Shoulder Anatomy

Introduction

Physical Therapy in Pearland, Houston for Shoulder

 


Welcome to ProActive Physical Therapy's patient resource about Shoulder problems.

The shoulder is an elegant piece of machinery. It has the greatest range of motion of any joint in the body. However, this large range of motion can lead to joint problems.

Understanding how the different layers of the shoulder are built and connected can help you understand how the shoulder works, how it can be injured, and how challenging recovery can be when the shoulder is injured. The deepest layer of the shoulder includes the bones and the joints. The next layer is made up of the ligaments of the joint capsule. The tendons and the muscles come next.

This article will help you understand:

  • what parts make up the shoulder
  • how these parts work together

Hear from some of our patients who we treated for Shoulder Pain
I had a long term injury to both my shoulders from the military and this team did an amazing job of making things so much better. I used to have constant pain, day and night, and they helped me get...
 I had a long term injury to both my shoulders from the military and this team did an amazing job of making things so much better. I used to have constant pain, day and night, and they helped me get back to doing what I love. Also the ladies in the front office are wonderful. Can’t say enough good things, so I’ll leave it at that 
Joe C
Pearland, TX
Having broken my shoulder was a rough time. Everyone has been so friendly and helpful. They make the hard time better and even make it fun as well. You have to work hard and the exercises are not fun...
 Having broken my shoulder was a rough time. Everyone has been so friendly and helpful. They make the hard time better and even make it fun as well. You have to work hard and the exercises are not fun but they are very encouraging and supportive. Even on the days I really wanted to quit and not be there, you get the support and push you need to make it through. I won’t go anywhere else! I want to say thank you to everyone in that office! 
Karen Shawn R.
Webster, TX
The people here are fantastic. Have been going to Proactive’s Clear Lake location for 8 weeks and although after 6 weeks of therapy I still needed surgery I am excited to get back to work at getting...
 The people here are fantastic. Have been going to Proactive’s Clear Lake location for 8 weeks and although after 6 weeks of therapy I still needed surgery I am excited to get back to work at getting my shoulder healthy! Taylor always makes your session personal and definitely makes your end goals his personal interest. The front desk staff are two of the best I have ever met at any doctor/medical office. They make it a point to know everyones name and make every interaction personal.If your doctor gives you a choice, I highly recommend you let Taylor and his staff get you back to healthy! 
Karl M
Webster, TX
After two weeks of walking bend over and having pain that did not allow me to sleep in my bed, l finally got an appointment with Pro Active in Pearland. Amy gave me a massage and some exceises and...
 After two weeks of walking bend over and having pain that did not allow me to sleep in my bed, l finally got an appointment with Pro Active in Pearland. Amy gave me a massage and some exceises and sent me home. The next morning I had no pain and could walk standing straight up. Amy and her staff are so awesome starting with the friendly reception staff!! There are not enough great words to say how thankful I am for these great folks. I have been a previous client here for a dislocated shoulder. They took care of it. I can’t say enough great things about these people. Julio Mendoza  US Army Retired. 
Julio M
Pearland, TX
I would definitely Recommend. I attended therapy due to frozen shoulder and was amazed how much it helped to gain back my range of mobility on my left shoulder after only 8 visits. Everyone is polite,...
 I would definitely Recommend. I attended therapy due to frozen shoulder and was amazed how much it helped to gain back my range of mobility on my left shoulder after only 8 visits. Everyone is polite, considerate and knowledgeable. Special thanks to Andre, April, Anissa and Cedrick for all your help and care. I will definitely go back to them, if medically necessary. 
Sandra G
Pasadena, TX
Lynda and Raymond were both fantastic during my therapy sessions. After the initial evaluation of my shoulder, Lynda gave me a work-out plan that was not too hard, but challenging, along with...
 Lynda and Raymond were both fantastic during my therapy sessions. After the initial evaluation of my shoulder, Lynda gave me a work-out plan that was not too hard, but challenging, along with homework. Lynda and Raymond are knowledgeable in their field, friendly, and easy to talk to. I actually was excited to come inside the facility each time because the facility is upbeat and so clean. If I ever have to return for any other physical health problems, I will certainly come back to this facility in The Woodlands. 
Lillian P
I went to my family physician to see if I should take a stronger pain medication other than “over the counter”. For the past year I was waking up with shoulder and muscle pain. My doctor said I...
 I went to my family physician to see if I should take a stronger pain medication other than “over the counter”. For the past year I was waking up with shoulder and muscle pain. My doctor said I should first try physical therapy. I was skeptical that this would help. To my surprise, after working with Dana Warren for a few sessions, I was waking up with no pain. I know I will have to continue with the exercises provided at home. It’s great to be able to put on a pullover shirt, reach back for my seat belt, comb my hair, put on a necklace, etc. without pain. So thank you Dana and Proactive. 
Margaret M
Webster, TX
This was the 3rd time I'm been there and every time they got me back on track, Tara and Iris did a great job to get my shoulder back to normal after surgery. I highly recommend them for anybody that...
