Supine Kettlebell Arm Bar

Latissimus Dorsi

The latissimus dorsi, or lats, are a flat, v-shaped muscle in the back. It supports respiration (breathing) and stabilizes the spine during movement.

Since the lats are connected to the humerus (an arm bone), they can straighten the arm behind the body, turn it inward, and bring the arm close. This exercise utilizes the lats to steady the shoulder and push the arm away from the body.

Obliques

The obliques are on the sides of the abdomen above the rib cage.

When healthy and strong, these abdominal muscles can better stabilize and protect the spine from injury. The obliques can more smoothly perform lateral bending and rotational movements in sports and daily life by stabilizing the trunk.

The obliques are activated as a secondary muscle in the supine kettlebell arm bar. They help stabilize the spine and rotate the working shoulder off the ground.

Quadriceps And Hamstrings

The quadriceps in the front of the upper leg are made up of four muscles that establish movement, like walking. On the opposite side of the leg are three muscles comprising the hamstrings, including the semimembranosus, biceps femoris, and semitendinosus. They stretch from below the knee up the back of the thigh, helping stabilize and control leg movement.

Keeping the quadriceps and hamstrings healthy is critical for supporting functional and athletic actions like walking, jumping, running, and sitting. In this exercise, these leg muscles help stabilize the body to increase engagement in the primary muscles.

Serratus Anterior

The serratus anterior is a fan-shaped muscle that stretches from the chest wall to the scapula (shoulder blade). It stabilizes the shoulder blades and supports arm movement, helping reduce injury risk to the shoulder. During the supine kettlebell arm bar, the serratus anterior stabilizes the shoulder while it executes the exercise’s movement pattern.

Wrist Extensors

The wrist extensors extend from the forearm to the wrist, enabling wrist adduction and extension. During wrist extension, the hand is drawn backward to the forearm. In contrast, during wrist adduction, the wrist bends inward towards the underside of the forearm.

In this exercise, these muscles stabilize the wrist to protect the joint from potential injury. The wrist extensors keep the working arm’s wrist straight while holding the kettlebell to prevent excessive bending and strain.

Clavicular Head of Pectoralis Major

Comprising the pectoralis major are three heads: the sternocostal, clavicular, and abdominal heads. The clavicular head surrounds the clavicle (collarbone) to establish movement in the collarbone and arm.

Anytime you raise your arm above your head, the clavicular head is activated to produce this action. Likewise, in this exercise, this muscle is engaged to raise the kettlebell above the head.

Posterior Deltoid

The posterior deltoid, or rear delt, is at the back of the shoulder. It creates arm movements like horizontal abduction, arm extension, and shoulder rotation.

The posterior deltoid is used in numerous daily actions, like pulling open doors or waving goodbye. In the supine kettlebell arm bar, the posterior deltoid drives the arm away from the body to lift the kettlebell.

Gluteus

The gluteals, or gluteus, is a collection of muscles that together make up the buttocks. These include the gluteus minimus, medius, and maximus muscles. Of the three, the gluteus maximus is the largest, reaching from the hip to the buttocks.

Altogether, the gluteus muscles stabilize the pelvis to preserve upper and lower body alignment. They create propulsion (forward motion) needed for functional and athletic movements like walking, jumping, and running. For this exercise, the gluteus keeps the hips stable and prevents them from lifting off the floor.

Upper Trapezius And Middle Trapezius

The trapezius is a muscle in the upper back popularly known as the traps. The traps can be categorized into sections: upper, middle, and lower.

Of the three sections, the upper trapezius is the smallest, covering the shoulders and base of the neck. It keeps the neck upright, stabilizes the scapula, moves the neck, and lifts the arms. Keeping the upper trapezius healthy is critical for preventing shoulder pain and supporting good posture.

The middle trapezius extends from the top of the shoulders into the back. It aids shoulder stabilization and upper body alignment, produces arm extension, and pulls the shoulders back. In this exercise, the upper and middle traps are integrated to stabilize the shoulders and preserve proper neck position.