mechanics of shoulder injuries based on clinical scenario

1. by RUTH
MPT 1st sem

3. Case Description
• The patient was a 68-year-old right-handed male who
presented with left shoulder pain and limited range of
motion (ROM) following a fall 7 months prior. The
patient had a past medical history of type II diabetes
mellitus. The diagnosis of adhesive capsulitis was
determined following radiographs, mechanism of injury,
past medical history, and physical therapy examination
and evaluation.

4. • The incidence of adhesive capsulitis is approximately 3 percent in the
general population. It is rare in children, and peaks between 40 and
70 years of age. Women are more often affected than men, but there
is no known genetic or racial predilection. It is common in persons
with insulin-dependent and non-insulin-dependent diabetes, and in
those with prediabetes (glucose intolerance).
• Persons with a history of adhesive capsulitis are at increased risk of
developing the condition on the contralateral side. Recurrence on the
affected side is also possible, especially in patients with diabetes.

5. • causes of adhesive capsulitis are not fully understood. There are some
underlying health conditions that can increase a patient’s risk for
developing a frozen shoulder. These include:
• Diabetes: Frozen shoulder symptoms in diabetic patients are typically
more severe and continue for a longer period of time.
• Female sex: More females have frozen shoulder than their male
counterparts
• Age over 40: Most often seen between ages 40-60
• Immobility: When the shoulder is not moved for an extended period of
time, usually as a result of a prior injury, can contribute to symptoms of
a frozen shoulder.

6. • Other underlying health conditions:
have also been linked to the
development of frozen shoulder,
including:Tuberculosis, Parkinson’s
Disease, Cardiac Disease,
Stroke,Thyroid disorders.
• The pathophysiology of adhesive
capsulitis is poorly understood.
Analysis of surgical specimens
suggests that capsular hyperplasia and
fibrosis have a role. The presence of
cytokines suggests a possible
autoimmune process, but the
relationship is not well established.

7. • The hallmark of adhesive capsulitis is decreased range of motion and
shoulder pain. There often is no identifiable cause or trigger. The pain is
often described as a poorly localized, deep ache. If the pain is localized, it is
usually in the area of the anterior or posterior capsule. The pain may radiate
to the biceps area. Patients may have progressive pain and stiffness when
reaching overhead, away, and behind the back. Weakness is often related to
pain or concomitant tendinopathy. Crepitus may be present on the involved
side. As with many shoulder conditions, pain may impair sleep. Unlike more
serious causes of shoulder pain, adhesive capsulitis does not cause red flag
symptoms such as fever, night sweats, and unexplained weight loss.
Neuropathic symptoms in the forearm and hand suggest another diagnosis,
such as cervical radiculopathy.

8. Palpation may yield vague, diffuse tenderness over the anterior and
posterior shoulder. Focal tenderness over a specific structure is rare; its
presence suggests another diagnosis or concomitant pathology, such as
rotator cuff or biceps tendinopathy.
Pain: acute condition, pain and spasm restrict the movement. Pain
experienced through out the abduction elevation movements.Chronic
condition, Pain experienced at the end range of existing limited abduction
elevation movement due to stretching of tight capsule.

9. • Patients with advanced adhesive capsulitis may have lost the natural
arm swing that occurs with walking.
• Muscle atrophy of the shoulder girdle may be present.
• As a result of impaired motion in the glenohumeral joint, abnormal
scapular movement may be observed with active forward flexion of
the affected shoulder
ROM: restricted in capsular pattern i.e. external rotation and abduction
restricted more, and internal rotation and flexion restricted to less er
extent.
Painful arc: pain may be present during mid range of abduction-
elevation

10. Posture: Head forward posture, increased thoracic kyphosis and
rounded shoulder disturb normal upward orientation of glenoid fossa
of scapula, which leads to loss of tension of superior joint capsule and
coracohumeral ligament. Over activity of rotator cuff increases tensile
stress over the capsular ligament to which the rotator cuff tendons
blend. The chronic inflammation thickens and fibrosed the capsule over
time.
Joint play: Amplitude of joint play restricted in the following order
with pain:
• Posterior to Anterior gliding of head of humerus is restricted
more limiting the external rotation most
• Inferior gliding restricted limiting abduction
• Posterior gliding restricting limiting internal rotation.

11. • Loss of motion with forward flexion, abduction, and external and internal
rotation should raise suspicion for adhesive capsulitis. It is important to
compare these maneuvers on the affected and unaffected sides to
accurately assess deficits.
• The patient should initially be asked to actively test the limits of motion (Fig
1); if loss of motion is observed, the physician may assist passively, with
scapular stabilization to ensure an accurate measurement of movement (Fig
2). The most widely accepted method for measuring internal rotation is the
Apley scratch test, usually expressed in terms of the highest vertebral level
reached (Fig 3).
• Full range of motion in any plane suggests another diagnosis. Because
adhesive capsulitis does not affect the dynamic stabilizers of the shoulder
(i.e., rotator cuff, biceps tendon, and deltoid muscle), strength should
theoretically be preserved in all planes.

