Welcome to. Not to be copied without the express permission of EDUCATA. Copyright 2014 EDUCATA. All rights reserved. 1. How to Navigate EDUCATA

Transcription

1 Welcome to Copyright 2014 EDUCATA. This presentation is not to be copied in whole or in part without the express permission of EDUCATA. How to Navigate EDUCATA The Shoulder Complex Mechanics, Muscle Function and Exercise Marilyn M. Pink PT, Ph.D. Copyright 2014 EDUCATA. All rights reserved. 1

2 Mechanics, Muscle Function and Exercise Describe the axis of rotation of the humeral head on the glenoid. Static and dynamic influences. Why is this important? Identify some of the intrinsic muscular components that affect the outcome of exercise programs. The beginning of this story: Axis of rotation The Shoulder Story Static influences on rotation The Shoulder Story Add the labrum and humeral head. Copyright 2014 EDUCATA. All rights reserved. 2

3 The Shoulder Story glenoid and labrum Lots of variation among people. No relationship between the size of the two. Two known consistencies: 1. The labrum is largest anteriorly and inferiorly. (Hata 1992) 2. The labrum approximately doubles the depth of the glenoid alone. (Howell 1988) The Shoulder Story Add the capsule and ligaments to the glenoid. Glenohumeral Ligaments Superior adduction Middle 45 Inferior 90 O Connell 1990; Ferrari 1990; Itoi 1993; Turkel 1981; Warner Copyright 2014 EDUCATA. All rights reserved. 3

4 Thickest inferiorly. (O Brien 1990; Turkel 1981) Capsule Neutral in scapular plane. (Johnston 1937) Stretching Think through why, how and where you d stretch. Non-contractile Tissues Can be overstretched which can not be un done by therapy. Wise stretching. Copyright 2014 EDUCATA. All rights reserved. 4

5 Axis of Rotation PROPERTIES On passing, 'Finish' button: On failing, 'Finish' button: Allow user to leave quiz: User may view slides after quiz: Show in menu as: Goes to Next Slide Goes to Next Slide After user has completed quiz At any time Multiple items Dynamic Stability Our muscles are estimated to have 16,000 positions that can be differentiated by < 1. Carpenter et al; Jobe 1996; Perry Copyright 2014 EDUCATA. All rights reserved. 5

6 The 4 P s of the Scapulohumeral Muscles Glenohumeral PROTECTORS Scapular PIVOTERS Arm PLACERS POWER drivers The 4 P s of the Scapulohumeral Muscles Glenohumeral PROTECTORS Rotator cuff Scapular PIVOTERS Scapular muscles Arm PLACERS Deltoids POWER drivers Lats and pecs Protectors Surrounded ~ 1/2 of glenohumeral joint. Closest insertion i to the axis of rotation. Long head of biceps brachii Superior GH lig. Middle GH lig. Subscapularis Inferior GH lig. Approximates the head and stabilizes the joint. Supraspinatus Labrum Infraspinatus Teres minor Capsule Turkel Copyright 2014 EDUCATA. All rights reserved. 6

7 Live Anatomy Long head of biceps brachii Supraspinatus Superior GH lig. Middle GH lig. Labrum Infraspinatus Subscapularis Teres minor Inferior GH lig. Capsule Arm at side (right arm) Arm at 90 /90 (left arm) Live Anatomy Capsule and ligaments are interwoven, and the rotator cuff as well. Is it possible to have: Isolated lesions? Inflammation? Rotator Cuff Muscles Each cuff muscle has a specific duty. The SUPRASPINATUS Is protecting the GH joint. The rotation of the supraspinatus keeps the humeral head near the axis of rotation in the glenoid. It is not a main humeral rotator. It functions closely with the deltoids. Copyright 2014 EDUCATA. All rights reserved. 7

8 Protectors and Placers Placers 3 heads of the deltoid. Function with Protectors as force couples. % MMT 100 Scaption: Mid Deltoid Supra Infra Teres Minor Subscap Reddy et al % MMT The Normal Shoulder During Freestyle Swimming post, mid, ant deltoids and supra Ant Deltoid Mid Deltoid Post Deltoid Supra Early Late Pull Through Early Recovery Late PHASE Copyright 2014 EDUCATA. All rights reserved. 8

9 Early Cocking in Baseball Pitching Nerve Block A nerve block to the supraspinatus inhibits elevation more than a block to the deltoid. Colachis SC, Strohm BR The Arm in the Dependent Position Supraspinatus ~ 3x more compressive force than shear force. Middle deltoids Almost twice as much shear force compared to compressive force. Copyright 2014 EDUCATA. All rights reserved. 9

