Moritani T, Oddsson L, Thorstensson A, Astrand P O
Department of Physiology III, Karolinska Institute, Stockholm, Sweden.
Acta Physiol Scand. 1989 Nov;137(3):347-55. doi: 10.1111/j.1748-1716.1989.tb08763.x.
The adaptation in activation patterns of the ankle extensor muscles to different functional demands was studied in adult men (n = 10) and 9-year-old boys (n = 10). The relative magnitude of the activation of the slow soleus (SOL) and the relatively fast medial gastrocnemius (MG) muscle was measured during various postures and hopping tasks on a force plate. In addition, the myo-electric activity was quantified in three different phases of the stretch-shortening cycles during hopping. Major differences between boys and adults were observed in the postural tasks, where the boys appeared to utilize the MG to a relatively larger extent. During maximal height hopping there was a clearly larger potentiation of the MG activity in the adults, particularly in the eccentric phase. On the other hand, there were striking similarities between boys and adults with respect to the degree of pre-activation of both muscles during the different hopping regimes as well as potentiation of muscle activity during the concentric phase of maximal height hopping. Thus, some aspects of the selective neural control of the ankle extensor muscles appear to be manifested in pre-pubertal boys. However, the data also indicate that other factors, such as utilization of stored elastic energy in the muscles and stretch reflex potentiation, will still continue to develop from the age of nine.
研究了成年男性（n = 10）和9岁男孩（n = 10）的踝伸肌激活模式对不同功能需求的适应性。在测力板上的各种姿势和跳跃任务中，测量了慢肌比目鱼肌（SOL）和相对较快的腓肠肌内侧头（MG）的激活相对幅度。此外，在跳跃过程中的拉长-缩短周期的三个不同阶段对肌电活动进行了量化。在姿势任务中观察到男孩和成年人之间的主要差异，其中男孩似乎相对更大程度地利用了MG。在最大高度跳跃期间，成年人的MG活动明显有更大的增强，特别是在离心阶段。另一方面，在不同跳跃方式下，男孩和成年人在两块肌肉的预激活程度以及最大高度跳跃的向心阶段肌肉活动的增强方面存在显著相似性。因此，踝伸肌的选择性神经控制的某些方面似乎在青春期前男孩中就已表现出来。然而，数据也表明，其他因素，如肌肉中储存的弹性能量的利用和牵张反射增强，从9岁起仍将继续发展。
