Flashcards in Shoulder Deck (21)
• Ball and Socket, Synovial joint
• Moves in 3 degrees/planes, and is Triaxial
• Flexion, Extension, Abduction, Adduction, Internal Rotation, External Rotation, Horizontal ABduction, Horizontal Adduction
• Greatest ROM of all joints
• Shoulder can compensate for loss of elbow/wrist motion
• If it gets injured, ADLs abilities are affected
The four joints of the shoulder:
1) Glenohumeral Joint (GH): head of humerus, glenoid fossa of scapula
2) Sternoclavicular Joint
3) Acromioclavicular Joint
4) Scapular Thoracic Gliding Mechanism
Connects upper limb to axial skeleton; the clavicle and scapula; AKA “pectoral girdle”
• Contains 5 different true and false joints
• 2 primary support functions:
- Stabilizing shoulder during static contractions
- Providing strong base of support for shoulder movements
Motion of the clavicle, scapula and humerus together to achieve full elevation of arm. Exists between the scapula in shoulder girdle and the GH joint.
• 2 purposes:
- Scapular upward rotation; allows GH muscles to maintain length/tension
- Simultaneous movement of humerus/scapula; prevents impingement betw greater tubercle of humerus and acromion process
• First 30˚ GH flexion/abd is “Setting Phase”
• 2nd phase betw 30-90˚; scapula upward rotates 1˚ for every 2˚ of GH flex/abd (1:2 ratio)
• 2:1 ratio not consistent after 90˚
Strength/Stability of Shoulder
• Greatest strength produced in aDduction
• Extension stronger than flexion
• Internal rotation is stronger than external
• Remember: strongest going INTO body
• Weakest muscles are rotators
• Shoulder very mobile, therefore LESS stable
• Most frequently dislocated joint
• Most common dislocation position is 90˚ aBd and external rotation (climbing, kayaking, throwing, monkey bars)
Subluxation vs. Dislocation
Can be used interchangeably, but technically SUBLUXATION is when arm pops back in place, and true DISLOCATION is permanent (needs intervention).
Nerves Innervating Shoulder
Innervated primarily by Brachial Plexus (with exception of long thoracic nerve and spinal accessory nerve, not part of plexus).
Nerves of Brachial Plexus
• Axillary Nerve (C5-C6): Delts, Teres Minor
• Musculocutaneous Nerve (C5-C7): Coracobrachialis, Biceps
• Suprascapular Nerve (C5, C6): Supraspinatus, Infraspinatus
• Upper Subscapular Nerve (C5, C6): Upper Subscapularis
• Lower Subscapular Nerve (C5, C6): Lower Subscapularis, Teres Major
• Thoracodorsal Nerve (C6-C8): Lats
• Lateral Pectoral Nerve (C5-C7): Pecs Major
• Radial Nerve* (C5, C6): Triceps brachii (*easily damaged)
What adds stability to shoulder?
• Rotator Cuff
• Joint Capsule
• 2: Glenohumeral and Coracohumeral ligaments (don’t need to remember names)
• Hold head of humerus in place with glenoid fossa to provide stability (in addition to rotator cuff’s 4 tendons)
Ring of fibrocartilage surrounding and deepening the socket and increasing articulation with the humeral head.
• Increases stability of GH joint.
• Glenoid fossa deepened by glenoid labrum, joint capsule, GH ligaments, and long head of biceps
• These structures increase surface contact area of humeral head in glenoid fossa
4 muscle tendon insertions that stabilize the humerus in the glenoid fossa when arm is in motion.
• Head of humerus allowed to rotate internally/externally via rotator cuff
• Remember “SITS”: Supraspinatus, Infraspinatus, Teres minor, Subscapularis
Muscles of Shoulder (GH Joint)
Most of larger/powerful muscles are superior, while smaller/weaker rotator cuff muscles are deeper.
• Flexion: Pecs Major, Ant Deltoid, Biceps
• Extension: Lats
• ABduction: Mid Deltoid, Supraspinatus
• ADduction: Pecs Major, Lats, Teres Major
• Internal Rotation: Pecs Major, Ant Deltoid, Lats, Teres Major, Subscapularis
• External Rotation: Post Deltoid, Teres Minor, Infraspinatus
• Horizontal ABduction: Post Deltoid
• Horizontal ADduction: Pecs Major, Ant Deltoid
Muscles of Shoulder Girdle (Scapula)
• Protraction: Rhomboids, Trapezius, Serratus Anterior, Pecs Minor
• Retraction: Rhomboids, Trapezius
• Elevation: Levator Scapula, Trapezius
• Depression: Pecs Minor, Trapezius
• Upward Rotation: Trapezius, Serratus Ant.
• Downward Rotation: Pecs Minor
Clinically known as “adhesive capsulitis.”
• Only occurs in shoulder
• Starts with inflammatory response to secondary injury
• Joint capsule contracts, joint becomes stiff (loss of ROM)
• Mostly in women age 40-50
• Usually resolves spontaneously
Hemiplegia and Subluxation post CVA
Paralysis of one side of body after cardiovascular accident (CVA)
• Paralysis of shoulder muscles leave arm unsupported/susceptible to dislocation.
• Tx: wear a sling, short-term
Abnormal posture of shoulder due to Brachial Plexus injury, usually in birth.
• Nerve roots C5, C6, C7 commonly affected
• Includes motor sensation
• Limb held in internal rotation, elbow extension, forearm pronation, wrist/finger flexion
• 1-2 babies per 1000 births
• Can heal in 6-12 mo, but 10% are permanent (leads to one-handedness)
• Wear brace during healing to promote proper/stable position
Rotator Cuff Tendonitis
Impingement from pressure on the surface of rotator cuff from acromion process when arm is lifted.
• Pain/stiffness occurs when raising arm
• Night pain, difficulty sleeping
• Often in patients with history of poor posture/kyphosis
Glenohumeral Joint (GH)
Where the humerus moves in synchronization with the scapula. Provides flexion, extension, aBduction, aDduction, internal rotation, external rotation, horizontal aBduction, and horizontal aDduction.
This protrusion of the rib through the back along with a protruding scapula, occurs when a person with structural scoliosis bends forward.