A brief description about the biomechanics of shoulder joint, the muscular attachments and Shoulder pathomechanics basics.

1. Dr. KEERTHI P KUMAR
(BPT, MPT)

2. The shoulder joint is a ball and socket joint. It is the major joint connecting the upper
limb to the trunk. The shoulder is located where the humerus, clavicle, and scapula
meet. The shoulder actually has four joints:
 The sternoclavicular joint is located where the clavicle meets the sternum at the
top of the chest.
 The acromioclavicular joint is located where the clavicle glides along the
scapula’s acromion. The acromioclavicular joint facilitates raising the arm over
the head.
 The glenohumeral joint is what most people think of as the shoulder joint. It’s
the major joint in the shoulder, where the head of the humerus nestles into a
rounded socket of the scapula called the glenoid.
 The scapulothoracic joint is sometimes considered a joint. It is located where the
scapula glides against the thoracic rib cage at the back of the body. No ligaments
connect the bones at this joint.

3. The shoulder is the most movable joint in your body. To remain in a stable or
normal position, the shoulder must be anchored by muscles, tendons, and
ligaments. Four of them are found on the anterior aspect of the shoulder,
whereas the rest are located on the shoulder’s posterior aspect and in the back.
Based on their location, the shoulder muscles are grouped into:
 Anterior shoulder muscles (thoraco-appendicular muscles): Anterior
shoulder muscles, also called the pectoral muscles. These muscles include
the pectoralis major, pectoralis minor, subclavius and the serratus anterior
muscle.
 Posterior shoulder muscles (scapulo-humeral muscles): The posterior
shoulder muscles are divided into two groups: extrinsic and intrinsic.
• The Extrinsic muscles are further subdivided into superficial
(trapezius and latissimus dorsi muscle), and deep layers (levator
scapulae and rhomboid muscles).
• The intrinsic muscles include the deltoid, teres major and the
muscles of the rotator cuff.

4. COMMON
SHOULDER
CONDITIONS
FRACTURE
DISLOCATION
IMPINGEMENT SYNDROME
TENDINITIS
BURSITIS
ROTATOR CUFF TEAR
FROZEN SHOULDER
ARTHRITIS
SPRAIN AND STRAIN

5. 1. FRACTURE
Fracture of clavicle
 Common fracture at all age groups, usually results from a fall on the shoulder
or sometimes on an out stretched hand.
 Most common site is the outer-third of the clavicle, usually displaced.
 Symptoms include pain, swelling, crepitus, Tenderness, Bruising, bulge on or
near your shoulder, grinding or crackling sound when you try to move your
shoulder, Stiffness or inability to move your shoulder
 Radiological findings: In most instances, the fracture is evident clinically and
easily identified on radiographs. It is common for clavicle fractures to be
displaced due to a combination of the weight of the upper limb pulling the
distal fragment down and the sternocleidomastoid pulling the medial
fragment upwards.

6. Fracture of scapula
It is less common and recover well without much treatment.
Most often it is undisplaced fracture. It usually results from a
direct or crushing injury or fall on the shoulder or on the
outstretched hand.
The scapula maybe fractured through:
 the body
 the neck
 the spine of scapula
 the coracoid process

7. Fracture of the humerus
There are three types of humerus fracture, depending on the location of
the break:
 Proximal: A proximal humerus fracture is a break in the upper part of
your humerus near your shoulder.
 Mid-shaft: A mid-shaft humerus fracture is a break in the middle of
your humerus.
 Distal: Distal humerus fractures occur near your elbow. This type is
usually part of a more complex elbow injury and sometimes involves
loose bone fragments.
SYMPTOMS INCLUDE: Swelling, Bruising, Tenderness to the touch,
Stiffness, A feeling of instability in the joint as if your elbow is going to
"pop out", In rare cases, the fractured bone may stick out of the skin
(open fracture).