10 What would happen clinically if the supra didn t fire and the deltoids did? Deltoids have a more distal insertion as they place the arm in space; supra is closer to the glenoid axis of rotation. More humeral head excursion on the glenoid. SLOPPY SHOULDER Implication for Exercise of Supra Low elevations Lighter weights, multiple repetitions Make sure supra is working optimally prior to specifically addressing the Placers. Rotator Cuff Muscles TERES MINOR External rotation and depression at higher elevations for challenging activities. INFRASPINATUS External rotation and depression at lower level elevations. Copyright 2014 EDUCATA. All rights reserved. 10

11 Baseball Pitching % MMT 100 Teres Minor Infraspinatus PITCHING PHASE Teres Minor and Infraspinatus Both function as external rotators of the humeral head in the glenoid during late cocking and the teres minor functions as a posterior check rein during acceleration and deceleration. Implications for Exercise of the Teres Minor and Infraspinatus Need to strengthen them separately. Low and high elevations Concentrically and eccentrically Copyright 2014 EDUCATA. All rights reserved. 11

12 Infraspinatus Teres Minor eccentric and concentric Teres Minor eccentric Copyright 2014 EDUCATA. All rights reserved. 12

13 Rotator Cuff Muscles The SUBSCAPULARIS is just outside the anterior capsule. Supraspinatus Subscapularis It is the first contractile defense against anterior instability. Infraspinatus Teres minor Subscapularis Huge muscle Internal rotation and depression Two innervations Upper subscapularis fibers more parallel Lower fibers angled Baseball Pitching % MMT Lower Subscap Upper Subscap PITCHING PHASE Copyright 2014 EDUCATA. All rights reserved. 13

14 % MMT The Shoulder During Freestyle Swimming normal and painful subscapularis Painful Normal Early Late Early Late Pull Through Recovery PHASE Implications for Exercise of the Subscapularis Upper fibers approximating the humeral head into the glenoid. Lower fibers depressing the humeral head within the glenoid at higher elevations. Together minimizing the translation of the humeral head in the glenoid (a.k.a., minimizing Sloppy Shoulder). Implications for Exercise of the Subscapularis Low weights High repetitions Various arcs of motion (after low arcs are stable and good strength has been achieved) Copyright 2014 EDUCATA. All rights reserved. 14

15 Implications for Exercise of the Placers Focus on exercise AFTER Protectors are good to normal strength. Heavier weights ih functional weights. ih The Rotator Cuff If you live long enough, you ll probably have a rotator cuff tear. Subacromial Impingement: Scaption % MMT Infraspinatus Normal Impingement Subscapularis * * * ARCS OF MOTION *Significant difference p <.05 Reddy et al Copyright 2014 EDUCATA. All rights reserved. 15

16 Subacromial Impingement: Scaption % MMT Supraspinatus Normal Impingement Teres Minor ARCS OF MOTION No significant differences. Depressive vectors are less functional than superior compressive vectors. PROPERTIES On passing, 'Finish' button: On failing, 'Finish' button: Allow user to leave quiz: User may view slides after quiz: Show in menu as: Goes to Next Slide Goes to Next Slide After user has completed quiz At any time Multiple items Pivotors The scapular Pivotors and the glenohumeral protectors are the only two groups of UE muscles that help keep the axis of rotation of the humeral head on the glenoid, where it should be. The Pivotors place the glenoid optimally for the humeral head, and the Protectors approximate the humeral head within the glenoid fossa. Copyright 2014 EDUCATA. All rights reserved. 16

17 Scapular Pivotors Serratus Anterior Winging Scapula EDUCATA blog: ptceu.wordpress.com/2012/02 Copyright 2014 EDUCATA. All rights reserved. 17

18 Scapular Winging Rhomboids Freestyle Swimming With Normal and Painful Shoulders % MMT 100 Normal shoulders Painful shoulders Serratus Anterior Lower Rhomboids Copyright 2014 EDUCATA. All rights reserved. 18

19 Freestyle Swimming With Normal and Painful Shoulders % MMT 100 Normal shoulders Painful shoulders Teres Minor Supraspinatus Force Couples for Scapular Rotation Upward rotation Medial retraction Protraction Inman Force Couples for Scapular Rotation Upward rotation Upper and lower trapezius, serratus anterior Medial retraction Middle trapezius, rhomboids (upper and lower trapezius, levator scapula) Protraction Serratus anterior (pectoralis minor) Inman 1944; Moseley Copyright 2014 EDUCATA. All rights reserved. 19

