Table: us_national_hockey_players_3
Columns: position
name
height_cm
weight_kg
birthdate
birthplace
1997_1998_team

Question: What position did the player play who weighed less thna 91 kg and was born on March 5, 1977?
SQL: SELECT "position" FROM us_national_hockey_players_3 WHERE "weight_kg" < 91 AND "birthdate" = 'march 5, 1977'