To drink frequently and heavily, esp whiskey: They cautioned him that maybe he was bending the elbow a little too often
To have a drink: We'll tip the elbow over at my place(1825+)
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
Idioms and Phrases with crook one's elbow
bend one's elbow. Drink liquor, especially a great deal. For example, Bill is known to crook his elbow now and then, or Uncle Joe rather overdoes it with bending his elbow. Both slangy expressions allude to the motion of lifting a drink to one's lips, which involves bending the elbow. The first dates from about 1820, and the second from about 1900.