Shoulder instability and rotator cuff issues


There is a high incidence of rotator cuff tendonitis among lifters and athletes. The most common cause of shoulder pain and injuries are rotator cuff disorders.

The mainstays of treatment include rest, anti-inflammatory medication and treatment. Research shows however that these conservative treatments can provide pain relief in the short term, but have NO success in the long term. Rotator cuff and shoulder stability exercises on the other hand are not only effective to reduce shoulder pain but also strengthen the tendons and improve shoulder function, treating the causes of shoulder pain in the long term.

A deeper look at the risk factors that contribute to the development of rotator cuff tendinopathy explains why specific exercises play a crucial role in the treatment and prevention. This article will also discuss how shoulder stability exercises provide a strong foundation to build a powerful press and can help improve performance.

Rotator cuff tendonitis is the most common cause of shoulder pain

Rotator cuff tendonitis is the most common cause of shoulder pain for professional athletes, recreational sporters and lifters, as well as physically inactive people.

Athletes engaged in sports with overhead activity, such as swimming, tennis, throwing, golf, weightlifting, volleyball, and gymnastics, are more prone to rotator cuff tendonitis. A study on elite swimmers showed that 69% suffered from supraspinatus tendinopathy [1]. Other studies among recreational and competitive badminton players reported that 52% had previous or present shoulder pain on the dominant side [2, 3].

Risk factors

The risk factors that contribute to the development of a rotator cuff tendon injury are both overuse (regular overhead lifting; shoulder impingement) and underuse (tendon degeneration).

  1. Excessive overhead lifting and overhead sports are important factors contributing to rotator cuff issues. There is a difference in fibre cross-sectional area between the different layers of the supraspinatus tendon [4]. The tendon fibres closer to the shoulder joint have a smaller cross-sectional area and hence are less able to withstand strain [5]. These fibres are strained the most during higher angles of arm abduction [6].
  2. Impingement: Before attaching to the head of the humerus the tendons of the rotator cuff muscles pass underneath a bony roof (the acromion, which is a part of the shoulder blade). This subacromial space is a confined space that even narrows when the shoulder is abducted or flexed [7]. During forward flexion or abduction of the shoulder, the supraspinatus tendon can get compressed against the acromion, leading to degeneration of the tendon and tendonitis [8].
  3. Underuse: The supraspinatus tendon is prone to degenerative changes. The supraspinatus tendon is poorly vascularized [9]. Poor blood-circulation can alter the tendon remodelling process (constant degradation and rebuilding of tendon tissue) and contributes to tendon degeneration in people with a less active lifestyle [10]. Especially the tendon fibres that receive the most strain when lifting overhead have poor vascularity [9]. A degenerated tendon is more susceptible to tendinopathy, partial and complete tears.

Narrowing of the subacromial space during shoulder abduction
Narrowing of the subacromial space during shoulder abduction

Anti-inflammatory treatment

The mainstays of treatment include rest, non-steroidal anti-inflammatory medications (NSAIDs), ultrasound and periodic local corticosteroid injections. Research shows however that these conservative treatments can provide pain relief in the short term, but have NO success in the long term [11].

There are two problems with this traditional treatment approach.

  1. Several studies demonstrate little or no inflammation is actually present in tendons exposed to overuse [12, 13].
  2. The changes that occur in tendons in response to overuse are degeneration due to an altered tendon remodelling process (constant degradation and rebuilding of tendon tissue) and disorganization of collagen fibres [12, 13]. The net result is degeneration and weakness of the tendon and pain.

Rotator cuff and shoulder stability exercises

Treatment for rotator cuff disorders should always consist of rotator cuff strengthening exercises and exercises to enhance scapulothoracic stability. Research shows that these exercises are effective to reduce pain and strengthen and recondition the rotator cuff tendons [14, 15, 16, 17, 18, 19, 20, 21]. Exercise increases blood circulation in the tendons of the muscles that are exercised, the metabolic activity of the tenocytes (tendon cells), the release of local growth factors and collagen synthesis [22, 23, 24].

