کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
874122 910326 2009 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Characterization of the mechanical properties of backpacks and their influence on the energetics of walking
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی پزشکی
پیش نمایش صفحه اول مقاله
Characterization of the mechanical properties of backpacks and their influence on the energetics of walking
چکیده انگلیسی

The objectives of the experiment were (i) to characterize the mechanical properties of backpacks and (ii) to study the influence of a flexible backpack on the energetics and kinematics of walking. Twelve subjects walked at different speeds on a treadmill with each of two backpacks loaded with 25% bodyweight, with either a rigid or a flexible link between the body attachment and the suspended loads. A single degree of freedom linear model of the link between the pack and the trunk was used to calculate the stiffness and damping coefficient of the two backpacks. The oxygen consumption (V˙O2) and the vertical acceleration of both the backpack and trunk were measured. The vertical excursion of the pack given by the model was significantly correlated with that actually measured (R=0.87, p<0.001). At 3.7 and 4.5 km h−1 the flexible pack induced lower acceleration peaks (respectively −22% and −8%; p  <0.05) and tended to reduce V˙O2 (p=0.055 at 4.5 km h−1) compared with the rigid one. At 5.2 and 6 km h−1 both the accelerative forces and V˙O2 increased with the flexible pack (p<0.05) mainly because of the high vertical movement of the pack. It was concluded that a simple model can be used to predict the vertical excursion of the pack and that a flexible backpack can provide energetic benefits when its oscillations are nearly in phase with those of the trunk. However, any resonance effect can lead to a modified walking pattern and an increased metabolic cost.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Biomechanics - Volume 42, Issue 2, 19 January 2009, Pages 125–130
نویسندگان
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