Background. Rotator cuff tears occur in approximately one in five people in the general population. The unpredictability of the dynamics of tears gives rise to studies of the patterns of their progression. It is known that massive rotator cuff tears form over a long period of time, as a result of which normal biomechanics are disrupted and cuff tear arthropathy develops. The loss of active elevation of the upper limb, developing due to a violation of the normal biomechanics of the shoulder joint, is called “shoulder pseudoparalysis”. There are a small number of studies devoted to risk factors for the occurrence of this condition, and they are completely absent in the domestic literature. These facts dictate the need to conduct research aimed at identifying risk factors for the development of shoulder pseudoparalysis, especially in our country. The aim isto evaluate, using our own clinical material, risk factors for the development of functional disorders in the shoulder joint in the form of shoulder pseudoparalysis in patients with full-thickness rotator cuff tears. Material and methods. A retrospective study was conducted of 254 patients who underwent surgery for full-thickness rotator cuff tears between January 2018 and August 2021. The analysis was based on data from medical histories, clinical, functional and instrumental studies. Results. 34.3% of patients had functional impairment in the form of shoulder pseudoparalysis; risk factors were: massive damage to the rotator cuff (p<0.001), irreparable ruptures (p<0.001), involvement of the subscapularis tendon (p<0.001), involvement of attachment points of “rotator cable” (p<0.001). More severe injuries to the subscapularis tendon aggravate the manifestations of shoulder pseudoparalysis (p<0.001). Involvement of a greater number of attachment points of the “rotator cable” aggravates the manifestations of shoulder pseudoparalysis (p<0.001) Conclusion. The data obtained demonstrate that massive irreparable tears of the rotator cuff of the shoulder joint with severe damage to the subscapularis tendon are the most dangerous from the point of view of disruption of normal biomechanics and, as a consequence, the development of shoulder pseudoparalysis