The Lifting Capacity Of Young Population

Purpose: Design the experiment for the purpose to prevent the harm due tooverload work. The experiment include different lifting height, different liftingfrequency and different horizontal distance. To explore the effects of heights,frequency and horizontal distance on maximum acceptable weights of lifting(MAWL),for an aim to provide an basis for the establish of Chinese hand lifting safety weightlimit.Methods: This study used a psychophysical methodology to determine theMAWL, heart rate and self-evaluation for10Chinese male subjects and10Chinesefemale subjects. The experiment include three variable factors: three lifting height(Floor to knuckle F-K, Floor to Shoulder F-S, Floor to Reach F-R), three liftingfrequency (1time/8h,1time/min,4times/min) and two horizontal distance (25cm and63cm). Participants should decision the maximum acceptable weights of lifting withthe conditions of continuous working in8hours and provide cause body hurt,overheating, weakness, or difficulty breathing, and can continue to work in the secondday. The date we need to measure is MAWL, heart rate and self-evaluation.Results:1.The MAWL was markedly decreased with the increase of liftingheight, lifting frequency and lifting horizontal distance both the male and female. TheMAWL reduce rate was19.52%and35.84%of male with the lifting height from F-Kto F-K and F-R, and the female was20.48%and20.48%. In the aspect of liftingfrequency, the MAWL reduce rate was36.29%and36.29%of male with the liftingfrom1/8h to1time/min and4times/min, female was31.09%and52.21%. It was11.64%and10.55%respectively between male and female with the lifting horizontaldistance from25cm to63cm. The MAWL of female was75%of the male.2. Chinese population had different lifting capacity with Occidental. The MAWLwas lighter than Occidental, and the rate of decrease in MAWL was sharper than thatof Occidental participants with the increase of lifting difficulty.3. The recommended weight limit of NIOSH was higher than the lifting capacityof Chinese population. The load constant of NIOSH equation should be change to18kg from23kg.4. Lifting frequency was the most significant factor to the effect of heart rate,between the three factors of lifting height, lifting frequency and lifting horizontaldistance. The increase rate of heart rate was16.70%and19.23%respectively betweenmale and female with the lifting frequency increased from1times/min to4times/min.The heart rate of female was11.78%higher than male.5. Present study found the most stressed body part was shoulder, wrist, and lowerback. With the change of lifting height,the effect of shoulder and wrist was most significantly, and the lower back was effected by lifting weight significantly.Conclusion: We got the characteristics of Chinese lifting capacity with thevariables of lifting height, lifting frequency and lifting horizontal distance. WeChinese population had different lifting capacity with Occidental. The load constantof NIOSH equation should be change to18kg before use to our country.