Kinesiological surface electromyography in normal children: range of normal activity and pattern analysis

Area of Science:

• Pediatric Gait Analysis
• Kinesiological Electromyography
• Biomechanical Research

Background:

• Establishing normative data for surface kinesiological electromyography (KEMG) in children is crucial for accurate clinical gait analysis.
• Previous research has lacked comprehensive datasets for pediatric KEMG patterns across a wide age range.

Purpose of the Study:

• To document the range of activity and patterns of normal surface KEMG in typically developing children aged 3 to 18 years.
• To develop and validate algorithms for analyzing KEMG curve patterns and determining muscle activity onset/cessation.
• To create a normal database for pediatric KEMG during free walking.

Main Methods:

• Evaluated 87 children (age 3-18) during free walking, analyzing 6307 gait cycles from 11 muscles.
• Developed custom software with algorithms for KEMG curve pattern recognition and amplitude/statistics-based criteria for activity detection.
• Collected data on timing, duration, anthropometrics (height, weight, BMI), cadence, stride length, and age for statistical analysis.

Main Results:

• Medial/lateral hamstrings, gluteus maximus/medius, and gastrocnemius showed the highest percentage of clinically relevant KEMG curves.
• Average background activity in most muscle groups was 11-15% of maximum amplitude.
• KEMG activity timing and duration showed weak correlations with age, height, weight, and BMI.

Conclusions:

• The ensemble average of linear envelope KEMG curves can serve as a normal database for pediatric clinical gait analysis.
• Identified specific muscles with high relevance in pediatric KEMG patterns.
• Highlighted the variability in KEMG timing and duration relative to anthropometric factors in children.