trapezius: u pper, middle, and lower fibers
DESCRIPTION
Trapezius: U pper, Middle, and Lower fibers. Axio-Scapular/ Axio-Clavicular group. Attachments: Proximal: Superior nuchal line on occipital bone (posterior skull) + C1-T12 vertebrae ( spinous process ) Distal: Upper: lateral clavicle Middle: acromion + spine of scapula - PowerPoint PPT PresentationTRANSCRIPT
Trapezius:Upper, Middle, and Lower
fibers
Axio-Scapular/ Axio-Clavicular group
Attachments:Proximal: Superior nuchal line on occipital bone (posterior skull) + C1-T12 vertebrae (spinous process)Distal:
Upper: lateral clavicleMiddle: acromion + spine of scapula Lower: base (medial end) of spine of scapula
Action: (scapular motion)U: UPWARD rotate, ADduct (retract), elevate M: ADduct (retract)L: UPWARD rotate, ADduct (retract), depress
PERIPHERAL NERVE + spinal cord level of origin:Cervical nerves + cranial nerve XI (spinal accessory nerve)
Spinal segments:C1,2,3,4,5
Levator scapulae
Axio-Scapular/ Axio-Clavicular groupAttachments:Proximal: upper cervical vertebrae (transverse process of C1-C4)Distal: medial boarder of scapula, superior to spine
Action: (scapular motion)Elevate, downward rotate
PERIPHERAL NERVE + spinal cord level of origin: Cervical nerves: 3,4 + dorsal scapular nerve: C5
Spinal segments: C3,4,5
Rhomboid minor
Axio-Scapular/ Axio-Clavicular group Attachments:Proximal: lower cervical vertebrae (spinous process of C7-T1)Distal: medial border of scapula, at base of spine
Action: (scapular motion)Elevate, ADduct (retract), downward rotate
PERIPHERAL NERVE + spinal cord level of origin: Dorsal scapular nerve: C5
Spinal segment: C5
Rhomboid major
Axio-Scapular/ Axio-Clavicular Attachments:Proximal: upper thoracic vertebrae (spinous process of T2-T5)Distal: medial border of scapula, inferior to spine
Action: (scapular motion)Elevate, ADduct (retract), downward rotate
PERIPHERAL NERVE + spinal cord level of origin Dorsal scapular nerve: C5
Spinal segment:C5
Serratus anterior
Axio-Scapular/ Axio-Clavicular group
Attachments:Proximal: lateral surface of ribs 1-8Distal: medial border of scapula, entire length, on COASTAL surface
Actions: (scapular motion)UPWARD rotate, ABduct (protract) – prevents winging
PERIPHERAL NERVE + spinal cord level of origin: Long thoracic nerve: C5,6,7
Spinal segments: C5,6,7
Pectoralis minor
Axio-Scapular/ Axio-Clavicular group Attachments:Proximal: anterior surface of ribs 3-5Distal: coracoid process of scapula
Actions: (scapular motion)ABduct (protract), downward rotate, depress
PERIPHERAL NERVE + spinal cord level of origin:Lateral + medial pectoral nerves: C5,6,7 + C8, T1
Spinal segments: C7,C8
Pectoralis major: Clavicular head (upper fibers)
Sternal head (lower fibers)
Axio- Humeral groupAttachments:Proximal: Clavicular head (CL) – medial clavicle
sternal head (ST) – sternum (manubrium and body of sternum, plus the adjacent costal cartilages of ribs 2-6)
Distal: All fibers to LATERAL lip of the intertubercular groove of the humerus (crest of the greater tubercle)
Actions:CL head: flex, ADduct, IR, H. AD the gleno-humeral joint ST head: extend (from 180), ADduct, IR, H. AD the gleno-humeral jointELEVATE TRUNK in closed kinematic chain with humerus stabilized (weight bearing on hands)
(ALSO: protract + depress shoulder girdle)
PERIPHERAL NERVE + spinal cord level of origin:CL head = LATERAL pectoral nerve: C5,6,7 ST head = Lateral + Medial pectoral nerves: C5,6,7 + C8, T1
Spinal segments: CL head: C5,6,7 ST head: C6,7,8, T1
Latissimus dorsi
Axio-Humeral group
Attachments:Proximal: Vertebral column from T7 to sacrum + iliac crest (T7-T12 is directly from spinous process of vert., while L+S levels and iliac crest are via thoraco-lumbar fascia) Also, (small attachment to inferior tip of scapula)Distal: FLOOR of intertubercular groove of humerus
Actions: Extend, ADduct, IR, H. AB at gleno-humeral joint ELEVATE TRUNK in closed kinematic chain with humerus stabilized (weight bearing on hands) (ALSO: retract + depress shoulder girdle, and downward rotate scapula via small attachment to inferior tip of scapula)
PERIPHERAL NERVE + spinal cord level of origin: Thoracodorsal nerve: C6,7,8
Spinal segments: C6,7,8
SupraspinatusMuscle of the ROTATOR CUFF
“S---” of “SITS”
Scapulo-Humeral groupAttachments:Proximal: supraspinous fossa of scapulaDistal: greater tubercle of humerus, UPPER facet
Actions: ABduct at gleno-humeral joint (does NOT rotate) Also; supports head of humerus in glenoid fossa
PERIPHERAL NERVE + spinal cord level of origin:Suprascapular nerve: C5,6
Spinal segment: C5
InfraspinatusMuscle of the ROTATOR CUFF
“-I--” of “SITS”
Scapulo-Humeral groupAttachments:Proximal: infraspinous fossa of scapulaDistal: greater tubercle of humerus, MIDDLE facet
Actions: External rotation of gleno-humeral joint. Also; depress head of humerus (compress + stabilize the GH jt)
PERIPHERAL NERVE + spinal cord level of origin:Suprascapular nerve: C5,6
Spinal segments: C5,6
Teres minorMuscle of the ROTATOR CUFF
“- -T-” of “SITS”
Scapulo-Humeral groupAttachments:Proximal: lateral boarder of scapula at mid-length Distal: greater tubercle of humerus, LOWER facet
Actions: External rotation of gleno-humeral joint. Also; depress head of humerus (Compress + stabilize the GH jt).
