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Meet Your Muscles - The Rotator Cuff

Posted Feb 10 2009 11:32am 1 Comment

Muscles...some people want to build them. Some people want to tone them. Some people want to shrink them. Some people want to flex them at parties. Some people just want to have them. Meet Your Muscles gives you a unique look at some of your 430+ skeletal muscles.

Today's Muscle:
#8 - The Rotator Cuff

Although #8 is marked on the naked muscle man above, you can't see the rotator cuff muscles from the picture above (#8 would more accurately show the deltoid ). 

That's because the rotator cuff is made up of a group of tiny musclesthat  are DEEP in the shoulder. 

To show you exactly where the rotator cuff muscles are, let's start at the skeletal bone of the shoulder joint.

I want you to take away four things from the picture above: 

1. This could be a picture of Lindsay Lohan or Nicole Richie's shoulder

2. The shoulder joint is a ball and saucer joint, which allows for great range of motion but little stabilit y.

3. The head of the humerus is the ball and the saucer is in the side of the scapula - the ball rotates around the saucer.

4. There is not a lot of space above'the ball' before you run into other bony structures

From the next picture I'd like you to see four more things:

1.  Lindsay and Nicole have been bulking up!

2. That there is muscle infront and abovethe scapula. 

3. Thetendonof the rotator cuff musclewraps up the ballof the shoulder joint.

4. And where once therewas space, is now tendon - between the ball and the bony structures right above it.

From the final picture we can now see allfour rotator cuff musclesin all their glory:
  • supraspinatus
  • infraspinatus
  • subscapularis
  • teres minor
We can also see that besides infront and abovethe scapula, there are also muscles on theback side and belowthe scapula too.

Now that we know where they are, 
TOMORROW you will find out what they do!

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Original article in Scientific American:

New analysis identifies pitchers at risk for shoulder injury: Scientific American Blog

Arm injuries are commonplace among Major League Baseball pitchers, and such impairments may have cost a few notable pitchers, such as Randy Johnson and Brandon Webb, a chance to play in the 76th All-Star Game tonight.

A pitcher’s shoulder joint can rotate as quickly as 7,000 degrees per second—nearly 20 complete revolutions in one second if the shoulder could rotate completely freely—during a pitch, making it one of the fastest movements possible by the body, and this repetitive motion of the arm contributes to the fatigue-related injuries. Ian Byram and his colleagues at Vanderbilt Medical Center are hoping to reduce the damage by identifying pitchers at risk for injury during the preseason, allowing teams to design unique strength training routines for susceptible athletes.


The group studied 144 major and minor league pitchers from the Colorado Rockies organization. Over a five-year period they took preseason strength measurements of the four muscles that make up the rotator cuff, which holds the shoulder joint intact. They found that weakness in the muscles for rotation away from the center of the body or for lateral movement increased a pitcher’s risk of sustaining an injury.

The results, presented at the American Orthopedic Society of Sports Medicine conference last week, are the first data directly correlating preseason strength of the specific rotator cuff muscles with injury.  Byram also showed the data to the Colorado Rockies trainer last weekend and says the team is excited that the finding may be another useful tool to study players’ injuries.   

My letter to the editor:

Re:Weak shoulder in preseason ups pitcher injury risk-  Ian Byram  Vanderbilt Medical Center
Last Updated: 2009-07-10 12:11:33 -0400 (Reuters Health)

By Megan Rauscher

Hi. My name is Brad Beldner. I am an Anat Baniel Practitioner and Feldenkrais Movement Teacher in the San Francisco Bay Area. It is disappointing that sports medicine still has limitations when trying to understand the dynamics of human movement, causes of repetitive stress injuries, and the ingredients needed to upgrade athletic performance. As a therapist and movement teacher working with many athletes, I find most rotator cuff pain and limitations in movement and performance of the arm, are usually a reflection of how a person organizes their whole body for the specific action they are trying to execute. The rotator cuff muscles will always get over used, inflamed and weak etc, when the rest of the body isn't organized well to support and participate with the movements of the arm. You create a stronger, more powerful, freer and efficient throwing arm, by not having the arm at odds with the rest of the body.  For example, if the structures of your chest (spine, ribs, sternum, clavicles) aren't free enough to organize themselves to accommodate what is happening with the actions of your arm, your arm will always have to work harder at the ball and socket joint and the rotator cuff (and junctions of the humerus, scapula, acromion process, clavicles and their supporting muscles, etc). In other words, any place our bodies do not have good distribution of effort (work load) and movement throughout, the places that aren't doing an efficient job at helping with an action, create pain and stress in the places that are taking on the brunt of the work ( i.e. pitching arm and its rotators cuff muscles). It is very simple to predict who will have a weak rotator cuff and inefficient pitching arm, by looking at how the rest of their body is supporting the action of pitching the ball. Trying to improve the pitching arm by only strengthening the rotator cuff (and surrounding muscles) is an attempt at trying to over power (or compensate for) the 90% of the body that is usually creating the difficulty. Success is attained when integrating the arm with the rest of the body to get the entire body all on the same page to perform the pitch. 

 Predicting performance outcomes and helping athletes organize themselves for optimal action is easier when you step out of the limitations of looking myopically at a one point in a dynamic system, and problem solve by examining the system as a whole and how it relates to its environment.

I am curious what others think about this idea especially Ian Byram and his colleagues  


Brad Beldner

Brad Beldner, CFT, SEP, NCMTB
Anat Baniel Method for Children
Feldenkrais Method
Somatic Experiencing
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