Motor fatigability during repetitive handgrip contractions in children with spina bifida: dynamometric and...

Area of Science:

• Pediatric physical therapy
• Neuromuscular function
• Developmental disabilities

Background:

• Spina bifida (SB) is a congenital condition affecting motor function.
• Assessing handgrip strength and fatigability is crucial for understanding functional limitations in children.
• Limited research exists on the specific handgrip performance and muscle activation patterns in children with SB.

Purpose of the Study:

• To compare handgrip pressure, fatigability, and muscle activation between typically developing children and those with spina bifida (SB).
• To investigate potential differences in neuromuscular responses during handgrip tasks in these groups.

Main Methods:

• A comparative study involving 68 typically developing children and 20 children with SB (aged 8-14 years).
• Maximal and fatigue handgrip tests using a bulb dynamometer.
• Simultaneous surface electromyography of finger flexor and extensor muscles.
• Statistical analysis using multiple linear regression models.

Main Results:

• Children with SB exhibited significantly lower handgrip pressure compared to typically developing children.
• No significant differences were found in handgrip fatigability, muscle activation, time-to-fatigue, or perceived effort between the groups.
• Despite lower absolute strength, children with SB did not demonstrate increased fatigability during repeated contractions.

Conclusions:

• Children with SB are weaker in handgrip strength but possess comparable fatigability to their typically developing peers.
• Neuromuscular activation patterns appear to compensate, preserving handgrip force during sustained or repetitive tasks in children with SB.
• These findings suggest a specific adaptive mechanism that maintains handgrip function in the presence of spina bifida.