This paper presents the development of a method to analyze the effect to lumbar spine by lifting shoulder bag with single shoulder and cross body bag. The influence to the left and right of waist muscles was analyzed when the shoulder bag and cross body bag were lifted. The single shoulder lifting operation and lifting operation in a cross shoulder were compared. Four times experiments were carried out for five each men and women, respectively. The effects on the lumbar spine is analyzed by measuring amplitude of left and right side of waist muscle by using EMG(Electromyography) signal. The average and the median values are used for analysis. And also the cumulative area of the amplitude from the EMG signal was analyzed using by normalizing data. The cumulative area is also meaningful value when the data is fluctuating. Normalization equations are suggested to compare the independent values of different side of EMG channels. In addition, the fatigue of muscles was analyzed by performing an FFT (Fast Fourier Transform). This study results in the lifting task by single should and cross body, the opposite side muscle to the spine comparing to same side muscle for the mass is loaded more than same side whether the mass is shoulder or cross body bag. In the cross body lifting operation, there is no evidence of better effect on the lumbar spine comparing the operation of lifting single shoulder bag. Also, there is trend of fatigue effect of waist muscle both shoulder bag lifting and cross body lifting operation