The present invention discloses a system and a method for monitoring a progression of low back pain rehabilitation in a real-time manner. The system comprises a wearable electromyography, EMG, assembly comprising a plurality of detection electrodes deployed on erector spinae muscles at a lumbar region of vertebrae L4 and L5, a signal detection module,an acquisition and transmission module and an inertia measurement module, and a monitoring and reporting unit deployed on a computing device configured for generating a progression report including a rate of improvement or deterioration associated with the progression of low back rehabilitation of a subject. The monitoring and reporting unit determines, based on digital EMG signal, a flexion relaxation ratio, FRR, and an extension relaxation ratio, ERR, associated with the said erector spinae muscles, and compares the same against that of a historical data to determine the said rate of improvement or deterioration.