Paeds Vivas · growth-development-and-behaviour
Motor delay, hypotonia and the floppy infant — branching viva
Branching viva on tone versus strength, central versus peripheral localisation, SMA, botulism, maternal myotonia and disposition.
On this page
Study tools
Target exams
RACP General PaediatricsRACP DCEMRCPCH ClinicalRCPSC Pediatrics
Prompt
You are in general paediatrics clinic/ward. A family presents with a floppy or motor-delayed infant. The examiner will test definitions, localisation, can't-miss pathways and counselling.
Stem
A 4-month-old is brought because she “goes through your hands” when held under the arms and is not rolling. The examiner starts with definitions, then branches into red-flag phenotypes. [1]
References7ShowHide
- [1]Peredo DE, Hannibal MC The floppy infant: evaluation of hypotonia. Pediatrics in review, 2009.PMID 19726697
- [2]Bodensteiner JB The evaluation of the hypotonic infant. Seminars in pediatric neurology, 2008.PMID 18342256
- [9]Finkel RS, Mercuri E, Darras BT Nusinersen versus Sham Control in Infantile-Onset Spinal Muscular Atrophy. The New England journal of medicine, 2017.PMID 29091570
- [10]Mendell JR, Al-Zaidy S, Shell R Single-Dose Gene-Replacement Therapy for Spinal Muscular Atrophy. The New England journal of medicine, 2017.PMID 29091557
- [16]Sarintra N, Ekdahl R, Sanders SC More Than Just a Floppy Baby: Maintaining High Clinical Suspicion of Infant Botulism. Cureus, 2026.PMID 41728439
- [17]Suzui R, Wada I, Matsubara M Undiagnosed Maternal Myotonic Dystrophy Type 1 Revealed by Congenital Myotonic Dystrophy in the Neonate. Cureus, 2026.PMID 42037975
- [5]Laverty CG Hypotonia in the Newborn Infant. Pediatric clinics of North America, 2025.PMID 40619196