20 What Is Scapular Lag? What Is Scapular Lag? Excessive scapular motion in individuals recovering from stiff and painful shoulders. Babyar SR. Phys Ther Mar;76(3):226 38; discussion rehab patients 81% adhesive capsulitis/frozen shoulder Average age: 60 years What Is Scapular Lag? Excessive scapular vertical motion? What muscles may be key? Copyright 2014 EDUCATA. All rights reserved. 20

21 Ready for a Break? PROPERTIES On passing, 'Finish' button: On failing, 'Finish' button: Allow user to leave quiz: User may view slides after quiz: Show in menu as: Goes to Next Slide Goes to Next Slide After user has completed quiz At any time Multiple items Power Drivers PECTORALIS MAJOR and LATISSIMUS DORSI Only UE muscles to positively correlate peak torque and pitching velocity. Bartlett et al Copyright 2014 EDUCATA. All rights reserved. 21

22 % MMT The Normal Shoulder During Freestyle Swimming pectoralis major and latissimus dorsi Pectoralis Major Latissimus Dorsi Early Late Early Late Pull Through Recovery PHASE % MMT The Normal Shoulder During Freestyle Swimming pectoralis major and teres minor Pectoralis Major Teres Minor Early Late Early Late Pull Through Recovery PHASE Directional Pull Copyright 2014 EDUCATA. All rights reserved. 22

23 % MMT The Normal Shoulder During Freestyle Swimming subscapularis and latissimus dorsi Subscapularis Latissimus Dorsi Early Late Early Late Pull Through Recovery PHASE The Subscapularis and the Axis of Rotation Implications for Exercise of Power Drivers Strengthen Power Muscles after Protectors and Pivotors Copyright 2014 EDUCATA. All rights reserved. 23

24 Axis of Rotation The axis of rotation in normal shoulders: Roll 3 mm first 30 & 1 mm thereafter Glide Poppen and Walker Passive versus active Axis of Rotation Axis is tighter in active elevation than passive. Qingyun Axis of Rotation Dysfunctional shoulders More excursion SLOPPY SHOULDER Poppen and Walker 1976; Ozaki 1989; Howell et al Copyright 2014 EDUCATA. All rights reserved. 24

25 PROPERTIES On passing, 'Finish' button: On failing, 'Finish' button: Allow user to leave quiz: User may view slides after quiz: Show in menu as: Goes to Next Slide Goes to Next Slide After user has completed quiz At any time Multiple items The Myth of Muscle Balance PCSA is proportional to the maximum tetanic tension in a muscle. Lieber et al Physiological Cross-Sectional Area (PCSA) PCSA PCSA (cm (cm 2 2 )) = muscle mass (g) x cosine (9 / cm 3 ) x fiber length (cm) = surface pennation angle = muscle density (1.056 g/cm 3 mammalian muscle) Copyright 2014 EDUCATA. All rights reserved. 25

26 PCSA Measurements Muscle PCSA Subscapularis 25 cm 2 Infraspinatus and teres minor 16 cm 2 Supraspinatus 8 cm 2 Deltoids Middle 9 cm 2 Anterior 8 cm 2 Posterior 8 cm 2 Latissimus dorsi 10 cm 2 Teres major 10 cm 2 Pectoral major Clavicular Sternal 5cm 2 13 cm 2 Results of PCSA Study Internal Rotators = 71cm 2 Subscapularis Anterior deltoid Latissimus dorsi Teres major Pectoralis major External Rotators = 24cm 2 Infraspinatus Teres minor Posterior deltoid PROPERTIES On passing, 'Finish' button: On failing, 'Finish' button: Allow user to leave quiz: User may view slides after quiz: Show in menu as: Goes to Next Slide Goes to Next Slide After user has completed quiz At any time Multiple items Copyright 2014 EDUCATA. All rights reserved. 26

27 What Can We Do About Sloppy Shoulders? Protectors, Placers and Power Drivers Electromyographic analysis of the glenohumeral muscles during a baseball rehabilitation program. Townsend H, Jobe FW, Pink M, Perry J. Am J Sports Med May Jun;19(3): exercises 30 arcs of motion Elevate hold lower Qualifying criteria 40% MMT over 3 consecutive arcs. Intensity = peak arc Duration = % of exercise qualified Ranked exercise by peak arc for each muscle. Protectors, Placers and Power Drivers study results 15 of 17 exercises qualified for at least one muscle. Townsend et al Copyright 2014 EDUCATA. All rights reserved. 27

