Shoulder Anatomy and Bones PDF

An illustration of the bones in a person's right shoulder joint. **The shoulder is a BALL & SOCKET JOINT** The three main shoulder bones are: Shoulder Blade -- SCAPULA Collarbone -- CLAVICLE Upper Arm Bone -- HUMERUS There is also **the Acromion**, sternum and rib cage to...

An illustration of the bones in a person's right shoulder joint. **The shoulder is a BALL & SOCKET JOINT** The three main shoulder bones are: Shoulder Blade -- SCAPULA Collarbone -- CLAVICLE Upper Arm Bone -- HUMERUS There is also **the Acromion**, sternum and rib cage to be aware of. The acromion comes off the scapula. A **JOINT i**s where the ends of two **bones make contact**. -- **to allow motion** There are four joints -- and they move the main shoulder bones: What are the joints called and what do they do. A **JOINT i**s where the ends of two **bones make contact**. -- **to allow motion** Bones & Joints of the Shoulder \| ShoulderDoc **JUST NEED THE FOLLOWING 3:** **SAG** [**SCAPULOTHORACIC JOINT** Scapula & Rib Cage ] [**ACROMIOCLAVICULAR JOINT** **AC** Acromion & Clavicle ] [**GLENOHUMERAL JOINT** Glenioid Fossa &] [Humerus] (Glenoid Fossa is the socket/cavity of the scapula where head of humerus sits) When athlete has a shoulder separation it is often at the AC JOINT [Some things to note:] In addition to the **Glenohumeral Jo**int (between the humerus and scapula) There is **also [the joints at each end of the clavicle]** -- The Sternoclavicular joint (sternum & Clavicle) and the **Acromioclavicular joint** which is the acromion & Clavicle) so the SC & AC are the only true joints. Finally, you have **the Scapulothoracic** Joint which is not really a joint but it has an important biomechanical link. You might prefer to remember the joints as SAG Scapulothoracic, Acromioclavicular Glenohumereal Shoulder joints including the glenohumeral joint, the acomioclavicular joint, the scapulothoracic joint, and the sternoclavicular joint. You have the SCAPULA (shoulder blade) , CLAVICLE (collar bone) and HUMERUS (arm) You also have the Acromion, Sternum (chest) and Rib Cage (To help understand joints) **The main joints** SCAPULOTHORACIC JOINT Joins the Scapula & Rib Cage **ACROMIOCLAVICULAR JOINT Joins Acromoin & Clavicle** GLENOHUMERAL JOINT Joints the Glenoid Cavity (The dip in the scapula) and humerus (arm) BALL & SOCKET JOINT Glenoid Fossa is the Socket Humeral Head is the Ball **MUSCLE ANATOMY** Around the shoulder you will find the 1. **BICEPS & TRICEPS (ANTERIOR & POSTERIOR)** **[BICEPS ]**  There **BICEPS** which is [short for BICEPS BRACHII] is located **on the front** of the upper arm. (so [if a question asks, what is **the Anterior** Humerus Muscle -- it is the biceps) ] **It helps with** FLEXION OF THE ELBOW (bring forearm toward upper arm) AND SUPINATION (Turning palms face up -- by rotating the forearm that turns palm up)) **[TRICEPS]** located at **the back** of the arm (posterior) -It helps with EXTENSION of the ELBOW. (straighten the arm) (And if a question asks you what is the **posterio**r humeral muscle -- its triceps) AND YOU WILL ALSO FIND **[ROTATOR CUFF ]** Whats the rotator cuff - a group of muscles and tendons around your shoulder joint. The tendons all come together and form a cuff around the head of the humerus. It connects your shoulder blade (scapula) to your upper arm -humerus They are important for stabilising the shoulder joint(keeping the ball in the socket) So you can raise your arm above your head and rotate your arm to and away from your body. (4 MUSCLES & 3 MOTIONS) There are 4 muscles in this group of muscles Supraspinatus Abduction Teres Minor External rotation Subscapularis Internal rotation The First 3 can be seen on the posterior (back) view of the rotator cuff) To help you understand where it all is: **SUPRA**SPINATUS (Supra means **superior)** -- so it's the first and superior one on top of the spine of scapula **INFRA**SPINATUS (Infra means inferior) -- so its inferior and below the spine of scapula Then **Teres minor** is below that.  Then the fourth one -- which can be see on the front of the rotator cuff is called SUBscapularis Partial Rotator Cuff Tears: Diagnosis And Treatment, 49% OFF **IDENTIFY WHETHER AN IMAGE IS A POSTERIOR OR ANTERIOR VIEW OF THE ROTATOR CUFF.