Last project of the semester focused in on a case study involving supraspinatus tendinopathy, more specifically tendinosis. Tables of anatomical actions and their associated muscles, origins/insertions, isolated functions, and planes of motion were omitted from this as the tables didn't transfer over well in this format. Additional animations (circles, arrows pointing to things in pictures, etc) also didn't make the cut. Videos are linked to MyDartfish, an analysis tool used in breaking down movement.
A former collegiate softball player and highly active recreational athlete with an exercise program encompassing Crossfit, high-intensity interval training and hypertrophy-focused work developed shoulder pain. Pain was present both anteriorly and posteriorly, impacted overhead mobility and strength as well as distal horizontal abduction or adduction in end range of motion. After consulting with an orthopedic doctor and physical therapist, a clean MRI ruled out any labral tear or other maladaptive structures in the shoulder. Supraspinatus tendinopathy, specifically tendonosis, was identified as the cause of pain and a rehabilitation program prescribed.
This article will discuss the potential causes that could have led to the development of supraspinatus tendonosis. Through movement examination and analysis, this document will look at shoulder biomechanics, specifically the glenohumeral (GH) and scapulothoracic (ST) joints, and how a predisposed internally rotated and anteriorly tipped shoulder imbalance has led to injury in a possibly overtrained and under-recovered athlete. Five key positions will break down the movement and establish potentially overactive and underactive tissues involved in present postural dysfunction with this athlete. Corrective exercise procedures will be given accompanied by video analysis of proper execution of the press.
Movement Analysis and Mechanism of Injury
Client has no prior incidence with any sort of shoulder injury and had no specific acute traumatic experience with the shoulder. Pain accrual was gradual, starting as an annoyance and progressing towards having an impact on activities of daily living (ADL), such as reaching for objects and impacting sleep. This pattern of pain progression suggests an overuse injury. Cook & Finch (as cited in Cools et al., 2015), define overuse injuries as resultant of the cumulative process of tissue damage. As demonstrated below, the left shoulder presents in obvious internal rotation (IR) and anterior tipping of the joint. This imbalance, coupled with her high volume program and possibly under-recovered system, may have exposed the shoulder to repetitive stress patterns, compensatory patterns of movement, and injury.
Below is the link to the movement and it’s associated dysfunction.
First Key Position - Postural Assessment
The standing position demonstrated in Figures 1a-d (below) point out a few observations of the left shoulder, giving possible insights into the potential causes of the gradual injury amplification the client identified. Figure 1A. shows the client’s upper trapezius is elevated, indicating hypertonicity and overactivity in comparison to the uninjured shoulder; this also includes the levator scapula. Figure 1B. point out unilateral scapular winging with the scapula clearly jutting out, suggesting a weak serratus anterior. Lastly, in comparing the healthy right shoulder to the injured left in Figures 1C-1D, there is clearly excessive protraction and internal rotation.
Analysis of this first position can indicate several dysfunctions in shoulder mechanics that with excess volume and load could lead to a degradation of the joint. This would make sense considering the client’s pain presentation pattern. Table 1.1 points out the basic movement patterns and muscles associated with internal rotation and anterior tipping, including the pectoralis (IR) major, latissimus dorsi (IR), teres major (IR), anterior deltoid (IR), subscapularis (IR), pec minor (protraction/anterior tipping), levator scapula (anterior tipping), and upper trapezius (anterior tipping). Brookbush (2017) states that common shoulder compensatory patterns involve an overactive latissimus dorsi, teres major, and subscapularis in regards to glenohumeral IR, while he also notes that the anterior tippers could also play an overactive role in this postural dysfunction. The upper trapezius hypertonicity on the left shoulder is a primary indicator of a muscle synergist overworking to create movement and stabilize the shoulder. Opposing this function, Brookbush adds that an underactive serratus anterior could be involved in the faulty shoulder mechanics due to the presence of scapular winging.
Figure 1a. L Shoulder Elevation Figure 1b. Elevation and Scapular Winging
Figure 1c. Protraction/Anterior Tipping Figure 1d. Healthy Right Shoulder
Second Key Position - Overhead Press Starting Position Assessment
The second key position further elaborates upon the points established in analyzing the first key position. Figure 2. demonstrates the natural shoulder position of the healthy right shoulder. The shoulder is slightly externally rotated, while the left shoulder, with the complications previously assigned to overactive anterior tippers and internal rotators, has a different starting position from which to initiate the overhead press. This builds on the ideas set forth in the first key position that this is a postural dysfunction.
Third Key Position - Concentric Portion of Overhead Press
As the participant presses overhead into the concentric phase of the movement, the postural deficiencies noted in the first two key positions display their impact on the action. The left upper trapezius becomes noticeably more engaged, elevating the scapula. In addition to this, examining external rotation of both shoulders shows that the right shoulder is better able to spin and glide in the glenoid fossa. The left shoulder, however, is unable to match that external rotation due to the above-mentioned postural asymmetry and this increases the likelihood that the humeral head is pulled anteriorly and superiorly in the glenoid fossa. Close inspection of the elbow angles also suggests a compensatory pattern has developed to allow the client to continue to press as the body will always search for the path of least resistance to accomplish a task.
Fourth Key Position - Overhead Isometric in Full Glenohumeral Flexion and Abduction
Upon reaching the top isometric position of the press, there is a small dysfunction present during the last 10° of flexion. In Figures 4A. and 4B. the right shoulder is fully able to get into 180° of flexion while the left shoulder, limited by postural deficits, can’t quite get through the full range of motion. As echoed previously, this places an asymmetrical pattern of loading on the body, which has the potential to lead to other compensatory patterns through the shoulder girdle, thorax and hip complex.
