探討成人以不同負重率及背負高度之生理負荷分析—以雙肩後背包為例

A Study on the Physiological Load Analysis of Adults by Different Weight Ratio and Backpack Position

林毓真(Yu-Chen Lin)

指導教授 ： 周永燦

中原大學/電機資訊學院/工業與系統工程研究所/碩士(2017年)

https://doi.org/10.6840/cycu201700642

摘要

肩頸及腰背肌肉疼痛一直是在背重行為時所造成的傷害中，最被大家所關注的，而背部疼痛與背包過重亦有非常大的關係，最常出現的症狀即為下背痛（low back pain, LBP）。從過去文獻中可以發現，背重議題多為探討兒童及青少年，但因健康因素，成年人使用雙肩後背包的比例越來越高。目前文獻多以身體姿勢角度及心率量測來探討成人背重問題，而本研究希望以不一樣的角度（肌肉負荷及主觀不適程度）來探究成人負重行為。故本研究旨在探討：在對身體不造成顯著傷害的情況下，成人建議之負重率及背負高度；以及不同負重率和不同背負高度下，人體肌力負荷及主觀不適程度為何；最後為探討成年男性與女性在肌力負荷及主觀不適程度上，是否在性別上有差異。本實驗共徵募12位受測者，男性與女性各為6位，其平均年齡為23.7 ± 0.5歲，身高平均167.2 ± 6.4公分，體重平均64.8 ± 9.1公斤，BMI之平均值為23.1 ± 2.0。受測者以雙肩後背的方式，背負四種體重（Body Weight, BW）比例之重量（0%、10%、12.5%及15%BW）及三種背負高度（T7、T12及L3），共12種背負實驗組合，每個組合背負2分鐘，並運用肌電儀記錄實驗期間肌肉活動（斜方肌、闊背肌及豎脊肌）之肌電訊號，以及在每組實驗結束後，請受測者填寫主觀不適評級量表，再運用SPSS對數據進行統計分析。研究結果顯示，在負重率為15%BW時，斜方肌及豎脊肌的肌肉活動明顯超出負荷；在12.5%BW以上時，受測者有明顯程度的主觀不適感。而闊背肌雖與負重率無顯著關係，但從本研究的分析結果中，仍可以發現其肌肉活動程度會隨著負重率越大而增加。至於背負高度則因斜方肌及豎脊肌皆與背負高度存在著顯著關係，而兩者皆在T12的背負位置時，所耗費之肌力最小。綜合上述結果，本研究歸納出，人體應盡量避免12.5%BW以上的背重行為，而背負高度則是以T12為對人體負荷相對較低的背負位置。

關鍵字

負重率 ； 背負高度 ； 肌電訊號 ； 主觀不適評比

並列摘要

On the behavior of load carrying, Myofascial pain syndrome and low back pain have been the physical injury that most people are concerned about. To understand the effects of different body weight (BW) ratio and height on the physiological load of adults is the purpose of this study. By analyzing the results of different experimental combinations to find a reasonable body weight ratio and the best backpack position. This study recruited twelve subjects to participate carrying backpack experiments. And they were six males and females with an average age of 23.7±0.5 years, height of 167.2±6.4 cm, weight of 64.8±9.1 kg, BMI of 23.1±2.0. Subjects carried four different body weight ratio (0%, 10%, 12.5%, and 15%BW) and three positions along spine (T7, T12, and L3) by way of backpack load. Each combination was performed two minutes, and use EMG to record muscle signals (trapezius, latissimus dorsi, and erector spinae). After finishing each combination, subjects filled in subjective discomfort rating scale. And finally use SPSS to analyze the data. The results showed that the muscle activities of trapezius and erector spinae were significantly overload at 15%BW. And at 12.5%BW or more, subjects had a significant degree of subjective discomfort. Although latissimus dorsi wasn’t significantly related to weight ratio, but the degree of muscle activity could be increased with the growth of it. As for the backpack position, trapezius and erector spinae cost the smallest muscle strength at T12. Based on the above results, this study suggests that the human body should try to avoid more than 12.5% BW of carrying load, and T12 is the position that relatively low load for the human body.

並列關鍵字

carrying load ； backpack position ； EMG ； subjective rating

參考文獻

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