The Hits

September Hits

1) The popliteus is an important structure of the knee that is often overlooked by many clinicians.  While it may not be the main contributor to knee dysfunction, it can still have a major impact.  Some patients need greater activation of this muscle, while othersbenefit from a release.  This is a good post on the popliteus and it's functional role in the knee joint.2) I recently had a patient with hamstring syndrome.  She had been previously mis-diagnosed with piriformis syndrome, ischogluteal bursitis, lumbar radiculopathy, and hamstring tendonosis.  Understanding how to differentially diagnose these patients may lead to a more specific treatment and a better outcome.3) Bret Contreas has a great post on Gray Cook.  It's hilariously titled, "50 Shades of Gray Cook".  I've been reading alot of Gray Cooks stuff lately.  The more I read it the more I begin to think he is one of the most important figures in the future advancements of human movement.  It's very innovative and complex without being very complicated.  Which is difficult to accomplish in anything.4) Chris Johnson wrote a great post on calf strains ("tennis leg").  Very useful information on the acute management of this injury.5) I like the idea of bridging the gap between post-rehab and personal training.  I think it would help rehab professionals to have a better understanding of training and the fitness industry.  Pavel Tsatsouline is a very outspoken fitness guru.  He has some great thoughts and opinions on training.  I personally like his idea of "greasing the groove" and anti-muscle-failure approach.  Chris Beardsly put it all in one place with his post of the top 10 Pavel Tsatsouline articles. 

Subacromial Space

Regardless of the patho-anatomical etiology, most shoulder injuries involve a disruption in the delicate subacromial space (SAS).  Once this space is altered the structures (joint capsule, articular cartilage, rotator cuff, biceps tendon, bursa) have increased risk for damage and misuse.  This also leads to subsequent changes in muscle length-tension relationships, arthrokinematics, and motor patterns.The subacromial space is only 10mm.  This is a very small amount of space to deal with; there is little room for error.  To put this in perspective keep in mind that a dime is a little over 1mm thick.   So even a very small change in the SAS could lead to potential clinical improvements.  This increase in space will allow for decreased compression on structures and increased blood flow to allow for healing.Managing this space is very important in expediting the recovery process, especially in the acute phase.  While assessing for movement dysfunction and physical impairments is important to develop an individualized plan of care, increasing the subacromial space will afford your patient decreased pain and increased function.

6 Ways to Increase Subacromial Space

• 1) Glenohumeral Adduction Force
• 2) Scapula Retraction, Upward Rotation, & Posterior Tilt
• 3) Increase Serratus Anterior Activation/Strength
• 4) Thoracic Extension
• 5) Good Posture & the Kinetic Chain
• 6) Rotator Cuff Co-Activation

Mechanism of Increasing Subacromial Space

1) Glenohumeral Adduction Force

Most impingement tests involve a provocative glenohumeral abduction moment to decrease the SAS.  So it would only make logical sense that glenohumeral adduction would increase SAS.  Research has agreed with this logic and shown an shown that adducting muscle forces lead to a significant increase of the subacromial space (138% at 90 degrees relative to abduction forces).  This adduction force can be used for everything from muscle energy techniques to simply holding a towel between your arm and torso.  The latter can have a great effect during the acute stage and ensure reciprocal inhibition of the deltoid to decrease its superior compressive force on the SAS.

2) Scapula Retraction, Upward Rotation, & Posterior Tilt

Clinically I find the scapula to have the greatest impact on patients with impingement.  A small alteration in the scapular orientation can greatly affect the amount of SAS.  There is an overwhelming amount of evidence displaying altered scapula kinematics in patients with SAIS.  More specifically, many studies have shown that scapula retraction, upward rotation, and posterior tilt increase the SAS.  One study found that scapula retraction increases SAS by 200%.  Most of these studies examine the kinematic differences between patients with impingement and pain free individuals.  Here is what these studies have found in patients with SAIS:

• Decreased Upward Rotation (significantly at the end of the 1st of 3 phases - with concurent decreased UT firing)
• Increased Anterior Tipping at the end of the 3rd phase
• Increased Scapular Medial rotation under loaded conditions

There is an abundance of corrective exercises for the shoulder (just search on youtube).  To emphasis an increase in SAS you should try to select exercises that strengthen/activate the muscles that produce scapula retraction, upward rotation, and posterior tilt.

3) Increase Serratus Anterior Activation/Strength

The serratus anterior gets its own section because of the unique role it has in controlling the inferior angle of the scapula against the thorax.  This feature helps lift the anterior acromion off of the most common site of impingement.   If you consider the scapula motionts that increase SAS  you will notice that the serratus anterior has a role in each of these motions.  Ludwig and Cook found that subjects with SAIS demonstrated decreased activity in this muscle across all loads and planes.