** How can you tell? This picture has **a SPINE of scapula** -- the bone going across/ through it (not above it). If you see that then you know it is the posterior view of the rotator cuff. **DELTOID MUSCLE** It is a superior muscle -- ie, it is on top and covers the top of your shoulder. Shape of a triangle or delta saign. It is like a baseball cap because it forms a cap on the shoulder Responsible **for Abduction** So whereas the biceps and triceps help with flexion, **The rotator cuff and deltoid help with ABDUCTION** **(raising arm away from the body)**  **And the [Rotator Cuff also] helps with INTERNAL & EXTERNAL SHOULDER ROTATION** Shoulder Rotation: Top 8 Strengthening Exercises \| Sidekick Blog **Recap --** Biceps do flexion and Triceps do extension of the elbow But the biceps ALSO does Flexion of the shoulder & Supination the rotator cuff and deltoid does ABDUCTION, but the rotator cuff also does internal/external shoulder rotation In other words -- the Rotator Cuff helps you turn and rotate your shoulder. **Scapulohumeral Rhythm** This is the way your shoulder blade (Scapula) and your upper arm (humerus) work together when you raise your arm above your head. When you lift your arm above your head, it is not just your upper arm moving. Your **scapula also rotates** to help make the motion smooth and give you more range. So, if only your arm moved, you would not be able to raise your arm very high without discomfort. It is the coordinated movement between the arm/humerus and the shoulder blade that allows you to raise your arm fully without straining your shoulder. **THEREFORE: Your scapula needs to rotate for proper shoulder flexion and abduction.** (flexion raising arm forward) (abduction lifting arm sideways).  The scapula & humerus move in RATION 1:2 (So for 180 degree move its 60:120) STRETCHING FOR STRENGTH FLEXIBILITY AND RANGE OF MOTION OF SHOULDER What is happening in each pic. General Stretching Booklet STRETCHING for Anterior muscles- FRONT of shoulders  STRETCHING -- BACK shoulders (called sleeper position) Shoulder Rotation: Top 8 Strengthening \...STRENGTHEN INTERNAL /EXTERNAL ROTATION Towel Stretch: flexibility to increase motion Shoulder Flexibility: Pendulum Exercise \... Moving hips in circle -- makes your arm sway -- PASSIVE ROM EXERCISE Called a PENDULUM EXERCISE -- ITS PASSIVE because you are not moving your arm which is helping to stretch the shoulder **ACROMIOCLAVICULAR JOINT SPRAIN** Remember : This joint (aka AC) is where the ACROMION joins the CLAVICLE (collar bone). And the Acromion (the part of the scapula that makes up the top of the shoulder). The acromioclavicular joint is SUPPORTED BY **[LIGAMENTS]** (attach bone to bone) It is these LIGAMENTS that can be **[SPRAINED OR TORN]** in a sprain. These ligaments provide stability.  THE GRADES 1 -- 3 ARE Categorised according **to PAIN, SWELLING & LOSS OF SENSATION.** +-----------------+-----------------+-----------------+-----------------+ | **Grade 1** | **Mild** Pain | **Mild** | **[No]{.underli | | | | Swelling | ne}** | | **Tear** | | | loss of | | | | | sensation | +=================+=================+=================+=================+ | **Grade 2** | **Moderate** | **Moderate** | **[No]{.underli | | | Pain | Swelling | ne}** | | **Tear** | | | to mild loss of | | | | | sensation | +-----------------+-----------------+-----------------+-----------------+ | **Grade 3** | **Severe** Pain | **Visible | **Loss of | | | | Deformity** | sensation** | | **Rupture** | | | | | | | **STEP** | | +-----------------+-----------------+-----------------+-----------------+ **HOW DOES THE INJURY HAPPEN?