Spiteri Tania, Newton Robert U, Nimphius Sophia
School of Health Science, The University of Notre Dame Australia, Fremantle, Australia; Centre for Exercise and Sport Science Research, Edith Cowan University, Perth, Australia.
School of Health Science, The University of Notre Dame Australia, Fremantle, Australia.
J Electromyogr Kinesiol. 2015 Aug;25(4):629-36. doi: 10.1016/j.jelekin.2015.04.009. Epub 2015 Apr 20.
The aim of this study was to first determine differences in neuromuscular strategy between a faster and slower agility performance, and second compare differences in muscle activation strategy employed when performing two closely executed agility movements. Participants recruited from an elite female basketball team completed an ultrasound to determine quadriceps muscle-cross sectional area; reactive isometric mid-thigh pull to determine the rate of muscle activation, rate of force development, pre-motor time and motor time; and multidirectional agility tests completing two directional changes in response to a visual stimulus. Peak and average relative muscle activation of the rectus femoris, vastus medialis, vastus lateralis, biceps femoris, semitendinosus and gastrocnemius were measured 100ms prior to heel strike (pre-heel strike) and across stance phase for both directional changes. Faster agility performance was characterized by greater pre-heel strike muscle activity and greater anterior muscle activation during stance phase resulting in greater hip and knee extension increasing propulsive impulse. Differences between directional changes appear to result from processing speed, where a greater delay in refractory times during the second directional change resulted in greater anterior muscle activation, decelerating the body while movement direction was determined.
本研究的目的，一是确定敏捷性表现较快与较慢时神经肌肉策略的差异，二是比较在执行两个紧密衔接的敏捷动作时所采用的肌肉激活策略的差异。从一支精英女子篮球队招募的参与者完成了一项超声检查，以确定股四头肌的横截面积；进行反应性等长大腿中部拉力测试，以确定肌肉激活速率、力量发展速率、运动前时间和运动时间；以及多向敏捷性测试，即对视觉刺激做出反应完成两次方向变化。在足跟触地前100毫秒（足跟触地前）以及两个方向变化的整个站立阶段，测量股直肌、股内侧肌、股外侧肌、股二头肌、半腱肌和腓肠肌的峰值和平均相对肌肉激活情况。较快的敏捷性表现的特征是，足跟触地前肌肉活动更强，且站立阶段前侧肌肉激活更强，从而增加髋部和膝部伸展，增强推进冲量。方向变化之间的差异似乎源于处理速度，其中第二次方向变化时不应期的延迟更大，导致前侧肌肉激活更强，在确定运动方向时使身体减速。
