Underlying mechanisms for shoulder stability: For its joint stability, the glenohumeral (GH) joint heavily depends on muscle strength, adequate synergistic activity between the neuromuscular structures, as well as a strong joint position sense (a subcategory of proprioception). Our ability to detect our limbs in space helps us to interact with our surroundings and contributes to the neuromuscular stability of our joints. A RCt is often associated with a subacromial impingement syndrome, where structures under the acromion become pinched during arm elevation. Such a compression during arm movements can include abnormal shoulder kinematics, as well as RC and scapular muscles performance deficits. This inadequate scapulothoracic muscle control is believed to contribute to a reduction of amplitude in posterior tilting and lateral rotation of the scapula, which causes the acromion to remain in a lower anterolateral position resulting in a dynamic narrowing of the subacromial space. Also, the abnormal muscle control is associated with superior migration of humeral head with respect to the glenoid fossa, which again leads to a dynamic narrowing of the subacromial space. These deficits contribute to the impingement of subacromial structures and often lead to the symptoms associated with an RCt. What makes the investigated approach unique in addressing RC disorders is the resource-effective exercise rehabilitation model the investigators propose; a motor control and strengthening approach well supported in the scientific literature and packaged in a conveniently resource-friendly protocol. This approach maximizes patient autonomy while being matched to a suitable level of physiotherapist supervision. The investigators believe that the Upper Extremity Neuromuscular Training Program (UpEx-NTP) provides a realistic and financially beneficial solution to a costly health care problem.