 This was the 3rd time I'm been there and every time they got me back on track, Tara and Iris did a great job to get my shoulder back to normal after surgery. I highly recommend them for anybody that needs rehab after surgery. Especially Iris for her knowledge on the muscles that needed work. Thank you for your hard work with me. 
Perry W
Pasadena, TX
My general physician prescribed physical therapy to help with my hurting shoulder. I was skeptical at first, but the therapists did a wonderful job of explaining how the different exercises and...
 My general physician prescribed physical therapy to help with my hurting shoulder. I was skeptical at first, but the therapists did a wonderful job of explaining how the different exercises and conditioning helps my shoulder. They were so patient in helping me correctly complete my exercises and therapy. 
Jill M
Pasadena, TX
Proactive has treated me 3 times (back, knee and now shoulder). Their directors are great! Each one has been very knowledgable about my injuries, skilled in my treatment and helpful setting up my post...
 Proactive has treated me 3 times (back, knee and now shoulder). Their directors are great! Each one has been very knowledgable about my injuries, skilled in my treatment and helpful setting up my post treatment care. I love Lisa Seller-Simon at the Pasadena clinic. She's treating my shoulder now and just like with the other 2 injuries every time I walk out of the clinic my pain levels are decreased and I physically felt better, stronger and more positive. This PT company also does a really really good job getting me in quickly when I start treatment or need to adjust schedule during treatment. In fact, I had treatment scheduled one day but work took me to another part of town. I called to cancel and instead they worked me in at another clinic close to where I was working. Seemly, excellent service! 
Martin K
Pasadena, TX
I have been treated at Proactive Physical therapy for several issues (shoulder, hips, and recovery from surgery) over the last couple of years. Dr. Randle and the entire staff are wonderful and truly...
 I have been treated at Proactive Physical therapy for several issues (shoulder, hips, and recovery from surgery) over the last couple of years. Dr. Randle and the entire staff are wonderful and truly care about their patients’ improvement and recovery. It’s a fun and relaxed environment, but don’t be fooled - the therapy is serious work! I highly recommend Proactive Physical Therapy! 
Candace W
Webster, TX
I injured my rotator cuff and used Proactive for physical therapy. Taylor was very professional and provided educational information on my injury. The Proactive team has been great! The energy upon...
 I injured my rotator cuff and used Proactive for physical therapy. Taylor was very professional and provided educational information on my injury. The Proactive team has been great! The energy upon arrival is very positive, starting with the receptionist and on until you complete the PT session. I highly recommend them! I appreciate the fact that they listened to me and trust my judgment on my progress. They do not push services that are not needed. A place you can trust! 
JN&IL P
Webster, TX
Very nice staff, helping me with injured shoulder.
 Very nice staff, helping me with injured shoulder. 
LizNgina1
Webster, TX
I’ve been to multiple physical therapy facilities over the years and they were all pretty much the same - they taught me some exercises and told me to do them at home every day. Then when I went for...
 I’ve been to multiple physical therapy facilities over the years and they were all pretty much the same - they taught me some exercises and told me to do them at home every day. Then when I went for my appointments they’d watch me do the same exercises I’d been doing at home and I wondered why I was paying to go there. But ProActive physical therapy is different. I still have exercises to do at home and I do those same exercises when I go for my appointments but they also work on my problem area, using massage and manipulation and other techniques to pinpoint the actual cause of my pain and get it resolved. They really care about reducing my pain and improving my quality of life. And every employee is friendly and caring and helpful. For the first time ever, I actually want to go to my appointments. My shoulder problem is improving and I’m very happy with the results thus far. 
Cindy P
Pasadena, TX
I started to get treated at Proactive for a shoulder injury not knowing what to expect, but I have been blown away with the exceptional service from all the Physical Therapist and the Techs that have...
 I started to get treated at Proactive for a shoulder injury not knowing what to expect, but I have been blown away with the exceptional service from all the Physical Therapist and the Techs that have helped me get back to feeling strong again! The front desk has exceptional customer service as well, keep me coming back for appts. They pay attention to details and care about the patients! 
Ann A
Webster, TX
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Important Structures

Acromioclavicular Joint

The important structures of the shoulder can be divided into several categories.

These include:

  • bones and joints
  • ligaments and tendons
  • muscles
  • nerves
  • blood vessels
  • bursae

Bones and Joints

The bones of the shoulder are the humerus (the upper arm bone), the scapula (the shoulder blade), and the clavicle (the collar bone). The roof of the shoulder is formed by a part of the scapula called the acromion.

Shoulder Bones

There are actually four joints that make up the shoulder. The main shoulder joint, called the glenohumeral joint, is formed where the ball of the humerus fits into a shallow socket on the scapula. This shallow socket is called the glenoid.

The acromioclavicular (AC) joint is where the clavicle meets the acromion.

