Muscle stiffness and strength and their relation to hand function in children with hemiplegic cerebral palsy

Area of Science:

• Neurology
• Pediatrics
• Rehabilitation Medicine

Background:

• Children with cerebral palsy (CP) often experience motor impairments affecting hand and wrist function.
• Understanding the biomechanical characteristics of wrist muscles in CP is crucial for developing effective interventions.

Purpose of the Study:

• To compare passive wrist flexor stiffness and wrist flexor/extensor strength between children with CP and typically developing (TD) children across different wrist positions.
• To investigate the relationship between these muscle characteristics and manual function in children with CP.

Main Methods:

• Passive stiffness and isometric strength of wrist muscles were measured in three wrist positions (30° flexion, neutral, 30° extension).
• Manual function was assessed using the Jebsen-Taylor Hand Function Test.
• Participants included 11 children with spastic hemiplegic CP and 11 age- and sex-matched TD children.

Main Results:

• Children with CP demonstrated significantly higher flexor muscle stiffness compared to TD children.
• Wrist flexor and extensor strength was reduced in children with CP when the wrist was in extension.
• Moderate correlations were found between manual function and wrist muscle strength and stiffness in the CP group.

Conclusions:

• Children with CP exhibit altered wrist muscle properties, including increased stiffness and reduced strength, consistent with habitual wrist flexion.
• These biomechanical differences are associated with functional limitations in manual tasks.
• Interventions targeting wrist muscle stiffness and strength may enhance manual function in children with CP.