4) Thoracic Extension

Thoracic extension is an important part of the kinetic chain.  It significantly alters scapular kinematics and is associated with decreased muscle force.  Looking at the position of the thoracic spine will often display a correlated scapula position.  For example, in the kyphotic thoracic spine the scapula would be anteriorly and superiorly tilted.We often consider treating patellafemoral patients by correcting the alignment and movement of the structures underneath the patella (dynamic valgus - femur & tibia).  You can use the same logic to treat shoulder patients.  Tom Myers has described the scapula as a sesamoid bone.  Using this theory you could affect the scapula orientation and shoulder muscle forces by simply correcting the thoracic spine dysfunction.

5) Good Posture & the Kinetic Chain

While local interventions may have the most immediate impact, it is worth considering the global view of increasing SAS.  Proper scapula position and thoracic extension are aspects of good posture, but in severe cases it is important to look at the bigger picture and modify posture from all angles.  Research has shown that normal motor patterns of voluntary upper extremity movement include preparatory lower extremity and trunk muscle activation.  Poor posture may alter optimal muscle length-tension relationships and effect the shoulder.  It could be helpful to integrate a kinetic chain approach to accelerate rehabilitation and restore normal motor patterns.

6) RTC Activation

This is classic physical therapy and the conventional local method for increasing SAS.  The rotator cuff externally rotates the greater tubercle away from the acromion and creates a concave compressive force.  Studies have shown that there is reduced co-activation of the rotator cuff in patients with SAIS during the initiation of elevation below 30°, but not at higher angles.  This validates the importance of reactive neuro-muscular training for the rotator cuff.

Bottom Line

This post was focused on the mechanisms and kinesiology that affects subacromial space.  A full assessment is imparitive for effective treatment.  By understanding the mechanisms that maximize the subacromial space you will have a better idea of what to look for and how to correct it.

6 Ways to Increase Space

1. Glenohumeral Adduction Force
2. Scapula Retraction, Upward Rotation, & Posterior Tilt
3. Increase Serratus Anterior Activation/Strength
4. Thoracic Extension
5. Good Posture & the Kinetic Chain
6. Rotator Cuff Co-Activation

References

Hinterwimmer, Stefan, Ruediger Von Eisenhart-Rothe, Markus Siebert, Reinhard Putz, Felix Eckstein, Thomas Vogl, and Heiko Graichen. "Influence of Adducting and Abducting Muscle Forces on the Subacromial Space Width." Medicine & Science in Sports & Exercise 35.12 (2003): 2055-059Solem-Bertoft E, Thuomas K-A¨ , Westerberg C-E. The influence of scapula retraction and protraction on the width of the subacromial space: an MRI study. Clin Orthop 1993;296:99-103Ludewig PM, Cook TM. Alterations in shoulder kinematics andassociated muscle activity in people with symptoms of shoulder impingement. Phys Ther 2000;80:276-91 (Best Article)McClure PW, Michener LA, Karduna AR. Shoulder function and 3-dimensional scapular kinematics in people with and without shoulder impingement syndrome. Phys Ther 2006 August;86(8):1075-90.Kebaetse, M. "Thoracic Position Effect on Shoulder Range of Motion, Strength, and Three-dimensional Scapular Kinematics." Archives of Physical Medicine and Rehabilitation 80.8 (1999): 945-50.Finley, M., and R. Lee. "Effect of Sitting Posture on 3-dimensional Scapular Kinematics Measured by Skin-mounted Electromagnetic Tracking Sensors☆." Archives of Physical Medicine and Rehabilitation 84.4 (2003): 563-68Myers JB, Hwang JH, Pasquale MR, Blackburn JT, Lephart SM. Rotator cu coactivation ratios in participants with subacromial impingement syndrome. J Sci Med Sport. 2009;12:603-608McMullen J, Uhl TL.  A Kinetic Chain Approach for Shoulder Rehabilitation.  J Athl Train. 2000 Jul-Sep; 35(3): 329–337.Cordo PJ, Nashner LM. Properties of postural adjustments associated with rapid arm movements. J Neurophysiol. 1982;47:287–308 --The main reason I do this blog is to share knowledge and to help people become better clinicians/coaches. I want our profession to grow and for our patients to have better outcomes. Regardless of your specific title (PT, Chiro, Trainer, Coach, etc.), we all have the same goal of trying to empower people to fix their problems through movement. I hope the content of this website helps you in doing so.If you enjoyed it and found it helpful, please share it with your peers. And if you are feeling generous, please make a donation to help me run this website. Any amount you can afford is greatly appreciated.

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Why You Should Use the Half-Kneeling Position

The half-kneeling position is a great way to assess and treat your patients hip and core stability.  While it seems like an easy exercise, it has many subtleties that can make or break the position.  Having a greater understanding of the half-kneeling position will help ensure that your patient achieves the maximal benefit.

