Hypotonia in Children

Hypotonia is a common clinical finding that is widely misunderstood. In this post, I hope to explain what congenital hypotonia means, providing helpful information to families and caregivers of children with hypotonia as well as the medical providers who work with them.

The diagnosis of hypotonia, or low muscle tone, is often used as a “catch all”. Hypotonia may be the presenting sign of both benign and serious conditions that affect motor control. Recognizing hypotonia, even in early infancy, is usually relatively straightforward, but determine the underlying cause can be much more complex.

The long term effects of hypotonia on a child’s development depend primarily on the severity of the hypotonia and the nature of the underlying cause. Some of these disorders have a specific medical treatment, but the principal treatment for most children with congenital hypotonia is Physical and Occupational Therapy.

Signs and Symptoms of Hypotonia

• Difficulty maintaining head control
• Difficulty sitting upright without significant lean or support
• Delayed acquisition of motor milestones
• Difficulty transitioning in and out of positions
• Clumsy or inefficient movement patterns
• Global developmental delay
• Difficulty with hand eye coordination
• Preference for less physically demanding activities
• Low frustration tolerance with physically challenging tasks
• Reduced endurance or increased fatigue during physical activity

Differential Diagnosis

It is important to identify or rule out any potential underlying causes of hypotonia, as some conditions may require more immediate medical intervention.

Detailed Patient and Family History: Details about the pregnancy, delivery and postnatal period can be extremely helpful. Family history of conditions that may present with hypotonia is also important.

Developmental Assessment: Understanding the child’s motor milestone acquisition can help identify how hypotonia is affecting physical, social and emotional development.

Physical Exam: Assessment my include muscle tone, neurologic reflexes, muscle strength, postural control, joint laxity, protective responses, and equilibrium/righting reactions.

Muscle Tone vs Muscle Strength

Muscle Tone is the level of resistance present in a muscle at rest and the muscle’s readiness to respond to movement or changes in position. Appropriate muscle tone helps a child to respond to changes in position through balance, righting, and protective reactions. 

Muscle Strength refers to the muscle’s ability to actively contract and generate force against resistance, such as pulling, pushing, or lifting. Although strength and tone are different, they work together to support efficient movement. A child with low tone may have difficulty maintaining an optimal position for movement, which can make it more difficult to generate and sustain force.

Hypotonia Through the Years

Newborns and Infants 

Newborns and infants may display poor head control. Babies may seem to “slip out of your hands”, and have trouble keeping their bodies supported when carried.

When lying on their backs, babies with hypotonia may rest with their arms and legs extended outward, and may have difficulty maintaining positions against gravity, including tummy time, supported sitting, or supported standing.

Young Children

Young children with hypotonia may lean excessively forward when sitting and have difficulty maintaining an upright position. They may favor a “W-sit” position to create a wider base of support and reduce the demands of active trunk control.

Children with low muscle tone may also experience delays in gross motor milestones and have difficulty learning to roll, sit, crawl, transition between positions, and walk independently.

Older Children

Older children with hypotonia may favor passive over active participation in school and extracurricular activities. They may have low frustration tolerance during physically challenging tasks and may fatigue more easily, with movements becoming more labored or less coordinated as they tire.

Prolonged sitting may also be physically demanding. A child may lose focus during classroom or tabletop activities because of the effort required to maintain an upright posture.

• Improving Proximal Strength and Support to Facilitate Distal Strength and Function
• Improve Postural Control
• Facilitate Motor Development and Foundations of Motor Planning
• Improve Postural Responses and Protective Reactions
• Address Fluidity and Efficiency of Movements
• Improve Functional Strength and Endurance

Treatment Strategies

Be Patient: Because children with hypotonia may not demonstrate motor response immediately, therapists and caregivers can sometimes be tempted to move on to another activity.

Patience is important. With adequate time and appropriate prompting, a child may be able to achieve the objective in some capacity. Give the child time to respond and modify the activity as needed to allow for active participation and success.

Follow Developmental Sequence: Children with hypotonia often struggle with acquiring motor milestones. Regardless of the child’s age when therapy begins, revisit foundational movement patterns and transitions that support more advanced skills.

Encourage transitions between important body positions, including supine, prone, seated, tall kneeling, half kneeling, and standing.

Promote Proper Alignment: Build strength over a properly aligned, symmetrical base of support. In sitting, check the position of the pelvis before beginning an activity. In standing, ensure the feet are appropriately aligned and weight bearing through the support surface to promote functional muscle development and reduce compensatory movement patterns. 

Grade Input: Try not to startle the child with sudden movements. Provide graded assistance that allows the child to contribute as much of the movement as possible.

Decrease Support Over Time: Start with a higher or more proximal base of support and gradually reduce support as the child gains control.

When addressing postural control, for example, begin with support at the upper back or shoulder girdle and slowly lower the point of support as the child develops greater activation and strength.

Make Tasks Functional: Focus on function. Talk with families and caregivers about activities that are important at home, school, and in the community. Whether the goal is getting dressed, getting in and out of a chair, or participating in play and sports, practice movement skills in ways that are meaningful and useful to the child.

Set Up for Success: Break tasks into manageable components. Allow the child the necessary time and energy to completed each task. And don’t forget about positive encouragement!

Activity Ideas

Therapy Ball Exercises

• Increase demands on the child and inhibit passive collapsing into gravity
• Facilitate motor control
• Promote muscle strength
• Facilitate transitions
• Provide vestibular input
• Practice righting reactions and protective responses

Prone weight shifting on therapy ball

Encourage Active PlayBilateral Play: Encourage the child to use both sides of their body and incorporate movements that cross midline.

Sports Skills: Choose activities that incorporate hand eye coordination, reaching, squatting, throwing, catching, kicking, and other functional movement skills.

Climbing: Climbing up and down stairs, playground equipment, or other age appropriate surfaces can target both concentric and eccentric muscle activation.