["Concentrated and dosed movements get the Powerball going, the faster the rotation the more intense the training with the hand trainer", "To start, insert the string into the hole of the rotor, wind it up and pull it out with a jerk - then start with circular movements", "Perfect training for those who rely on strength in their hands, such as athletes, musicians, and people with manual labor", "Prevents complaints such as carpal tunnel syndrome, RSI (Repetitive Strain Injury), tennis elbow, or tension in the arm, neck, and shoulder", "Increases finger grip strength and coordination, also trains the shoulders, forearms, and upper arms"]
