Other expressions

быть по коленоa to be knee-high
У берега вода была мне по колено. Near the shore the water was up to my knees.
стоять [no Pf.] по коленоa в Np to stand up to one's knees in N
NB N = вода "water," грязь "mud," песок "sand," etc.
входить/войти в Na по коленоa to go into N up to one's knees
идти [no Pf.] по коленоa в Np to walk in N up to one's knees
NB N = вода "water," грязь "mud":
Они шли по колено в воде. They were walking in water up to their knees.
N до коленg N to one's knees, knee-length
NB N = платье "a dress," юбка "a skirt," сапоги "boots," носки "socks," etc.
N выше коленg N above the knee
NB N = платье "a dress," юбка "a skirt," сапоги "boots," etc.
N ниже коленg N below the knee
NB N = платье "a dress," юбка "a skirt," сапоги "boots," etc.