Scapular Kinematics: So how is the scapula supposed to move?

Lori Michener PhD, ATC, PT, SCS Department of Physical Therapy

Rm 100, West Hospital Virginia Commonwealth University – Medical College of Virginia

Richmond, VA 23298 lamichen@vcu.edu

Methods of measurement of scapular kinematics

1. Two – dimensional: Radiographs, goniometers, video 2. Three – dimensional: Radiographs, digitizers, magnetic tracking device

Scapular Kinematics

q Normal motion q 3 Rotations: Upward Rotation (UR) / Downward rotation (DR) Internal rotation (IR) / External rotation (ER) Anterior tilt (AT) / Posterior tilt (PT) q 2 Positions / Translations: Superior / Inferior Anterior / Posterior

q Translations defined by clavicular motion because the scapula is constrained at AC jt

q With GH elevation, via direct bone pins the scapula : (McClure et al, JSES, 2001): q Rotations:

q UR (Mean = 50°) q ER (Mean = 24°) q PT (Mean = 30°)

q Positions / Translations: q Clavicular elevate (Mean = 10°) q Clavicular retraction (Mean = 21°)

Ant / PostTilting AC

Internal / ExternalRotation

Ant / PostTilting

Up / Down Rotation

q Scapulohumeral Rhythm q 2:1 is standard q 5:4 (Poppen & Walker, JBJS, 1976); 1.7: 1 (McClure et al, JSES, 2001); 1.5 – 2.4: 1 (Graichen et

al, Clin Ortho, 2000); 2.15 : 1, 0-30: 4.23 : 1 (> H), 91-120: 1.65: 1 (Padua D et al, MSSE, 2003)

Scapular Kinematic Control and Limitations by: q Scapular muscles, RC muscles, Spine (thoracic and cervical), pathology of the

shoulder joint, ligaments, GH joint capsule, clavicle (via AC joint) Scapular muscle fatigue and weakness:

q ↑ed UR w/ upper trap & serratus anterior fatigue (McQuade et al, JOSPT, 1998)

q ↓ed UR and PT w/ upper & lower trap fatigue (McQuade et al, Clin BIomech,1995)

q ↓ed PT, ER, UR w/ ↓ed serratus & ↑ed lower trap activity (SAIS) (Ludewig & Cook, Phys Ther, 2000)

q External load alters kinematics; fatigue?? (Pascoal et al, Clin Biomech, 2000; McQuade, 1995)

Rotator cuff muscle fatigue and weakness: q ↓ed PT with infraspinatus & teres minor fatigue (Tsai et al, Arch Phys Med Rehab, 2003)

q Same effect with RC tendonitis?

Muscle fatigue and weakness: scapular or rotator cuff muscles

q Alters scapular kinematics q Less scapular stability? q Is it a motor control issue, rather than strength? q Altered GH kinematics?....evidence for this later q Implication: overhead athletes / workers?

Spinal posture

q ↑ed cervical flexion q ↓ed UR & PT (Ludewig & Cook, J Occ Rehab, 1996)

q ↑ed thoracic flex (change of 12 degrees from upright ): q ↑ed (sup) position, & ↓ed posterior tilt q ↓ed GH abduction force (Kaebeatse et al, Arch Phys Med Rehab, 1999)

q Slouched posture vs. upright: q ↓ed posterior tilt & ↓ed external rotation (Finley & Lee, Arch Phys Med Rehab, 2003)

Others q Ligaments, Clavicle : No evidence q Capsule: posterior

q Simulated tightness and clinical exam: q ↓ed GH IR, limited cross-body adduction at 90 deg (PSTT), ↑ed superior

translation of HH (Tyler, et al, AJSM, 2000; Harryman et al; JBJS, 1990; Branch et al; AJSM, 1995)

q Pathology

q SAIS, RCT, instability, AC jt arthritis, Humeral head position

Impingement Syndrome and scapular kinematics q Kinematics (during glenohumeral elevation):

q ↓ed PT (Ludewig & Cook, Phys Ther, 2000., Lukasiewicz et al, JOSPT, 1999., McClure et al, JOSPT, 2002; Endo et al, J Orthop Sci, 2001 (x-ray))

q ↓ed ER (Ludewig & Cook, Phys Ther, 2000; Hebert, LJ et al, Am Phys Med Rehab, 2002)

q ↓ed UR (Ludewig & Cook, Phys Ther, 2000; Endo et al, J Orthop Sci, 2001 (x-ray))

q Position: q ↑ed winging (AT & IR) (Warner JJ et al, 1992)

q ↑ed Sup & Med trans (Lukasiewicz et al, JOSPT, 1999)

q Adequate scapular motion required for “maintenance” of adequate SA space q Pattern of decreased UR, ER, and PT has been demonstrated to decrease the area of the

