Clavicular Head Of Pectoralis Major

The pectoralis major is made up of three heads: the clavicular, sternal, and abdominal head. This muscle comprises a large part of your chest musculature. The clavicular head is the topmost head and attaches to the bottom of the collarbone just above the breastbone. It connects to the side of the upper arm bone.

The clavicular head is primarily activated when raising and internally rotating the shoulders. It also supports movements involving bringing the arm across the body. During the hand-release pushup, the clavicular head assists in pushing the body upward and extending the arms to the sides.

Studies have shown the pectoralis major can reach activation levels of 300—400 mV during push-up variations. This represents the velocity generated to initiate muscle contraction. It is an effective way to measure the muscle’s effort during this exercise.

Sternal Head Of Pectoralis Major

The sternal head of the pectoralis major sits just below the clavicular head. It spans across the breastbone and attaches to either side of your obliques (side ab muscles).

The sternal head is active during shoulder adduction (bringing the arm across your body) and lengthening the shoulder when flexed. This makes it important during daily activities involving throwing, pulling, and pushing.

During the hand release push-up, the sternal head works with the clavicular head to support the shoulders and upper back. It also aids in maintaining spinal stability and reduces strain on the lower back.

Abdominal Head Of Pectoralis Major

The abdominal head of the pectoralis major is the lowest of the three heads. It originates just beneath the breastbone and spans the abdomen. Like the other two heads, it connects to each side of the upper arm bones.

The abdominal head functions mainly to bring the arms into the body, and flex and extend the shoulders. This is crucial during the hand-release push-up especially as you extend your arms out to the sides. The abdominal head also engages to stabilize the chest and upper abs, applying tension to hold your torso steady.

Anterior Deltoid

The anterior deltoid muscle originates from the lateral part of the collarbone and inserts into the deltoid tuberosity of the upper arm bone. It forms the large rounded contour of the shoulder. It actively supports movements required to raise the arm forward and away from the body and rotate the shoulder.

The anterior deltoid is mainly activated during the hand-release push-up to stabilize the upper arms keeping them steady throughout the movement. It also supports shoulder rotation and prevents shoulder joint injuries.

Strengthening this muscle also benefits daily activities involving shoulder rotation like getting dressed, reaching for objects, and washing your hair.

Triceps Lateral Heads

The triceps lateral head is one of three heads that make up the triceps brachii. It originates from the back of the upper arm and is inserted into the forearm at the elbow. It is active in daily activities requiring elbow joint stability like pushing yourself up or playing catch with your kids.

The hand-release push-up is a valuable exercise for strengthening this muscle. During the lifting and lowering phases, the lateral head works with the other triceps heads to extend the forearm. It also provides stability to the elbow joint to protect against joint injuries.

Triceps Medial Heads

The triceps medial head is the second muscle that makes up the triceps brachii. Like the lateral head, it originates from the back side of the upper arm extending down to the elbow joint.

The triceps medial head is active in extending the forearm and stabilizing the elbow. This makes it a crucial component in all daily activities involving lifting, pulling, and carrying.

The hand-release push-up targets the triceps medial head throughout the range of motion. When you lower yourself down, the triceps contract to flex the elbow and activate the medial head. By keeping your upper arms stable throughout the movement, you will maximize the medial head’s engagement.

Triceps Long Heads

The triceps long head is the third muscle that makes up the triceps brachii. It originates from the bottom of the shoulder blade and, like the other tricep heads, inserts into the forearm. However, it is the only tricep head that crosses the shoulder joint, taking part in both shoulder and elbow extension.

This muscle is particularly active during overhead extension, playing a key role during the hand-release push-up. It activates to support the shoulder and elbow joints during the lowering and pushing-up phases. Additionally, the movement to extend both arms to the sides stretches the muscle, increasing its activation.

Upper Rectus Abdominis

The upper rectus abdominis forms the upper section of the rectus abdominis — the long frontal trunk muscle known as abs. It spans from the front of the pelvis up to the bottom of the breastbone. It is actively involved in all activities requiring core strength and stability.

The upper rectus abdominis supports spinal flexion during the hand-release push-up to engage the torso while in the plank position. It also encourages core stabilization to prevent the lower back from arching or dropping out of alignment.

Many fitness enthusiasts wonder do push-ups work abs — this exercise confirms that multiple variations of the push-up are effective in targeting your abs.

Lower Rectus Abdominis

The lower rectus abdominis forms the lower section of the rectus abdominus. It works closely with the upper section to provide core strength and stability during torso lengthening activities.

The lower rectus abdominis works with the upper section during this exercise to lengthen the torso and protect the lower back. It contributes to increased spinal stability and alignment which also supports proper posture. Furthermore, it assists in keeping the torso strong and stable while you’re in the plank position.

Obliques

The obliques are the outer part of your abdominal wall, extending from the bottom of the ribs down to the pelvis. They are active during trunk flexion and rotation and provide support to the spine during core engagement activities. They also assist during digestive activities.

The obliques primarily work along with the other ab muscles to stabilize the trunk during this exercise. Additionally, they protect the spine, maintaining postural alignment and preventing lower back strain.

This depicts how the muscles of the core and spinal column are very impactful as a group. They work together to support postural alignment, core strengthening, and trunk stabilization.

Serratus Anterior

The serratus anterior is an influential shoulder muscle that functions as a prime mover during shoulder retraction exercises. This refers to contracting to bring the shoulder blades together. It supports many daily activities involving the shoulders like shrugging, throwing, and reaching for objects.

The serratus anterior is a secondary mover during the hand-release push-up assisting with shoulder flexion and stability as you lower down. It also supports the upper back muscles to maintain proper spinal alignment, improving posture.

Erector Spinae

The erector spinae comprises a group of muscles that run along the spine. They originate from the back of the pelvis, extending up along the back to the neck. It is composed of three main muscle groupings: the iliocostalis, the longissimus, and spinalis.

The erector spinae is primarily activated during the hand-release push-up to provide spinal stability and prevent straining the lower back. It helps maintain a neutral, aligned spine and contributes to improving posture.