Hypotonia in Children

Hyptonia is a common diagnosis, that is widely misunderstood. In this post I hope to highlight the meaning of Congenital Hypotonia, 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 diagnosing the underlying cause can be quite arduous.

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

Signs and Symptoms of Hypotonia

• Difficulty maintaining head control
• Difficulty sitting upright without significant lean or support
• Slow to attain motor milestones
• Difficulty transitioning in and out of positions
• Clumsy or inefficient movement patterns
• Global developmental delay
• Difficulty with hand eye coordination
• Prefer to observe rather than participate
• Low frustration tolerance with physically challenging tasks

Differential Diagnosis

It is important to rule out any potential underlying etiology that may be presenting as Hypotonia. Some of these conditions may require more immediate medical intervention.

• Detailed Patient and Family History: Details of the pregnancy, delivery and postnatal period are extremely helpful. Any family history of conditions that present like hypotonia are also important.
• Developmental Assessment: To understand the acquisition of motor milestones and the implications on the child’s physical, social and emotional development.
• Physical Exam: Includes muscle tone, neurologic reflexes, muscle strength, postural control, joint laxity, protective responses, and equilibrium/righting reactions.

Muscle Strength vs Muscle Tone

The muscles in our bodies each have a resting muscle tone. Muscle Tone is defined as a muscle’s potential ability to respond or counter an outside force, a stretch, or a change in direction. Proper muscle tone enables a child to respond quickly to an outside force, either through balance responses, righting reactions or protective reactions. It also allows a child’s muscles to quickly relax once the perceived change is gone. A child with hypotonia has muscles that are slow to initiate a contraction against an outside force, and are unable to sustain a prolonged muscle contraction.

Muscle Strength refers to the muscle’s ability to actively contract and create a force to respond to resistance (pulling, pushing, lifting, etc). Although strength and tone are different, when a muscle is not in an ideal position to be ready for a contraction, the muscle strength will be impaired.

Hypotonia Can Manifest As Deficits in:

• Sensory Processing, in which the vestibular, proprioceptive and/or tactile systems fail to alert the brain of changes in body position.
• Praxis or Motor Planning, in which the body is unable to formulate the proper motor response.
• Balance, with the body unable to sustain co-activation of muscle groups working against gravity both statically and dynamically.
• Coordination, with difficulty coordinating upper and lower body movements or visual system to produce fluid and efficient movements.

Hypotonia Through the Years

Newborns and infants may display poor head control. Babies may seem to “slip out of your hands”, and have trouble keeping body erect when you carry them. When lying on their backs, babies with hypotonia will often rest with arms and legs extended outward, and sometimes resist bearing weight when placed on stomachs, held in supported sitting or supported standing.

Young children with hypotonia may tend to lean excessively forward when they are sitting up, failing to activate the trunk musculature to keep them erect. They may favor “W-sit” position to lock into sitting, without engaging their core and postural muscles. Children with low muscle tone may display delays in achieving gross motor milestones, and have difficulty learning to roll, sit, crawl, and walk independently.

Older children with hypotonia may favor passive vs. active participation in school and extracurricular activities, displaying low frustration tolerance during physically challenging tasks. They may get tired easily and with fatigue movements become more labored and clumsy. Children with hypotonia may struggle in the classroom setting, despite their cognitive abilities. Sitting for prolonged time at a desk or during table top activities may prove challenging and children may lose focus simply because of physical stress. As children get older, hypotonia may impact gait and running patterns. Children may turn out feet and present with little to no arch support.

• Address Proximal Strength and Support in order 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

Treatment Strategies

1. Be Patient: Because children with hypotonia often do not demonstrate motor response immediately, both therapists and caregivers have a tendency to give up on what they are doing and move onto another activity. Patience is important, as with adequate time and proper prompting the child will be able to achieve objective in some capacity. Waiting for this response is key. By sustaining the same activity and modifying that activity to ensure success, you can facilitate muscle activation and fluidity of movement patterns.

2.  Follow Developmental Sequence: Children with hypotonia often struggle with acquisition of motor milestones. Allow the child to experience each developmental stage sequence regardless of the age therapy is initiated. Encourage transitions between each important body position: supine, prone, seated, tall kneel, half kneel, and standing.

3. Promote Proper Alignment: Build strength over properly aligned symmetrical base of support in all developmental stages. If you are working in sitting, before beginning activity ensure pelvis is in neutral position. If you are working in standing ensure feet are properly aligned and weight bearing through support surface in order to promote functional muscle development and eliminate potential compensations.

4. Grade Input: Try not to startle child with sudden movements, do not push or pull, allow child to activate on his or her own to maximize work and minimize collapse.

5. Decrease Support Over Time: Start with higher or more proximal base of support while handling and slowly lower as child gains control. When addressing postural control, begin with upper back/shoulder girdle support and slowly lower as child begins to activate and strengthen, allowing child to achieve more functional independence.

6. Make Tasks Functional: Focus on function. Talk with family and caregivers about day to day needs. Whether it is assisting with activities of daily living (ADLs) such as dressing or getting in and out of chair at school, help with motor planning in both a practical and helpful manner.

7.  Set Up for Success: Break down tasks into manageable components. Allow child necessary time and energy to achieve each task. And do not forget about positive encouragement!

Activity Ideas

Use the Therapy Ball to:

• Increase demands on 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

In Quadruped: Direct graded force through pelvis to elongate spine and to elicit symmetric weight bearing through upper and lower extremities (can use foam roller to facilitate).

In Tall Kneel: Utilize support at pelvis to help child weight shift over lower center of gravity, encourage trunk activation, and aid in transition from tall kneel through half kneel to stand without use of upper extremities.

• Joint Compressions, when done appropriately, can help to promote increased co-activation of muscles around the joint and help child maintain joint in alignment against gravity.
• Perform compressions on well aligned joints (begin proximal to distal).
• Use graded force to approximate the joints without overloading them, and joint distraction that is graded to align the joints without over stressing them.

• By facilitating appropriate muscles during therapeutic intervention, we can help child build awareness and promote initiation of force production.
• Tactile input can promote co-activiation of muscles which support joint.
• Light pressure massage also helps promote muscle activation, increase bone growth and mineralization in children with hypotonia.

Encourage Active Play

• Facilitate bilateral play (promoting utilizing both sides of body and movements which cross midline)

• Sports Skills (activities that incorporate hand eye coordination, reaching, squatting, balance)

• Navigating obstacles like play tunnels are always a fun way to build strength, motor planning and endurance!

• Climbing up and down (targeting concentric and eccentric muscle activation)

• Supported standing, cruising and walking

•  Find activities that interest, engage and motivate! Whether it is swimming, horseback riding, biking, dance…active play should be a daily part of all of our children’s lives!

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