Behavioral assessment, such as systematic scoring or biomechanical measurement, is often used to evaluate the extent of the damage and the degree of recovery after spinal cord injury. However, the use of these methods in standardized evaluation is limited because they are subjective and require complex test systems to implement. Here, we report a novel, flexible, microstructure-based pressure sensor and demonstrate its superior sensitivity (235.12 kPa-1 for 5.5~135 Pa and 2.24 kPa-1 for 0.6~25 kPa), good waterproofness, fast response and recovery times (response time: 8 ms, recovery time: 12 ms), stable response over 8000 loading/unloading cycles, and wide sensing range. These features readily allow the sensor to be comfortably attached to the hindlimbs of mice for full-range, real-time detection of their behavior, such as crawling and swimming, helping to realize quantitative evaluation of animal motor function recovery after spinal cord injury.