Former President George H.W. Bush, who was hospitalized this month after falling and breaking a bone in his neck, sent a thank-you tweet on Thursday.

“Who knew jumping out of planes was safer than getting out of bed? Thanks to all for your kind get-well messages,” the message says. It is accompanied by a photo of Bush wearing what appears to be a neck brace and giving a double thumbs-up.

Bush, 91, fell at his summer home in Kennebunkport and spent four days at Maine Medical Center in Portland. Doctors said when he was released July 19 that they expect him to make a full recovery in a few months.