Rotator cuff exercises will also improve shoulder function and prevent rotator cuff impingement (a shoulder defect characterised by increased pinching of the rotator cuff tendons due to a narrowed subacromial space) and pathologies. The function of the rotator cuff is to stabilise the head of the humerus in the socket of the shoulder blade. A strong and functional rotator cuff widens the subacromial space during shoulder flexion and abduction and prevents rub of the rotator cuff tendons against the acromion [7].

Train and/or rehab the shoulder as a unit

The shoulder complex consists off two joints: the scapulathoracic joint (joint formed by ribcage and shoulder blade) and the glenohumeral joint (joint formed by shoulder blade and upper arm).

Shoulder instability and concurrent rotator cuff tendonitis or tears are often related to a loss of function of the scapulathoracic joint. Only strengthening the rotator cuff will not solve the problem. To effectively stabilise the shoulder, the rotator cuff muscles need to operate from a stable scapular base.

Muscle imbalances of the muscles that attach to the scapula alter the resting position and normal scapular motion and will result in time in shoulder injuries. A common imbalance in people that often lift overhead is a strong upper part of the trapezius, compared to a weaker middle and lower part of the trapezius [25].

The upper part of the trapezius is, due to its postural role, highly active in upper body exercises or movements executed while standing or seated. Especially overhead movements in an upright position and exercises for the deltoid muscles (big shoulder muscle) highly activate the upper part of the trapezius with little contraction of the lower and middle part [26]. This explains why rotator cuff exercises that highly activate the deltoid muscles and upper part of the trapezius (lateral raise, Cuban press) are not effective and are likely causing the issues they are trying to fix.

Hence shoulder stability exercises that strengthen the rotator cuff in concert with enhancing scapular balance and stability are more functional and effective. The shoulder must be considered as a unit, instead of individual muscle groups.

Shoulder stability routine for treatment and prevention

A shoulder stability routine for the acute phase of rotator cuff related shoulder pain:

  1. Side lying external shoulder rotation 3 x 15 reps@ (@ means each side)
    Side lying external shoulder rotation
  2. Dumbbell reverse flies 3 x 15 reps
    Dumbbell reverse flies

These exercises primarily focus on the subscapularis, infraspinatus and teres minor muscles, without too much activation of the supraspinatus muscles. Even in the acute phase, it should be possible to carry out these exercises without pain.

These exercises also promote lower and middle trapezius activation with minimal activity in the upper trapezius, which will improve scapular motion and stability.

A shoulder stability routine for the sub-acute phase or for prevention:

  1. Row-external rotation-press 3 x 15 reps@ (@ means each side)
    Row-external rotation-press
  2. YMCA 3 x 8-14 reps (add 2 reps/week, when you reach 14 reps, return to 8 reps, but add 1-2 lbs.)
  3. Horizontal shoulder abduction 2 x 15-20 reps@
    Horizontal shoulder abduction
  4. Inverse row 3 x 10 reps + 1 set to failure
    Inverse row

These shoulder stability routines you can add to your workout. Focus in the beginning a lot on horizontal pull exercises and shoulder stability exercises.

Once you go back to lifting normal, keep focusing on a balance in sets between horizontal puling and pressing and between overhead pressing and vertical pulling exercises. An overemphasis of upper body pressing strength leads to bad posture and injury-prone shoulders.

A good alternative for bench press are push-ups. Push-ups promote the co-contraction of the rotator cuff musculature. Push-ups also activate the serratus anterior muscle more compared to the bench press. Because the scapula is not supported by the bench during the push-up, a stronger contraction is required from the serratus anterior to prevent the scapula from winging. Some push-ups in addition to bench press and its variations add variety to your workout. The elastic band push-up is a push-up that enhances co-contration even more.

elastic band push-up

Shoulder stability exercises provide a strong foundation to build a powerful press and can help improve performance.

Proper scapular stability and function will not only prevent injuries but also provide a strong foundation to build a powerful press. The stronger the foundation, the taller the building that can be constructed on this foundation. Good balance and proper activation of the scapular muscles will result in proper scapular motion during the vertical or horizontal press. Proper scapular mechanics enable the rotator cuff muscles to contract close to their ideal length, so they can effectively stabilise the glenohumeral joint with maximal force. Muscles operate with greatest active force when close to an ideal length (often their resting length). When stretched or shortened beyond this, the maximum active force generated decreases. This decrease is minimal for small deviations, but the force drops off rapidly as the length deviates further from the ideal [27].

