Recumbently
The Century Dictionary and Cyclopedia
In a recumbent manner or posture.
Wiktionary, Creative Commons Attribution/Share-Alike License
adverb.
In a
recumbent
manner; while lying down.
Word Usage
"The paper-pad will be found most useful to travelling writers who use ink, and those authors whom gout, or some other respectable ailment, compels to work recumbently in bed or on sofa."