Factors Predicting Postoperative Range of Motion and Muscle Strength one Year after Shoulder Arthroplasty

Document Type : RESEARCH PAPER


1 School of Physical Therapy, Western University, London, Ontario, Canada

2 1 School of Physical Therapy, Western University, London, Ontario, Canada 2 Roth McFarlane Hand and Upper Limb Centre, St. Joseph’s Health Care London, London, Ontario, Canada

3 Roth McFarlane Hand and Upper Limb Centre, St. Joseph’s Health Care London, London, Ontario, Canada


Background: Shoulder arthroplasty improves shoulder range of motion (ROM), strength and function in patients
with advanced shoulder disease. However, clinical outcomes vary and are not always predictable among patients.
Pre-operative factors and patients’ characteristics may influence improvement after surgery. This study examined the
impact of the pre-operative objective measures range of motion (ROM) and strength, age, sex, and comorbidities on
shoulder ROM, strength status and the amount of improvement one year following shoulder arthroplasty.
Methods: 140 patients were assessed pre-operatively and one year after shoulder arthroplasty in this prospective
cohort study. Pearson’s correlations and multiple regression analyses were performed to test the impact of potential
predictors on abduction, flexion, internal rotation and external rotation ROM as well as on shoulder abductors, flexors,
internal rotators and external rotators strength at one year.
Results: Pre-operative ROM significantly predicted 10% - 37% of the improvement in ROM after surgery. Less preoperative
ROM was associated with a greater improvement in ROM. Less pre-operative muscle strength was associated
with a greater improvement in strength after surgery. Pre-operative shoulder muscles predicted 28% - 38% of the
strength status at one year, and 24% - 43% of the improvement in strength postoperatively. Older age was associated
with less improvement in ROM and strength at one year. With other predictors, age explained 37% of the change in
ROM and 36% of the change in strength. Male sex was associated with greater improvement in muscle strength. Sex
significantly predicted 24% - 36% of the change in strength.
Conclusion: Pre-operative ROM and strength, age, and sex are significant predictors of the improvement in the
shoulder ROM and strength one year after shoulder arthroplasty. The improvement in these measures is expected to
decline with age and men are expected to gain more strength than women following this surgical intervention.
Level of evidence: II


1. Association AO. National joint replacement
registry: Hip, knee & shoulder arthroplasty. 2018.
Available from: https://aoanjrr.sahmri.com/
documents/10180/576950/Hip%2C Knee %26
Shoulder Arthroplasty
2. Orfaly RM, Rockwood CA, Esenyel CZ, Wirth MA. A
prospective functional outcome study of shoulder
arthroplasty for osteoarthritis with an intact rotator
cuff. J Shoulder Elb Surg. 2003;12(3):214–21.
3. Matsen III FA, Antoniou J, Rozencwaig R, Campbell B,
Smith KL. Correlates with comfort and function after
total shoulder arthroplasty for degenerative joint
disease. J Shoulder Elb Surg. 2000;9(6):465–9.
4. Levy JC, Ashukem MT, Formaini NT. Factors
predicting postoperative range of motion for
anatomic total shoulder arthroplasty. J Shoulder Elb
Surg. 2016;25(1):55–60.
5. Schwartz DG, Cottrell BJ, Teusink MJ, Clark RE,
Downes KL, Tannenbaum RS, et al. Factors that
predict postoperative motion in patients treated
with reverse shoulder arthroplasty. J shoulder Elb
Surg. 2014;23(9):1289–95.
6. Iannotti JP, Norris TR. Influence of preoperative
factors on outcome of shoulder arthroplasty for
glenohumeral osteoarthritis. JBJS. 2003;85(2):251–8.
7. Alsubheen SA, MacDermid JC, Overend TJ, Faber
KJ. Does diabetes affect functional outcomes after
shoulder arthroplasty? J Clin Orthop Trauma.
8. Cools AM, De Wilde L, Van Tongel A, Ceyssens C,
Ryckewaert R, Cambier DC. Measuring shoulder
external and internal rotation strength and range
of motion: comprehensive intra-rater and interrater
reliability study of several testing protocols. J
shoulder Elb Surg. 2014;23(10):1454–61.
9. MacDermid JC, Chesworth BM, Patterson S, Roth JH.
Intratester and intertester reliability of goniometric
measurement of passive lateral shoulder rotation. J
Hand Ther. 1999;12(3):187–92.
10. Sabari JS, Maltzev I, Lubarsky D, Liszkay E, Homel P.
Goniometric assessment of shoulder range of motion:
comparison of testing in supine and sitting positions.
Arch Phys Med Rehabil. 1998;79(6):647–51.
11. Roy J-S, MacDermid JC, Orton B, Tran T, Faber KJ,
Drosdowech D, et al. The concurrent validity of a
hand-held versus a stationary dynamometer in
testing isometric shoulder strength. J Hand Ther.
12. Dollings H, Sandford F, O’conaire E, Lewis JS. Shoulder
strength testing: the intra-and inter-tester reliability
of routine clinical tests, using the PowerTrackTM II
Commander. Shoulder Elb. 2012;4(2):131–40.
13. Field A. Discovering statistics using IBM SPSS
statistics. 4th ed. London,UK: Sage; 2013.
14. Barnes CJ, Van Steyn SJ, Fischer RA. The effects of age,
sex, and shoulder dominance on range of motion of
the shoulder. J Shoulder Elb Surg. 2001;10(3):242–6.
15. Hughes RE, Johnson ME, O’Driscoll SW, An K-N.
Age-related changes in normal isometric shoulder
strength. Am J Sports Med. 1999;27(5):651–7.
16. Alsubheen SA, MacDermid JC, Overend TJ, Faber
KJ. Predictors of Clinical Benefits and One-
Year Functional Outcomes Following Shoulder
Arthroplasty. Iowa Orthop J. 2019;39(1):69.
17. Yu W, Ravelo A, Wagner TH, Barnett PG. The
relationships among age, chronic conditions, and
healthcare costs. Am J Manag Care. 2004;10(12):
Volume 9, Issue 4
July and August 2021
Pages 399-405
  • Receive Date: 07 May 2020
  • Revise Date: 14 September 2020
  • Accept Date: 20 October 2020
  • First Publish Date: 15 November 2020