These models incorporate anatomical data from BodyParts3D, Database Center for Life Science (DBCLS), Japan [Mitsuhashi N, Fujieda K, Tamura T, Kawamoto S, Takagi T, Okubo K. BodyParts3D: 3D structure database for anatomical concepts. Nucleic Acids Res. 2009;37(Database issue):D782–D785. doi:10.1093/nar/gkn613], an open-access database.
Source: https://lifesciencedb.jp/bp3d/
Source: https://lifesciencedb.jp/bp3d/
1.1. Upper extremity muscle groups:
Three-dimensional model of the muscle groups of the upper extremity, extending from the shoulder girdle to the forearm and hand.
Three-dimensional model of the muscle groups of the upper extremity, extending from the shoulder girdle to the forearm and hand.
1.2. Shoulder muscles innervated by the brachial plexus
Three-dimensional postero-lateral view of the shoulder region, displaying the shoulder muscles innervated by plexus brachialis levator scapulae, rhomboids, latissimus dorsi, serratus anterior, teres major, supraspinatus, infraspinatus. Pectoralis major m. is preented on another 3D model. Trapezius m. is not presented here but can be found in paraspinal muscles section of the atlas:
Muscles:
• Levator scapulae – arising from the transverse processes of C1–C4 and inserting at the superior angle and medial border of the scapula; elevates and assists in downward rotation of the scapula.
• Rhomboid minor and major – extending from the nuchal ligament and spinous processes of C7–T5 to the medial border of the scapula; retract and stabilize the scapula against the thoracic wall.
• Latissimus dorsi – forming the large superficial layer, originating from T7–T12, thoracolumbar fascia, iliac crest, and lower ribs, inserting into the floor of the intertubercular sulcus of the humerus.
• Teres major – arising from the inferior angle of the scapula and passing anteriorly to insert on the humerus; acts in adduction and medial rotation.
• Serratus anterior – originating from the lateral surfaces of ribs 1–8 and inserting along the medial border of the scapula; responsible for protraction and upward rotation of the scapula.
Nerves and vessels:
• Dorsal scapular nerve and artery (supplying levator scapulae and rhomboids).
• Long thoracic nerve (running along the lateral thoracic wall to innervate serratus anterior).
• Thoracodorsal nerve and artery (coursing along the deep surface of latissimus dorsi).
• Posterior circumflex humeral artery (emerging near the quadrangular space).
Three-dimensional postero-lateral view of the shoulder region, displaying the shoulder muscles innervated by plexus brachialis levator scapulae, rhomboids, latissimus dorsi, serratus anterior, teres major, supraspinatus, infraspinatus. Pectoralis major m. is preented on another 3D model. Trapezius m. is not presented here but can be found in paraspinal muscles section of the atlas:
Muscles:
• Levator scapulae – arising from the transverse processes of C1–C4 and inserting at the superior angle and medial border of the scapula; elevates and assists in downward rotation of the scapula.
• Rhomboid minor and major – extending from the nuchal ligament and spinous processes of C7–T5 to the medial border of the scapula; retract and stabilize the scapula against the thoracic wall.
• Latissimus dorsi – forming the large superficial layer, originating from T7–T12, thoracolumbar fascia, iliac crest, and lower ribs, inserting into the floor of the intertubercular sulcus of the humerus.
• Teres major – arising from the inferior angle of the scapula and passing anteriorly to insert on the humerus; acts in adduction and medial rotation.
• Serratus anterior – originating from the lateral surfaces of ribs 1–8 and inserting along the medial border of the scapula; responsible for protraction and upward rotation of the scapula.
Nerves and vessels:
• Dorsal scapular nerve and artery (supplying levator scapulae and rhomboids).
• Long thoracic nerve (running along the lateral thoracic wall to innervate serratus anterior).
• Thoracodorsal nerve and artery (coursing along the deep surface of latissimus dorsi).
• Posterior circumflex humeral artery (emerging near the quadrangular space).
2. 1. Rotator cuff and shoulder muscles
Three-dimensional view of the rotator cuff muscles and additional shoulder girdle muscles.
Rotator Cuff (SITS muscles):
1. Supraspinatus – located in the supraspinous fossa of the scapula, coursing under the acromion to insert on the greater tubercle of the humerus.
