Q&A: 4 Month Old with Stiff Upper Body

Tamara GuoChild Development, Infants 3 - 12 Months

My grandson is 4-1/2 months old. I believe he has hypertone in his upper body (he arches his back  “stiff” when being held body-to-body) that may be showing up in his legs now (he’s starting to “scissor” – to hold his mom’s arms with his legs as his diaper is being changed). Is there anything that can explain hypertonicity in layman’s terms? A pictorial of behavioral tendencies/assessments? An infant developmental specialist in San Diego that’s familiar with hypertonicity?

In response to your questions, let me start by saying that your keen observations and reporting provided a clear portrayal of your grandson’s movement patterns. I believe that your observations warrant concern. Hypertonicity is often called high tone, spasticity, hypertonia and rigidity.

Movements will appear stiff and awkward because the muscles may be tight, and tone is not balanced. Hypertonic babies will arch their backs and will stiffly extend/straighten legs. Babies with high tone will often stand on stiff legs when given the opportunity. You may also see him standing on his toes and scissoring his legs tightly when held upright or during diaper changes. Fluctuating tone will be a combination of low/weak tone when resting and high tone/rigidity during active movements. Whether you have high tone, low tone or fluctuation, there is no damage to the muscles or nerves; but it is the brain’s inability to control the muscles during movement. You need balance between all muscle groups involved to have smooth, coordinated movement.

As a therapist, I cannot diagnose, but I recommend that you speak with your grandson’s pediatrician as soon as possible. Ask for a referral to either a pediatric neurologist or a physiatrist for more extensive assessment. You can also seek out early intervention services (from birth to age 3) in your area without a referral. Contact the Infant/Toddler Alliance in your area for an evaluation. Your grandson does not need a diagnosis to be evaluated for services. A physical therapist can help with development of motor skills, and improve strength, posture and range of motion. She can help you with how to handle your grandson during daily care and play.

For now, position your grandson on his belly often. If he has difficulty in this position, use a Boppy pillow or a small blanket under his chest. Place toys in front of him to encourage reaching. Promote hand-to-feet play (play ‘patty-cake’ with his feet) when he is lying on his back and help him as needed. This will help him to move in patterns opposite to the stiffness.