Seite - 146 - in Intelligent Environments 2019 - Workshop Proceedings of the 15th International Conference on Intelligent Environments

that is done, they will flex their knee again and place the item on the ground. This routine of movements will be counted as one. This routine shall be repeated as many time as the subject could complete, and as fast as he/she can complete. If this routine takes more than 4 seconds, or if the subject wishes to finish, the trial will be finished. (The movement is in line with the suggested movement by the Japanese Ministry of Health Labor and Welfare, “Guideline to prevent back pain in workplaces”) Two patterns below will be conducted randomly. Pattern 1 With the assistance of the coil spring (Coil spring strength 224 N) Pattern 2 No assistance An angle of the knee extension will be analyzed using motion analysis software (OpenPose) [8] . An angle of the knee will be used to measure the duration between initial standing state to the next standing state. The ratio from the average duration over time was calculated. For example, if the duration was the same as the average duration between motion it will be counted as 1 and if it is half the time of the duration between motion, it will be recorded as 0.5. EMG on the skin surface of knee extension muscle (Quadriceps muscle) and hip extension muscle (The gluteus maximus) will be measured through the electrodes attached to the skin surface. Average RMS (Root Mean Square) per 0.01 seconds in the gluteus maximus and quadriceps muscle was measured under the assistance and no assistance setting. In addition, Small wireless multifunction sensor (TSND 121, ATR Promotions, Inc), EMG amplifier (TS-EMG 01, ATR Promotions, Inc). Disposable electrodes (Vitrode, Nihon Kohden Corporation ) was used. Fig 2. Lifting test 2.3 Comparison of a feeling of assistance between the strength of coil springs 2 subjects were recruited to see how the changes in assistance level affect the reduction of workload. 2 subjects must not have a mental or physical disorder which may have an impact upon verifying the effect of reduction of workload. Weight to be T.Nakazawaetal. /Advancementof IoH/IoT“Assist Suits” toSupportWorkplaces146