2. Infraspinatus – arises from the infraspinous fossa, inserting on the posterior aspect of the greater tubercle.
3. Teres minor – originates from the lateral border of the scapula, inserting adjacent to infraspinatus on the greater tubercle.
4. Subscapularis – arises from the subscapular fossa (anterior surface of scapula), inserting onto the lesser tubercle of the humerus.
Vascular Supply:
• Branches of the subscapular artery, suprascapular artery, and circumflex humeral arteries.
Innervation:
• Suprascapular nerve (C5–C6): supraspinatus, infraspinatus.
• Axillary nerve (C5–C6): teres minor, deltoid.
• Upper and lower subscapular nerves (C5–C6): subscapularis.
Function of the Rotator Cuff:
• Supraspinatus: initiates arm abduction (first 15°).
• Infraspinatus: lateral rotation of the humerus.
• Teres minor: lateral rotation and stabilization.
• Subscapularis: medial rotation and adduction.
• Collectively, these muscles stabilize the humeral head in the glenoid fossa during arm movements.
Three-dimensional view of the rotator cuff muscles and additional shoulder girdle muscles.
Rotator Cuff (SITS muscles):
1. Supraspinatus – located in the supraspinous fossa of the scapula, coursing under the acromion to insert on the greater tubercle of the humerus.
2. Infraspinatus – arises from the infraspinous fossa, inserting on the posterior aspect of the greater tubercle.
3. Teres minor – originates from the lateral border of the scapula, inserting adjacent to infraspinatus on the greater tubercle.
4. Subscapularis – arises from the subscapular fossa (anterior surface of scapula), inserting onto the lesser tubercle of the humerus.
Vascular Supply:
• Branches of the subscapular artery, suprascapular artery, and circumflex humeral arteries.
Innervation:
• Suprascapular nerve (C5–C6): supraspinatus, infraspinatus.
• Axillary nerve (C5–C6): teres minor, deltoid.
• Upper and lower subscapular nerves (C5–C6): subscapularis.
Function of the Rotator Cuff:
• Supraspinatus: initiates arm abduction (first 15°).
• Infraspinatus: lateral rotation of the humerus.
• Teres minor: lateral rotation and stabilization.
• Subscapularis: medial rotation and adduction.
• Collectively, these muscles stabilize the humeral head in the glenoid fossa during arm movements.
2.2. Deltoid m.
Three-dimensional model of the deltoid muscle, highlighted with its three portions: anterior (blue), middle (green/blue), and posterior (yellow), covering the shoulder and forming the rounded contour of the deltoid region.
Attachments:
• Anterior fibers: lateral third of clavicle. • Middle fibers: acromion. • Posterior fibers: spine of scapula. • Insertion: Deltoid tuberosity of the humerus.
Vascular Supply:
• Primarily from the thoracoacromial artery (deltoid branch).
• Additional supply from the posterior circumflex humeral artery.
Innervation:
• Axillary nerve (C5–C6).
Function:
The deltoid muscle is the primary abductor of the arm, also assisting in flexion, extension, and rotation of the shoulder.
The 3D model presents two important regions: the triangular space (foramen trilaterum) is bordered superiorly by the teres minor, inferiorly by the teres major, and laterally by the long head of the triceps, transmitting the circumflex scapular artery without any major nerve. The quadrangular space (foramen quadrilaterum) lies between the teres minor above, teres major below, the long head of the triceps medially, and the surgical neck of the humerus laterally, allowing passage of the axillary nerve together with the posterior circumflex humeral artery and vein.
Three-dimensional model of the deltoid muscle, highlighted with its three portions: anterior (blue), middle (green/blue), and posterior (yellow), covering the shoulder and forming the rounded contour of the deltoid region.
Attachments:
• Anterior fibers: lateral third of clavicle. • Middle fibers: acromion. • Posterior fibers: spine of scapula. • Insertion: Deltoid tuberosity of the humerus.
Vascular Supply:
• Primarily from the thoracoacromial artery (deltoid branch).
• Additional supply from the posterior circumflex humeral artery.
Innervation:
• Axillary nerve (C5–C6).
Function:
The deltoid muscle is the primary abductor of the arm, also assisting in flexion, extension, and rotation of the shoulder.
