What Causes Low Muscle Tone In Infants?

When a baby is born, parents are eager to see their little one hit developmental milestones like holding up their head, grasping objects, and rolling over. However, some infants face challenges in meeting these milestones due to low muscle tone, also known as hypotonia.

If you’ve noticed your baby seems unusually floppy, has trouble moving, or struggles with activities like feeding or rolling over, it might be due to low muscle tone. But what causes low muscle tone in infants, and how can it impact their development?

Innovative Interventions supports families by identifying the causes of low muscle tone and creating personalized intervention plans to enhance your child's progress.

What Is Muscle Tone, and Why Does It Matter?

Muscle tone refers to the natural tension or firmness in muscles that helps maintain posture and movement. When muscle tone is at a normal level, babies can develop motor skills and control their movements effectively.

Low muscle tone, on the other hand, is characterized by a lack of muscle strength and coordination, which can make movement difficult. Infants with hypotonia may appear excessively relaxed or "floppy" as they don’t have the muscle control necessary to hold their body or head in a more controlled way.

The impact of low muscle tone on infants extends beyond simple physical challenges. It can delay motor skills, hinder speech development, and even affect a child’s ability to engage with their environment.

But what causes low muscle tone in infants? Let’s find out.

Genetic and Congenital Disorders

One of the most common causes of low muscle tone in infants is genetic or congenital disorders. Conditions such as Down syndrome, Prader-Willi syndrome, and other chromosomal abnormalities are linked to hypotonia. These conditions affect the nervous system, muscles, and even the developmental pathways that support a baby’s growth.

Down syndrome, for example, is a genetic condition caused by an extra chromosome. This extra chromosome disrupts the normal development of the muscles and nervous system, resulting in low muscle tone. Infants with Down syndrome may have trouble with motor skills like lifting their head, rolling over, or sitting up.

Prematurity

Premature babies born before 37 weeks of gestation are at an increased risk of developing low muscle tone. Prematurity often leads to underdeveloped muscles and nerves, as these babies haven’t had the full amount of time in the womb to develop physically.

As a result, premature infants may experience delays in reaching physical milestones such as holding up their head, grasping objects, or crawling.

These challenges are common and are often addressed through physical therapy services that focus on building strength, coordination, and motor control. With appropriate care, many premature infants will eventually catch up to their peers as their muscles strengthen over time.

Neurological and Muscular Disorders

Low muscle tone can also be a result of neurological or muscular disorders that impact the brain or spinal cord, affecting motor function and muscle control.

Conditions like cerebral palsy, muscular dystrophy, and spinal muscular atrophy can cause significant hypotonia in infants. These conditions often result in weakness and delayed movement due to damage or dysfunction in the nervous system or muscles.

Cerebral palsy, for example, is caused by brain damage that affects muscle control. Infants with cerebral palsy may experience severe hypotonia, making it difficult for them to perform basic movements.

Muscular dystrophy, on the other hand, is a genetic disorder that causes progressive muscle weakness, also leading to low muscle tone. These neurological and muscular conditions require specialized care.

Metabolic Disorders and Low Muscle Tone

Some metabolic disorders can also contribute to low muscle tone in infants. These disorders affect how the body produces and uses energy, which is necessary for muscle function. Mitochondrial diseases and metabolic myopathies are examples of conditions that can impair muscle strength and coordination, leading to hypotonia.

Metabolic disorders can disrupt energy production in cells, including muscle cells, making it harder for the body to perform everyday tasks.

Symptoms of Low Muscle Tone in Infants

Low muscle tone in infants often manifests in several noticeable symptoms. Babies with hypotonia may seem unusually floppy or soft when held, and they may have trouble holding their head up or rolling over. You might also notice that your baby has difficulty feeding, sucking, or swallowing due to weak oral muscles.

Other signs include:

• Struggling to move limbs or lift the body

• Difficulty sitting or crawling without support

• Limited facial expression and poor head control

• Trouble grasping objects or holding toys

These symptoms may vary depending on the severity of the hypotonia and the underlying cause.

Diagnosing Low Muscle Tone in Infants

Diagnosing low muscle tone typically involves a physical examination by a pediatrician or a specialist. The doctor may assess your baby’s motor skills, muscle strength, and reflexes.

In addition to a physical examination, further tests may be recommended to identify any underlying causes, such as genetic tests, metabolic screenings, or brain imaging. If the pediatrician suspects that your infant’s low muscle tone is caused by a neurological or genetic disorder, they may refer you to a specialist for a more detailed diagnosis.

Addressing Low Muscle Tone

Our team uses several approaches to support infants with low muscle tone. Physical therapy is one of the most common interventions, focusing on strengthening muscles, improving coordination, and developing motor skills.

Occupational therapy also helps infants with fine motor tasks, such as grasping objects, and developing sensory processing skills that are crucial for everyday activities.

Therapists may also use gentle stretching exercises, strength-building activities, and play-based interventions designed to engage children and promote muscle development. Other activities for low muscle tone include tummy time and supported sitting to help build muscle strength and improve mobility.

Seek the Right Intervention at the Right Time

Low muscle tone in infants can stem from a variety of causes, including genetic conditions, prematurity, neurological disorders, and metabolic issues. Recognizing the signs early and seeking the right interventions can make a significant difference in your child’s development.

We work with families to create individualized therapy plans that support their child's growth and development. Through our physical therapy services, occupational therapy, and targeted activities for low muscle tone, your child can gain the strength and coordination they need to thrive.

If you notice any signs of low muscle tone in your baby, don’t hesitate to reach out. Early diagnosis and intervention can help your child achieve their developmental goals and lead a fulfilling life.