GS Certificate Functions: Strengthening the muscles in upper limbs, shoulder and back, and improving the flexibility, agility and coordination of shoulder joints and elbows; good for healing inconvenience of bending and stretching hindrances of joints in shoulder and elbow,muscular atrophy, frozen shoulder, tennis elbow, etc. Instructions: Sit on the chair with back towards the equipment and hold the handles with both hands. Push upward slowly with force and recover slowly. Repeat the process. According standards:EN957