physioplux Clinical Trials

RCT has kickoff in 2019 on January.

In collaboration with


Shoulder complaints occur frequently in the general population, the lifetime prevalence ranges from 6.7 to 66.7%. (1) The most frequently occurring shoulder complaints are subacromial pain syndrome (SPS) and glenohumeral instability (GHI). Of all shoulder complaints 44-65% is diagnosed as SPS. (2)

The humerus is attached to the glenoid, through the joint capsule and the rotator cuff. These 2 structures form a functional entity. (3) The glenoid as a part of the scapula is not attached to the thorax through any passive structures. Therefore, the scapula depends greatly on muscle function for stability. Muscular stabilization of the scapula, relative to the thorax, is accomplished by the M. lower trapezius and M. serratus anterior (SA). (4) If muscular stability decreases the shoulder may be susceptible to injury. (5) Decreased stability of the scapula can be observed as an altered scapular movement or position, when comparing the left-to-right side. This asymmetry in movement or position is called scapular dyskinesis. (4)

Scapular dyskinesis has been found in patients with SPS as well as GHI. It is estimated that 64% of patients with GHI have scapular dyskinesis. (6) Even though the exact nature of the relationship between shoulder complaints and scapular dyskinesis is currently unclear, there is a general consensus that when scapular dyskinesis is diagnosed, it is necessary to quantify and treat it. (4,7,8)

Scapular dyskinesis can have several causes. First, decreased muscle function of the Lower Trapezius and/or Serratus Anterior, which will result in decreased activity or delayed muscle onset. Secondly, increased activity of the Upper Trapezius, and an altered scapula resting position can also contribute to scapular dyskinesis. In turn these changes in muscle activity can be brought about by several mechanisms such as fractures, rotator cuff ruptures, cervical complaints, GHI and SPS. (4,7,9)

Exercise therapy is often used as a treatment strategy within shoulder rehabilitation. Several studies have investigated the effectiveness of scapulothoracic exercise on shoulder function in patients with shoulder complaints, and found it to be effective (10–12) Scapulothoracic exercises are used frequently in the first phases of the rehabilitation. (13) These exercises can be performed under supervision of a physical therapist and/or at home. Regular exercise therapy, aimed at improving scapulothoracic muscle function, can be augmented using surface electromyography (sEMG). Using the sEMG augmentation, patients can perform their home exercise schedule with real-time sEMG. Possibly this could improve the patient satisfaction and therefore motivation to perform the exercises, the exercise technique, and adherence. Increases in all or any of these factors could improve treatment outcomes.

The sEMG augmentation of the home exercises uses an external focus of attention. By using this motor learning strategy, the emphasis is placed upon focusing on the result of a movement, rather than focusing on the body or shoulder, which is called an internal focus of attention. Providing an external focus of attention increases the efficiency of the motor learning process. (14) There are increasing amounts of evidence for the efficacy of an external focus of attention in motor learning, although mainly for lower extremity tasks. (15–17) For upper extremity tasks less studies have been performed. (18)

This study aims to investigate the effectiveness of adding real-time sEMG during home exercise performance to shoulder rehabilitation, and to compare this to regular shoulder rehabilitation in which real-time sEMG is only provided during treatment sessions and to shoulder rehabilitation without any form of real-time sEMG.

