The pop star has been treated in A&E after a fall during an evening bike ride with her husband along the Thames Path in London.
She posted a picture on Instagram showing injuries to her head and arm, telling her 237,000 followers: "I've put the photo in black and white so it's not too gory."
Explaining how she hurt herself, Ellis-Bextor wrote: "I am ok, just a bit bruised and sore. I want to thank the ambulance crew and the staff at west mid hospital (where I was born, as it happens) for gluing me back together."
The singer also thanked four runners - Lucas, Colin, Josh and Willow - who stopped to help.
She said: "You were so calm, thoughtful and reassuring. Thank you very much. I hope you see this message as I didn't get your details. You're all lovely people. Xxxx"
Stars including Natalie Imbruglia, Dermot O'Leary, Lauren Laverne and Sophie Dahl were quick to wish Ellis-Bextor a speedy recovery.
Later updating her post, she thanked fans and friends for their "lovely messages", adding: "I should have said that the main reason I posted was to thank the incredible folk who stopped and helped (although the sympathy is very cheering) so don't worry I'm ok and being well looked after."
She also thanked her husband, The Feeling bass player Richard Jones, for "being amazing" and said "the kids are being very sweet" too.
The 41-year-old Murder On The Dancefloor singer welcomed her fifth child with Jones last year.
Ellis-Bextor's Kitchen Disco Instagram shows, in which she performed a song from her home wearing lots of sparkles every Friday night, has seen her popularity surge during lockdown.