Gagnon M
Can J Appl Sport Sci. 1980 Mar;5(1):49-59.
Seven instructors in cross-country skiing were filmed during the performance of the alternate stride at three different velocities: maximal, medium and slow. The dynamic characteristics of the movement were analyzed. On the basis of spatio-temporal analyses, it was found that the alternate stride is a motion essentially propulsive with the predominance of the superior limbs to propulsion. The skier maintains or increases his velocity at the beginning of the glide which is possibly attributed to the transfer of momentum of the recovery leg. A decrease in horizontal velocity is observed at the end of the glide. At maximal speed, the asynchronous character of the actions by the superior and inferior limbs is more important; there is a reduced emphasis in the actions by the superior limbs. At medium speed, the following characteristics are observed: a reduced importance in the asynchronous actions, a larger preponderance to the gliding phase and a smaller elevation of the skier's center of gravity.
七名越野滑雪教练在以三种不同速度（最大速度、中等速度和慢速）进行交替滑行时被拍摄下来。对该动作的动态特征进行了分析。基于时空分析发现，交替滑行本质上是一种推进动作，上肢在推进中占主导地位。滑雪者在滑行开始时保持或增加速度，这可能归因于回收腿动量的传递。在滑行结束时观察到水平速度下降。在最大速度时，上下肢动作的异步特征更为明显；上肢动作的重点减少。在中等速度时，观察到以下特征：异步动作的重要性降低，滑行阶段占比更大，滑雪者重心升高幅度更小。
