锋线摇摆人（英语：Cornerman），也被称为双前锋（Combo forward）或延伸四号（Stretch four），是指篮球中一个新兴的位置，俗称「大后锋」。指具有外线能力的大前锋。代表着「有外线能力、能让禁区不那么拥挤的大前锋」。著名的球员包括德克·诺威斯基、贾许·史密斯、肖恩·马里昂、钱宁·弗莱、凯文·乐福等人。

通常球队采取此阵容，代表队上有善于切入的球员，为避免在该球员切入时遭到大前锋的补防，或为了给予其更大的切入空间，因应球队战术的安排。

In basketball, a stretch four (sometimes called combo forward or cornerman) is a player who plays in the power forward position. "Stretch" describes the effect such a player has on the opposition defense, and the power forward position is also known as the "four position"; hence "stretch four". The stretch four is a fairly recent innovation in the NBA (with an "explosion" of players coming through since the 1999-2000 season), but is still becoming increasingly common in today's game, as many NBA coaches now use the "small-ball" line-up/tactical play.