8. Proximal humeral fracture:
Proximal humerus fractures are common
fractures often seen in older patients with
osteoporotic bone following a ground-level fall
on an outstretched arm. The parts that most
commonly produce fracture are the humeral
head, the greater and lesser tuberosities, and
the surgical neck
Distal humeral fracture
Distal humerus fractures are traumatic
injuries to the elbow that comprise of
supracondylar fractures, single column
fractures, column fractures or coronal shear
fractures.
Mid-shaft fracture
Midshaft humeral fractures usually occur
due to a direct blow to the upper arm, which
commonly results from falls, motor vehicle
accidents, or motorcycle accidents. In the
elderly, this fracture can also occur due to a
fall on an outstretched arm.

9. Fracture of greater tuberosity of humerus
It is of 2 types:
 Contusion fracture of the greater tuberosity: a fall on the side of the
shoulder results in a comminated fracture of the greater tuberosity.
A direct blow to the side of the shoulder can also cause this injury.
 Avulsion fracture of the greater tuberosity: results from a fall on
the outstretched hand. Contraction of the supraspinatus tendon
against resistance causes avulsion of a small fragment of the bone
which may or may not be displaced from its original position.

10. Glenohumeral joint dislocation
The shoulder joint is the body's most mobile joint. It can turn in many directions, but this
advantage also makes the shoulder an easy joint to dislocate.
Shoulder dislocations are of two types:
1. A Partial dislocation (subluxation): The head of the humerus bone is partially dislocated
from the socket, meaning part of the humerus comes out of the ball and socket joint and the
other part still fixated in the joint.
2. Complete dislocation: In this type of injury, the humerus bone comes off entirely from
the socket.
Both partial and complete dislocation cause grinding sort of pain and restricts the movement
of the shoulder. Sometimes a dislocation may tear ligaments or tendons in the shoulder or
damage nerves. The shoulder joint can dislocate forward, backward, or downward. A
common type of shoulder dislocation is when the shoulder slips forward (anterior
instability).

11. The symptoms of a dislocated shoulder include:
• Severe shoulder pain
• Swelling and bruising of your shoulder or upper arm
• Numbness and/or weakness in your arm, neck, hand, or fingers
• Trouble moving your arm
• Your arm seems to be out of place
• Muscle spasms in and around your shoulder
There are 3 types:
• Anterior
• Posterior
• Inferior

12. Dislocation of sterno-clavicular joint
It is a rare injury that occurs following a major road accident, the mechanism of injury is lateral compression of the shoulder or a direct blow to the
chest. The displacement can be anterior (common) or posterior.

13.  Dislocation of acromio-clavicular joint
This injury occurs from a fall on the shoulder with impact on its outer side. There is tenderness and swelling of the joint. It is an
Uncommon injury, caused by fall on outer prominence of the shoulder.

14. Shoulder impingement occurs when the acromion, rubs against (“impinges on”) or pinches your rotator cuff beneath it, causing pain and
irritation. Rubbing of the rotator cuff tendons result in swelling, which further narrows the space below the acromion. In some cases, bone spurs
on the acromion bone can contribute to impingement by causing the space where the rotator cuff sits to be even more narrowed.
Symptoms of shoulder impingement syndrome include:
 Pain when your arms are extended above your head.
 Pain when lifting your arm, lowering your arm from a raised position or when reaching.
 Pain and tenderness in the front of your shoulder.
 Pain that moves from the front of your shoulder to the side of your arm.
 Pain when lying on the affected side.
 Pain or achiness at night, which affects your ability to sleep.
 Pain when reaching behind your back, like reaching into a back pocket or zipping up a zipper.
 Shoulder and/or arm weakness and stiffness.
 Symptoms usually develop gradually over weeks to months

