Isokinetic Muscle Strength and Muscle Endurance by the Types and Size of Rotator Cuff Tear in Men

Kim, In Bo;Kim, Do Keun

  • Received : 2014.07.14
  • Accepted : 2014.11.02
  • Published : 2014.12.30


Background: Our study was to determine the effect on shoulder isokinetic muscle strength and muscle endurance in isolated full-thickness supraspinatus tendon tear and combined other rotator cuff tear. Methods: Total of 81 male patients (mean age $57.8{\pm}7.4$ years) who were diagnosed as a full-thickness supraspinatus tendon tear were included. They were classified into isolated or combined tear. The isokinetic muscle strength and muscle endurance were measured using the Biodex multi-joint system $PRO^{(R)}$ (Biodex Medical Systems, Shirley, NY, USA) in following movements: shoulder abduction, adduction, flexion, extension, external rotation, and internal rotation. Then, the difference in muscle function according to the type of tears were assessed. Fifty-seven patients had isolated supraspinatus tendon (mean age $56.9{\pm}7.3$ years). They were classified into either anteroposterior tear or modified mediolateral tear. The size were measured using T2-weighted magnetic resonance imaging scans in sagittal plane. Results: Between subjects categorized into the type of tear, we found significant inter-categorical differences in isokinetic muscle strength during abduction, adduction, flexion, extension, and internal rotation, and in muscle endurance during flexion, extension, and internal rotation. Anteroposterior diameter tear, we did not show significant differences in either isokinetic muscle strength or muscle endurance during any movements. However, with modified mediolateral diameter, we found significant differences with isokinetic muscle strength during adduction, and in muscle endurance the external rotation and internal rotation. Conclusions: We found that a supraspinatus tendon tear associated with more numbers of rotator cuff tears has lower isokinetic muscle strength and muscle endurance than a tear found alone.


Rotator cuff;Tear;Muscle strength;Isokinetic test


  1. Cameron BD, Iannotti JP. Clinical evaluation of the painful shoulder. In: Zlatkin MB, ed. MRI of the shoulder. 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 2003. 47-84.
  2. Bigliani LU, Morrison DS, April EW. The morphology of the acromion and its relationship to rotator cuff tears. Orthop Trans. 1986;10:228-35.
  3. Soslowsky LJ, Carpenter JE, Bucchieri JS, Flatow EL. Biomechanics of the rotator cuff. Orthop Clin North Am. 1997;28(1):17-30.
  4. Dunn WR, Kuhn JE, Sanders R, et al. Symptoms of pain do not correlate with rotator cuff tear severity: a cross-sectional study of 393 patients with a symptomatic atraumatic full-thickness rotator cuff tear. J Bone Joint Surg Am. 2014;96(10):793-800.
  5. Ellman H, Hanker G, Bayer M. Repair of the rotator cuff. End-result study of factors influencing reconstruction. J Bone Joint Surg Am. 1986;68(8):1136-44.
  6. Gore DR, Murray MP, Sepic SB, Gardner GM. Shoulder-muscle strength and range of motion following surgical repair of full-thickness rotator-cuff tears. J Bone Joint Surg Am. 1986;68(2):266-72.
  7. Rabin SI, Post M. A comparative study of clinical muscle testing and Cybex evaluation after shoulder operations. Clin Orthop Relat Res. 1990;(258):147-56.
  8. Walker SW, Couch WH, Boester GA, Sprowl DW. Isokinetic strength of the shoulder after repair of a torn rotator cuff. J Bone Joint Surg Am. 1987;69(7):1041-4.
  9. Kibler WB, Chandler TJ, Stracener ES. Musculoskeletal adaptations and injuries due to overtraining. Exerc Sport Sci Rev. 1992;20:99-126.
  10. Forthomme B, Croisier JL, Ciccarone G, Crielaard JM, Cloes M. Factors correlated with volleyball spike velocity. Am J Sports Med. 2005;33(10):1513-9.
  11. Shklar A, Dvir Z. Isokinetic strength relationships in shoulder muscles. Clin Biomech (Bristol, Avon). 1995;10(7):369-73.
  12. Marino M, Nicholas JA, Gleim GW, Rosenthal P, Nicholas SJ. The efficacy of manual assessment of muscle strength using a new device. Am J Sports Med. 1982;10(6):360-4.
  13. Davies GJ, Ellenbecker TS, Wilk KE. Isokinetic testing and rehabilitation of the shoulder complex. In: Wilk KE, Reinold MM, Andrews JR, eds. The Athlete's shoulder. 2nd ed. Philadelphia: Churchill Livingstone; 2009. 719-47.
  14. Basmajian JV. Therapeutic exercise. 4th ed. Baltimore: Williams and Wilkins; 1984. 88.
  15. Ivey FM Jr, Calhoun JH, Rusche K, Bierschenk J. Isokinetic testing of shoulder strength: normal values. Arch Phys Med Rehabil. 1985;66(6):384-6.
  16. Mccardle WD, Katch FI, Katch VL. Exercise physiology. Energy, nutrition and human performance. Philadelphia: Lea & Febiger; 1981. 288-94.
  17. Kirschenbaum D, Coyle MP Jr, Leddy JP, Katsaros P, Tan F Jr, Cody RP. Shoulder strength with rotator cuff tears. Pre- and postoperative analysis. Clin Orthop Relat Res. 1993;(288):174-8.
  18. Ben-Yishay A, Zuckerman JD, Gallagher M, Cuomo F. Pain inhibition of shoulder strength in patients with impingement syndrome. Orthopedics. 1994;17(8):685-8.
  19. Burkhart SS. Reconciling the paradox of rotator cuff repair versus debridement: a unified biomechanical rationale for the treatment of rotator cuff tears. Arthroscopy. 1994;10(1):4-19.
  20. Tae SK, Kim JY, Park JS. MRI follow-up study after arthroscopic repair of multiple rotator cuff tendons. J Korean Shoulder Elbow Soc. 2008;11(2):96-103.
  21. Clark JM, Harryman DT 2nd. Tendons, ligaments, and capsule of the rotator cuff. Gross and microscopic anatomy. J Bone Joint Surg Am. 1992;74(5):713-25.
  22. Romanes GJ. Cunningham's textbook of anatomy. 12th ed. London; New York: Oxford University Press; 1981. 373-7.
  23. Miller MD, Thompson SR. DeLee & Drez's orthopaedic sports medicine: principles and practice. 4th ed. Philadelphia: Elsevier; 2014. 442-4.
  24. Andrade Mdos S, de Lira CA, Vancini RL, de Almeida AA, Benedito-Silva AA, da Silva AC. Profiling the isokinetic shoulder rotator muscle strength in 13- to 36-year-old male and female handball players. Phys Ther Sport. 2013;14(4):246-52.
  25. Minagawa H, Itoi E, Konno N, et al. Humeral attachment of the supraspinatus and infraspinatus tendons: an anatomic study. Arthroscopy. 1998;14(3):302-6.
  26. Watson MS, Surgical disorders of the shoulder. New York: Churchill Livingstone; 1991.