What does hypotonia mean?
Hypotonia is the medical term for abnormally reduced muscle tone. It describes a condition in which muscles resist movement less strongly than expected, making a limb or the body appear limp, soft, or unusually floppy. The term is particularly associated with the assessment of infants and children, but it can also be used in neurology, rehabilitation, and other clinical contexts. Hypotonia may occur in isolation or as a feature of a wider condition affecting the brain, spinal cord, muscles, or nerves. It should not be confused with atonia, which denotes a complete absence of muscle tone, or with hypotension, which means abnormally low blood pressure. In a physical examination, clinicians may look for reduced resistance to passive movement, unusual posture, poor head control, or difficulty maintaining a normal position. The word is therefore most useful when precise clinical description is needed, particularly when distinguishing reduced tone from weakness, stiffness, or a generalized loss of muscular activity.
nounAbnormally reduced muscle tone, causing a limb or the body to feel unusually limp or floppy. The term is used especially in neurology, paediatrics, and rehabilitation.
- Abnormally reduced or diminished muscle tone, especially in a muscle, limb, or whole body.
"The infant was referred for assessment after developmental doctors noted marked hypotonia in both legs."
"Physical examination revealed generalized hypotonia and reduced muscle bulk."
"Occupational therapy was recommended to help improve strength and coordination in the child with hypotonia."
The plural is rarely needed because the condition is usually discussed in the singular or as generalized or localized hypotonia.
"The records included several cases of hypotonia in children awaiting neurological assessment."
Severe hypotonia in a newborn is the basis of the familiar but informal description of a “floppy infant.”
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does hypotonia come from?
Hypotonia was formed in medical usage from the combining form hypo-, meaning “under” or “below,” and tonia, meaning “tension.” These elements come from the Greek hypoklinos, meaning “inclined or leaning,” and tonos, meaning “stretching” or “tension.” The related terms hypertonia, atonia, tonus, and tonicity belong to the same classical and medical vocabulary of muscle tension.
Related word forms
How hypotonia is actually used
This is a technical medical term rather than everyday vocabulary. It is usually used when muscle tone is lower than expected for a person's age and context, although some clinicians also distinguish between generalized and localized hypotonia.
Easily confused with hypotonia
Hypotonia means diminished muscle tone, whereas atonia denotes a complete absence of normal muscle contraction or tone.
Hypotonia concerns reduced muscle tone, while hypotension means abnormally low blood pressure.