SA space (Solem-Bertolf, Clin Ortho, 1993)

Rotator Cuff Full- thickness tears and scapular kinematics q ↑ed humeral head superior translation during simulated or active GH elevation; in

patients or cadavers with FT RCT (Thompson, AJSM, 1996; Poppen & Walker, 1976; Deutsch, 1996; Paletta, 1997; Yamaguchi, 2000)

q No evidence of altered scapular kinematics q This may cause altered scapular position or kinematics with RC weakness

Glenohumeral instability and scapular kinematics q Position: ↑ed winging (AT & IR) (Warner JJ et al, 1992) q Abnormal scapular DR disrupts the “shelf mechanism” of the inferior glenoid fossa

support of the humeral head…resulting in inferior instability (Itoi et al; JSES; 1992) Adhesive capsulitis and scapular kinematics

q Patients with shoulder adhesive capsulitis (n=10) q Altered SHR, increased contribution of scapular upward rotation q Altered in elevation in scaption, flexion, and abd (Vermeulen HM et al, Ann Rheum Dis, 2002)

q With a stiff GH joint, the ST articulation appears to be able to compensate to allow for total shoulder ROM

Altered scapular kinematics

q Can we capture differences? q With treatment or comparison to healthy?

q Consider the “robustness” of the neuromuscular system q Is the “best” measure to examine kinematics with a combination of all 3 rotations or 3

rotations and 2 positions q Is a larger insult needed to see “obvious” measurable differences?

Scapular Dyskinesis: Examination and Intervention in Patients with Upper Quarter Dysfunctions Clinical Evaluation of the Scapula: Phil McClure PhD, PT Arcadia University - 1 -

Existing Literature Kibler Am J Sp Med 981 Sobush et al JOSPT 96 (Lennie Test)2 Odom et al Phys Ther 20013 Johnson et al JOSPT 20014

Basic Problem: Attempts to capture a 3-dimensional, dynamic phenomenon with static, 2-dimensional measurements are likely to fail

Judgements Based on Visual Observation Kibler et al. JSES 20025 Type 1 (Inf angle prominence) TypeII (medial border prominence) Type III (early scap elevation)

Intertester K=(0.31-0.42) Intratester Κ=(0.40-0.59)

McClure et al JOSPT 2003 (abstract)6

7 prescribed tasks Winging (medial or inf angle) OR Dysrhythmia (abnormal upward rot or elevation) Intertester Kappa=0.6, 72% agreement

Tate et al JOSPT 2004 (abstract)7 -validation of visual judgements using 3D motion analysis -Dyskinesia group showed ant tilt, internal rotation, protraction Our Current Approach Scapular Dyskinesia Test

- 5 test movement (flexion, abduction with and without weight, flip test) - Winging OR Dysrhythmia - posterior and superior view

Scapular Reposition Test - alteration of symptoms during provocative tests by repositioning scapula - move scapula toward posterior tilt and external rotation by grasping shoulder girdle from

behind and bringing forearm obliquely across medial border - look for decreased pain or increased strength for + test

Other Important Considerations Specific muscle testing

- Trapezius - Serratus Anterior - Distinguishing between true weakness (palsy) vs motor control deficit Key Areas of Hypomobility - upper thoracic extension - pec minor - posterior capsule

Scapular Dyskinesis: Examination and Intervention in Patients with Upper Quarter Dysfunctions Clinical Evaluation of the Scapula: Phil McClure PhD, PT Arcadia University - 2 -

References 1. Kibler WB. Role of the Scapula in Athletic Shoulder Function. Am J Sports Med. 1998;26(2):325-

337.

2. Sobush DC, Simoneau GG, Dietz KE, Levene JA, Grossman RE, Smith WB. The Lennie Test for Measuring Scapular Position in Healthy Young Adult Females: A Reliability and Validity Study. J Orthop Sports Phys Ther. 1996;23(1):39-50.

