These researchers created second spine, an upper body assistive device for human load carriage. They wanted to reduce musculoskeletal injuries caused due to carrying heavy loads. What they designed was a wearable upper body device that can prevent musculoskeletal injuries during human load carriage by providing a secondary load pathway to transfer the loads from shoulders to pelvis while also allowing a good range of torso motion to the wearer. Loads were transferred through segmented columns between the shoulder support and hip belt. The design had had two primary considerations: load distribution between shoulders and pelvis, and preserving the range of torso motion. A further iteration compensates for inertial forces by real-time sensing of human motion and actuation of the motors in a way that the backpack motion is kept nearly inertially fixed.