15. Tendinitis is the severe swelling of a tendon. Tendinitis usually happens after repeated injury to
an area. Shoulder tendinitis occurs as a result of sports injuries, by repetitive use or overuse of
the tendons, or from a sudden, more serious injury. Shoulder tendonitis is an inflammation of
your rotator cuff or biceps tendon. Your rotator cuff consists of the muscles and tendons in your
shoulder. They connect your upper arm bone to your shoulder blade.
Your injury may range from mild to severe inflammation of most of your rotator cuff. When
your rotator cuff tendon gets inflamed and thickened, it is also called rotator cuff tendonitis.
Your rotator cuff tendon may get trapped under the top bone of your shoulder (acromion). It is
formed by a part of your shoulder blade (the scapula)Tendons are flexible bands of tissue that
connect muscles to bones. They help your muscles move your bones.
Improper technique in any sport is one of the primary causes of overload on tissues including
tendons, which can contribute to tendinitis. It causes pain and soreness around a joint. Some
common forms of tendinitis are named after the sports that increase their risk.

16. A bursa is a small, fluid-filled sac that acts as a cushion between a bone and other
moving parts, such as muscles, tendons, or skin. Bursitis occurs when a bursa
becomes inflamed. People get bursitis by overusing a joint. It can also be caused
by an injury. It usually occurs at the knee or elbow. Doing the same kinds of
movements every day or putting stress on joints increases your risk.
Symptoms of bursitis include pain and swelling.

17. Rotator cuff injuries can range from mild to severe. They tend to fall into one of two categories: acute or chronic. Tendinitis (acute) or
tendinopathy (chronic) is typically caused by overuse of the rotator cuff muscle. This causes it to become irritated. The tendons that connect
muscles to bones can overstretch (strain) or tear, partially or completely.
The rotator cuff is a commonly injured area. The most common injuries are strains, tears, and tendinitis. Common rotator cuff injury symptoms
include:
 significant pain that causes you to avoid certain activities
 pain or tenderness when reaching overhead
 trouble reaching behind the back
 difficulty reaching out to the side
 progressive weakness of the shoulder
 pain in the shoulder, especially at night
 difficulty sleeping on the affected shoulder

18. Frozen shoulder is the common name for adhesive capsulitis, which is a shoulder condition that limits your range of motion. When the tissues in your
shoulder joint become thicker and tighter, scar tissue develops over time. As a result, your shoulder joint doesn’t have enough space to rotate properly.
Common symptoms include:
 swelling
 pain
 stiffness

19. Shoulder arthritis is damage to the cartilage inside the shoulder joint. When the
cartilage in the shoulder begins to break down on the surface and eventually in the
deeper layers, it’s called shoulder arthritis. Shoulder arthritis usually results from
gradual wear and tear of the cartilage. Cartilage is present in every joint in the body; it
covers the surface of the bones inside the joints. This makes the contact between bones
softer. If the cartilage is intact, it can take multiple rotations with no wear of the
surface because it’s smooth.
There are several different forms of shoulder arthritis. Main 2 types are:
 Osteoarthritis of the Shoulder: Osteoarthritis is also known as degenerative joint
disease. It is often associated with wear and tear related to aging. It can also affect
other joints besides the shoulder and is the most common form of arthritis.
 Rheumatoid Arthritis of the Shoulder: Rheumatoid arthritis is an autoimmune
disorder, which means your body attacks your own healthy cells, which may include
the lining of the joint. This inflammatory arthritis can be present in both shoulders at
the same time.

20.  Sprain: it is a stretched or torn ligament. Falling, twisting, or getting hit can all cause a sprain. Ankle and wrist sprains are common.
Symptoms include pain, swelling, bruising, and being unable to move your joint. You might feel a pop or tear when the injury
happens.
 Strain: it is a stretched or torn muscle or tendon. Twisting or pulling these can cause a strain. Strains can happen suddenly or develop
over time. Back and hamstring muscle strains are common. Many people get strains playing sports. Symptoms include pain, muscle
spasms, swelling, and trouble moving the muscle.

21. THANKYOU