前扑（打击）
Also known as: 扑向来球, 身体前倒
前扑是一种时机毛病，打者过早地把重心和跨步投入向前——通常是在试图追赶球速或猜测来球时——在挥棒真正开始之前就耗尽了旋转力量。
良好的跨步和蓄力会让重心保持在后侧的平衡状态，直到挥棒本身把髋部向前发力。前扑打破了这一顺序：前脚重重落地，身体重心在挥棒真正开始之前就已经向前冲出，导致接触瞬间没有任何东西可供旋转对抗。髋部和躯干本应带着储存的弹性能量爆发式打开，此时却已经被用来吸收身体重心向前跌落的冲力而耗尽。
前扑往往是一种猜球习惯，而不是单纯的时机问题——打者预判会来一记变速球，或者仅仅是面对速球型投手感到焦虑，从而过早出手，而不是信任自己正常的蓄力—跨步节奏。由于前侧在接触瞬间已经向前塌陷，前扑型挥棒对优质变速球也异常脆弱，因为一旦重心已经投入，就没有能力再做调整。
修正方法更多基于节奏而非动作机制：重新建立一种由投手投球动作触发、而非由焦虑或猜测触发的蓄力，使跨步准时落地而非提前落地，让后侧保持蓄力状态，直到真正的挥棒决策做出为止。
Example
他一直在等一记始终没来的变速球，结果在速球上前扑，髋部已无余力驱动挥棒。
Why it matters
前扑会同时悄悄限制力量和好球区覆盖范围。SwingVantage会追踪重心分布和跨步时机相对于投球出手点的关系，标记出打者是否在真正做出挥棒决定之前就已经把重心投入向前。
How it shows up on video
The front foot lands hard and the body's center of mass drives forward well before the hips begin rotating. This leaves the back leg straightened and disconnected rather than staying flexed and loaded through contact.
Common mistakes
- Guessing pitch type or location and committing weight forward before the ball is out of the hand
- Rushing the load out of anxiety against a hard thrower rather than trusting normal timing
- Trying to fix lunging with a longer stride, which often makes the forward commitment worse rather than better
Related terms
Related guides & benchmarks
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