Differences of the ankle plantar flexor length in typically developing children and children with spastic hemiplegic...

Area of Science:

• Orthopedics
• Neurology
• Biomechanical Engineering

Background:

• Spastic hemiplegic cerebral palsy (CP) is a neurological disorder affecting muscle tone and movement.
• Muscle length alterations in the lower extremities are common in children with CP, potentially impacting gait.
• Quantitative assessment of skeletal muscle structure is crucial for understanding CP-related motor deficits.

Purpose of the Study:

• To quantitatively analyze and compare the lengths of medial gastrocnemius, lateral gastrocnemius, and soleus muscles in children with spastic hemiplegic CP versus typically developing children.
• To assess structural differences in skeletal muscles affected by spastic hemiplegic CP.
• To investigate the relationship between muscle length and motor function in CP.

Main Methods:

• Utilized gait analysis and interactive musculoskeletal modeling software to model skeletal muscle length.
• Assessed medial and lateral gastrocnemius and soleus muscle lengths across various knee (0°, 45°, 90°) and ankle (-10°, 0°, 15°, 30°) angles.
• Included 10 children with spastic CP and 10 typically developing children in the study.

Main Results:

• Muscle length in the paretic group was generally shorter than in the typically developing and nonparetic groups across all measured angles, though not statistically significant.
• Normalized muscle lengths revealed a statistically significant difference in the lateral gastrocnemius muscle length between the CP and typically developing groups.
• Observed muscle shortening on the paretic side in children with CP.

Conclusions:

• Muscle shortening, particularly in the plantar flexor muscles (gastrocnemius and soleus), is evident on the paretic side in children with spastic hemiplegic CP.
• Restoration of adequate plantar flexor muscle length is a critical factor for improving normal gait and motor function in children with CP.
• These findings highlight the importance of addressing muscle length deficits in the rehabilitation of children with CP.