The form, position, angle and the bump's height in tsurumakura are very important, and if the form is not good, the problems happen, for example, a bow cannot be drawn properly or an arrow cannot fly and so on.
弦枕の形状、位置、角度、段差の高低が極めて重要で、形が悪いとまともに弓が引けない、矢が飛ばない等の弊害が出る。