 

Acromioclavicular and Glenohumarel Joints

 

The sternoclavicular (SC) joint supports the connection of the arms and shoulders to the main skeleton on the front of the chest.

Sternoclavicular and Scapulothroacic Joints

A false joint is formed where the shoulder blade glides against the thorax (the rib cage). This joint, called the scapulothroacic joint, is important because it requires that the muscles surrounding the shoulder blade work together to keep the socket lined up during shoulder movements.

Articular cartilage is the material that covers the ends of the bones of any joint. Articular cartilage is about one-quarter of an inch thick in most large, weight-bearing joints. It is a bit thinner in joints such as the shoulder, which don't normally support weight. Articular cartilage is white and shiny and has a rubbery consistency. It is slippery, which allows the joint surfaces to slide against one another without causing any damage. The function of articular cartilage is to absorb shock and provide an extremely smooth surface to make motion easier. We have articular cartilage essentially everywhere that two bony surfaces move against one another, or articulate. In the shoulder, articular cartilage covers the end of the humerus and socket area of the glenoid on the scapula.

Ligaments and Tendons

There are several important ligaments in the shoulder. Ligaments are soft tissue structures that connect bones to bones. A joint capsule is a watertight sac that surrounds a joint. In the shoulder, the joint capsule is formed by a group of ligaments that connect the humerus to the glenoid. These ligaments are the main source of stability for the shoulder. They help hold the shoulder in place and keep it from dislocating.

Ligaments attach the clavicle to the acromion in the AC joint. Two ligaments connect the clavicle to the scapula by attaching to the coracoid process, a bony knob that sticks out of the scapula in the front of the shoulder.

A special type of ligament forms a unique structure inside the shoulder called the labrum. The labrum is attached almost completely around the edge of the glenoid. When viewed in cross section, the labrum is wedge-shaped. The shape and the way the labrum is attached create a deeper cup for the glenoid socket. This is important because the glenoid socket is so flat and shallow that the ball of the humerus does not fit tightly. The labrum creates a deeper cup for the ball of the humerus to fit into.

The labrum is also where the biceps tendon attaches to the glenoid. Tendons are much like ligaments, except that tendons attach muscles to bones. Muscles move the bones by pulling on the tendons. The biceps tendon runs from the biceps muscle, across the front of the shoulder, to the glenoid. At the very top of the glenoid, the biceps tendon attaches to the bone and actually becomes part of the labrum. This connection can be a source of problems when the biceps tendon is damaged and pulls away from its attachment to the glenoid.

 

Labrum

The tendons of the rotator cuff are the next layer in the shoulder joint. Four rotator cuff tendons connect the deepest layer of muscles to the humerus.

Muscles

The rotator cuff tendons attach to the deep rotator cuff muscles. This group of muscles lies just outside the shoulder joint. These muscles help raise the arm from the side and rotate the shoulder in the many directions. They are involved in many day-to-day activities. The rotator cuff muscles and tendons also help keep the shoulder joint stable by holding the humeral head in the glenoid socket.

Rotator Cuff Tendons

The large deltoid muscle is the outer layer of shoulder muscle. The deltoid is the largest, strongest muscle of the shoulder. The deltoid muscle takes over lifting the arm once the arm is away from the side.

Deltoid Muscle

Nerves

All of the nerves that travel down the arm pass through the axilla (the armpit) just under the shoulder joint. Three main nerves begin together at the shoulder: the radial nerve, the ulnar nerve, and the median nerve. These nerves carry the signals from the brain to the muscles that move the arm. The nerves also carry signals back to the brain about sensations such as touch, pain, and temperature.

Blood Vessels

Traveling along with the nerves are the large vessels that supply the arm with blood. The large axillary artery travels through the axilla. If you place your hand in your armpit, you may be able to feel the pulsing of this large artery. The axillary artery has many smaller branches that supply blood to different parts of the shoulder. The shoulder has a very rich blood supply.

Bursae

Sandwiched between the rotator cuff muscles and the outer layer of large bulky shoulder muscles are structures known as bursae. Bursae are everywhere in the body. They are found wherever two body parts move against one another and there is no joint to reduce the friction. A single bursa is simply a sac between two moving surfaces that contains a small amount of lubricating fluid.

Think of a bursa like this: If you press your hands together and slide them against one another, you produce some friction. In fact, when your hands are cold you may rub them together briskly to create heat from the friction. Now imagine that you hold in your hands a small plastic sack that contains a few drops of salad oil. This sack would let your hands glide freely against each other without a lot of friction.

 

 

Summary

As you can see, the shoulder is extremely complex, with a design that provides maximum mobility and range of motion. Besides big lifting jobs, the shoulder joint is also responsible for getting the hand in the right position for any function. When you realize all the different ways and positions we use our hands every day, it is easy to understand how hard daily life can be when the shoulder isn't working well.

Portions of this document copyright MMG, LLC.