The shoulder joint is the most mobile joint in the human body and is therefore very unstable. The structure that stabilizes the shoulder is a rotator cuff. It consists of muscles: supercharged muscle (lat. m. supraspinatus), subgressive muscle (lat. m. infraspinatus), podlopupatic muscle (lat. m. supscapularis) and a small muscle lining (lat. m. teres minor). Rotator cuff syndrome is mostly performed by people who are engaged in daily chores that require the use of hands. In rotator cuff syndrome, pain in the shoulder rim occurs and the range of movement in the shoulder joint itself is reduced. Rotator cuff problems affect middle or older age, more often women than men. Degenerative changes begin already in middle age, tendons become stiffer and less bloodsucked. As a rule, the cause of such conditions is prolonged activity with the hand raised above the head, or frequent, but short and strong activity with a raised hand. The most common sports that contribute to rotator cuff damage are volleyball, handball, swimming and water polo. A person with a rotator cuff injury feels pain over the deltoid muscle at the top and outside of the shoulder, especially when the hand is raised and extended to the sides. Movements like these, especially when dressing, can be extremely painful. The shoulder is weak, especially when trying to raise the hand to a horizontal position. Pain or weakness when performing the internal or external rotation of the hand may indicate damage to the tendons of the rotator cuff. Complications that can arise are rotator cuff ruptures, calcifying tendinitis, shoulder arthrosis, and luxations. The assessment of patients with rotator cuff syndrome includes measuring the range of movement and manual muscle test. By measuring the circumference of movement, the amplitude of all movements in the shoulder is measured, and a manual muscle test examines the strength of a particular muscle. Treatment is carried out by physical therapy and movement therapy. Movement therapy includes static exercises, passive exercises, actively assisted movement, active dynamic exercises, stretching exercises, proprioception exercises and resistance exercises. Diadynamic currents, TENS, ultrasound and laser are used from electrotherapy procedures for the purpose of treatment.