For rehabilitation or assistance applications, a new class of wearable devices called ‘soft exoskeletons’ or ‘exosuits’ emerged this last decade. Exosuits are lightweight with compliant material, soft actuators and respect of biological joints. The design of these devices is challenging, particularly in terms of cable routing and physical human-robot interactions, which impose safety and comfort criteria. Literature reveals various approaches ranging from bioinspired methods to optimization aimed at reducing contact forces or ensuring human workspace. Then energy savings for users are assessed experimentally using prototypes. This study aims to implement a human model wearing a cable-driven exosuit in a closed loop simulation and optimise placement of cable anchors considering metabolic cost and interaction forces. In this way, safety constraints are met and energy expenditure is quantified before creating a less energy-consuming device.