Biomechanical analysis of workload on the nurse

2004 Fiscal Year Final Research Report Summary

• Project/Area Number: 14370809
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 基礎・地域看護学
• Research Institution: University of Shizuoka
• Principal Investigator: KIMURA Tadanao University of Shizuoka, School of Nursing, Professor, 看護学部, 教授 (70102374)
• Co-Investigator(Kenkyū-buntansha): NISHIGAKI Masaru Nihon Fukushi University, Department of Social Development and Management, Professor, 福祉経営学部, 教授 (40101109) ; SHIGA Yumi University of Shizuoka, School of Nursing, Assistant Professor, 看護学部, 講師 (30295555) ; HAMAI Taeko University of Shizuoka, School of Nursing, Research Associate, 看護学部, 助手 (50295565) ; SHIRAISI Yoko University of Shizuoka, School of Nursing, Research Associate, 看護学部, 助手 (10305500)
• Project Period (FY): 2002 – 2004
• Keywords: erector spine muscle / muscle fiber composition / center of gravity / three dimensional analysis / weight load / EMG / patient transfers / workload on the nurse (or caregiver)

Research Abstract

To clarify a caregiver's load during manual patient transfer we conducted anatomical and biomechanical studies that gathered histological, mechanistic, and physiological information. The anatomical study was performed a histological analysis of muscle fiber composition in erector spine muscles taken from human cadavers. The analysis indicated a higher percentage of red muscle slow twitch fibers. The biomechanical studies were started with a three-dimensional motion analysis of the center of gravity of the caregiver during such a transfer. First, after confirming the error range for the three dimensional motion analysis, we calculated the center of gravity for both patient and caregiver, and found that a caregiver's total movement distance was 637.0 cm, with maximum speed 96.90 cm/sec. Then, a caregiver's movement during patient transfer could be categorized into 5 types depending on the location and the velocity of the center of gravity, constraints on movement from holding the patient, and the work posture. Next, we measured the weight load on the caregiver during patient transfer, and found that a caregiver transfers a maximum weight load of 5-18 Kg. This showed that the weight load on a caregiver often exceeded 24% of the caregiver's own weight, exceeding the recommendation established by the Ministry of Health, Labour, and Welfare. Finally, we analyzed the load on a caregiver's erector spine muscles using weight load values and electromyogram (EMG). The EMG study indicated that the maximum load on a caregiver's lower back during patient transfer occurred when the caregiver elevated a patient against gravity; it was also observed that the caregiver worked the lower back muscles asymmetrically during patient transfer. This study indicated that preventive measures should be taken to avoid damage to the lumbar region.