PERIPHERAL NERVE+ spinal cord level of origin:Axillary nerve: C5,6
Spinal segments: C5,6
SubscapularisMuscle of the ROTATOR CUFF
“- - - S” of “SITS”
Scapulo-Humeral group
Attachments:Proximal: subscapular fossa of scapulaDistal: lesser tubercle of humerus
Actions: Internal rotation of gleno-humeral joint. Also, depress head of humerus
PERIPHERAL NERVE + spinal cord level of origin:Upper + lower subscapular nerves: C5,6
Spinal segments: C5,6
Deltoid: Anterior, Middle, and Posterior
fibers
Scapulo-Humeral groupAttachments:Proximal:
Anterior: lateral clavicleMiddle: acromion process of scapulaPosterior: spine of scapula
Distal: ALL to deltoid tuberosity of humerus(Compare this to gluteus medius arrangement, especially the actions)
Actions: A: ABduct, flex, IR and H. AD at GH jtM: ABduct GH jt P: ABduct, extend, ER, and H. AB at GH jt
PERIPHERAL NERVE + spinal cord level of origin:Axillary nerve: C5,6
Spinal segments: C5,6
Teres major
Scapulo-Humeral groupAttachments:Proximal: lateral boarder of scapula at inferior angle Distal: MEDIAL lip of intertubercular groove of humerus (crest of lesser tubercle)
Actions: Extend, ADduct, IR at GH jt
PERIPHERAL NERVE+ spinal cord level of origin:Lower subscapular nerve: C5,6
Spinal segment: C6
Coracobrachialis
Scapulo-Humeral group
Attachments:Proximal: coracoid process of scapulaDistal: mid-humerus, medial side
Actions: Flex, ADduct at GH jt
PERIPHERAL NERVE + spinal cord level of origin:Musculocutaneous nerve: C5,6,7
Spinal segments: C6,7
Biceps brachii: Long head, Short head
Scapulo-Forearm groupAttachments:Proximal:
Long head: supraglenoid tubercle of scapulaShort head: coracoid process of scapula
Distal: BOTH heads; radial tuberosity + bicipital aponeurosis
Actions: Both heads: flex GH jt + flex elbow, supinate forearm
PERIPHERAL NERVE + spinal cord level of origin:Musculocutaneous nerve: C5,6,7
Spinal segments: C5,6
Triceps brachii:Long head, Lateral head, and
Medial head (deep)
Scapulo-Forearm groupAttachments:Proximal:
Long head: infraglenoid tubercle of scapulaLateral head: posterior humerus, superior to radial groove Medial head (deep): posterior humerus, inferior to radial groove
Distal: ALL 3 heads; olecranon process of ulna
Actions:Long head: extend GH joint ALL 3 HEADS: extend elbow joint
PERIPHERAL NERVE + spinal cord level of origin:Radial nerve: C5-T1
Spinal segments: C7,C8
Anconeus
Scapulo-Forearm group
Attachments:Proximal: lateral epicondyle of humerusDistal: olecranon process of ulna
Actions: Extend elbow joint
PERIPHERAL NERVE + spinal cord level of origin: Radial nerve: C5-T1
Spinal segments: C7,C8
Brachialis
Elbow: muscles of the brachium acting at the elbow
Attachments:Proximal: anterior distal shaft of humerusDistal: anterior proximal shaft of ulna (ulnar tuberosity)
Actions: Flex elbow
PERIPHERAL NERVE + spinal cord level of origin:Musculocutaneous nerve: C5,6,7
Spinal segments: C5,6
Brachioradialis
Elbow: muscles of the brachium acting at the elbow
Attachments:Proximal: lateral supracondylar ridge of humerusDistal: styloid process of distal radius
Actions: Flex elbow
PERIPHERAL NERVE + spinal cord level of origin: Radial nerve: C5-T1
Spinal segments: C5,6