is permitted when only the upper muscle fibers of the trapezius muscle ( one side) are engaged and fixing scapulas of the same side in a steady position (watch the video ).
As the Trapezius muscle is linked with the cervical spine and scapulas, it can cause different injuries or conditions affecting the neck and shoulders.
Trapezius muscle injuries can be caused by many conditions such as overuse, poor posture, and trauma.
Here are some of the most common injuries and conditions associated with the trapezius muscle:
Treatment for Trapezius muscle injuries and conditions typically involves a combination of rest, physical therapy, stretching exercises, strengthening exercises, sports therapy such as sports massage, and pain management techniques. In severe cases or when conservative treatments are ineffective, medical interventions such as injections or surgery may be considered.
We advise you to seek a healthcare professional help such as a sports therapist or physiotherapist for an accurate diagnosis and tailored treatment plan if you suspect you have a trapezius muscle injury or related condition.