Physiological strain due to load carrying.

摘要: In an experimental study of load carrying the effects mass (0, 5.4, 10.4 kg) and type support (on shoulder or on waist) parameters physiological strain were quantified to determine factor(s) which limit time. Four categories investigated: metabolic (in terms oxygen uptake), cardiovascular heart rate), muscular EMG activity) skin pressure under straps. young male subjects tested a treadmill using different combinations speed. While standing, uptake was not influenced by backpack, averaged 10% maximal uptake. The rate increased significantly 9 beats per min while standing wearing independent backpack. walking both carried, but types remained below tolerance limits for prolonged wear. Standing supporting did increase root mean square value signal trapezius pars descendens muscle. walking, value, and, converted force, largest amounted 2.7% force kg suspended from shoulders. This levels producing fatigue, also indicated absence changes in median power frequency signal. straps during shoulders more than factor three times higher threshold tissue irritation. Load transfer waist with flexible frame reduced pressures far value. On basis these results it concluded that even relatively low loads limiting skin, if belt relieve such