Learning path upper extremity
1. The shoulder (cingulum pectorale)
1.1. Bones and joints of the shoulder
Instruction: Study the bony structures of the shoulder; the clavicula, scapula and humerus. Take note
of their orientation in the body, the connection to each other and the trunk. Study the shoulder joints
with the different ligaments.
Watch Acland 1.1.2 The clavicle and scapula and 1.1.4 The shoulder joint and its movement
1.1.1 Bones of the shoulder
The shoulder girdle connects the upper extremity to the axial skeleton. The bony part of the shoulder
consists out of the clavicula and scapula. We also take the humerus in consideration for this section,
because of its connection to the scapula.
1) Clavicula
The medial extremity of the clavicula is round (extremitas sternalis) and articulates with the
sternum, the lateral extremity is flat, as is the acromion of the scapula (extremitas acromialis). You
can palpate the concave medial half and convex lateral half on yourself.
Almost all attachments for ligaments and muscles are at the inferior side of the clavicula. The easiest
way to orientate the clavicula is to look for the tuberculum conoideum (attachment for the lig.
conoideum), which is always oriented lateral, inferior and dorsal. Next you can identify a groove for
the m. subclavius and the lig. costoclaviculare, the sulcus musculi subclavii.
,2) Scapula
The scapula is a triangle shaped flat blade with two pronounced protrusions, the processus
coracoideus and spina scapulae with the acromion. The spina scapulae is the dorsal spine,
separating the posterior surface into two fossae: the fossa supraspinata (for the muscle with the
same name, the m. supraspinatus) and the fossa infraspinata with the lineae musculares for the m.
infraspinatus, the m. teres minor and m. teres major. At the ventral side, the m. subscapularis is
attached to the fossa subscapularis.
The cavitas glenoidalis is the articular surface for the shoulder joint. Above the cavitas glenoidalis is
the tuberculum supraglenoidale and below the tuberculum infraglenoidale, for the insertion of the
m. biceps brachii (caput longum) and the m. triceps brachii (caput longum) respectively. The cavitas
glenoidalis is a very shallow structure and is therefore lined by labrum (glenoidale). This
fibrocartilaginous rim deepens the socket for the humerus.
,3) Humerus
The humerus is basically constructed out of a head (caput humeri), a neck (collum anatomicum) and
a pair of hands (tuberculum majus and minus), a body (diaphysis or corpus humeri) and feet
(condylus humeri).
The caput humeri is facing medial. It has a flat surface fitting into the cavitas glenoidalis. The
tuberculum majus is positioned laterally and has three facets for the insertion of m. supraspinatus
(upper facet), m. infraspinatus (medial facet) and m. teres minor (lower facet). The tuberculum
minus, facing ventrally, is the insertion point for the m. subscapularis. In between the two tubercles
is a groove, called the sulcus intertubercularis, which houses the tendon for the caput longum of the
m. biceps brachii.
The attachment of the m. deltoideus can be found halfway the corpus humeri as a V-shaped
tuberosity (tuberositas deltoidea). Posterior from this, you can find the groove for the nervus radialis
(the sulcus nervi radialis).
The distal epiphysis is formed by the condylus humeri, which is formed out of two joint surfaces
(trochlea humeri and capitulum humeri) and two epicondyli (epicondylus medialis and epicondylus
lateralis). Medial of the throchlea humeri, there is a groove for the n. ulnaris, the sulcus n. ulnaris.
Demo exercise: Find a set of left or right bones of the shoulder gridle, pair them. Identify the
structures mentioned above in bold.
, 1.1.2. Joints
The connection of the upper extremity to the trunk is formed by different ligaments and joints.
Between the shoulder girdle and trunk there are two synovial joints: the sternoclavicular joint (SC-
joint or articulatio sternoclaviculare) and the acromioclavicular joint (AC-joint or acticulatio
acromioclaviculare). The SC-joint is formed by the lig. sternoclaviculare (anterius and posterius) and
the lig. costoclaviculare.
The most important ligaments of the AC-joint are the lig. coracoacromiale, the lig.
acromioclaviculare and the ligg. coracoclaviculare. This last named ligament is composed out of two
parts: the lig. trapezoideum and the lig. conoidum.
