2. APPLIED ANATOMY
• Movement of the shoulder is critical to maintain the
positioning of the humeral head relative to the
glenoid.
• Helps control humeral head movement
• Rotator Cuff contraction, they dynamically tighten
the capsule
– Helps center the humeral head relative to the glenoid.
• Crucial with ANY over head activity
• Scapulohumeral Rhythm
– As humerus elevates to 30’ no movement
– 30-90’ scapula abducts & upwardly rotates
– 180’ humeral abduction & sternoclavicular jt. moves
3. Costs of Dynamic Stabilization of the
Glenohumeral Joint
When all stabilization factors are intact, the
head of the humerus rotates into flexion or
abduction around a relatively stable axis with
minimal translation. Over time, however, even
normal stresses resulting from the complex
dynamic stabilization process may lead to
degenerative changes or dysfunction at the GH
joint. Any disruption in the synergistic action
of the dynamic stabilization factors may
accelerate degenerative changes in or around
the joint.
4. The supraspinatus muscle is a particularly key
structure in dynamic stabilization. The supraspinatus is
either passively stretched or actively contracting when
the arm is at the side (depending on load); it also
participates in humeral elevation throughout the ROM.
Mechanical compression and impingement of the
stressed supraspinatus tendon can occur when the
subacromial space is reduced by osteoligamentous
factors, when there is increased superior or anterior
translation of the humeral head center with less
favorable GH mechanics, when the scapula does not
posteriorly tip or upwardly rotate adequately during
humeral elevation, or when occupational factors require
heavy lifting or sustained overhead arm postures.
5. Symptomatic and asymptomatic rotator cuff
tears are seen in almost all people over the age of
70, with the supraspinatus likely to show lesions
before the other tendons of the cuff. Rotator cuff
tendinitis or typically produce pain between 60 and
120 of humeral elevation in relation to the trunk.
This range constitutes what is known as the painful
arc. It is within this ROM that the tendons of the
rotator cuff are passing beneath the coracoacromial
arch. Beyond 120, the tendons have rotated past the
overlying arch structures.
6.
7. Degenerative changes in the AC joint may
result in pain in the same area of the shoulder
as pain from supraspinatus or rotator cuff
lesions. Pain due to AC degeneration is more
typically found when the arm is raised beyond
the painful arc or when the arm is adducted
across the body, compressing the AC joint
surfaces. The long head of the biceps brachii
similarly can produce pain in the
anterosuperior shoulder.
8. Because the long head of the biceps tendon
also passes directly beneath the impinging
structures of the coracoacromial arch, it is
subject to some of the same degenerative
changes and the same trauma seen in the
tendons of the rotator cuff. Whether the biceps is
actively contributing to elevation of the arm or to
joint stabilization or is passive, the tendon of the
biceps must slide within the bicipital groove and
under the transverse humeral ligament as the
humerus moves around any of its three rotatory
axes.
9. If the bicipital tendon sheath is worn or
inflamed, or if the tendon is hypertrophied (as
often seen with rotator cuff tears), the gliding
mechanism may be interrupted and pain
produced. A tear in the transverse humeral
ligament may result in the tendon of the long
head popping in and out of the bicipital
groove with rotation of the humerus, a
potentially wearing and painful microtrauma.
10. RECOGNITION OF SPECIFIC INJURIES
• Fractures:
– Acromioclavicular (common)
• Caused by outstretched arm, fall on the tip of shoulder, direct
impact
• Athletes usually supports the fx’d. side, tilts head and chin to
opposite side
• Deformity, pain, swelling
– Scapular (infrequent)
• Direct impact, or when force is transmitted through humerus to
scapula
• Pain with movement
– Humeral
• Shaft- (occasionally)
– Direct blow, fall on the arm
– Comminuted or transverse with deformity due to muscular
pull
• Proximal – dangerous to nerves and blood supply
– Direct blow, dislocation, impact received by falling on an
outstretched arm
• Head of humerus (Epiphyseal fx)
– Occur in ages 10 or younger
– Direct blow or indirect blow
– Difficult to recognize
12. • Sprains
– Sternoclavicular (uncommon)
• Initiated by a direct force transmitted through the
humerus
– Acromioclavicular
• Extremely vulnerable especially in collision sports
• Direct impact to the TIP of the shoulder that forces the
acromion process downward, backward, and inward
– The clavicle is pushed down against the rib cage
15. DISLOCATIONS
Dislocation is an injury to the joint in which the
ends of the bones are forced from their normal
positions.