What it Does

• Taps into the CNS hard-wired developmental stage
• Increases hip & core stability
• Is a self-limiting position - if they can't do it they will lose posture
• Challenges lateral and rotary stability
• Creates a stable position to produce movement from (Reactive/Reflexive Stabilization)
• Kneeling eliminates the ability of the ankle and knee joints to provide stability.  This means less degrees of freedom to compensate with. All efforts to maintain posture will achieved through the hip and core.

3 Keys to Performance

1. Never let the trunk move.  Remain in a tall stable spine posture.
2. Keep the shoulder, hip, and knee in line - spine should be neutral
3. Front foot should be in line with the back leg (narrow base of support)

Clinical Use

Examination

Any patient with a LE asymmetry or hip/core impairment should be tested.  To test, simply place them in this position for 30 seconds and look for a loss of posture.  By assessing bilaterally you will be able to determine any asymmetries.  You can also look at their direction of loss of postural control to further determine where their specific impairment is located.  After placing your patient in this position you will have a better assessment of their hip and core stability, as well as any asymmetries in the proximal kinetic chain.

Intervention

You'll be surprised by how many people can not simply maintain this position without losing postural control.  Before progressing with dynamic exercise it is of paramount importance that they are able to maintain stability for at least 1 min.  If you don't develop proximal stability before distal mobility then you will be setting yourself up for compensations later on in the plan of care.Once the patient displays stability the flood gates open and you can start letting your creativity run wild.  The greatest part about half-kneeling is that it is just a base of support.  You could add an asymmetrical load to further challenge lateral and rotary stability or simply add a symmetrical load to increase the force.  The possibilities are endless.  It simply depends on your patients impairments and your clinical intentions.By performing an UE movement through the static half-kneeling position you are training the correct muscle recruitment and timing pattern.  Keep in mind that "when a extremity is used to challenge the position of the body, a reactive force is produced within the body that is equal in magnitude but opposite in direction to the forces producing the destabilizing movement." (Hodges 1997)Example Progressions:

Chop and Lift

PNF Patterns

Shoulder Rows

Pallof Press

1 Arm Landmine Press

”The act of not moving in the presence of movement is neuromuscular stabilization” - Gray Cook

References

Voight ML, Hoogenboom BJ, Cook G. The chop and lift reconsidered: Integrating neuromuscular principles into orthopedic and sports rehabilitation. N Am J Sports Phys Ther. 2008;3:151–159Hodges PW, Richardson CA. Relationship between limb movement speed and associated contractions of the trunk muscles. Ergonomics. 1997;40:1220-1230. --The main reason I do this blog is to share knowledge and to help people become better clinicians/coaches. I want our profession to grow and for our patients to have better outcomes. Regardless of your specific title (PT, Chiro, Trainer, Coach, etc.), we all have the same goal of trying to empower people to fix their problems through movement. I hope the content of this website helps you in doing so.If you enjoyed it and found it helpful, please share it with your peers. And if you are feeling generous, please make a donation to help me run this website. Any amount you can afford is greatly appreciated.

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Paris Course - S1 - Spinal Evaluation & Manipulation

This past month I had the pleasure of taking a University of St. Augustine continuing education course with instructor Larry Yack.  The course went over spinal evaluation and manipulation (skilled passive movement of a joint).  There was a tremendous amount of useful information and techniques.  Here's some random notes.

Random Seminar Notes

◊ Don't chase pain.  Pain can be misleading.  One study showed that the injection of saline solution into the interspinous ligament produced similar referred dermatomal pain patterns as disc pathologies.  In other words, there are many structures that refer pain down the leg.  Don't assume where the pain is coming from.  Find the mechanical impairments/dysfunction.◊ The importance of manual contact on patients - Ectoderm = Brain and Skin.◊ The MRI results are not the end all be all.  44% are false positive.◊ There are many reasons to manipulate - psychological, neurophysiological, biomechanical, and chemical effects.  But as a clinician the primary reason to manipulate should be because research shows that it simply improves patient outcomes.◊ Clinical Signs of Instability - demonstration of tissue creep (inability to sit still), increase muscle tone, presence of a spinal "step" or rotation, disappearance of muscle tone, step, or rotation on prone lying, shaking/juddering/aberrant motion during forward bending, difficulty coming up from forward bending, grade 5 or 6 on passive motion palpation◊ "First Aide" for the spine should be ice, rest to allow tissues to settle down, prone backward bending, no lifting or forward bending, and maintain lordosis - Larry Yack◊ Assess AROM for motion restrictions.  Use passive intervertebral motion (PIVM) to confirm hypothesis and increase specificity.◊ Facet Capsular Pattern : Lumbar = SB and Rot Opposite : Cervical=SB and Rot Same.  If the restriction matches the facet capsular pattern then a joint manipulation may be indicated.◊ Axial extension (upright posture) is of paramount importance for cervical patients◊ Consider performing exercises prior to manual interventions with chronic back patients - "don't make them passively comfortable and then expect them to become active"◊ Find the reason why the muscle is in a hypertonic state - spasm, hypertrophy, involuntary guarding, chemical muscle holding, or voluntary muscle guarding◊ Aerobic exercise is great for back patients (non-acute stage).  Get them active.  Get them moving.◊ It's easy to assume it's a disc and just give press-ups.  Assess what is really driving the dysfunction/impairment.  For a disc pathology look for 4 objective signs: true sensation loss (pin prick), motor weakness, SLR + < 30 degrees, and diminished or absent reflexes◊ Assess for Pelvic Obliquity in standing AND sitting.  If it resolves in sitting then the obliquity may be a result of a functional shortening further down the kinetic chain.◊ Try to increase contact area (increased proprioceptive input) when performing manual interventions