12. ROM restrictions in capsular pattern
• Patients with frozen shoulder commonly present with ROM restrictions
in capsular pattern. A capsular pattern is a proportional motion
restriction unique to every joint that indicates irritation of the entire
joint.
• The shoulder joint has a capsular pattern where external rotation is
more limited than abduction which is more limited than internal
rotation (ER limitations > ABD limitations > IR limitations). In the case of
frozen shoulder, ER is significantly limited when compared to IR and
ABD, while ABD and IR were not seen to be different.
• If there is a tightening of these specific structures (GH ligaments), we
can observe a change to the arthrokinematics of the shoulder joint, with
increased anterior superior translation in flexion.

13. fig 1 Active forward flexion. The
patient cannot move his right arm
past approximately 85 degrees. The
left shoulder is in full forward
flexion (approximately 155
degrees).
fig 2 Passive forward flexion
with scapular stabilization. Even
with assistance, the patient's
right shoulder cannot move
beyond 90 degrees.
fig 3 The Apley scratch test
to measure internal
rotation. The patient
reaches under the involved
shoulder to the highest
vertebral level possible.
However, patients with adhesive capsulitis may not have enough range of motion to
perform strength testing. Resisted strength testing can result in pain-related “breakaway”
weakness that mimics true weakness. Patients with advanced adhesive capsulitis may also
have muscular atrophy that can cause weakness.

15. Scapular kinematic Alterations Associated With Adhesive
Capsulitis or Shoulder Stiffness.
• Only recently have investigators started to study scapular
kinematics during humeral elevation in subjects with adhesive
capsulitis or shoulder stiffness.Three studies identified
significant increases in scapular upward rotation on the
affected side of subjects with adhesive capsulitis as compared
to their nonaffected side.
• Vermeulen et al were also able to show a change toward a
more “normalized” scapular upward rotation after physical
therapy intervention, supporting the premise that the
increased scapular upward rotation was compensatory to
maximize overall range of motion overhead in the presence of
reduced mobility at the glenohumeral joint.

16. • The alteration in scapular kinematics we observed may be
considered a useful adaptation that may help patients by
providing a more effective scapular position for arm
elevation. Patients may develop an alternative elevation
strategy and make increased use of the redundancy of the
motor system ( Cirstea and Levin, 2000 ; Roby-Brami et al.,
2003 ), particularly by recruiting excessive scapular
movement during arm elevation. Thus, increased scapular
lateral rotation for patients with GH frozen shoulder may
help with arm elevation.

18. (a) The left scapula (affected side) showing an increase in upward rotation.
(b) Overlap image between two different positions indicating a decrease in
medical rotation of scapula at abduction

19. • Scapular lateral rotation compensation appears to be greater
in patients with frozen shoulder.
• scapulohumeral rhythm:
• SHR was inversely correlated with maximal arm elevation
angle of the affected shoulder. Thus, the greater the
limitation of GH ROM, the higher the scapular lateral
rotation.
• SHR may represent the compensation rate of shoulder
adaptation to the ROM limitation.

20. Among the different muscles of the shoulder girdle, the
trapezius and the serratus anterior muscles are important for
the scapulothoracic motion, producing scapular lateral
rotation and retraction ( Inman et al., 2020 ; Ludewig et al.,
1996 ).
A recent study by Lin et al. (2023) showed increased trapezius
muscle activity in patients with frozen shoulders, with an
imbalance in muscle activation between the upper and lower
trapezius muscle. Thus, further studies are needed to
investigate the chronology of muscular recruitment and the
relation between EMG evidence of scapulothoracic muscle
activity and severity of GH limitation.

21. Healthy Adhesive Capsulitis
Primary scapular
motion
secondary scapular
motion
accessory scapular
motion
presumed implications
Upward rotation
Posterior tilting
Variable internal/external
rotation
Maximize shoulder range of
motion and availabe
subacromial space
Greater upward rotation
no consistent evidence for
alteration
no consistent evidence for
alteration
Presumed compensatory to
minimize functional
shoulder range-of-motion
loss

23. • Fouad Fayad et.al study on Three-dimensional scapular kinematics and
scapulohumeral rhythm in patients with glenohumeral osteoarthritis or
frozen shoulder
• Peter J. Rundquist PT, PhD et.al study on Shoulder kinematics in subjects
with frozen shoulder
• PAULA M. LUDEWIG et.al study on The Association of Scapular
Kinematics and Glenohumeral Joint Pathologies
• Youbin Yi et.al study on Biomechanical properties of the glenohumeral
joint capsule in hemiplegic shoulder pain
• Lou-Ren Chang et.al study on Anatomy, Shoulder and Upper Limb,
Glenohumeral Joint