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