28 Protectors, Placers and Power Drivers study results: infraspinatus Exercise Peak Duration (% MMT ±SD) (% exercise) Peak arc Horizontal abduction ER 88 ± External rotation 85 ± Horizontal abduction IR 74 ± Abduction 74 ± Flexion 66 ± Scaption ER 60 ± Deceleration 57 ± Push up (hands together) 54 ± Townsend et al Townsend Study table 2: order of exercises that qualified for a given muscle Deltoids Exercise Ant. Mid. Post. Pec. Lat. Supra. Infra. Teres Subscap. Flexion Scaption IR Scaption ER Abduction Rowing 6 3 Horizontal abd. IR Horizontal abd. ER Horizontal add. Push up (hands together) 8 Push up (hands apart) 2 Bench press Military press Press up 1 1 Deceleration Extension 4 Internal rotation External Townsend rotation et al Prevention for Protectors, Placers and Power Drivers Three exercises among top two for every muscle: Scaption Horizontal abduction w/ ER Press up Townsend et al Copyright 2014 EDUCATA. All rights reserved. 28

29 Prevention for Protectors, Placers and Power Drivers Horizontal abduction Scaption Press up Townsend et al Scapular Muscles and Exercise EMG analysis of the scapular muscles during a shoulder rehabilitation program. Moseley JB Jr, Jobe FW, Pink M, Perry J, Tibone J. Am J Sports Med Mar Apr;20(2): Same methodology as Townsend, but with scapular Pivotors. Scapular Muscles study results: middle serratus Exercise Peak duration % MMT peak arc Peak range Flexion Abduction Scaption Military press peak Push up with a plus Plus maneuver Push up (hands apart) Last arc of push up Peak function Upward rotation and protraction Moseley et al Copyright 2014 EDUCATA. All rights reserved. 29

30 Moseley Study table 3: order of exercises qualifying for a given muscle Trapezoids Serratus anterior Exercise Upper Mid. Lower Lev. scap Rhomb. Mid. Lower Pec minor Flexion Scaption Abduction Rowing Horizontal abd Horizontalabd abd. ER Push up with a plus Push up (hands apart) Bench press Military press Shrug 3 Deceleration Extension (prone) 3 5 Internal rotation External rotation Press up 1 Moseley et al Moseley Study function of the muscles during peak activity Upper and lower trapezius Upward rotation and retraction ( ) Middle and lower Upward rotation and serratus anterior protraction ti ( ) 150 ) Middle trapezius and rhomboids Levator scapulae Isometric: Retraction Isometric: Retraction and elevation Moseley et al Prevention for Scapular Pivotors Four exercises used seven muscles optimally twice (UT, MT, MSA, LSA, LS, Rh) and P min once. Moseley et al Copyright 2014 EDUCATA. All rights reserved. 30

31 Prevention for Scapular Pivotors Scaption Rowing Moseley et al Push up plus Press up Exercises Should Be Augmented Injury/weakness specific exercises Arc of motion of weakness Isometric/concentric/eccentric Sport specific exercises PROPERTIES On passing, 'Finish' button: On failing, 'Finish' button: Allow user to leave quiz: User may view slides after quiz: Show in menu as: Goes to Next Slide Goes to Next Slide After user has completed quiz At any time Multiple items Copyright 2014 EDUCATA. All rights reserved. 31

32 Summary GH Protectors: rotator cuff Each w/ a specific role Vital force couples approximating the humeral head in glenoid Scapular Pivotors: scapular muscles scapular muscles Intrinsic and vital force couples to position the glenoid Humeral Placers: deltoids Position arm in space More distal attachment on lever arm Not a lot of strength needed for most activities Power Power Drivers: pectoralis major major and and latissimus dorsi dorsi Distal attachment on lever arm Don t overstretch. Summary axis of rotation Make certain the Protectors and Positioners are good normal strength before bf working on the Placers and Power Drivers. Summary the 4 P s Protectors Pivoters Positioners Power Di Drivers Copyright 2014 EDUCATA. All rights reserved. 32

33 The Myth of Muscle Balance humeral rotators Internal rotators = 71 cm 2 External rotators = 24 cm 2 Prevention Protectors, Positioners, Power Drivers Scaption Horizontal abduction w/ external rotation Press up Scapular Pivoters Scaption Rowing Push up plus Press up Be Sure to Consider The role of the muscle: Type of contraction Range Speed Strength/endurance/flexibility Is it an isolated lesion? Copyright 2014 EDUCATA. All rights reserved. 33

34 Copyright 2014 EDUCATA. All rights reserved. 34