The HOS - E111 Multifunctional hard pull trainer mainly targets the back muscles like the latissimus dorsi and the middle - lower trapezius, which lift weights and stabilize the spine during deadlifts, enhancing back strength. The gluteus maximus contracts strongly when standing up, extending the hip joint and shaping the buttocks. The hamstrings on the back of the thighs also cooperate throughout the movement, improving their strength and flexibility.