Literature review about the (in-)effectiveness of anti-inflammatory treatment:

  • NSAIDs: NSAIDs can give some short-term pain relief, but long-term NSAID intake may negatively influence tendon healing [28]. Evidence exists for a negative influence of NSAIDs on the stem cell population [29]. These stem cells are responsible for tissue regeneration.
  • Rest: Rest means you avoid all painful movements, like overhead activities. With complete rest, without any exercise particularly of the rotator cuff muscles, it will take forever for your shoulder to heal, due to the poor blood circulation. Rest also causes deconditioning of the rotator cuff tendons and muscles.
  • Corticosteriod injections: An extensive review study reported no evidence to support the use of corticosteroid injections in the treatment of rotator cuff disorders [11]. There is even a question of safety with using intratendinous corticosteroid injections.
  • Ultrasound and LLLT: Both treatment methods have no beneficial effects [30, 31].


  1. [^] Sein, M. L., Walton, J., Linklater, J., et al. "Shoulder Pain in Elite Swimmers: Primarily Due to Swim-volume-induced Supraspinatus Tendinopathy." Br J Sports Med, 2008.
  2. [^] Fahlström, M., Yeap, J. S., Alfredson, H., et al. "Shoulder pain – a common problem in world-class badminton players." Scand J Med Sci Sports 16(3): 168-73, 2006.
  3. [^] Fahlström, M. and Söderman, K, Decreased shoulder function and pain common in recreational badminton players, Scand J Med Sci Sports 17(3): 246-51, 2007.
  4. [^] Nakajima, T., Rokuuma, N., Tomatsu, T., et al. "Histologic and biomechanical charateristics of supraspinatus tendon." J Shoulder Elbow Surg 3: 79-87, 1994.
  5. [^] Lohr, J. F. and Uhthoff, H. K.,"The microvascular pattern of the supraspinatus tendon." Clin Orthop Relat Res(254): 35-8, 1990.
  6. [^] Reilly, P., Amis, A. A., Wallace, A. L., et al.,"Mechanical factors in the initiation and propagation of tears of the rotator cuff. Quantification of strains of the supraspinatus tendon in vitro." J Bone Joint Surg Br 85(4):594-9, 2003.
  7. [^ A B] Thompson MD, Dynamic acromiohumeral interval changes during scapular plane arm motions, Dissertation submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Department of Kinesiology, 2010.
  8. [^] Luo, Z. P., Hsu, H. C., Grabowski, J. J., et al. "Mechanical environment associated with rotator cuff tears." J Shoulder Elbow Surg 7(6): 616-20, 1998.
  9. [^ A B] Rathbun, J. B. and Macnab, I. "The microvascular pattern of the rotator cuff." J Bone Joint Surg Br 52(3): 540-53, 1970.
  10. [^] Lo, I. K., Marchuk, L. L., Hollinshead, R., et al. "Matrix metalloproteinase and tissue inhibitor of matrix metalloproteinase mRNA levels are specifically altered in torn rotator cuff tendons." Am J Sports Med 32(5): 1223-9, 2004.
  11. [^ A B] Koester MC, Dunn WR, Kuhn JE, Spindler KP. The efficacy of subacromial corticosteroid injection in the treatment of rotator cuff disease: A systematic review. J Am Acad Orthop Surg. 15:3–11, 2007.
  12. [^ A B] Khan KM, Cook JL, Bonar F, Harcourt P, Astrom M. Histopathology of common tendinopathies. Update and implications for clinical management. Sports Med. 27:393–408, 1999.
  13. [^ A B] Soslowsky LJ, Thomopoulos S, Tun S, Flanagan CL, Keefer CC, Mastaw J, Carpenter JE. Neer Award 1999. Overuse activity injures the supraspinatus tendon in an animal model: a histologic and biomechanical study. J Shoulder Elbow Surg. 9:79–84, 2000.</li>
  14. [^] Brox JI, Staff PH, Ljunggren AE, Brevik JI. Arthroscopic surgery compared with supervised exercises in patients with rotator cuff disease (stage II impingement syndrome). BMJ, 307:899–903, 1993.
