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Mild body tension is normal for newborns. This is called physiological hypertonia: arms and legs are flexed, fists are clenched. It usually resolves by 2–3 months. If the tension increases, appears on one side only, or interferes with development — talk to your doctor. Warm baths, babywearing, gentle massage, and exercises can help.

What’s Inside

When a baby has physiological hypertonia, their muscles are overly tense

This happens to all newborns. It’s not a disease, but part of normal development as the baby adjusts to life outside the womb.

In the womb, babies stayed curled up in a tight space. After birth, their flexor muscles (those that bend the body) are still dominant over the extensors.

This process is normal and helps babies gradually adapt to new conditions, cope with gravity, and develop motor skills.

Hypertonia can appear in different parts of the body

• Fetal position: arms and legs are often flexed and drawn toward the body.

• Fists: babies often clench their fists, with thumbs tucked in.

• Resistance to straightening: when you try to straighten the baby’s arms or legs, you feel resistance — then they bend back again.

• Frog-leg posture: in the prone position, legs are pulled toward the tummy, feet turned inward.

• Extended neck and head tilt: especially noticeable when laying the baby on their back.

• Restlessness: the baby may seem fussy, sleep poorly, or startle often.

• Feeding difficulties: sometimes increased tension in the jaw can affect feeding.

The causes of hypertonia are natural and normal

• Immature nervous system. Newborns don’t yet have developed inhibitory systems in the brain to regulate muscle tone.

• Intrauterine posture. The baby spent nine months curled up, and their muscles adjusted to that position.

• Gravity. For the first time after birth, the baby experiences gravity fully, and their muscles have to adapt.

• Hormonal factors. Hormones passed from the mother during birth may also influence tone.

Sometimes hypertonia is pathological — and has its own signs

It’s important to distinguish normal physiological hypertonia from a condition that requires medical help.

Signs of physiological hypertonia (normal)

• Symmetrical (same on both sides of the body)

• Decreases gradually with age

• Does not interfere with motor development

• No other neurological symptoms

Signs of pathological hypertonia (needs medical attention)

• Asymmetry (one side more affected than the other)

• Increases with age

• Delays in motor milestones

• Other neurological signs (tremors, head tilting, stiff neck)

• Frog-leg posture while lying on the back

• Standing on tiptoes when held upright

Gentle routines can support healthy development

• Swaddling. Use free swaddling — it creates a sense of security without restricting movement. This reminds the baby of the womb.

• Sleep positioning. Lay the baby on their back. You can use small rolled towels or positioning aids to create a “nest.”

• Holding the baby often. Close contact helps them relax, especially with babywearing.

• Warm water. Bathing at 36–37°C helps relax muscles. Avoid adding chamomile or herbal infusions — they can dry the skin and trigger allergies.

• Tactile contact. Gentle stroking, light massage, and skin-to-skin contact help relax the baby and trigger endorphins — for both baby and parent.

• White noise. Sounds like a hairdryer, soft appliances, or white noise apps can soothe.

• Comfortable environment. Dim lighting, quiet surroundings, and a room temperature of 20–22°C help babies feel safe.

• Feeding. For breastfeeding — ensure good latch. For bottle-feeding — choose a suitable bottle.

Massage and exercises also help with hypertonia

Massage

• Soft strokes from center to limbs

• Gentle tapping with fingertips

• Circular motion around joints

• Cross-back stroking

Exercises

• Bicycle: gently bend and straighten the baby’s legs like pedaling

• Butterfly: gently open and close legs outward and inward

• Swimming: in tummy time, support under the chest to let arms and legs move freely

• Side rolls: gently roll the baby from side to side

• Stretching: gently stretch arms and legs, softly overcoming any resistance

All exercises should be done gently, when the baby is relaxed and in a good mood. Never forcefully straighten limbs or make sharp movements.

Essentials for baby care many parents choose

Sources

• Volpe J.J. (2018). Neurology of the Newborn. 6th edition. Elsevier, 1120 p. Hardback ISBN: 9780323428767

• American Academy of Pediatrics. (2022). Caring for Your Baby and Young Child: Birth to Age 5. 7th edition. Bantam, 1178 p. ISBN-13: 978-1-61002-716-8

• Field T. Massage therapy research review. Complement Ther Clin Pract. 2016 Aug;24:19-31. doi: 10.1016/j.ctcp.2016.04.005. Epub 2016 Apr 23. PMID: 27502797; PMCID: PMC5564319. https://pubmed.ncbi.nlm.nih.gov/27502797/. Accessed 2 Apr. 2025.

• Einspieler C, Prechtl HF, Ferrari F, Cioni G, Bos AF. The qualitative assessment of general movements in preterm, term and young infants--review of the methodology. Early Hum Dev. 1997 Nov 24;50(1):47-60. doi: 10.1016/s0378-3782(97)00092-3. PMID: 9467693. https://pubmed.ncbi.nlm.nih.gov/9467693/. Accessed 2 Apr. 2025.

• Hadders-Algra M. Early human motor development: From variation to the ability to vary and adapt. Neurosci Biobehav Rev. 2018 Jul;90:411-427. doi: 10.1016/j.neubiorev.2018.05.009. Epub 2018 May 9. PMID: 29752957. https://pubmed.ncbi.nlm.nih.gov/29752957/. Accessed 2 Apr. 2025.