Bottom Line

The S1 Spinal Evaluation & Manipulation course from University of St. Augustine was a great course and has improved my evaluation and treatment skills.  Before this course I was relying on treatment based classification system (TBCS) for low back pain.  While the TBCS is an effective method, it doesn't emphasize the patients biomechanical motion restrictions or spinal arthrokinematics.  With the S1 Spinal course I have gained a better understanding of the intricacies in the evaluation and treatment of the spine. --The main reason I do this blog is to share knowledge and to help people become better clinicians/coaches. I want our profession to grow and for our patients to have better outcomes. Regardless of your specific title (PT, Chiro, Trainer, Coach, etc.), we all have the same goal of trying to empower people to fix their problems through movement. I hope the content of this website helps you in doing so.If you enjoyed it and found it helpful, please share it with your peers. And if you are feeling generous, please make a donation to help me run this website. Any amount you can afford is greatly appreciated.

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Shoulder Stability - Dynamic Stabilizers (3 of 3)

Dynamic Stabilizers of the glenohumeral joint include the contractile tissues and the associated sensorimotor system involved with proprioception, kinesesia, and the sensation of resistance.  For optimal shoulder stabilization the dynamic stabilizers must be working in an efficient synergistic fashion.

Rotator Cuff

The rotaor cuff muscles have a smaller cross-section area and size, a closer to center of rotation on which they act, their lever arm is shorter, and they generate smaller forces.  Which means they are made to provide stability to a dynamic fulcrum during GH movement.  It is also important to realize that the rotator cuff tendons blend with the joint capsule.  They not only help to dynamically stabilize and move the humerus, but they reinforce the joint capsule (dynamic ligament tension).In addition to the concatity-compression effect to stabilize the humeral head in the center of the glenoid fossa, the rotator cuff helps to externally rotate and depress the humeral head to avoid contact (impingement) of the greater tubercle with the acromion.  While external rotation comes mainly from the teres minor/infraspinatus, the downward depressive moment comes from the force couple of the subscapularis and teres minor/infraspinatus.  This downward force component helps to prevent the dominance of the deltoid's upward force (depressive forces at maximum between 60 and 80 degrees of elevation).   This is synergistic relationship often referred to as the RTC/Deltoid force couple.Assessing for adequate dynamic stability in every direction requires knowledge of the contractile structures around the joint and how they function with each humeral vector force.  There are 3 ways I tend to look at this dynamic stability.

1. Resistance to translation from opposite side pull of muscles
2. Support of same side structures through muscle stiffness/capsular tensioning
3. Synergistic force coupling for efficient controlled axis of rotation/motion

We'll use anterior translation of the humerus during external rotation at 90° as an example since it is the most common clinically.  On the posterior side of the GH joint, the external rotators would fire to "pull" the humeral head back.  It has been proven in research that the external rotators help to prevent anterior translation of humerus (Kuhn et al 2005).  On the anterior side of the joint, the internal rotator would provide anterior capsule tightening and act as a sling to prevent excess anterior translation.  The force couples of the scapular musculature, teres minor/infraspinatus and subscapularis, and supraspinatus would help to stabilize the humeral head in the glenoid fossa.