1. The shoulder (cingulum pectorale)
1.1. Bones and joints of the shoulder
Instruction: Study the bony structures of the shoulder; the clavicula, scapula and humerus. Take note
of their orientation in the body, the connection to each other and the trunk. Study the shoulder joints
with the different ligaments.
Watch Acland 1.1.2 The clavicle and scapula and 1.1.4 The shoulder joint and its movement
1.1.1 Bones of the shoulder
The shoulder girdle connects the upper extremity to the axial skeleton. The bony part of the shoulder
consists out of the clavicula and scapula. We also take the humerus in consideration for this section,
because of its connection to the scapula.
1) Clavicula
The medial extremity of the clavicula is round (extremitas sternalis) and articulates with the
sternum, the lateral extremity is flat, as is the acromion of the scapula (extremitas acromialis). You
can palpate the concave medial half and convex lateral half on yourself.
Almost all attachments for ligaments and muscles are at the inferior side of the clavicula. The easiest
way to orientate the clavicula is to look for the tuberculum conoideum (attachment for the lig.
conoideum), which is always oriented lateral, inferior and dorsal. Next you can identify a groove for
the m. subclavius and the lig. costoclaviculare, the sulcus musculi subclavii.
,2) Scapula
The scapula is a triangle shaped flat blade with two pronounced protrusions, the processus
coracoideus and spina scapulae with the acromion. The spina scapulae is the dorsal spine,
separating the posterior surface into two fossae: the fossa supraspinata (for the muscle with the
same name, the m. supraspinatus) and the fossa infraspinata with the lineae musculares for the m.
infraspinatus, the m. teres minor and m. teres major. At the ventral side, the m. subscapularis is
attached to the fossa subscapularis.
The cavitas glenoidalis is the articular surface for the shoulder joint. Above the cavitas glenoidalis is
the tuberculum supraglenoidale and below the tuberculum infraglenoidale, for the insertion of the
m. biceps brachii (caput longum) and the m. triceps brachii (caput longum) respectively. The cavitas
glenoidalis is a very shallow structure and is therefore lined by labrum (glenoidale). This
fibrocartilaginous rim deepens the socket for the humerus.
,3) Humerus
The humerus is basically constructed out of a head (caput humeri), a neck (collum anatomicum) and
a pair of hands (tuberculum majus and minus), a body (diaphysis or corpus humeri) and feet
(condylus humeri).
The caput humeri is facing medial. It has a flat surface fitting into the cavitas glenoidalis. The
tuberculum majus is positioned laterally and has three facets for the insertion of m. supraspinatus
(upper facet), m. infraspinatus (medial facet) and m. teres minor (lower facet). The tuberculum
minus, facing ventrally, is the insertion point for the m. subscapularis. In between the two tubercles
is a groove, called the sulcus intertubercularis, which houses the tendon for the caput longum of the
m. biceps brachii.
The attachment of the m. deltoideus can be found halfway the corpus humeri as a V-shaped
tuberosity (tuberositas deltoidea). Posterior from this, you can find the groove for the nervus radialis
(the sulcus nervi radialis).
The distal epiphysis is formed by the condylus humeri, which is formed out of two joint surfaces
(trochlea humeri and capitulum humeri) and two epicondyli (epicondylus medialis and epicondylus
lateralis). Medial of the throchlea humeri, there is a groove for the n. ulnaris, the sulcus n. ulnaris.
Demo exercise: Find a set of left or right bones of the shoulder gridle, pair them. Identify the
structures mentioned above in bold.
, 1.1.2. Joints
The connection of the upper extremity to the trunk is formed by different ligaments and joints.
Between the shoulder girdle and trunk there are two synovial joints: the sternoclavicular joint (SC-
joint or articulatio sternoclaviculare) and the acromioclavicular joint (AC-joint or acticulatio
acromioclaviculare). The SC-joint is formed by the lig. sternoclaviculare (anterius and posterius) and
the lig. costoclaviculare.
The most important ligaments of the AC-joint are the lig. coracoacromiale, the lig.
acromioclaviculare and the ligg. coracoclaviculare. This last named ligament is composed out of two
parts: the lig. trapezoideum and the lig. conoidum.
