Hotspur's suggestion that his father's absence is a "perilous gash" (see above) to the rebel forces isn't the only reference to maiming. The play is full of allusions to body mutilation, both literal and figurative. Let's discuss. In the play's opening speech, King Henry describes the English soil as a mother whose body has been "bruise[d]," gouged, and "trench[ed]" by civil warfare, even as the cannibal earth feeds on the bloodied bodies of her "children" (buried English soldiers). Such violent and vivid imagery gets at the unnaturalness of civil warfare, which is imagined by Shakespeare as some seriously violent family drama.
A few lines later, we hear that 1,000 English soldiers have been "butchered" by Welsh fighters and the corpses subject to "beastly shameless transformation" at the hands of the Welshwomen (1.1.1). Here, Shakespeare refers to historical accounts (including a major source for the play, Raphael Holinshed's Chronicles) of how the Welshwomen mutilated the genitals of English corpses. Gross. Literary critics tend to agree that this reference in the play registers larger fears of emasculation at the hands of rebellious forces. In other words, if England is imagined as a collective body, then warfare and rebellion threaten to weaken and enfeeble the entire kingdom.
The play's preoccupation with castration is repeated again, perhaps more comically, when Lady Percy, on two separate occasions, threatens to break her husband's "little finger" or, his "head." Hotspur is certainly worried that physical contact with his wife will make him effeminate or soft, and we talk about this more in "Gender" and "Family."
Lady Percy never castrates her husband but, in one of the last scenes of the play, Falstaff mutilates Hotspur's corpse by stabbing the body in the thigh. We can't help but notice the way Falstaff's actions recall the story of the Welshwomen's mutilation of English corpses in Act 1. Literary critics Jean E. Howard and Phyllis Rackin suggest that, in this way, Falstaff's antics are associated with what the play imagines as a very female and emasculating threat. Makes sense to us. Given that Prince Hal, the heir to the English throne, has been lured away from his princely duties by Falstaff's topsy-turvy Eastcheap world, it's not so surprising that Falstaff would be associated with other rebellious figures that overtly threaten the kingdom's collective "body."