** **CAUSES: FALLING ON SHOULDER OR DIRECT BLOW TO THE SHOULDER** **falling on the shoulder**. (note, they may sometimes refer to an AC Joint sprain as an AC Joint separation) like in cycling or skiing. It can also be caused by a **direct blow to the shoulder**. (like in contact sports -- ie: rugby) What happens is that when the force from the fall pushes the scapula down, the collarbone, which is attached to the rib cage can't move to follow the scapula. Something has to give -- so the result is that the ligaments around the AC Joint begin to tear or separate (rupture, dislocate) the Acromioclavicular (AC) Joint. So, look out for questions that talk about falling on your shoulder, or talk about hitting your shoulder during a contact sport. So while **pain & Swelling** is present in **all** grades, (at different levels) the **visible deformity** is a characteristic of grade **3. (visible deformity = bump at top of shoulder) It is called a [STEP Deformity]** Shoulder Injuries Acromioclavicular Joint & Sterno Clavicle **[\*\*HOW DO WE TEST?] [SHEAR TEST]** PURPOSE OF TEST: Reproduce pain in the AC Joint to assess integrity & stability Examiner places one hand on front of shoulder and other on the back **to cup the shoulder** **and SQUEEZE** Results: A POSITIVE RESULT -- If patient feels pain Therefore there is an AC joint injury. So a +ve result suggests an AC Injury **GLENOHUMERAL DISLOCATION** This is when the HEAD OF THE HUMERUS (the ball) **[is forced out]** of the GLENOID CAVITY (the socket of the scapula). Shoulder Dislocations Images -- Browse 2,016 Stock Photos, Vectors, and Video \| Adobe Stock There are 3 kinds of shoulder dislocation:- They all involve how the humeral head moves. 1. MOST COMMON 90% ANTERIOR DISLOCATION The humeral head moves FORWARD 2. LESS COMMON 2% POSTERIOR DISLOCATION The Humeral head is displaces BACKWARD 3. RARE INFERIOR DISLOCATION The humeral head moves DOWNWARD 4. NEVER SUPERIOR DISCLOCATION NOTE: SUPERIOR DISLOCATION DOES NOT HAPPEN- Because superior means upward and THERE IS BONE STICKING OUT WHICH STIOS THE HUMERAL HEAD MOVING UPWARDS. **[CAN BE ACUTE OR CHRONIC]** **ACUTE -- SUDDEN** Usually has nerve damage and possible fractures. SYMPTOMS Nerve tingling, severe pain. WHAT TO DO: HOLD ARM AGAINST BODY **CHRONIC -- LONG STANDING/RECURRENT** Athletes experience instability As the number of times you have a dislocated shoulder, the impact you need to dislocate decreases. So, the more times you have a dislocation, the level or force of the impact you need to dislocate your shoulder decreases. SYMPTOMS: Less pain than acute. Arm 'Goes Dead' COMMON: Tennis follow through, extension in bench pressing , blocking in football, swimming. IMPORTANT- for MCQ; if you get a question that describes the position / rotation to choose the type of disclocation: ANTERIOR The shoulder is in Abduction (arm lifted away) & External Rotation (facing outward) POSTERIOR The shoulder is in Abduction (arm lifted away) and Internal Rotation (facing inward) It makes sense -- if you think it through -- the arm is away from body and you rotate so your palm faces outward -- then the humeral rotates to the front -- anterior dislocation. Same for posterior if you rotate inwards, humeral rotates to the back. Or think to yourself Anterior is the fron, if I rotate outwards that to the front or anterior. If I rotate internal / backward that's to the back/ posterior **ROTATOR CUFF INJURY** Lets remind ourselves: The rotator cuff is a group of 4 muscles around your shoulder joint. The tendons all come together and form a cuff around the head of the humerus. It connects your shoulder blade (scapula) to your upper arm -humerus The Four muscles are: **S** Supraspinatus ABDUCTION Happens due to overuse of repetitive movements. **Overhead movements** -- like serving in tennis Especially basebell in cocking phase of pitching. The force is 80-120% of athlete's body weight. TYPES OF INJURY PARTIAL OR FULL TEARS A Partial tear does not completely detach the tendon from the bone A Full Tear a part of the tendon detaches from the bone. (if its incomplete then just a small part of the tendon has detached) otherwise it completely detaches. **IMPINGEMENT INJURY --** AFFECTS the Rotator cuff. Because there is less space of the [subacromial space]. Results in compression of the space where the rotator cuff is. Causes limitation of movement. Painful to reach above shoulder or put your arm behind you. There are 2 types Acromion or Sub Acromial Bursa **The injury affects the SUPRAPSINATUS AND THE SUBACROMIAL BURSA**  In ACROMION - This happens when the bones in your shoulder rub against or pinch your rotator cuff. COMPRESSION: It happens when swelling in your shoulder makes your rotator cuff too big to fit comfortably between your bones. Deep Pain ATHLETES FEEL WORSE AT NIGHT -- BECAUSE SLEEPING WITH ARMS ABOVE HEAD **BICIPTAL TENDINITIS** Reminder: Bicep Brachii (which are your biceps) does elbow and shoulder flexion. Inflammation of the upper bicep tendon which is the **long head of the biceps tendon.