Shoulder Anatomy 101: Keeping Your Shoulders Healthy & Pain Free

The shoulders withstand a lot daily, from lifting objects overhead to carrying bags and even playing sports. As such, we should remember to take proper care of the shoulder and the surrounding area to ensure that the shoulder is healthy and robust.


Shoulder anatomy

From a skeletal perspective, the shoulder includes:

  • The clavicle

  • The scapula

  • The humerus

Source: Washington University Orthopedics https://www.ortho.wustl.edu/mm/images/Shoulder%20Illustration%201.jpg


These bones are connected by ligaments and are cushioned by cartilage. The bones in the shoulder form two joints that facilitate its movement:

  • The acromioclavicular (AC) joint (knob on top of shoulder): Point where the acromion (part of the scapula) and the clavicle meet

  • The glenohumeral joint (Ball and socket joint): Point where the humeral head and the glenoid meet

The shoulder joint is highly movable (Miniato, Anand & Varacallo, 2021). The acromioclavicular joint facilitates gliding movement and is stabilized by three ligaments (Wong & Kiel, 2021). The glenohumeral joint facilitates the humerus's abduction, adduction, flexion, and rotation (McCausland, Sawyer, Eovaldi, and Varacallo, 2021).


Since the joint is highly movable, the rotator cuff muscles and tendons of the biceps and triceps brachii work to stabilize it (Miniato, Anand & Varacallo, 2021). This joint is also an attachment point for numerous muscles from the body's posterior, anterior, and lateral sides. Some of these muscles include the infraspinatus, the teres minor, etc. The long head of the biceps brachii is attached to the shoulder near the acromioclavicular (AC) joint. Some muscles, like the rotator cuff muscles, originate from one bone and connect to another. The rotator cuff muscles originate from the scapula and attach to the humerus. Other muscles, like rhomboids or the latissimus dorsi, originate at the vertebral column and connect to the scapula.


Source: Champions Certifications


Neglecting shoulder strengthening and mobility exercises can result in shoulder issues because the muscles need to work in tandem (synergistically) to create movement and not dysfunction.

The following section will briefly explore common injuries, exercises, and stretches to strengthen and stabilize the shoulder.


Common injuries

Some common words or injuries that you may hear related to the shoulder are:

  • Shoulder impingement

  • Rotator cuff injuries

  • Labral tears

  • Frozen shoulder

  • Bursitis.

Shoulder impingement is pinching where a tendon catches on a bone during the movement of the arm.


Rotator Cuff Injuries include partial-thickness tears (an incomplete tear where the tendon is damaged but not completely severed) or full-thickness tears of the rotator cuff tendons (a complete tear that separates the tendon from the bone).


Labral Tears can occur from acute or chronic injury. There are four types of labral tears: Superior Labrum Anterior-Posterior (SLAP) tears, anterior tears, posterior tears, and Bankart tears (Beacon Orthopaedics and Sports Medicine, n.d.).


Frozen Shoulder (Adhesive Capsulitis) is characterized by pain and stiffness that slowly develops in the shoulder. It occurs when the connective tissue in the shoulder tightens.


Bursitis happens the bursae that cushion the bones, tendons, and muscles near the joints become inflamed.


How to improve mobility and strengthen shoulders

Improving flexibility and mobility will help restore full range and ease of motion while strengthening the shoulders will help to stabilize the shoulder, relieve pain and prevent future injury. Injuries can still happen, but strengthening the shoulders will keep the frequency of injuries at bay.


Some stretches and mobility exercises to improve range of motion are:

  • The posterior deltoid stretch (crossover arm stretch)

  • The anterior deltoid stretch (wall pec stretch)

  • The sleeper stretch

  • Wall Angels

  • Prone Snow Angels


Some exercises to strengthen the muscles in the shoulder are:

  • Internal and external rotation exercises (lying or standing)

  • Scapular push-ups

  • Lateral raises.


One combination exercise that addresses mobility and strength in the shoulders is the IYTA. The IYTA consists of movements in various directions to gain more range of motion in the shoulder.

The IYTA can be done as a warm-up exercise to gain mobility and ease of motion in the shoulder before a workout. It can also be done weighted as part of the workout. With the IYTA, you can play with tempo and isometric holds to challenge the shoulders.


Executing the IYTA



  • Lay on the physioball in a prone position. Position the ball around the pelvis or low abdominal region. Maintain a straight back and draw the shoulders down and away from the ears.

  • Extend arms up with thumbs pointing toward the ceiling. The biceps should be near the ear. Return to starting position.

  • With thumbs still pointing to the ceiling, bring arms up at a 45-degree angle and return to starting position.

  • To get to the T position, bring the arms out to the side, with thumbs pointing to the ceiling. Squeeze the shoulder blades and then return to the starting position.

  • Bring the arms back along the torso. The triceps should face the ceiling, and the thumbs should be pointed toward the floor.

  • All four movements are one rep. Repeat for the specified number of reps.


A variation for the IYTA is standing IYTs. If the placement of the physioball is uncomfortable or the client cannot balance, do the exercise from a standing position. The starting position would be at the end position for a front raise (the arms are elevated to shoulder level). In the variation, it is wise to do these unweighted or with light dumbbells, preferably 3lbs. Alternatively, it can also be performed with a resistance band attached to an anchor point.


To learn more about anatomy and strength training, enroll in our Certified Personal Trainer Program!


References

Athwal, G.S. & Armstrong, A.D. (2017). Rotator cuff tears. Retrieved from https://orthoinfo.aaos.org/en/diseases--conditions/rotator-cuff-tears/#:~:text=The%20rotator%20cuff%20tendons%20cover,when%20you%20move%20your%20arm.


Beacon Orthopaedics and Sports Medicine (n.d.). Shoulder Labral Tears. Retrieved from https://www.beaconortho.com/blog/shoulder-labral-tears/


McCausland C, Sawyer E, Eovaldi BJ, & Varacallo, M. Anatomy, Shoulder and Upper Limb, Shoulder Muscles. [Updated 2021 Aug 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534836/


Miniato MA, Anand P, Varacallo M. Anatomy, Shoulder and Upper Limb, Shoulder. [Updated 2021 Jul 31]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK536933/


Wong M, Kiel J. Anatomy, Shoulder and Upper Limb, Acromioclavicular Joint. [Updated 2021 Jul 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK499858/