  15. [^] Conroy, D. E. and Hayes, K. W., "The effect of joint mobilization as a component of comprehensive treatment for primary shoulder impingement syndrome." J Orthop Sports Phys Ther 28(1): 3-14, 1998.
  16. [^] Bang, M. D. and Deyle, G. D.,"Comparison of supervised exercise with and without manual physical therapy for patients with shoulder
    impingement syndrome." J Orthop Sports Phys Ther 30(3): 126-37, 2000.
  17. [^] Ludewig, P. M. and Borstad, J. D.,"Effects of a home exercise programme on shoulder pain and functional status in construction workers."
    Occup Environ Med 60(11): 841-9, 2003.
  18. [^] Walther, M., Werner, A., Stahlschmidt, T., et al.,"The subacromial impingement syndrome of the shoulder treated by conventional
    physiotherapy, self-training, and a shoulder brace: results of a prospective, randomized study." J Shoulder Elbow Surg 13(4): 417-23, 2004.
  19. [^] Haahr, J. P., Ostergaard, S., Dalsgaard, J., et al.,"Exercises versus arthroscopic decompression in patients with subacromial impingement: a randomised, controlled study in 90 cases with a one year follow up." Ann Rheum Dis 64(5): 760-4, 2005.
  20. [^] Senbursa, G., Baltaci, G. and Atay, A.,"Comparison of conservative treatment with and without manual physical therapy for patients with
    shoulder impingement syndrome: a prospective, randomized clinical trial." Knee Surg Sports Traumatol Arthrosc 15(7): 915-21, 2007.
  21. [^] Lombardi, I., Jr., Magri, A. G., Fleury, A. M., et al.,"Progressive resistance training in patients with shoulder impingement syndrome: a randomized controlled trial." Arthritis Rheum 59(5): 615-22, 2008.
  22. [^] Kjaer M, Magnusson P, Krogsgaard M, Boysen Møller J, Olesen J, Heinemeier K, Hansen M, Haraldsson B, Koskinen S, Esmarck B, Langberg H, Extracellular matrix adaptation of tendon and skeletal muscle to exercise, J Anat, Apr;208(4):445-50, 2006.
  23. [^] Kjaer M, Langberg H, Skovgaard D, Olesen J, Bülow J, Krogsgaard M, Boushel R, In vivo studies of peritendinous tissue in exercise, Scand J Med Sci Sports, Dec;10(6):326-31. Review, 2000.
  24. [^] Langberg H, Bülow J, Kjaer M, Blood flow in the peritendinous space of the human Achilles tendon during exercise, Acta Physiol Scand, Jun;163(2):149-53, 1998.
  25. [^] Cools AM, Witvrouw EE, Declercq GA, Danneels LA, Cambier DC., Scapular muscle recruitment patterns: trapezius muscle latency with and without impingement symptoms., Am J Sports Med, Jul-Aug;31(4):542-9, 2003.
  26. [^] Ludewig PM, Cook TM, Nawoczenski DA: Three-dimensional scapular orientation and muscle activity at selected positions of humeral elevation. J Orthop Sports Phys Ther 24: 57–65, 1996.
  27. [^] Gordon, A. M.; Huxley, A. F.; Julian, F. J. "Variation in isometric tension with sarcomere length in vertebrate muscle fibres." Journal of Physiology (London) 184 (1): 170–192, 1966.
  28. [^] Chan KM, Fu SC, Anti-inflammatory management for tendon injuries - friends or foes?, Sports Med Arthrosc Rehabil Ther Technol, Oct 13; 1(1):23, 2009.
  29. [^] Mackey AL, Mikkelsen UR, Magnusson SP, Kjaer M, Rehabilitation of muscle after injury - the role of anti-inflammatory drugs, Scand J Med Sci Sports, 2012 Aug;22(4):e8-14. doi: 10.1111/j.1600-0838.2012.01463.x. Epub 2012 Mar 26.
  30. [^] Robertson, V. J. and Baker, K. G. "A review of therapeutic ultrasound: effectiveness studies." Phys Ther 81(7): 1339-50, 2001.
  31. [^] Basford, J. R. "Low intensity laser therapy: still not an established clinical tool." Lasers Surg Med 16(4): 331-42, 1995.