Swimmers have a tendency to drop the elbow in backstroke. That is, they let the elbow lead the hand. This should be avoided, as it decreases stroke efficiency.
有些人在有仰泳时有沉肘的倾向，就是他们用肘部来带动手的动作。这个动作应该避免，因为这个动作可能会降低划水效率。
A key to improving one's technique and stroke efficiency is to improve hip rotation.
提高游泳技术和划水效率的关键是提高转髋的能力。
A key to improving one 's technique and stroke efficiency is to improve hip rotation.
提高游泳技术和划水效率的关键是提高转髋的能力。
For the foam-filled double tube structure, the stroke efficiency and the energy absorption efficiency under the outer tube tear failure mode is higher than that under the progressive buckling mode.
双管夹芯结构中外管撕裂模式的结构行程利用率和能量吸收效率高于相应的外管周期折叠模式。
For the foam-filled double tube structure, the stroke efficiency and the energy absorption efficiency under the outer tube tear failure mode is higher than that under the progressive buckling mode.
双管夹芯结构中外管撕裂模式的结构行程利用率和能量吸收效率高于相应的外管周期折叠模式。
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