Michael A. Shaffer

MSPT, OCS, ATC

University of Iowa Sports Medicine

August 11, 2005

Function of the Scapula

•      Glenoid serves as a platform for the humeral head

•      Muscle attachment (17)

•      Transfer of force from the trunk to the upper extremity

Scapular Stability

•      How do we maintain the scapula on the posterior body wall?

–   Clavicle acts as an anterior strut

–   AC and CC ligaments

–   Scapular muscles

Resting Position

•      Medial border almost vertical

 

•      Abducted approximately 6 cm

 

•      Anteriorly tilted approximately 20°

Resting Position:
Plane of the Scapula 

•      Approximately 30-45° anterior to the coronal plane

Resting Position:
Effect of Hand Dominance

•      Right shoulder:

 a) Medially Rotated           b) Anteriorly Tilted

Resting Position:
Effect of Hand Dominance

•      Anterior Tilting- Right shoulder higher posteriorly, lower anteriorly

Movements of the Scapula

Scapulohumeral Rhythm

•      Scapula must elevate and laterally rotate so the greater tuberosity can clear the acromion

Scapulohumeral Rhythm-
Setting Phase

•      60° flexion/ 30Ί abduction

•      Inconsistent scapular motion

•      Most often adduction

 

 

 

Scapulohumeral Rhythm

•      After setting phase- humeral/ scapular ratio

     = ~ 2/1

–    Inman (1944): 2/1

–    Saha (1961): 2.3/1

–    Freedman & Munro (1966): 3/2

–    Doody et. al. (1970) : 1.74/1

–    Poppen and Walker (1976): 1.25/1

But….not always 2:1.

•      McQuade and Smidt (1998)

–  PROM-  7.9:1  to  2.1:1

–  With load- 1.9:1  to  4.5:1

 

•       McQuade, Dawson, and Smidt (1998)

–  Fatigue increased scapular motion

 

Scapulohumeral Rhythm -
With a “Twist”

Force Couples

•      Inman 1944

–  3 Necessary Force Couples

•   1)  Upward Rotation

•   2)  Medial Stabilization

•   3)  Anterolateral Force from the Inferior Angle

Force Couples

“Essential” Muscles

•      Laumann 1987

•      4 “Essential” Muscles for Shoulder Function

–  Deltoid

–  Supraspinatus

–  Serratus Anterior

–  Trapezius

Serratus Anterior

Trapezius

Serratus- Lower Trapezius
Synchrony

What happens if……

 

A) You lose Serratus Anterior?

–    1) Can’t orient the scapula towards the sagittal plane

–    2)  Scapula assumes a more elevated, adducted, and medially rotated position

–    3)  Winging- inferior angle

 

What happens if…….

B) You lose Trapezius?

–   1)  Can’t orient the scapula towards the frontal plane

–   2)  Scapula assumes a more depressed abducted, and laterally rotated position

–   3)  Winging- medial border

Scapular Dysfunction θ Pathology

•      Serratus Anterior- Impingement, Posterior Instability, Poor energy transfer (acceleration), RC tendinitis

 

•      Trapezius- Impingement, Anterior Instability, Poor energy transfer (cocking phase), RC tendinitis 

Scapular Dysfunction- Pathology

•      Solem- Bertoft et. al. 1993

–   Passively protracted scapula- β’d SA space-

MRI (4 subjects)

•      Culham and Peat 1993

–   IR and Anterior Tilt increased with age and increasing thoracic kyphosis

•      Greenfield et. al. 1995

–   Impingement was correlated with increased cervical lordosis

 

 Scapular Kinematics

•      Warner et. al. 1992

•      Ludewig et. al. 1996

•      Lukasiewicz et. al. 1999

 

Warner et. al.

•      Moirι topography

•      22 asymptomatic, 22 unstable,

       7 impingement

•      Static Test-  0°, 90°

•      Dynamic Test- 10 reps., picture ~ 30-60°

Warner et. al.

Warner et. al.

•      Abnormal rest positions

–   14% asymptomatic

–   32% instability

–   57% impingement

•      Involved shoulder

–   Depressed- instability

–   Elevated- impingement

Warner et. al.

•      Abnormal movement patterns

–   18% asymptomatic

–   64%  instability

–   100%  impingement

 

 

Ludewig et. al.

•      25 healthy subjects

•      Right shoulder only (92% R.H.D.)

