Physiological Strain Due to Wearing a Backpack

摘要

In the study the strain due to the carrying of two types of backpack with loads of 5.4 and 10.4 kg was quantified. One backpack (Mil) suspended most of the weight on the shoulders and the other backpack (Cust) with a frame, supported most of the weight by the hips. A reference condition without a backpack was included. Four categories of strain were distinguished: metabolic strain; cardiovascular strain; muscular strain; skin pressure. During standing the oxygen uptake, used as an indicator for metabolic strain, was not influenced by the type of backpack or the load weight and averaged 10% VO2max. However, the heart rate, used as an indicator for cardiovascular strain, was significantly augmented with 9 beats/min during standing with a backpack. There were neither significant differences between the two loads, nor between the two types of backpack. The metabolic and the cardiovascular strain found in the study are below the tolerance limits for prolonged wear, and thus do not limit the time of load carriage.