The availability of efficient, adaptable, and flexible wearable exoskeletons represents an interesting solution to enhance rehabilitation processes for the hand and the upper limb. Nevertheless, due to the complexity of the hand kinematic structure and the strict constraints needed to limit device size and weight, the design of effective systems is still an open challenge. This paper integrates a modular hand exoskeleton with a system for interaction force estimation. The system utilizes a pair of force-sensitive resistors (FSRs) positioned on the finger module base, to accurately measure the interaction forces between the exoskeleton and the user’s hand during flexion/extension movement. The first goal is to provide feedback to both the user and clinicians, optimizing rehabilitation exercises and improving training effectiveness.