•      POS elevation: 0°, 90°, 140°

•      Measured up./ down. rotation, IR/ ER, ant./ post. tipping

•      Surface EMG: Lev .Scap., Rhomboids, Serratus, Trapezius

 

Ludewig et. al.

•      All subjects showed α’d upward rotation and posterior tipping

 

•      84% showed progressive β in IR

 

 

Ludewig et. al.

•      0-90Ί: All muscle activity α’d

 

•      90-140Ί : UT and Serratus  α’d

 

•      90-140 Ί - LT variable

Lukasiewicz et. al.

•      20 asymptomatic

•      17 patients with 3/6 impingement criteria

•      Digitized 6 bony landmarks

•      POS elevation

•      0°, 90°, Full elevation

Lukasiewicz et. al.

Lukasiewicz et. al.

•      For all subjects:

–   2D: found α’d adduction, α’d elevation

 

Lukasiewicz et. al.

•      For all subjects:

–   3D: found α’d upward rotation, β’d internal rotation, and α’d posterior tilt

Lukasiewicz et. al.

•      Impingement patients

–   α’d superior translation **

–   β’d posterior tilt

–   β’d overall ROM**

 

•    **= bilaterally

New Research- Summary

•      No significant difference in scapular resting position

 

•      Scapula adducts, ER’s and tips posteriorly

 

 

 

New Research- Summary

•      Patients with impingement show increased upward translation

–  Warner- Post. capsular tightness

–  Ludewig- Attempt to increase SA space

–  Lukasiewicz- RC Vs. deltoid strength deficiency

 

•      Present Bilaterally

New Research- Summary

•      Patients with impingement show less posterior tipping

•      Unilateral

•      \ Rx.= Pec. Minor stretching and Serratus strengthening 

 

Scapular Dysfunction- Impingement
Conclusions??

 

•      1) Upward Translation/ Rotation

•      2) Posterior Tipping

•      3) GH Impairments

Chicken or the Egg?

•      1) Scapular dyskinesia  θ Impingement

 

•      2)  Impingement θ Scapular dyskinesia

 

•      3)  GH Impairments θ Impingement

                κ

     Scapular dyskinesia

 Evaluation of the Scapula

•      Qualitative examination

•      Manual Muscle Testing

•      “Functional” Strength Testing

•       Lateral Scapular Slide

Qualitative Examination

•      Resting Position

–  Elevation/Depression

–  Abduction/ Adduction

–  Med./ Lat. Rotation

–   Winging

–   Atrophy

MMT- Middle Trapezius

MMT- Lower Trapezius

MMT- Serratus Anterior

Functional Testing-
Scapular Adduction

 

•      Isometrically contract scapular adductors

•      Hold for 15-20 seconds

•      Scapular weakness θ pain in

    < 15 seconds

“Functional Testing”-
Wall Push Up

“Functional” Testing-
Lateral Scapular Slide

•      Measure the distance from the Inferior Angle to the Spine

–    1) Hands at Side

–    2) Hands on Hips

–    3) Elevated to 90°

•      1- 1.5 cm side to side difference at any one position is pathologic

 

 

Long Thoracic Nerve-
Serratus Anterior

•      C5-C6-C7

•      Motor Only

•      Injured by:

–   Contusion

–   Stretch

–   Brachial Neuritis (Parsonage Turner Syndrome)

–   Idiopathic

Long Thoracic Nerve

Long Thoracic Nerve Palsy-
Clinical Implications

•      Pain

•      Resting position- medial rotation, adduction, and elevation

•      Weak MMT

Long Thoracic Nerve Palsy-
Clinical Implications

•      Limited elevation

•      Winging- Inferior Angle

•      Worse in sagittal plane

Long Thoracic Nerve Palsy-
Clinical Implications

Long Thoracic Nerve Palsy-
Prognosis

•      Improvement through 2 years

–  Average= 8 mos. (Gregg 1979)

•      Pain resolves

•      Early fatigue, weakness remain

•      No improvement

–  Pectoralis Major Tendon Transfer

 

Long Thoracic Nerve-
Pectoralis Major Transfer

Spinal Accessory Nerve-
Trapezius

•      Cranial Nerve XI

•      Also motor to SCM

•      C4 contribution-

–   proprioceptive

•      Injured by:

–   Iatrogenic

–   Compression

–   Traction

 

Spinal Accessory Nerve Palsy-
Clinical Implications

•      Atrophy

•      “Drooped Shoulder”

•      Pain

•      Limited Elevation

•      Winging- Medial Border

•      Worse in frontal plane

 