This injury temporarily deforms and immobilizes the
joint and may result in sudden and severe pain.
The shoulder is more prone to dislocate than any
other joint.
This due to :
• laxity of the capsule
• Disproportionate area of articular surfaces
Occurs when the arm is abducted
16. • Account for 50% of all dislocations
– Two Types
• Anterior
– Most common
– Direct impact to the posterior aspect of shoulder
» Forced abduction, external rotation, and
extension that forces the humeral head out (arm
tackle)
– Bankart’s Lesion (Labrum tear)
– Hill Sachs Lesion (creates a divot in humeral head)
– Slap Lesion (injury to labrum and long head of
biceps)
• Posterior
– Account for 1 – 4.3%
– Extremely Rare
– Forced Adduction and Internal rotation of shoulder
or fall on an extended internally rotated arm
17.
18. LABRUM TEAR
SLAP stands for "superior labrum, anterior to
posterior"-in other words, "the top part of the
labrum, from the front to the back."
The labrum is described like a clock face with
12 o'clock being at the top (superior), 3 o'clock at
the front (anterior), 6 o'clock at the bottom
(inferior) and 9 o'clock at the back (posterior).
Clinicians may reverse the 3 o'clock and 9 o'clock
for left shoulder describing 3 o'clock at the back.
19.
20. IMPINGEMENTS
– Involves mechanical compression of Supraspinatus
tendon, subacromial bursa, and long head of
biceps tendon
– Related to shoulder instability and overhead
activities
– Failure of RC muscles to maintain position.
Shoulder impingement has primary (structural)
and secondary (posture & movement related)
causes.
21.
22. • Bursitis
– Overuse
– Chronic Inflammation
– Shoulder bursitis and tendonitis
pain will be particularly
acute when the arm is
raised about shoulder level
23. Biceps Brachii Ruptures
– Caused by powerful concentric & eccentric contraction
• occurs near the origin of muscle
• athlete will hear a “snap”, then feels sudden intense
pain
• consequences of loss of strength:
- 30 % decrease in flexion strength
- 40 % loss of supination strength
• after the injury there is usually localised pain at the
front of the elbow, with bruising and swelling. the
biceps muscle may retract up the upper arm crating a
prominent bump, known as the 'popeye' sign. this is
often visibly different to the other biceps when
contracting the muscle.
25. FROZEN SHOULDER
• Frozen shoulder is an extremely painful condition in
which the shoulder is completely or partially
unmovable (stiff). It is one of the most painful
conditions of the shoulder (the others being calcific
tendonitis or referred nerve pain from the neck).
• Frozen shoulder often starts out of the blue, but may
be triggered by a mild injury to the shoulder. The
condition usually goes through three phases, starting
with pain, then stiffness and finally A stage of
resolution as the pain eases and most of the
movement returns. This process may take A long
time, sometimes as long as two or more years.
26.
27. • The lining of the shoulder joint, known as the
'capsule', is normally a very flexible elastic
structure. It's looseness and elasticity allows
the huge range of motion that the shoulder
has. With a frozen shoulder this capsule (and
its ligaments) becomes inflamed, swollen, red
and contracted. The normal elasticity is lost
and pain and stiffness set in.
28. Baseball Players and their Shoulder
Injuries
• Shoulder pain is a common complaint among
baseball players, especially
pitchers, regardless of age or level of play. Pain
experienced during the throwing motion
results in an inability to throw with
velocity, causing what is commonly referred to
as "dead arm" syndrome. The cause of pain is
most often injury to either the bones or the
soft-tissue structures of the shoulder joint.
29. Throwing Mechanics
• Consists of 5 Phases
–Windup or Preparation
•1st movement until ball leaves glove
•Lead leg strides forward
•Both shoulders abduct, externally
rotate and horizontally rotate
–Cocking
•Begins when hands separate
•Ends when Maximum external
rotation of humerus has ocurred
•Lead foot touches ground
30. – Acceleration
• Lasts from Maximum external rotation until ball release
• Humerus abducts, horizontally abducts, and internally
rotates
• Scapula elevates, abducts, and rotates upward
– Deceleration
• From ball release until Maximum shoulder internal
rotation
• External rotators of the RC muscles contract
eccentrically (lengthening) to decelerate the humerus
• Rhomboids contract eccentrically to decelerate the
scapula
– Follow-through
• From Maximum shoulder internal rotation until the end
of motion
• When athlete is in balanced position