Table 2.

The surface landmarks and anatomical structures deep to the 15 MaSPs

		Vertical of line		Horizontal line		Muscles	Nerves	Vessels
	MaSP	Surface landmarks	Mean length (cm)	Surface landmarks	Mean length (cm)
1	SH-1	Downward from the top of acromion of scapula	12.8 ± 1.3	Medially from line of spinous process of vertebra	14.5 ± 1.8	• M. Infraspinatus (s) • M. Teres minor (s) • M. Teres major (s)	-	• Circumflex scapular artery (d)
2	SH-2	Upward from upper border of clavicle	7.7 ± 1.0	Laterally from body midline	11.5 ± 1.3	• M. Platysma (s) • M. Sternocleidomastoid (m) • M. Levator scapulae (d) • M. Scalenus posterior (d) • M. Scalenus medius (d)	• Cervical plexus (m)	• External jugular vein (s)
3	SH-3	Upward from upper border of clavicle	6.6 ± 0.9	Laterally from body midline	10.2 ± 1.3	• M. Platysma (s) • M. Sternocleidomastoid (m) • M. Levator scapulae (d) • M. Scalenus posterior (d) • M. Scalenus medius (d)	• Cervical plexus (m)	• External jugular vein (s)
4	SH-4	Upward from upper border of clavicle	1.6 ± 0.4	Laterally from body midline	7.5 ± 0.9	• M. Platysma (s) • M. Sternocleidomastoid (s) • Inferior belly of M. Omohyoid (m) • M. Scalenus medius (d) • M. Scalenus anterior (d)	• Brachial plexus (d)	• The 3rd part of subclavian artery (m)
5	SH-5	Posteriorly from the anterior axillary fold	7.8 ± 0.9	Midaxillary line	0	• M. Latissimus dorsi (s) • M. Teres major (s) • M. Subscapularis (m)	• Thoracodorsal nerve (s) • Axillary nerve (d) • Radial nerve (d)	• Thoracodorsal artery & vein (s) • Anterior & posterior circumflex humeral arteries (d) • Circumflex scapular artery (d)
6	MA-1	Downward from the greater tuberosity of humerus	9.1 ± 1.3	Laterally from the anterior axillary fold	2.8 ± 0.9	• M. Biceps brachii (short head) (s) • M. Coracobrachialis (s) • M. Biceps brachii (long head) (d)	• Median nerve (s)	• Brachial artery & vein (s)
7	MA-2	Downward from the greater tuberosity of humerus	15.4 ± 1.4	Medially from medial bicipital furrow	1.8 ± 0.5	• M. Biceps brachii (long head) (s) • M. Coracobrachialis (s) • M. Brachialis (d)	• Median nerve (s) • Ulnar nerve (s)	• Basilic vein (s) • Brachial artery & vein (s)
8	MA-3	Downward from the medial cubital fossa	0	Laterally from the middle point of medial cubital fossa	0	• Biceps brachii tendon (m) • Bicepital aponeurosis (m) • M. Brachialis (d)	• Median nerve (m)	• Cephalic vein (s) • Medial cubital vein (s) • Basilic vein (s) • Brachial artery & vein (m)
9	MA-4	Downward from the medial cubital fossa	11.4 ± 1.0	Laterally from the middle point of medial cubital fossa	2.5 ± 0.8	• Pronator teres tendon (s) • M. Flexor carpi radialis (s) • Palmaris longus tendon (s) • M. Flexor digitorum superficialis (s) • M. Flexor pollicis longus (d) • M. Flexor digitorum profundus (d)	• Median nerve (s) • Ulnar nerve (s) • Anterior interosseous nerve (d)	• Ulnar artery & vein (s) • Radial artery (s) • Anterior interosseous artery & vein (d)
10	MA-5	Downward from the medial cubital fossa	22.8 ± 1.5	Laterally from the middle point of imaginary line was drawn from radial styloid process to ulnar styloid process	0	• Flexor carpi radialis tendon (s) • Palmaris longus tendon (s) • Flexor digitorum superficialis tendon (s) • Flexor carpi ulnaris tendon (s) • M. Pronator quadratus (m)	• Median nerve (s) • Ulnar nerve (s) • Anterior interosseous nerve (d)	• Radial artery (s) • Ulnar artery & vein (s) • Anterior interosseous artery & vein (d)
11	LA-1	Downward from the top of acromion of scapula	10.6 ± 1.2	Medially from line of spinous process of vertebra	12.4 ± 3.5	• M. Deltoid (s) • M. Teres minor (s) • M. Infraspinatus (m)	-	• Suprascapular artery and vein (d)
12	LA-2	Downward from the top of acromion of scapula	19.5 ± 2.1	Laterally from the imaginary line was drawn from greater tuberosity of humerus to lateral epicondyle	1.9 ± 0.8	• M. Triceps brachii (lateral head and long head) (s)	• Radial nerve (main branch) (d)	• Radial collateral artery and vein (d)
13	LA-3	Downward from the medial cubital fossa	0	Medially from the lateral epicondyle	2.3 ± 0.5	• M. Brachiolradialis (s) • M. Extensor carpi radialis longus (s) • M. Extensor carpi radialis bravis (m) • M. Brachialis (d)	• Radial nerve (d)	• Radial recurrent artery & vein (d)
14	LA-4	Downward from the medial cubital fossa	0.01 ± 0.2	Laterally from the medial epicondyle	2.1 ± 0.6	• M. Pronator teres (s) • M. Flexor carpi radialis (s) • M. Palmaris longus (s) • M. Flexor carpi ulnaris (s) • M. Flexor digitorum superficialis (d)	-	-
15	LA-5	Downward from the lateral lepicondyle	9.5 ± 0.9	Laterally from the imaginary line was drawn from lateral epicondyle to ulnar styloid process	2.5 ± 0.6	• M. Extensor carpi radialis bravis (s) • M. Extensor digitorum (s) • M. Extensor digiti minimi (s) • M. Supinator (d) • M. Abductor pollicis longus (d)	• Posterior interosseous nerve (d)	• Posterior interosseous artery & vein (d)

Mean length is mean between left and right sides. No differences between left and right sides (p > 0.05)

Abbreviations: s superficial layer, m middle layer, d deep layer