• Supraspinatus - compression, abducts, and generates a small ER torque , peaks at 30°-60°, generates most force in scapular plane
• Infraspinatus & Teres Minor - compression, generates inferoposterior force, provides great ER torque, generates most force at 0° abduction
• Subscapularis - compression, provides anterior stability, generates IR torque, generates most force at 0° abduction, primary IR at 90° abduction

Long Head of Biceps Brachii

The LHB as a stabilizer of the shoulder joint has been a topic of controversy for a long time now.  Some believe that the forces of the LHB are negligible and do not function to stabilize the glenohumeral joint.  Others believe it is anywhere from a secondary to tertiary stabilizer of the shoulder.  Although, there are many different views as to how the muscle functions as a stabilizer.  It has been theorized that the LHB is a humeral head depressor, reduces anterior translation in late cocking phase of throwing and can increase the torsional rigidity of the joint resisting ER, and some have pointed out that at low levels of elevation it stabilizes the joint anteriorly when the arm is in IR and posteriorly when the arm is in ER.Research still seems to be inconclusive as to the function of the LHB in stabilizing the shoulder joint.  However, the fact that the biceps tendon often plays a role in symptoms (anterior shoulder pain) and pathologies (SLAP lesions) leads me to believe that the LBH plays a role in stabilizing the shoulder joint.

Scapula

The scapula is of great importance when considering shoulder stability.  Achieving proper balance of force couples, resolving any muscle-length limitations, and ensuring dynamic stabilization of the scapula throughout the entire ROM is necessary for optimal functioning of the shoulder joint.  It is important to ensure a retracted and slightly depressed scapula during all shoulder exercises.A discussion of the influence of the scapula is beyond the scope of this article.  A future post will provide more detail.

Examination

Examination and assessment of the dynamic stability of the shoulder complex can be very difficult.  Most special tests do not provide adequate specificity or sensitivity, subjective complaints may be misleading, and there are many structures they may be involved.  I have found it helpful to assess the shoulder in various degrees of motion in all 3 cardinal planes.For example, I will preform the kennedy-hawkins in 3 different transverse plane degrees to attempt to differentiate the influence of pain from the acromial and/or coracoid.  I usually MMT IR/ER and abduction strength in 3 different frontal plane degrees in attempt to determine a more specific directional instability and to assess the RTC force coupling efficiency.  I also find it helpful to consider the sagittal plane and palpate the humerus and scapula to determine if and where any uncontrolled motion is coming from.

Bottom Line

Assessing and treating dynamic stability of the shoulder joint is a very complex task.  A thorough understanding of the kinesiology and structures involved is necessary to determine the specific dynamic stability impairments.  Since the shoulder joint has the most mobile joint in the body, it is important to consider all planes of motion to locate the uncontrolled motion.

Best of the Web

http://www.eorif.com/Shoulderarm/Shoulder%20anat/Shoulderanatomy.htmlhttp://www.mikereinold.com/2011/03/6-key-factors-in-the-rehabilitation-of-shoulder-instability-part-1.htmlhttp://www.mikereinold.com/2010/11/shoulder-impingement-3-keys-to.htmlhttp://www.shoulderdoc.co.uk/http://www.physiodigest.com/376/shoulder-examination/http://www.orthoontheweb.com/shoulder.asphttp://thebodymechanic.ca/2011/01/18/shoulder-impingement-rehabilitation-part-one/http://www.thesportsphysiotherapist.com/subacromial-impingement-syndrome-posterior-capsule-tightness-and-the-%E2%80%9Cdiablo-effect%E2%80%9D/http://robertsontrainingsystems.com/blog/5-more-shoulder-saving-tips/http://optimumsportsperformance.com/blog/?p=2076

References

Ticker JB, Beim GM, Warner JJ.  Recognition and treatment of refractory posterior capsular contracture of the shouder.  Arthroscopy.  2000;16:27-34Sethi PM, Tibone JE, Lee TQ.  Quantitative assessment of glenohumeral translation in baseball players: a comparison of pitchers versus nonpitching athletes.  Am J Sports Med.  2004;32:1711-5Terry GC, Thomas M, Chopp.  Functional Anatomy of the Shoulder.  Journal of Athletic Training.  2000;35(3):248-255Izumi T, Aoki M, Tanaka Y et al.  Stretching positions for the coracohumeral ligament: Positional strain during passive motion using fresh/frozen cadaver shoulders.  Sports Medicine, Arthroscopy, Rehabilitation, Therapy & Technology 2011.Kuhn JE, Huston LJ, Soslowky LJ et al.  External rotation of the glenohumeral joint: ligament restraints and muscle effects in the neutral and abdcuted positions.  Journal of Shoulder and Elbow Surgery.  2005;14(1):S39-S48.Myers JB, Lephard SM.  The Role of Sensorimotor System in the Athletic Shoulder.  Journal of Athletic Training.  200;35(3):351-363Reinold MM, Escamilla R, Wilk KE.  Current Concepts in the Scientific and Clinical Rationale Behind Exercises for Glenohumeral and Scapulothoracic Musculature.  JOSPT.  2009;39(2)105-117Mike Reinold On-Line Shoulder Course - Recent Advances in Evidenced-Based Evaluation and Treatment of the Shoulder --The main reason I do this blog is to share knowledge and to help people become better clinicians/coaches. I want our profession to grow and for our patients to have better outcomes. Regardless of your specific title (PT, Chiro, Trainer, Coach, etc.), we all have the same goal of trying to empower people to fix their problems through movement. I hope the content of this website helps you in doing so.If you enjoyed it and found it helpful, please share it with your peers. And if you are feeling generous, please make a donation to help me run this website. Any amount you can afford is greatly appreciated.

