kin ch 9 and 10

Force couple: downward rotation of scapula

-achieved through a force couple of pec minor, rhomboid and levator scapula -pec minor contracts to depress scapula (pulldown) -Rhomboids contract to retract scapula (pull in) -Levator Scapula contracts to elevate scapula(pull up) -Downward rotation occurs with GH ext

Force couple: upward rotation of scapula

-upper trap, lower trap and serratus anterior work as a force couple to produce upward rotation of scapula when GH Joint is flexed or abducted -upper trap contracts to elevate the scapula at the acromion -Lower Trap contracts to depress the scapula at the vertebral border -serratus anterior contracts to pull the scapula outward in a horizontal direction

Pec Major, clavicular and sternal portions

A: Shoulder Adduction, medial rotation, and horizontal adduction N: Lateral and medial pectoral nerve

Upper Trap Insertion

Acromial end of clavicle; accordion process

What joints allow shoulder girdle motion

Acromioclavicular and sternoclavicular joint

Shoulder Complex describes:

Acromioclavicular joint; Sternoclavicular joint; Glenohumeral joint and Scapulothoracic articulation

Scapula

Attaches indirectly to trunk: Ligamentous attachment to the clavicle

All sections of Delt are innervated by what

Axillary nerve

Lower Trap Insertion

Base of the scapular spine

Levator Scapula Origin

Cervical vertebrae 1-C4 spinous process

Extension

Downward rotation; retraction

GH Joint is

Extremely mobile; compromise stability for mobility

Scapulohumeral Rhythm

From thirty degrees to the end range of motion, the scapula must upwardly rotate one degree for every two degrees that the GH joint flexes or abducts.

Scaption

GH flexion when the shoulder in the scapular plane (30 degrees forward of the frontal plane. most common functional activities occur in scapular plane)

Shoulder Joint: Anatomical name?

Glenohumeral Joint

Scapula

Located between second and seventh rib (resting position)

Angle of Pull (in shoulder girdle)

Muscles with a greater horizontal pull: most effective in protraction/retraction -ex. middle trap - protraction

Angle of Pull (in shoulder girdle)

Muscles with a more equal horizontal and vertical pull: have a role in both motions -ex: rhomboids - protraction and elevation

Middle Delt

O: Acromion process I: deltoid tuberosity A: Shoulder abduction

Teres Minor

O: Axillary border of scapula I: Greater tubercle of humerus (post) A: Shoulder lateral (external) rotation, horizontal abduction N: Axillary nerve

Teres Major

O: Axillary border of scapula near the inferior angle (Posterior) I: Anterior medial surface of the humerus near proximal end (inferior to lat dorsi attachment) A: Shoulder ext, adduction, and medial rotation (same actions as lat doors) N: Lower sub scapular nerve

Coracobrachialis

O: Coracoid process of scapula I: Medial surface of the humerus near the midpoint A: Stabilizes the humeral head in the glenoid fossa N: Musculocutaneous nerve

Infraspinatus

O: Infraspinous fossa of scapula I: Greater tubercle of humerus A: Shoulder lateral (external) rotation, horizontal abduction N: Suprascapular nerve

Deltoids Anterior Delt

O: Lateral third of the clavicle I: Deltoid tuberosity A: Shoulder Abduction; flexionl medial rotation; horizontal adduction

Pec Major, clavicular portion

O: Medial third of clavicle I: lateral lip of bicipital groove of humerus A: shoulder flexion: 0-60 degrees

Posterior Delt

O: Spine of Scapula I: Deltoid Tuberosity A: Shoulder Abduction; extension; hyperextension; lateral rotation; horizontal abduction

Pec Major, Sternal Portion

O: Sternum, costal cartilage of first six ribs I: Lateral lip of bicipital groove of humerus A: Shoulder Ext: 0-60 degrees (from 180 of flexion down to -120)

Subscapularis

O: Subscapular fossa of the scapula I: Lesser tubercle of the humerus A: Shoulder medial (internal) Rotation N: Upper and lower sub scapular nerve

Supraspinatus

O: Suprasinous fossa of scapula I: Greater tubercle of the humerus A: Shoulder abduction; stabilizing the head of the humerus in the glenoid fossa N: Suprascapular nerve

Latissimus Dorsi

O: spinous processes of T7-L5(dorsocolumbar fascia), posterior surface of sacrum, iliac crest and lower three ribs(post attachment) I: Medial floor of bicipital groove of humerus (anterior attachment) A: Shoulder ext, adduction, medial rotation, hyperext N: Thoracodorsal nerve

Upper Trapezius Origin

Occipital bone and upper cervical spinous process

Origin

Proximal attachment

Shoulder Complex describes:

Scapula, Humerus, sternum, clavicle and rib cage

Middle Trap Action

Scapular Retraction

Middle Trap Insertion

Scapular Spine

Upper Trap Action

Scapular elevation and upward rotation

Action

Scapular retraction, elevation and downward rotation

Shoulder Joint

Shoulder Girdle

Shoulder Complex includes:

Shoulder Girdle, Shoulder Joint, Scapulothoracic articulation

Lower Trap Origin

Spinous Processes of middle and lower thoracic vertebrae (T4-T12)

Middle Trap Origin

Spinous process C7-T3

Rhomboids Origin

Spinous processes of C7-T5

trap and lat lie superficially to majority of muscles on post neck, thorax and lumbar regions

True

Serratus Anterior Origin

Upper eight ribs - lateral surface

Force Couple

Upward rotation of scapula

Scapula

Vertebral (medial) border is located 2-3 inches from spinous process

Insertion

Vertebral border of scapula between the spine and the inferior angle

Levator Scapula Insertion

Vertebral border of scapula between the superior angle and the spine

Anatomical Neck

a groove separating the head of the humerus from the tuberosities, giving attachment to the articular capsule

Prime mover muscles of shoulder joint Flexion Extension Hyperextension Abduction Adduction Horizontal Abd Horizontal Add Lateral rotation Medial Rotation

ant delt, pec major (clavicular) Post delt, lat, teres major Lat, post delt Delt, supraspinatus pec major, theres major, lats post delt, infraspinatus, teres minor pec major, anterior delt infraspinatus, teres minor, post delt Lats, theres major, subscapularis, pec major

Coracoid process

anterior scapular, attachment for short head of biceps brachia; pec minor and coracobrachialis

insertion

anterior surface of scapula - vertebral border

Subscapular fossa

anterior surface; attachment for subscapularis muscle

Muscles acting on the GH joint Deltoid

anterior, middle and posterior fibers

Hyperextension:

approx. 45 degrees available

Bicipital ridges

are the edges that form the groove. think of a valley. Anterior surface

Glenohumeral Joint

articulation of the head of the humerus within the glenoid fossa of the scapula

AC Joint

articulation of the lateral end of the clavicle with the accordion process of scapula

acromion process

attachment for middle deltoid muscle

superior angle

attachment of levator scapula muscle

Vertebral Border (medial)

attachment point for rhomboid muscles (post) and serrates ant

Synovial

ball and socket joint - three degrees of freedom (3 planes and axes)

Rotator cuff

blending together of the tendinous insertions of the supraspinatous, infraspinatous, teres minor and sub-scapularis muscles. They keep the humeral head rotating on the glenoid fossa during joint motion

Biceps and Triceps Brachii

both are two-joint muscles as they cross both shoulder and the elbow

Acromian process

broad, flat surface on superior lateral scapula; attachment for upper trap

Body Landmarks of Scapula Glenoid Fossa

concave surface on superior-lateral aspect. Articulates with humeral head

Glenoid Fossa

concave surface that articulates with humeral head on superior lateral side above the axillary borer and below the accordion process

surgical neck

constriction below the tubercles of the greater tubercle and lesser tubercle

insertion

coracoid process

Muscles of the shoulder girdle

deep to muscles of shoulder joint attach to both the trunk and scapula function to stabilize or to move scapula

Glenoid Labrum

deepen that socket and increase stability

Insertion

distal attachment

adduction

downward rotation

Scapular (shoulder girdle) Motions

elevation and depression Protraction(Abd) and Retraction (Add) Scapular Tilt

Motions at SC Joint

elevation, depression, protraction, retraction and rotation

Glenoid Labrum

fibrocartilaginous rim attached around the margin of the glenoid cavity in the shoulder blade. The shoulder joint is considered a 'ball and socket' joint.

Motions at Glenohumeral Joint

flexion, extension, abduction, adduction, medial rotation, lateral rotation, horizontal abd and adduction

Scapulohumeral Rhythm

from 0-30 degrees: no scapular movement from 30 - onward: 2:! ratio GH degrees of movement: scapular degrees upward rotation

Abduction and Adduction

frontal plane along sagittal axis

Convex humeral head

glides, rolls and spins on the concave glenoid fossa

SC Joint

has joint capsule and 3 stabilizing ligaments and an articular disk

shoulder joint

humerus and scapula

infraspinous fossa

is a structural feature on the scapula bone (also known as the shoulder blade or shoulder bone).

supraspinous fossa

is a structural feature on the scapula bone (also known as the shoulder blade or shoulder bone).