1.        Luime JJ, Koes BW, Hendriksen IJM, Burdorf A, Verhagen AP, Miedema HS, et al. Prevalence and incidence of shoulder pain in the general population; a systematic review. Scand J Rheumatol [Internet]. 2004 Jan [cited 2015 Nov 1];33(2):73–81. Available from:
2.        van der Windt DA, Koes BW, de Jong BA, Bouter LM. Shoulder disorders in general practice: incidence, patient characteristics, and management. Ann Rheum Dis [Internet]. 1995;54(12):959–64. Available from:
3.        Burkhart SS, Esch JC, Jolson RS. The rotator crescent and rotator cable: an anatomic description of the shoulder’s ‘suspension bridge’. Arthrosc  J Arthrosc Relat Surg [Internet]. 1993 Jan [cited 2015 Dec 26];9(6):611–6. Available from:
4.        Kibler WB, Ludewig PM, McClure PW, Michener LA, Bak K, Sciascia AD. Clinical implications of scapular dyskinesis in shoulder injury: the 2013 consensus statement from the ‘Scapular Summit’. Br J Sports Med [Internet]. Shoulder Center of Kentucky, Lexington, KY 40504, USA.; 2013;47(14):877–85. Available from:
6.        Warner J. Scapulothoracic motion in normal shoulders and shoulders with glenohumeral instability and impingement syndrome. A study using Moiré topographic analysis. 1992. p. 191–9. 
7.        Cools AMJ, Struyf F, De Mey K, Maenhout A, Castelein B, Cagnie B. Rehabilitation of scapular dyskinesis: from the office worker to the elite overhead athlete. Br J Sports Med [Internet]. 2014;48(8):692–7. Available from:
8.        Ludewig P, Reynolds J. The association of scapular kinematics and glenohumeral joint pathologies. J Orthop Sports Phys Ther. [LaCrosse, Wis.]: [Orthopaedic and Sports Medicine Sections of the American Physical Therapy Association]; 2009;39(2):90–104. 
9.        Struyf F, Cagnie B, Cools A, Baert I, Brempt J Van, Struyf P, et al. Scapulothoracic muscle activity and recruitment timing in patients with shoulder impingement symptoms and glenohumeral instability. J Electromyogr Kinesiol [Internet]. Elsevier Ltd; 2014;24(2):277–84. Available from:
10.      De Mey K, Danneels L, Cagnie B, Cools AM. Scapular Muscle Rehabilitation Exercises in Overhead Athletes With Impingement Symptoms: Effect of a 6-Week Training Program on Muscle Recruitment and Functional Outcome. Am J Sports Med [Internet]. 2012/07/13 ed. New York, N.Y.: Elsevier; 2012;40(8):1906–15. Available from:
11.      Santos C, Matias R. Short and long-term effectiveness of a scapular-focused protocol for patients with shoulder dysfunctions. Unpubl data. :1–28. 
12.      Worsley P, Warner M, Mottram S, Gadola S, Veeger HEJ, Hermens H, et al. Motor control retraining exercises for shoulder impingement: Effects on function, muscle activation, and biomechanics in young adults. J Shoulder Elb Surg [Internet]. St. Louis, MO: Mosby; 2013;22(4):e11–9. Available from:
13.      Ellenbecker TS, Cools A. Rehabilitation of shoulder impingement syndrome and rotator cuff injuries: an evidence-based review. Br J Sport Med [Internet]. 2010/04/08 ed. 2010;44(5):319–27. Available from:
14.      Wulf G. Attentional focus and motor learning : A review of 15 years. Int Rev Sport Exerc Psychol. 2013;6(1):77–104. 
15.      Dallinga J, Benjaminse A, Gokeler A, Otten E, Lemmink K. Effect of an internally versus externally focused acl injury prevention program on injury risk. Br J Sport Med [Internet]. 2014;48(7):583. Available from:
16.      Gokeler A, Benjaminse A, Welling W, Alferink M, Eppinga P, Otten B. The effects of attentional focus on jump performance and knee joint kinematics in patients after ACL reconstruction. Phys Ther Sport [Internet]. Elsevier Ltd; 2014;16(2):1–7. Available from:
17.      Welling W, Benjaminse A, Gokeler A, Otten B. Enhanced retention of drop vertical jump landing technique: A randomized controlled trial. Hum Mov Sci [Internet]. Elsevier B.V.; 2016;45:84–95. Available from:
18.      Lohse KR, Sherwood DE, Healy AF. How changing the focus of attention affects performance, kinematics, and electromyography in dart throwing. Hum Mov Sci [Internet]. [Amsterdam]: Elsevier B.V.; 2010;29(4):542–55. Available from: