Written 4/19/2016 by: DJ Edwards
To follow Dr. Nick???s post from last week, we will be touching on a few different topics I see on the performance training side. This is how we begin our approach to all our athletes that come into the facility. Whether it???s a shoulder issue they come to us about or a brand new athlete to our facility that needs their initial assessment done. It is our outline on how we begin to build an athletes program. We may lose you here, this is pretty in-depth stuff.
Most athletes have abnormal motion, our job is to teach them how to control it. Structure dictates function, function dictates whether there is dysfunction. We need to get the athlete to start in proper alignment. The shoulder internally rotates the humerus between 7000-8000 degrees per second. Throwing a baseball is the most violent motion in all of sports. MRI???s reveal that more than 80% of shoulders in baseball players have tears in the labrum or fraying in the UCL. The difference is how many of those are symptomatic? Studies have shown about 30% of the shoulders had symptoms. To help keep the athletes asymptomatic or ???healthy???, we like to start by looking at the resting posture and active assessments.
We like to look for adducted posture (scaps are pulled together) puts the elbows behind the shoulder and drives the humeral head forward. If we see this, it can mean we need to look at rhomboids being over active because the rhomboids are a scapular downward rotator. This can determine where the humeral head goes. We usually use a wall slide variation to fix this. Most baseball players over forward rolled shoulders. If the athlete is in extension (anterior pelvic tilt) the head of the humerus can be driven forward in the GH Joint and the lat is pulling down the scap. The lat???s fascia connects to the pelvis, as you can see all the muscles are effected by each other.
Extension posture is seen very often in the baseball population. A few things we look at in our screens that may cause this type of posture are; breathing patterns, resting posture, anterior core stability and control, over head flexion, thoracic mobility, scapulohumeral rhythm, hip mobility, how much internal/external rotation of the hip/shoulder the athlete has, knee stability and ankle mobility.
When we look at internal rotation of the shoulder we look at both active IR and ER. The lat being an internal rotator to the humerus, (Dr. Nick Thurlow will talk about this later) we see an over work of the lat when it comes to strength and conditioning programs dealing with baseball players. When the lat is over worked it can cause scapular depression, the anterior shoulder capsule to drive forward and drive some one into gross extension. The lat being the dominate muscle that it is can deviate the glenohumeral joint and cause scapular dyskinesia also known as a SICK Scap.
Lat tightness and glenohuemral instability all go together. Shoulder instability implies a certain symptom is present. Acquired external rotation drives more anterior instability of the glenohumeral joint. Working with a baseball population where we see guys with the ability to externally rotate more than the normal population, we never want to stretch the shoulder into external rotation. This will increase the instability and irritate the biceps tendon which can pick up the stability role when instability is present. When you have anterior shoulder issues there more than likely is something else going on. (nick talk about this)
First we need to know what a healthy shoulder is before we can discuss a SICK scap. There are three primary motions that take place at acromioclavicular joint. They are internal/external rotation, anterior/posterior tilting and upward/downward rotation. All of the motions take place on the scapular plane. If you train in our program you will hear the coaches say work in the scapular plane, what we mean by that is we want the humerus 15 degrees in front of the frontal plane. Scapular upward rotation occurs when the arm abducts more than 30 degrees and at the acromioclavicular joint perpendicular to the scapular plane. The glenohumeral joint is surrounded by a very loose capsule that tightens when the humerus is abducted. There are three ligaments in the glenohuneral joint. Those being superior (anterior and inferior joint stability), middle (anterior joint stability) and inferior (anterior joint stability). As you can tell these ligaments along with the rotator cuff provide dynamic reinforcement. The most common dislocation of the glenohumeral joint is anteriorly. The labrum adds support to the humerus sitting in the glenoid fossas well as The rotor cuff. This is why we get the athlete into throwing positions instead of static positions to test for faulty patterns.
As soon as the gelnohumeral joint begins to abduct the capsule tightens and increases joint stabilization. The deltoid is the prime mover along with the supraspinatus for abduction of the shoulder. The anterior deltoid is the prime mover for flexion. Scapular humeral rhythm is what happens when the shoulder moves over head and how the scapula upwardly rotates and how congruent with the humerus. What we are looking for is 55 degrees of upward rotation of the medial border of the scap. This is why we use wall slides, yoga push ups and some soft tissue work to round out the upper back.
So why do we see impingements? Impingements prevent full range of motion. It is likely the humerus will glide superiorly into the subacromial space. The more the abduction of the arm the the greater the impingement. The subacromial impingement will be seen early in abduction as the AC joint will be more at the top end of abduction. There may be bone spurs present, scapula and GH may be unstable, lack of t-spine mobility, increased IR, and as everyone knows the hot topic of breathing patterns.
I Hope this was not to geeky for you, hope you read all the way through this lengthy post. We will explain more next time on how to prevent humeral gliding and increasing posterior cuff strength from a training stand point.
If you would like more in depth material or have any questions please feel free to contact us at firstname.lastname@example.org