3. Odom CJ, Taylor AB, Hurd CE, Denegar CR. Measurement of scapular asymetry and assessment of shoulder dysfunction using the Lateral Scapular Slide Test: a reliability and validity study. Phys Ther. Feb 2001;81(2):799-809.

4. Johnson MP, McClure PW, Karduna AR. New method to assess scapular upward rotation in subjects with shoulder pathology. J Orthop Sports Phys Ther. 2001;31(2):81-89.

5. Kibler WB, Uhl TL, Maddux JW, Brooks PV, Zeller B, McMullen J. Qualitative clinical evaluation of scapular dysfunction: a reliability study. J Shoulder Elbow Surg. Nov-Dec 2002;11(6):550-556.

6. McClure P, Tate A, Egner M, Greenberg E, Yops R, Neff N. Development and Inter-rater Reliability Testing of a System of Classification for Scapular Dysfunction. Journal Orthopaedic and Sports Physical Therapy. 2003;33(2):A23-24.

7. Tate A, McClure P, Neff N. Validity of a Visual Classification System for Scapular Motion. J Orth Sport Phys Ther. 2004;34:A42.

SCAPULAR DYSKINESIS: EXAMINATION AND INTERNVENTION IN PATIENTS WITH UPPER EXTREMITY DYSFUNCTION

REHABILITATION CONSIDERATIONS

Tim L. Uhl PT, PhD, ATC Division of Athletic Training, Department of Rehabilitation Science, University of Kentucky, Lexington, KY 40536, tluhl2@uky.edu Description: Rehabilitation goals following shoulder injury is to implement a continuum of exercises that restores optimal function while protecting the anatomic integrity of the injured or repaired tissues. The exercises should allow a progression of intensity and load that is within the healing tissue’s capabilities. A key element in rehabilitation is the successful transition in the flow of exercises from the protected exercises of the acute phase to the functional phase. Emphasis of this presentation will be on the component of scapular muscle exercises. The scapular muscles are not exercised in isolation of the other shoulder musculatures but need to work synergistically with the other shoulder girdle musculature for upper extremity function. Exercise selection for scapular musculature strengthening exercises based on EMG research is readily available. 7-9,26 This presentation attempts to organize the previous available information along with new information obtained by the presenter into logical progression from low to high demand exercises in order to better rehabilitate your patients. Objectives: To describe treatment interventions to facilitate mobility, strength and neuromuscular control of the shoulder. To provide evidence and or scientific rationale that is available to support these interventions. Key Points:

• Therapeutic Exercises are beneficial in rehabilitation of patients with • Shoulder instability11 • Rotator cuff pathology 12,25 • Appear to be helpful in recover of associated scapular dysfunctions long thoracic

neuropathy and snapping scapula35

• Proximal Stability • Without proximal control distal structures are moving on poor foundation • Motion and force applied by distal upper extremity initiates proximally 17,37 • Strength and endurance of upper extremity is dependent on trunk16

• Posture of spine effects scapular position, motion, and shoulder strength14 • Position and motion of the scapula effects glenohumeral joint function and subacromial

space • Impingement patients have decreased scapular mobility19,21 • Tight pectoralis major decreases scapular motion 4

• Neuromuscular Control of scapular musculature is diminished in the presence of

pathology 19,29,30 • Diminished force production of scapular musculature6 • Scapular muscular activation diminished due to imbalance and pain27,29,30

• Exercises that facilitate posterior tilting and external rotation (retraction) of scapula are critical for overhead function

• Exercise that facilitate lateral translation and internal rotation (protraction) of scapula are critical for accelerating sport implements and absorbing energy

• Therapeutic Interventions need to address: • Proximal stability and posture

• Flexibility to reverse anterior tilt and internal rotation posture • Shoulder mobility associated with improved function23 • Rehabilitation programs may positively effect posture and scapular position34 • Integrate the kinetic chain to facilitate activation of trunk24 • Transmission of force along kinetic chain typically incorporates rotation (Serape

muscles) • Rehabilitation of the shoulder should incorporate exercises to promote erect

trunk posture and stable scapular position.31 • Strengthening exercises should progress from low to high demand22

• Progressive resistive exercises can increase shoulder strength and improve patient function23,34

