Arm Circle

Anterior Deltoid

The anterior deltoid is one of three heads that make up the shoulder's deltoid muscle. Located at the front of the shoulder, it is often called the “front delt.” This muscle promotes forward and rotational arm movement. 

The anterior deltoid is used in numerous activities in our daily lives. For example, this muscle is used when you pick up a bag or reach to pull open a door. Keeping this muscle functional is crucial for supporting these everyday actions. 

During arm circles, the anterior deltoid helps establish the circle pattern of the movement. It lifts the arm forward at the beginning of the movement and rotates it. Other exercises, like the shoulder press, actively engage the anterior deltoid to improve its strength and functionality.

Lateral Deltoid

The lateral deltoid is another one of the three heads of the shoulder muscle. The function of this muscle is to promote up, down, and side movement of the arm. Like all the deltoid heads, the lateral deltoid or “side delt” is crucial for stabilizing the shoulder joint. 

This muscle supports everyday arm movements, like washing your hair or pulling your seatbelt on. Any action that involves lifting the arm requires the lateral deltoid to support its movement. This is included in the arm circles exercise, where the arm is lifted and rotated in a large circle pattern. 

As you perform the arm circle, the lateral deltoid is engaged to support the motion. This, in turn, helps strengthen the muscle to support the shoulder joint better. 

Posterior Deltoid

The posterior deltoid is the last of the three heads of the shoulder muscle. The posterior deltoid or “rear delt” is found at the back of the shoulder. It is responsible for the external rotation of the shoulder, backward extension of the arm, and horizontal abduction of the shoulder. 

External shoulder rotation involves moving the upper arm away from the torso. Backward extension of the arm is when we reach behind our body to grab something with our hand. Horizontal abduction of the shoulder means the arm is moved away from the body’s midline. 

Maintaining strength and health in the posterior deltoid is crucial for supporting a healthy shoulder joint. It reduces injury risk and aids the arm's functional performance in everyday activities, like pulling a chair out. 

In arm circles, the posterior deltoid is incorporated through the backward extension of the arm in the circle motion. This encourages muscle engagement of the rear delt to improve strength and range of motion in the shoulder joint.

Upper Trapezius

The upper trapezius is a small part of the broader trapezius muscle of the back. This muscle is shaped like a flat triangle and spreads across the back, neck, and shoulders. The smaller section of the upper trapezius stretches across the base of the neck and the top of the shoulders. 

We use the upper trapezius in daily movements like shrugging our shoulders or glancing both ways at a street. This muscle establishes movement in the neck and arms, allowing the neck to rotate and the arms to lift. 

Prioritizing strength in the upper trapezius is crucial for spinal support and healthy posture. Exercises like arm circles can promote a healthy range of motion and improve strength in the upper trapezius. This will help improve posture, establish healthy shoulder and neck mobility, and reduce injury risk in these areas. 

Middle Trapezius

The middle trapezius is another part of the trapezius muscle. Also known as the “mid trap,” it runs across the shoulder below the upper trapezius. It supports numerous bodily functions, like pinching the scapula back, stabilizing the shoulders, and moving the arm backward. 

The importance of the middle trapezius should not be overlooked in everyday actions. By retracting the shoulder blades, arm movement is accessed freely. From throwing a ball to pulling a car door open, the capacity to retract the scapula allows for these actions. 

Performing arm circles is beneficial because of the active engagement of these muscles used to perform the movement. It can help release tension and stress in the muscles, improve strength, and increase range of motion. Incorporate this exercise into your shoulders and traps workout as an effective dynamic stretch. 

Serratus Anterior

The serratus anterior is a muscle located between the chest wall and the scapula. It is an expansive fan-shaped muscle known as the “big swing muscle” or “boxer’s muscle.” The muscle supports arm movement and stabilizes the scapula to the ribcage when at rest or during movement. 

When we wash our hair and change clothes, the serratus anterior lifts the arm. In the arm circle exercise, it acts as a secondary muscle to support arm movement and stabilize the shoulder blades. 

Sternal Head Of Pectoralis Major

The pectoralis major of the chest is a large, fan-shaped muscle that consists of three heads, including the sternal head. Of the three heads, the sternal or “sternocostal” head is the largest. It is responsible for arm extension and adduction when the arm moves toward the body. 

Maintaining health and strength in the sternal head is crucial. This muscle is used in seemingly inconsequential actions, like grabbing our car keys and opening doors. Exercising this muscle is essential for functionality in our daily lives. 

In the arm circles exercise the sternal head of the pectoralis major helps rotate and stabilize the scapula. It actively protects the shoulder joint and promotes arm movement throughout the exercise. 

Clavicular Head Of Pectoralis Major

The clavicular head is another of the three heads of the pectoralis major muscle in the chest. This head is found in the clavicle or collarbone area. It establishes movement in the collarbone, necessary for shoulder and arm motion. 

We use the clavicular head to raise our hand above our head and grab things from the fridge. Without a healthy and functional clavicular head, basic actions in our day-to-day lives wouldn’t be easy or possible. Incorporating exercises like arm circles into our routine can promote improvements in the strength and functionality of the muscle.