物流業配送員下背受力分析

The Workload and Biomechanical Evaluation of Lower Back for Logistic Delivery Workers

物流服務需求大增的同時，也增加了物流業配送員的工作負荷。物流業配送員工作內容為長時間車輛駕駛（vehicle driving）與人工物料搬運（manual material handling）雙重任務容易造成下背部肌肉骨骼不適。然而，對於物流業配送員在長時間工作下背部腰椎受力情形與相關生物力學分析資料卻仍有不足，因此，本研究目的為首先經由文獻資料整理、問卷調查與現場觀察來瞭解物流業配送員工作特性。透過問卷設計收集物流業配送員工作經驗、與人工物料搬運相關之工作內容、肌肉骨骼不適狀況與個人基本資料。其次，透過生物力學軟體模擬工作姿勢與一般工作情境，分析計算單次搬運下背受力與量化下背部（L5/S1）的累積負荷。研究結果發現，物流業配送員在中、下背部肌肉骨骼不適最高；其次是上肢與肩、頸部位。在模擬現場搬運作業，在無護腰等輔具及極度彎腰等不良姿勢下，運用麥茵茲多特蒙德劑量模式（Mainz Dortmund Dose Model, MDD）生物力學估算連續工作10年，每天連續搬運1小時在下背部受力累積量未超過MDD建議一生累積負荷閾值（25×10^6 Nh）。然而當每天連續搬運2小時，持續時間增加受力累積量即會超出一生累積負荷閾值。這些結果進一步與職業性腰椎椎間盤突出認定參考指引建議比較，提出相關建議避免物流業配送員職業性腰椎椎間盤傷病的發生。

With the abundant demanding of logistic services, it increases the workload for delivery staffs. Delivery workers who undergo with double tasks including long term vehicle driving and a lot of manual material handling task have higher musculoskeletal discomfort in the lower back. However, there is still ambiguity to identify and quantify the biomechanical lumbar workload of lower back for logistic delivery personnel after. Hence, the purpose of this study is, firstly, to identify the work contents through literature reviews, questionnaire survey and work field observation. A questionnaire was designed to collect relevant information about logistic delivery staff, including work experiences, work content relating manual material handlings, musculoskeletal discomfort status and personal demography. Secondly, the study tries to quantify the workload of the lower back (L5/S1) through the biomechanical analysis with the simulated work postures in common situations. The results of the study indicated that logistic delivery staffs have remarkable musculoskeletal discomfort in the middle and lower back; followings are upper limbs, shoulder and neck areas, respectively. For the biomechanical analysis of Mainz Dortmund Dose Model (MDD), it is estimated that delivery staffs work with usual posture (awkward posture without waist belt protection), the cumulative amount on the lower back does not exceed the recommended lifetime cumulative dose (25 x 10^6 Nh) for continuously manual handling for 1 hour a day. Increasing the duration of time (more than 2 hours) will cause the cumulative risk of workload to exceed the recommended limit for the cumulative amount. These findings are further compared with the ＂Occupational Lumbar Intervertebral Disc Herniation Reference Guideline＂, and specific management suggestions are provided for the logistics industry's delivery personnel.