Figures 4A. and 4B.
Fifth Key Position - Eccentric Portion of Overhead Press
The final position presents a similar disposition to that seen during the concentric portion of the press expanded upon in the third key position. However, there are a few noticeable differences. First, despite a slightly uneven bar path, the arms present in a better angle that suggests more overall control of the movement and the upper traps are closer to symmetrical when compared to Figure 3. This may indicate that the client has better mechanics for pressing during the eccentric portion of the press, which may help guide exercise prescription for the rehabilitation process.
Understanding Supraspinatus Tendinosis and Corrective Exercise Applications
According to Bass (2012), tendinosis is a “degeneration of the tendon’s collagen in response to chronic overuse; when overuse is continued without giving the tendon time to heal and rest, such as with repetitive strain injury, tendinosis results”. Bass goes on to sate that tendinosis shows an increase in immature type III collagen fibers as opposed to the mature type I fibers that are normally considered healthy. These fibers are unable to link properly, and as such, their ability to handle load becomes compromised. In addition to this, Weber (2017) notes that there is increased cellularity and neovascularization that are common conditions associated with tenodonosis. Cells found in tendinosis are degenerative in nature, with Khan describing the types of degeneration as mucoid, which causes softening of the area, or lipoid, which is an abnormal increase in lipid material in the tendon. In neovasularization, new blood vessels are arranged randomly, with blood vessels having even been found to form perpendicularly to the original origination of the fibers (Weber). In regards to treatment, Weber (2017) states that treatment starts with stopping the degenerative cycle and then restoring normal collagen synthesis, strength, and function.
From a corrective exercise perspective, Brookbush (2017) suggests addressing joint imbalances with a release, stretch and integration model of therapy, which can be tailored to both training and therapy professions. This process involves first releasing overactive tissue, stretching the same tissue, and then activating and integrating the weak and long structures in the joint.
While this is a simplified model for the purposes of this project, it is an effective implementation process for the corrective exercise specialist.
Based on the findings with the five key positions, the tissues identified as overactive include, but are not limited to the anterior tippers - pectoralis minor and levator scapula specifically - and the internal rotators, primarily the subscapularis, latissimus dorsi, and teres major. An example of the release for the pectoralis minor can be seen below. Basic guidelines for release are dependent on the client, but typically a period of 30-120 seconds works to release the tissue, allowing for the next step of stretching the same tissue. An example of a stretch for the pectoralis minor is also seen below.
Pec Minor Release
Pec Minor Stretch
Lastly, the process comes down to activating and integrating weakened tissue. KIM, SY; et al (2015) found that concentric and eccentric training for the supraspinatus can have equal value in strength development, but that eccentric training may have the added advantage of maintaining or improving muscle fiber bundle length and could help promoted tendon healing. With a focus on utilizing eccentrically-controlled tempos (4.0.1 for example), the goal of strengthening the supraspinatus takes precendence, with the lateral band raise providing an example below. Execution will take the arm angle to about 90°, which is within the active range of motion for the suprapinatus. On top of this, it would be recommended to address the external rotators - teres minor, infrapsinatus, and posterior deltoid - which would help create better balance with the overactive internal rotators listed above, the lower trapezius to aid in strengthening scapular depression, and the serratus anterior, to address scapular winging. Examples of activation exercises are provided below.
Supraspinatus - Lateral Raise with 4.0.1 Eccentrically-controlled tempo.
External Rotators - External Rotation - 4.0.1. Eccentrically-controlled tempo
Lower Trap - Trap 3 Raise - 4.0.1. Eccentrically-controlled tempo
Serratus Anterior - KB Protraction - Controlled
Proper Video Analysis of Overhead Press Movement, Related Biomechanics, and Potential Movement Deficiencies
Bass, E. (2012). Tendinopathy: Why the Difference Between Tendinitis and Tendinosis Matters. Retrieved June 25, 2017, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3312643/
Brookbush, B. (2017, January 06). Introduction to Activation Exercise. Retrieved June 25, 2017, from https://brentbrookbush.com/articles/corrective-exercise-articles/activation/introduction-to-activation-exercise/
Brookbush, B. (2017, April 08). Upper Body Dysfunction (UBD). Retrieved June 25, 2017, from https://brentbrookbush.com/articles/postural-dysfunction-movement-impairment/upper-body-dysfunction-ubd/
Brookbush, B. (2017, June 21). Shoulder (Glenohumeral) Joint. Retrieved June 25, 2017, from https://brentbrookbush.com/articles/anatomy-articles/joint-anatomy/shoulder-glenohumeral-joint/
Cools, A. M., Johansson, F. R., Borms, D., & Maenhout, A. (2015). Prevention of shoulder injuries in overhead athletes: a science-based approach. Brazilian Journal Of Physical Therapy / Revista Brasileira De Fisioterapia, 19(5), 331-339.
Heber, D. (n.d.). Tendinosis vs. Tendonitis. Retrieved June 25, 2017, from http://elitesportstherapy.com/tendinosis-vs--tendonitis/
Khan, KM., Cook, JK. Overuse Tendon Injuries: Where does the pain come from? Clinical Sports Medicine
Kim, S. Y., Ko, J. B., Farthing, J. P., & Butcher, S. J. (2015). Investigation of supraspinatus muscle architecture following concentric and eccentric training. Journal Of Science & Medicine In Sport, 18(4), 378-382.