The main function of the rhomboid major muscle is to pull the scapula towards the spine and rotate it downward. This action is known as scapular retraction and helps to stabilize the shoulder blade and support the shoulder joint.
The rhomboid major muscle works in conjunction with the rhomboid minor muscle and the trapezius muscle to perform these actions. The trapezius muscle, which covers much of the upper back and neck, helps to elevate and rotate the scapula. Together, these muscles help to maintain proper posture and support the shoulder joint during movement.
In addition to its role in posture and shoulder stability, the rhomboid major muscle also plays a role in arm movement. It assists in moving the arm backwards and upwards, such as when reaching for an object above the head.
Injuries to the rhomboid major muscle can cause pain and weakness in the upper back and shoulder area. Common causes of injury include strain from lifting heavy objects, poor posture, and overuse. Treatment may include rest, ice, physical therapy, and in severe cases, surgery.