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دانلود رایکان مقاله انگلیسی ISI با موضوع چمباتمه زدن، دولا شدن، و یا یک حالت بینابینی؟

عنوان فارسی مقاله:

چمباتمه زدن، دولا شدن، و یا یک حالت بینابینی؟

عنوان انگلیسی مقاله:

Squat, stoop, or something in between?

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بخشی از مقاله انگلیسی :

3. Biomechanical consequences of different techniques

Lifting technique has typically been defined in terms of the posture adopted just before the load is lifted. It has commonly been proposed that the postures adopted to lift loads from a low level may be characterised in terms of two extremes. One extreme, described as a stooped posture, is one in which the knee joints are almost fully extended and the hip joints and vertebral column are flexed to reach the load (see Fig. 1A). The second extreme, described as a full squat, is one in which the knee joints are fully flexed and the trunk is held as vertical as possible (Fig. 1C). It has become a matter of dogma that the latter posture is the ‘‘correct’’ manner of lifting. The authors of the otherwise influential 1981 NIOSH ‘‘Work Practices Guide for Manual Lifting’’ observed that the full squat posture reduced stability (the heels are inevitably lifted from the ground and the knees are in an unstable ‘‘loose packed’’ posture when maximally flexed) leading to the possibility of injury due to unexpected perturbations; and that the technique increased the distance of wide loads from the spine (increasing the load moment and consequently the resulting extensor moment and compressive forces). It was concluded that the squat lift recommendation was based on simplistic mechanical logic which failed to take dynamic loading on the back and the knees into account. More recently, van Dieen et al. (1999) conducted a comprehensive review of 27 biomechanical studies comparing stoop and squat technqiues, and similarly concluded that no justification existed for advocating a squat technique.