** The tendon is irritated while it is passing over the Bicipital groove (where the long head runs) biceps tendinitis It is caused by repeated overhead movement. Any movement that involves rotating the shoulder or stretching the shoulder will cause pain. WHY: If you rotate the shoulder (internal or external) the tendon moves within the groove and irritates the inflamed tendon. If you stretch our your arm you are increasing the tenson in the tendon. If you ignore it -- can lead to rupture Note: There are two ends of the bicep but we are only learning about the part that is near the shoulder -- so the question may include the word proximal -- proximal to shoulder. All it means is near. **BICEP TENDON RUPTURE** **A complete tear of the bicep tendon** **Looks like POPEYE** **Caused by Flexion with Great Resitance** **=** When your elbow is bent (flexed) against a sudden or heavy force.  Overwhelms the biceps **THORACIC OUTLET SYNDROME** This is a condition **when nerves and vessels (veins/arteries**) which pass through a small 'ourtlet are compressed In your armpit (axilla) or Neck  The Thoracic outlet is the passageway between the collarbond and the first rib that allows the blood vessesls to pass down to the arms and hands. COMMON IN Weightliftinf and Swimmin. BECAUSE: they involve frequent overhead movement which places stress on mucles/bones around the thoracic outlet = ROTATIONAL OVERHEAD STRESS WITH RESISTANCE. SYMPTOMS: Tingling (pins & needles), Pain, Weakeness in the hand, weak grip, waste away of muscle/lose mass in the hand. **FRACTURES** **[CLAVICULAR FRACTUE -- BROKEN COLLARBONE] (positioned between shoulder/sternum)** **Absorbs much of the force from hit to shoulder** **COMMON IN:** Ice Hockey, martial arts, lacross, cycling **Why?** Because it is caused by a DIRECT BLOW or FALL ON SHOULDER **80%** of fractues occue in the MIDDLE section. WHY? It is the WEAKEST POINT The clavicle is divided into three parts. At the end nearer to the neck -- SCM pulls up the bone On the other side -- Gravity pulls the other end of the bond Down (from weight of arm/shoulder) The MIDDLE IS WEAKER than the other ends, so more likely to break when you fall/take a hit (force goes through your shoulder) **[SCAPULAR FRACTURE] (Uncommon)** The scapula (shoulder blade) looks like a triangle. It is on the upper back and connects with the clavicle. **WHY MEDICAL EMERGENCY?** A scapular fracture is rare, caused by a direct trauma from the back or side. (contact sport/car crash) BUT are accompanied by other injuries like fractures of shoulder, rib, head, lungs, spinal chord. WHY: because for the scapula to break it needs a high energy trauma to cause the injury **SYMPTOMS: MINIMAL DEFORMITY? Why?** The scapula is **well protected by** layers of thick muscles. **So it deep position, muscle coverage and bone structure limit deformity.** and cant move in abduction motion (away from body) How do they fix it? INTERNAL FIXATION Scapular Fracture (Broken Shoulder Blade) \| Reno Orthopedic Center **[HUMERAL FRACTURE] Broken upper arm bone** **Fall on shoulder, or outstretched hand with extended elbow** [**GLENOID LABRUM (LABRAL) TEARS**.] Reminder -- the glenoid is the socket part of the shoulder joint. Glenoid labrum **is cartilidge** -- lines the socket. It deepens your shoulder -- helps with stability. The Bicep long head attaches to the glenoid labrum -- to the superior (top) part **SLAP TEARS** means a superior tear. (superior means top) But -- the tear is therefore: **At the Top -- from front to back**, where the bicep tendon anchors the labrum. **TELL TALE SIGN -- CLICKING CATCHING LOCKING** NOTE: The word AVULSION might be used. This means torn away