Understanding the intricate interplay of factors influencing the healing process is paramount to optimizing fracture healing. This study addresses interfragmentary movement and focuses on the central role of partial weight bearing, muscle attachments, and rehabilitation exercises in generating perfect boundary conditions for ideal healing. Considering the dynamic nature of the healing phases - from initial connective tissue to fibrous cartilage to soft callus - we try to define the fracture stimulus thresholds for each phase depending on the fracture situation at hand. As part of this methodology, healthy subjects (n=20) underwent various partial weight and rehabilitation scenarios. In addition, careful measurements were taken to actively record incorrectly adjusted walking aids and over- and under-weight bearing scenarios. To thoroughly investigate the nuanced effects of partial loading and rehabilitation exercises, state-of-the-art instruments include measurable insoles and hand force sensors from novelTM. These instruments actively facilitated the recording of forces during crutch walking, complemented by using EMG sensors by DelsysTM and XsensTM motion capturing system. The individual collected data are integrated into the AnyBodyTM musculoskeletal simulation system (Figure 1 a) and b)), which enables precise joint and muscle forces and moments computation. The collected monitoring data from five patients with tibia fractures now enable the fit customization for each patient. Digital twins of the respective bone-implant systems are generated based on post-operative clinical imaging, with simulations applying the customized boundary conditions. This customization involves identifying the optimal fracture stimulus and interfragmentary movement for every healing phase, every partial weight bearing, and every rehabilitation exercise typical for a tibia fracture. The subsequent integration and evaluation of this diverse data set through musculoskeletal simulations results in a comprehensive understanding of the factors contributing to perfect boundary conditions for fracture healing. Linking local stresses and strains in the fracture gap to the healing window (Figure 1 c)), cf. [1] and [2] and analyzing the healing progress with an inhouse bone healing model based on [3] help to unravel the complexity of the healing process to ultimately develop strategies for optimal rehabilitation and create ideal conditions for fracture healing.