• Avoiding inflaming healing tissues • Pain inhibits muscle activation at a central level 5,28 • Altering central motor drive may effect muscle activation patterns for

movement • Arm supported activities diminishes muscular demand36 • Progression of muscular demand can be monitored by load placed through arm33

• Re-establish neuromuscular control of shoulder musculature • Closed kinetic chain exercises promote joint compression and activation of

proximal musculature to provide stabilization1 • Scapular re-education can be accomplished through several tasks • Consider upper trapezius/serratus anterior EMG ratio during exercise selection to

minimize superior scapular translation (shrug) and facilitate medial scapular border control20

Clinical Application Incorporation of rehabilitation techniques that address trunk, scapular, and humeral mobility and control appear to effectively address impairment of diminished strength, motion, and pain commonly seen in patients with musculoskeletal disorders. Gradual introduction of therapeutic exercises while minimizing inflammation of healing tissue and restoring neuromuscular control is the ultimate goal of re-establishing function.

Acute Phase Exercises graded by (%MVIC + S.D.) Exercise Deltoid Supra-

spinatusUp.

Trap.Ser. Ant.

Low. Trap.

Supine PROM15 3 + 1 1 + 6 1 + 2 2 + 2 2 + 2

Forward Bow15 2 + 1 5 + 6 2 + 3 5 + 4 2 + 2

Sidelying Elevation10 10 + 6 2 + 6 2 + 3 11 + 7 8 + 5

Towel Slides10 12 + 7 7 + 7 4 + 3 7 + 4 1 + 1

Supine Press-up 1#15 11 + 4 3 + 7 1 +3 16 + 8 1 + 1

T-Bar10 24 + 9 9 + 9 9 + 8 17 + 6 10 + 10

N.A. = Not available

Sub-acute Phase Exercises graded by (%MVIC + S.D.) Exercise Deltoid Supra-

spinatusUp.

Trap.Ser. Ant. Low.

Trap.

Wedge Press-up15 20 + 9 8 + 11 11 + 11 17 + 8 2 + 1

Ball Rolls10 25 + 8 11 + 10 9 + 3 21 + 7 5 + 4

Ipsilateral Step- up15 21 + 7 22 + 20 21 + 8 15 + 5 13 + 6

Active Elevation10 32 + 8 19 + 12 19 + 9 23 + 7 19 + 8

Standing Press-up15 30 + 11 30 + 17 24 + 8 29 + 13 9 + 5

Rows with elastic tubing7,13

N.A

PK39 + 16

AVG9 + 2

PK34 + 23

AVG9 + 6

PK 10 + 6

AVG 5 + 4

N.A.

Shrugs with elastic tubing13

N.A.

PK 44 + 25 AVG

10 + 6

PK 53 + 29

AVG 13 + 8

PK 31 + 24

AVG

5 + 4

N.A.

Forward Punch13

PK 39 + 23 AVG

9 + 4

PK 48 + 83 AVG

8 + 3

N.A.

PK 49 + 14 AVG

10 + 3

N.A.

N.A. = Not available PK = peak amplitude during phase AVG = average amplitude during phase Functional Phase Exercises graded by (%MVIC + S.D.) Exercise Deltoid Supra-

spinatusUp.

Trap.Ser. Ant. Low.

Trap.

Scaption > 120°9,32 72 + 13 64 + 28 79 + 19 96 + 24 61 + 19

Scaption < 80°2,9 91 + 26 82 + 27 72 + 19 62 + 18 50 + 21

Unilateral Rows9,32 72 + 20 N.A. 63 + 17 14 + 6 45 + 17

Prone Flexion @ 135° ABD9

N.A. N.A. 79 + 18 43 + 17 97 + 16

Diag Flex/ Horiz Add/ Ext. Rot.9

N.A. N.A. 66 + 10 100 + 24 39 + 15

Military Press26,32

72 + 24 56 + 48 64 + 26 82 + 36 N.A.

Unilateral shoulder press supine w/plus9

N.A N.A 7+ 3 62 + 19 11 + 5

Push up w/plus18 N.A. N.A 50 140 30

Prone Horizontal ABD3,9

79 + 20

78 + N.A. 66+ 18 9 + 3 74 + 21

Prone ER @ 90°3,9 N.A.

50 + N.A. 20+ 18

57 + 22

79 + 21

N.A. = Not available

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