The Effect of Humeral Head Depressor Muscle Co-Activation Training in Terms of Functional Outcomes
Condition: Rotator Cuff Tears; Surgery
MeSH terms: Rotator Cuff Injuries
Study type: Interventional

Summary: 
      Recent systematic reviews, and meta-analyses concluded that rotator cuff and scapular
      strengthening exercises should be included in rehabilitation programs for patients with
      middle-size rotator cuff muscle tear. Superior translation of the humeral head is one of the
      factors adversely affecting this rehabilitation process. Aside from rotator cuff muscles,
      opposition of superior humeral head translation can be achieved by the glenohumeral adductors
      (i.e. pectoralis major, latissimus dorsi muscles, and teres major), which act as humeral head
      depressors by means of the medio-inferior vector created by the orientation of their tendons.
      Recruitment of the glenohumeral adductors has been shown to decrease subacromial narrowing in
      elevated arms in asymptomatic individuals, and is thought to be a coping mechanism to
      decrease pain in individuals with rotator cuff tear. However, to the best of our knowledge,
      the efficacy of humeral head depressor muscle co-activation training on functional outcomes
      in patients undergoing arthroscopic shoulder surgery after middle-size rotator cuff muscle
      tear has never been evaluated in patients with middle-size rotator cuff muscle tear. Since
      recruitment of those muscles could prevent a decrease in subacromial space during arm
      elevation, it could potentially lead to improved exercise performance, earlier benefits and
      better treatment outcomes compared to routine rotator cuff strengthening exercises. Thus, the
      aim of this study was to investigate the efficacy of the humeral head depressor muscle
      co-activation training on functional outcomes in patients undergoing arthroscopic shoulder
      surgery after middle-size rotator cuff muscle tear.
    

Detailed description: 
      Shoulder pain is one of the most common types of musculoskeletal pain syndroms in the general
      population as its prevalence has been estimated between 7% and 26% and its annual incidence
      between 0.9% and 2.5%. Rotator cuff tear is one of the most common causes of painful
      shoulders. Lack of coordination or weakness of scapulothoracic and scapulohumeral muscles is
      one of the main factors thought to lead to muscle tears in shoulder. More specifically, the
      inability of the scapular muscles to achieve superior rotation and posterior tilt, as well as
      the failure of rotator cuff muscles to counter the superior humeral head translation imposed
      by deltoid contraction can lead to impingement of the subacromial soft tissues while
      performing overhead dynamic tasks. This increases the rotator cuff tears' prevalance. Aside
      from rotator cuff muscles, opposition of superior humeral head translation can be achieved by
      the glenohumeral adductors (i.e. pectoralis major, latissimus dorsi muscles, and teres
      major), which act as humeral head depressors by means of the medio-inferior vector created by
      the orientation of their tendons. Recruitment of the glenohumeral adductors has been shown to
      decrease subacromial narrowing in elevated arms in asymptomatic individuals, and is thought
      to be a coping mechanism to decrease pain in individuals with rotator cuff tear. However, to
      the best of our knowledge, the efficacy of humeral head depressor muscle co-activation
      training on functional outcomes in patients undergoing arthroscopic shoulder surgery after
      middle-size rotator cuff muscle tear has never been evaluated in patients with middle-size
      rotator cuff muscle tear. Since recruitment of those muscles could prevent a decrease in
      subacromial space during arm elevation, it could potentially lead to improved exercise
      performance, earlier benefits and better treatment outcomes compared to routine rotator cuff
      strengthening exercises. Thus, the aim of this study was to investigate the efficacy of the
      humeral head depressor muscle co-activation training on functional outcomes in patients
      undergoing arthroscopic shoulder surgery after middle-size rotator cuff muscle tear.
    

Intervention name(s): Humeral Head Depressor Muscle Co-Activation Training- Experimental Group; Control Group
Intervention type(s): Other; Other
Intervention description(s): In addition to the conservative treatment, humeral head depressor muscle co-activation training will be applied for 14 weeks. Participants in the coactivation group will perform the glenohumeral exercises while recruiting the pectoralis major, latissimus dorsi, and teres major muscles. To achieve this, voluntary recruitment of the pectoralis major, latissimus dorsi, and teres major will be taught prior to the demonstration of the glenohumeral exercises using visual feedback provided by EMG Biofeedback. When recruitment is correctly executed (50% of the maximum voluntary contraction signal), it should be maintained while performing the glenohumeral exercises. This will be confirmed by visualizing EMG signals during the exercise training session. During each appointment with the therapist, participants will be evaluated on their capacity to achieve the exercises while performing co-activation.; The American Society of Shoulder and Elbow Therapists' consensus statement on rehabilitation following arthroscopic rotator cuff repair will be used as guideline for rehabilitation of patients (Thigpen, C. A., Shaffer, M. A., Gaunt, B. W., Leggin, B. G., Williams, G. R., & Wilcox III, R. B. (2016). The American Society of Shoulder and Elbow Therapists' consensus statement on rehabilitation following arthroscopic rotator cuff repair. Journal of shoulder and elbow surgery, 25(4), 521-535.).
Individuals in the control group will use shoulder straps for 6 weeks after arthroscopic shoulder surgery. These patients will be referred to physiotherapy clinics 6th week. Patients between 6 and 20 weeks (a total of 14 weeks) will be admitted to the rehabilitation program according to the guideline mentioned above.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Randomized
Masking: Single (Care Provider)
Primary purpose: Treatment
Keywords: rotator cuff; tear; rehabilitation