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Force Coupling for the Lumbo-Pelvic-Hip-Complex

Force Closure

Force closure is a biomechanical myofascial system that helps to produce a “self-locking” mechanism for joints.  It occurs when contraction of the muscles/fascia that cross a joint results in increased stability of the joint.  This external dynamic myofascial force can increase stability by producing a closed pack articular position (increased congruency), generating segmental stiffness, and increasing compression perpendicular to the joint.The result of force closure is very valuable for movement efficiency.  Maximizing the force closure mechanism will decrease translational/shear/torsional forces, increase segmental control, allow for greater load bearing stability, and decrease the stress on passive stabilizing structures.  This concept is not exclusive to one part of the body and should be considered with any patients with an instability impairment.  (Photo: Vespar Avenue)

Posterior Oblique Sling or Back Functional Line

The Posterior Oblique Sling (A. Vleeming, D. Lee, P. Chek) or Back Functional Line (T. Myers) consist of the latissimus dorsi, posterior layer of the thoracolumbar fascia, and the contralateral gluteus maximus.  This sling/line runs from the intertubercular groove of the humerus to the contralateral tibial tuberosity.  It is an important component of force closure of the Sacroiliac Joint.   Vleeming et al 1995 found that activation of the LD and contralateral GM creates a force perpendicular to the SIJ.  Along with force closure of the SIJ, it functions to assist with proper load transfer between the spine, pelvis, and legs.  Andrew Vleeming has advocated the training of the gluteus maximus, latissimus dorsi, and erector spinae muscles to assist in force closure of the SIJ and stabilization of the lumbar spine.

Anatomy

Latissimus Dorsi

Has an axial origin at the iliac crest, lumbar vertebrae, lower thoracic vertebrae, and thoracolumbar fascia and inserts into to inferior surface of the intertubercular groove.  It also has attachments into the inferior angle of the scapula and inferior 3 or 4 ribs.  The LD functions to extend, medially rotate, and adducts the humerus.  It can also have synergistic function of anterior tilting the pelvis (lumbar extension) and lateral flexion.

Posterior Layer of the Thoracolumbar Fascia

Research has shown that the posterior layer of the thoracolumbar fascia has strong attachments to the latissimus dorsi and contralateral gluteus maximus.  Some studies have also showed some smaller attachments into the external oblique and trapezius muscle.

Gluteus Maximus

Has an axial origin at the posterior aspect of dorsal ilium posterior, posterior superior iliac crest, posterior inferior aspect of sacrum and coccyx, and sacrotuberous ligament.  It inserts into the posterior iliotibial band and the gluteal tuberosity on the posterior femur.  The GM functions to extend an laterally rotate the hip.  The upper and middle third assist in abduction.  The deep sacral fibers of the GM play an important stabilizing role and function to assist with posterior pelvic tilt.

Bottom Line

Utilizing the force closure concept by training the posterior oblique sling/back functional line may help to provide additional stability and SIJ/LBP patients.  Of course it is first necessary to assess if the myofascial structure is weak, restricted, or a combination of both.  Look for a future post on a strengthening and stretching exercise for this mechanism.

• Force closure can increase stability
• Force closure does so by producing a closed pack articular position, generating segmental stiffness, and increasing compression perpendicular to the joint
• Posterior Oblique Sling/Back Functional Line = Latissimus Dorsi, Posterior Layer of Thoracolumbar Fascia, and contralateral Gluteus Maximus
• POS/BFL may help to provide additional stability for the SIJ and Low Back

References

Vleeming A, Pool-Goudzwaard AL, Stoeckart R, et al.  The posterior layer of the thoracolumbar fascia.  It's function in load transfer from spine to legs.  Spine (Phila Pa 1976).  1995 Apr 1;20(7):753-8Vleeming A, Snijders CJ, Stoeckart R.  Transfer of lumbosacral load to iliac bones and legs.  Part 1: Biomechanics of self-bracing of the sacro-iliac joints and its significance for treatment and exercise.  Clinical Biomechanics 1993 (8) 285-294Vleeming A, Mooney V, Snijders C, et al. Movement, Stability and Low Back Pain: The Essential Role of the Pelvis. New York: Churchill Livingstone, 1997.DonTigny R.  Mechanics and treatment of the sacro-iliac joint.  Journal Manual & Manipulative Therapy. 1993 (1):3-12[subscribe2]

Shoulder Stability - Static Stabilizers (2 of 3)

Static stabilizers are the non-contractile tissue of the glenohumeral joint.  They are very important in shoulder stability at end-range ROM and/or when there is a dysfunction of the dynamic stabilizers.  These static stabilizers set the base of support for the shoulder joint.

Articular Surface

The articular surface is much like the meniscus of the knee joint.  It thicker at the periphery, provides foundation for concativy-compression effect of RTC.

Labrum

The labrum is a firbrous connective tissue which increases articular surface area for the humeral head by deepening the glenoid fossa.  Provides attachment of the glenohumeral ligaments, long head biceps tendon, capsule, and scapular neck.  Contributes to approximately 50% of depth of shoulder joint.  Stretches out anteriorly with external rotation, stretches out posteriorly with internal rotation.  A loss of labrum integrity has been shown to decrease the resistance to translation by 20%.

Joint Capsule

The capsule is twice the size of the humeral head.  Has most extensibility anteriorly and inferiorly.  "Winds up" in abduction and external rotation.  The joint capsule and glenohumeral ligaments are intimately adherent anatomically and mainly function as stabilizers at the extremes of motion.  This static end-range stabilization is very important when all other stabilizing mechanisms are overwhelmed.The joint capsule has an inherit negative intra-articular pressure that holds the joint together.  The osmotic action of the synovium removes free fluid, keeping a slightly negative pressure within the joint.  This slightly negative intra-articular pressure holds the joint together much like "2 wet microscopic slides placed together" (Terry GC et al 2000).

Ligaments

Glenohumeral

There are 3 main ligaments in the glenohumeral joint:

1. The Superior Ligament limits inferior translation and parallels the course of the coracohumeral ligament.
2. The Middle Ligament limits ER at 45° of abduction, anterior translation in 60-90° of abduction.
3. The Inferior Ligament is the thickest of the ligaments and has 3 different portions: anterior band, posterior band, and the axillary pouch.

It is important to consider that the anterior band of the inferior ligament is the primary stabilizer against anterior translation in the throwing position of abduction and external rotation.

Coracohumeral Ligament

Limits anterior and inferior translation.  Is taught at lower levels of elevation, extension, and extension with adduction (Izumi et al 2011).

“Circle Stability Concept”

For a full dislocation to occur, both sides of the capsule and ligaments must be damaged.  The capsule preventing the direction of location would be considered the primary restraint and the opposite side would be considered the secondary restraint.

Examination

Using the sulcus test and the drawer/load and shift tests at different angles of abduction, the clinician can differentiate between these 3 different ligaments to determine the specific structure involved.  Consider the magnitude of translation and primary and secondary restraints involved with these movements.

Sulcus Test

Position the patient in a relaxed seated position with the arms at the side resting on the thighs.  An inferior translation force is applied through the humerus.  Assessment of the amount of inferior translation will determine if there is a positive "sulcus sign".

• 0-20° Abduction = Primary Restraint is Superior Glenohumeral Ligament
•  45° Abduction = Primary Restraint is Anterior Band of the Inferior Glenohumeral Ligament
• 90° Abduction = Primary Restraint is Posterior Band of the Inferior Glenohumeral Ligament

Anterior Drawer / Load and Shift Test

Patient is positioned in the same position as the sulcus test.  Stabilize the scapula with one hand and genlty shift the humeral head obliquely forward in the plane of the scapula.  A "normal" shoulder reaches a firm end point with only slight anterior displacement and no clunking, popping, or pain.  This test can also be performed supine if the patient has difficulty relaxing.

• 0° Abduction = Primary Restraint is Superior and Middle Glenohumeral Ligament
• 45° Abduction = Primary Restraint is Middle Glenohumeral Ligament
• 90° Abduction = Primary Restraint is Inferior Glenohumeral Ligament

Bottom Line

Understanding the static stability of the shoulder allows the clinician to assess the baseline stability independent of dynamic support.  Finding the direction of impaired static stability will also help to reveal which dynamic stability structures need to be emphasized in the plan of care.

Shoulder Stability

Shoulder Stability - Osteo-ArthrokinematicsStatic Shoulder StabilityDynamic Shoulder Stability[subscribe2]

Links

It doesn't take a subscription to a peer-reviewed medical journal to gain knowledge and understanding in the orthopedic world.  Today there is a plethora of websites and blogs with so much free information that you can practically get free continuing education online.  Here's a list of some helpful sites.  I've tried to focus on the ones that are more focused on concepts and education instead of product placement and marketing.  Let me know if there is anything I'm missing.

