## 6 Illustrative Hypothetical Case: Blockchain-Enabled Motor Development Analysis  
To better illustrate the features of blockchain technology applicable to PARFSET, we developed an imaginary case that integrates key applications and quality attribute benefits,providing a comprehensive and cohesive overview Figure 5. The case involves gross motor skill development analysis in participants using wearable and camera sensors, IoT, and blockchain technology. Consider a system that uses wearable sensors and cameras to monitor and analyze the gross motor development skills of individuals participating in a physical training program. Figure 5: Illustrative hypothetical case: Utilizing a blockchain for secure recording and monitoring of gross motor skill development data. Wearable devices capture movement data, such as joint angles, speed, and balance, while camera sensors provide visual input for detailed motion analysis. The collected data is then transmitted through IoT infrastructure. Since the data streamed from sensors can be extensive, the blockchain can be used to record only the transactions of receiving new data chunks, while the actual data is stored separately across multiple data stores, locally or on cloud, in an encrypted format. However, metadata such as ownership, access-logs, and even some main features from the original data can securely be stored in a blockchain network. A blockchain's data immutability and traceability ensure that once movement records are logged, they cannot be altered, preserving data accuracy and integrity. This is particularly valuable for assessing long-term changes in participants' motor skills, or assessing the interventions which were supposed to improve those motor skills. The use of decentralized data storage ensures that all sensor data is securely distributed across multiple nodes, reducing the risk of data breaches or loss due to centralized server failures. Here, the blockchain performs as the core that integrates all those distributed pieces. This guarantees consistent availability and protection of participants' data throughout the analysis process. Smart contracts provide automated access control, allowing only authorized users, such as trainers or researchers, to access specific data. For instance, a trainer might access a participant's motor data through a smart contract, which verifies their authorization and logs the access in the blockchain, ensuring accountability and traceability. Furthermore, smart contracts can be executed automatically when specific conditions are met. For example, if a pattern indicating an injury is detected in the signals, a smart contract can grant emergency access to the participant's location to an emergency response team. Similarly, when a trainee reaches a certain level of improvement in gross motor skills, a new trainer can be assigned to them, automatically receiving permission to access relevant exercise data. To motivate participants, gamification elements can be integrated through a blockchain. Participants can receive tokenized rewards for achieving specific motor milestones, such as improved balance or agility. These rewards are managed by smart contracts that verify progress and automatically distribute tokens when conditions are met, fostering engagement and encouraging consistent participation. Scalability is supported through a blockchain's capability to manage large volumes of data from multiple participants without performance degradation. As the number of participants and data points grows, the blockchain network can accommodate the increase effectively, ensuring smooth and consistent performance. Personalization is facilitated by using data collected over time to create tailored training programs for gross motor skill development for individuals, thereby enhancing motor development outcomes. A blockchain ensures that participants' data remains secure while enabling trainers to make adjustments based on individual progress.