Lesser Tubercle

it is situated in front, and is directed medially and anteriorly

action

joint actions in which it is a prime mover

Axillary Border

lateral

axillary border

lateral border; attachment point for theres minor and theres major muscles

where is the supraspinatus located

located deep in the trap

Deltoid Tuberosity

more lateral side - where delts attach

Glenohumeral osteokinematic motions three degrees of freedom

motion along three axes in 3 planes of motion

SC motions accompany

motions of the shoulder girdle

Angle of Pull (in shoulder girdle)

muscles with a greater vertical angle of pull: most effective in election/depression -ex. levator scapula - elevation

Stability of GH Joint is provided by:

musculature (dynamic stabilizers), ligaments or joint capsule (static stability)

Very mobile

not very stable

Reversal of muscle action

occurs when distal extremity is fixed, not moving and the insertion point is moving closer to the fixed distal point (closed kinetic chain) ex: the action of the pec major in a push up verses a dumbbell chest press? ex: the action of the rhomboids in bent over row verses incline pull up?

Sternoclavicular Joint

only attachment of the shoulder girdle to the trunk; plane-shaped, synovial joint has a double-gliding motion

AC Joint is

plane shaped, synovial joint

inferior angle

point where vertebral and axillary borders meet; point that determines scapular rotation.

Spine of Scapula

projection on posterior scapula, runs from vertebral border to acrimony process. Attachment points for middle and lower trap

horizontal adduction

protraction

medial rotation

protraction

What do the muscles of the rotator cuff do?

pull humeral head into fossa, stabilizing joint

GH Ligaments

reinforce the anterior GH joint. Pleated folds of the joint capsule: Superior, middle, inferior

horizontal abduction

retraction

lateral rotation

retraction

Pec Minor origin

ribs 3-5, anterior surface

GH movement Arthrokinematics

roll, spin and glide

Force couple of delt and rotator cuff muscles

rotate the humeral head in the glenoid fossa during shoulder abduction

Greater Tubercle

rotator cuff locator points

flexion and extension where?

sagittal plane along frontal axes

scapulothoracic articulation

scapula moves over rib cage of the thorax: not a joint/indirectly connected via clavicle

Shoulder girdle

scapula, clavicle and sternum

Lower Trap Action

scapular depression and upward rotation

action

scapular depression, protraction, downward rotation and tilt

Scapular Motions

scapular elevation and depression

Levator Scapula Action

scapular elevation and downward rotation

Scapular Motion

scapular protraction and retraction

action

scapular protraction and upward rotation

hyperextension

scapular tilt

scapular motion

scapular upward and downward rotation

Body Landmarks of the humerus Humeral Head

semi-rounded proximal end; articulates with scapula at glenoid fossa

"AC Joint" sprain is called

separated shoulder

Scapulohumeral Rhythm

starting in anatomical position, the GH joint can flex or abduct the first thirty degrees of motion without the scapula moving.

thoracolumbar fascia

superficial fibrous sheer; provides broad attachment for muscles

Muscles of shoulder joint

superficial to the muscles of the shoulder girdle attach to the scapula and to the humerus function to move the arm

Scapular Tilt (occurs with GH hyperext

superior end of scapula tilts anterior inferior end of scapula tilts posterior

Rotator Cuff group

supraspinatus, infraspinatus, teres minor, subscapularis

Scapulohumeral Rhythm

the "dance" between the humerus and the scapula during shoulder movement

circumduction

the arc or circle of motion possible at the shoulder. combo of all ranges of motion

GH capsule and ligaments GH Joint capsules

the collective term for the capsular tissue and ligaments that form and seal that synovial joint

Glenoid fossa is

the concave surface

Humeral head is

the convex surface

Shaft

the elongated rodlike portion of the humerus between the surgical neck proximally and the emergence of the supracondylar ridges distally.

Scapulohumeral Rhythm

the shoulder joint, glenohumeral joint (humerus articulating with scapula) can move only a very limited range without the scapula moving to assist the movement

Muscles of the Shoulder Girdle and shoulder joint work together for what?

to produce optimal movement of the shoulder complex

Horizontal Add and Abd

transverse plane along vert axis

medial(internal) and lateral(external) rotations where?

transverse plane along vertical axis

Muscles of the Shoulder Girdle 5 muscles primarily responsible for moving scapula

trapezius: upper, middle and lower Levator scapula Rhomboids: Major and Minor Serratus anterior Pectoralis minor

R, S and G keep the humeral head articulating with glenoid fossa

true

abduction

upward rotation

Flexion

upward rotation; protraction

bicipital groove

valley. long head of biceps sits in the valley

Clavicle moves

while the sternum remains stationary

Roll, spin and glide occur when

with every osteokinematic motion