The 3D model presents two important regions: the triangular space (foramen trilaterum) is bordered superiorly by the teres minor, inferiorly by the teres major, and laterally by the long head of the triceps, transmitting the circumflex scapular artery without any major nerve. The quadrangular space (foramen quadrilaterum) lies between the teres minor above, teres major below, the long head of the triceps medially, and the surgical neck of the humerus laterally, allowing passage of the axillary nerve together with the posterior circumflex humeral artery and vein.
3. Biceps brachii and brachialis m.
Three-dimensional model of the arm flexor compartment, highlighting the biceps brachii (superficial, red) and brachialis (deep, green) muscles, with their relationship to the brachial vessels
Attachments:
Biceps brachii muscle
• Long head – supraglenoid tubercle of scapula.
• Short head – coracoid process of scapula.
• Insertion – radial tuberosity and bicipital aponeurosis into the deep fascia of the forearm.
Brachialis muscle
• Origin – distal half of anterior humeral shaft.
• Insertion – coronoid process and tuberosity of ulna.
Vascular Supply:
• Muscular branches of the brachial artery.
Innervation:
• Biceps brachii muscle: Musculocutaneous nerve (C5–C6).
• Brachialis: Musculocutaneous nerve (C5–C6) and radial nerve (lateral portion).
Function:
• Biceps brachii: Flexes elbow
• Brachialis: Primary flexor
Three-dimensional model of the arm flexor compartment, highlighting the biceps brachii (superficial, red) and brachialis (deep, green) muscles, with their relationship to the brachial vessels
Attachments:
Biceps brachii muscle
• Long head – supraglenoid tubercle of scapula.
• Short head – coracoid process of scapula.
• Insertion – radial tuberosity and bicipital aponeurosis into the deep fascia of the forearm.
Brachialis muscle
• Origin – distal half of anterior humeral shaft.
• Insertion – coronoid process and tuberosity of ulna.
Vascular Supply:
• Muscular branches of the brachial artery.
Innervation:
• Biceps brachii muscle: Musculocutaneous nerve (C5–C6).
• Brachialis: Musculocutaneous nerve (C5–C6) and radial nerve (lateral portion).
Function:
• Biceps brachii: Flexes elbow
• Brachialis: Primary flexor
4. Triceps and coracobrachialis m.
Three-dimensional model of the triceps brachii muscle, with its three heads color-coded: long head (blue), lateral head (yellow), and medial head (green), converging to a common tendon inserting on the olecranon of the ulna.
Attachments:
• Long head: Infraglenoid tubercle of scapula → olecranon of ulna.
• Lateral head: Posterior humerus, superior to radial groove → olecranon of ulna.
• Medial head: Posterior humerus, inferior to radial groove → olecranon of ulna.
Vascular Supply:
• Profunda brachii artery (deep brachial artery).
Innervation:
• Radial nerve (C6–C8).
Function:
• Primary extensor of the forearm at the elbow;
Coracobrachialis m
Attachments:
• Origin: Coracoid process of scapula (together with the short head of biceps brachii).
• Insertion: Medial surface of the humeral shaft, at the middle third.
Vascular Supply:
• Muscular branches of the brachial artery.
Innervation:
• Musculocutaneous nerve (C5–C7), which pierces the muscle.
Function:
• Flexion and adduction of the arm at the shoulder;
Three-dimensional model of the triceps brachii muscle, with its three heads color-coded: long head (blue), lateral head (yellow), and medial head (green), converging to a common tendon inserting on the olecranon of the ulna.
Attachments:
• Long head: Infraglenoid tubercle of scapula → olecranon of ulna.
• Lateral head: Posterior humerus, superior to radial groove → olecranon of ulna.
• Medial head: Posterior humerus, inferior to radial groove → olecranon of ulna.
Vascular Supply:
• Profunda brachii artery (deep brachial artery).
Innervation:
• Radial nerve (C6–C8).
Function:
• Primary extensor of the forearm at the elbow;
Coracobrachialis m
Attachments:
• Origin: Coracoid process of scapula (together with the short head of biceps brachii).
• Insertion: Medial surface of the humeral shaft, at the middle third.
Vascular Supply:
• Muscular branches of the brachial artery.
Innervation:
• Musculocutaneous nerve (C5–C7), which pierces the muscle.
Function:
• Flexion and adduction of the arm at the shoulder;