Spinal Accessory Nerve Palsy-
Clinical Implications

Scapular Winging

 Medial Border              Inferior Angle

 Spinal Accessory                 Long Thoracic

Spinal Accessory Nerve-
Prognosis

•      Conservative Treatment=  Poor

•      Sling

•      EMG (6 weeks)

•      Nerve Grafting- 1 year (6 mos)

•      Muscle Transfer-  > 1 year

 

           

 

Spinal Accessory Nerve-
Muscle Transfer

Axillary Nerve-
Deltoid, Teres Minor

•      C5-C6

•      Motor AND Sensory

•      Injured by:

–   Inferior dislocation (60%)

–   Iatrogenic

–   Quadrilateral Space Syndrome

Axillary Nerve Palsy-
Clinical Implications

•      Deltoid Atrophy

•      Painless

•      Elevation- WFL

•      “Silver Dollar Sign”

Axillary Nerve Palsy-
Clinical Implications

•      Weak Abduction

–   60% loss

      (Colachis, Stohm 1969)

•      Weak ER

–   90°

•      Weak Horizontal Abduction

Axillary Nerve Palsy-
Clinical Implications

•      Weak extension

–   60%  loss

      (Colachis, Stohm 1969)

 

–   “Swallow Tail Sign”

                  (Nishigima 1995)

 

–   Deltoid Extension Lag Sign

                  (Hertel 1998)

Axillary Nerve-
Prognosis

•      Excellent

•      80% will resolve

•      EMG 3-4 weeks

•      If no resolution….

–  surgical exploration

–  nerve grafting

Suprascapular Nerve-
Supraspinatus, Infraspinatus

•      C5-C6

•      Motor Only

•      Injured by:

–   Compression

–   Traction

–   Dislocation

–   Cyst

Suprascapular Nerve Palsy-
Clinical Implications

•      Suprascapular Notch

–  Atrophy of supraspinatus, infraspinatus

–  Weak abduction (30-60%)

–  Weak ER (50%)

•      Spinoglenoid Notch

–  Infraspinatus atrophy

–  Weak ER  (50%)

»   (Colachis and Strom 1969)
 

Suprascapular Nerve-
Prognosis

•      Excellent

•      EMG confirms location of injury

•      If no improvement by 6 mos-

–  Surgical exploration/ decompression

Musculocutaneous Nerve-
Biceps, Coracobrachialis, Brachialis

•      C5-C6-C7

•      Motor AND Sensory

•      Injured by:

–   Iatrogenic injury

Musculocutaneous Nerve Palsy-
Clinical Implications

•      Atrophy of Biceps and Brachialis

•      Weak elbow flexion

•      Weak supination

•      Decreased sensation lateral forearm

Musculocutaneous Nerve Palsy-
Prognosis

•      Excellent

•      If complete lesion and no improvement by 6 mos.

–  Nerve grafting

Rehabilitation- Isotonics

•      Mosely et. al. 1992

•      4 “Key Exercises”

–   Push-Ups with a Plus- Serratus Anterior, Pec. Minor

–   Scaption (ER, full ROM)- Serratus Ant., Rhomboids,  Lower Trapezius, Upper Trapezius

–   Rowing- Upper Trapezius, Levator Scapula, Middle Trapezius, Rhomboids

–   Press-Ups- Pectoralis Minor

 

Rehabilitation- Elastic Resistance

•      Hintermeister et. al. 1998

–  Shrugs- Trapezius, Serratus Anterior

–  Forward Punch- Serratus Anterior

–  Seated Rowing (wide grip)- Trapezius 

Rehabilitation-
Serratus Anterior Progression

•      Decker et. al. 1999

–   Shoulder Extension

–   Press Up

–   Forward Punch

–   Knee Push-Up Plus

–   Scaption

–   Serratus Anterior Punch

–   Dynamic Hug

–   Push-Up Plus

Push-Up Progression

•      Lear and Gross 1998

•      Serratus and Upper Trap.

–  Standard Push-Up Plus

–  Push-Up Plus with feet elevated

–  Push-Up Plus with feet elevated and hands on minitramp

Alexis Progression

 

Rehabilitation

Rehabilitation

–    Press Up

–    Forward Punch

–    Knee Push Up Plus

–    Scaption (“Full Can”) to 90°

–    Serratus Anterior Punch

–    Dynamic Hug

–    Push-Up Plus

Rehabilitation

Rehabilitation

Rehabilitation

“Can we watch a movie?”