Websites

Physical Therapy

Physiotherapy Site, Local Physiotherapists, Qualified PhysiotherapistCyber PTShoulder DocYouTube - OptimumCareProviders's ChannelTrigger PointsFMSPostural Restoration InstitutePosture, etiology of a syndromeAPTA Learning Center: HomeThe DonTingy Method - SIJ and Low Back Pain websiteMy Physical Therapy SpaceInternational Spine & Pain Institute

Orthopedic

eOrthopod.com | Orthopedic Information, News, Patient Guides, FAQs and moreMedScape - News, Reference, EducationOrthopedic News | ORTHOSuperSiteMedlinePlus: Videos of Surgical ProceduresAAOSSpineUniverse.comCyriax Orthopaedic MedicineStone Clinic :: Welcome

Training

TESTOSTERONE MUSCLE | Unapologetic Muscle-Building ElitistsExRx (Exercise Prescription) on the NetPersonal Training Programs - Exercise database, muscles, equipment ACE Fitness - Health and Fitness Information

Endurance

Endurance CornerSlow TwitchThe Science of SportCoachr.org | Latest information for Track and Field - AthleticsCrossfitNatural Running Center  

Pilates & Yoga

Balance Body - PilatesFull Fitness - PilatesYoga JournalYoga BasicsBandhaYoga

Anatomy / Kinesiology / Pathology

Muscle Atlas — Musculoskeletal Radiology — UW RadiologyAnatomy Trains | KMI | Welcome!Kinetic ControlKinesiology, NTUPTNeurokinetic Therapy - David WeinstockHand KinesiologyAnatomy and Physiology Functional KinesiologyGetBodySmart: Interactive Anatomy & Physiology TutorialsMaster Muscle List Home PageAnatomy LessonHumpath.com - Human pathology - Photos - pictures - videosMuscle PhysiologyANATOMYReal BodyWork | MusclesRunning Barefoot: Home

Neuro

Body in Mind - Brain & Mind in Chronic PainNOI - Neuro Orthopedic Institute (David Bulter)

Blogs

Physical Therapy

MikeReinold.com - A Blog for Physical Therapy, Athletic Training, and Sports MedicineBill HartmanThe Sports PhysiotherapistGray Cook, Physical Therapist, Lecturer, AuthorGreg Lehman - The Body MechanicPhysiodigest - David FitzgeraldMark Perren-Jones - Neck Pain and ExercisesThe Athletic Development BlogThe PT ProjectMyPhysicalTherapySpace.comPT Think TankPhysiotherapy Info » Research Analyzed by Clinicians, For CliniciansFITS TorontoErson Religioso - The Manual TherapistLeaps and BoundsCharlie WeingroffSherry McLaughlinNeil Poulton - PhysiobloggerRon HruskaKelly Starrett - MobilityWODSomastruct - James SpeckMyRehabExerciseRehabEducation (NASMI)Seth Oberst

Chiropractors

Craig LiebensonJeff CubosPerry Nickelston - Stop Chasing PainDr. Andreo Spina - Functional Anatomy Seminars -Ryan DeBell - The Movement Fix

Orthopedist

Shane Mangrum - The Back Exercise DoctorDr. Mazzara - Patient Information and Surgical Procedures

Manual Professionals

Leon Chaitow - Complementary health careSports Performance Coach and Licensed Massage Therapist — Patrick Ward, MS CSCS LMTErik Dalton Myoskeletal Alignment Techniques BlogSave Yourself

Training & Fitness

XLathleteEric CresseyMobilityWOD - Kelly StarrettRobertson Training Systems | High Octane Corrective Exercise & Performance EnhancementStrength Coach.com - Mike BoyleNick Tumminello Fitness | Baltimore MD Personal Trainer | Sports Performance & BodybuildingJohn Izzo's Trainer AdviceReality-Based Fitness - Keats SnidemanKelvin Miyahira - Golf Swing Analysis Paul Ingraham - Save Yourself from Aches, Pains & InjuriesPilates Teacher Tips | information and ideas to keep it freshNerd Fitness - Steve KambCharles PoliquinEliteFTS8 Weeks Out - Joel Jameson Breaking Muscle

Endurance Athletes / Running

Chris JohnsonBruce Wilk - Running Rehabilitation & Physical Therapy for MiamiJay DicharryRunningPhysio

Ergonomics / RSI

Ergomatters

Pilates, Yoga & Other

Liz Koch - Core AwarenessPilates Teacher Tips | information and ideas to keep it freshThe Daily BandhaDr. Weil 

Neuro & Pain

Better MovementHealth Skills - Behavior, Psychology, Chronic Pain ManagementMichael Shacklock's Neurodynamic Solutions (NDS)BBoy Science - Tony Ingram Louis Gifford

Bottom Line

Keep in mind that some of these websites/blogs have been around for a long time and have a tremendous amount of information in their archives.  Be sure to take your time and thoroughly explore these sites to get the maximal benefit from them.I think it's important that healthcare professionals continue to progress in the on-line world.  It improves the quality of our services, raises the standard of care, and delivers useful information to people who need it.