Related Experiment Video
Updated: Jul 13, 2026
Experimental Methods to Study Human Postural Control
Published on: September 11, 2019
The development of balance control in children: comparisons of EMG and kinetic variables and chronological and
L Sundermier1, M Woollacott, N Roncesvalles
1Department of Exercise and Movement Science and Institute of Neuroscience, University of Oregon, Eugene 97403, USA.
Insights
Developmental level, not chronological age, better predicts balance control in children. Improved muscle coordination and strength enhance reactive balance responses, reducing center-of-pressure sway.
Area of Science:
- Developmental Pediatrics
- Motor Control
- Biomechanics
Background:
- Reactive balance control is crucial for preventing falls in children.
- Understanding the interplay between muscle activity and body movement is essential for assessing balance development.
Purpose of the Study:
- To investigate the relationship between electromyographic (EMG) and kinetic variables during reactive balance responses in children.
- To compare the effectiveness of grouping children by developmental level versus chronological age for analyzing balance control.
Main Methods:
- Cross-sectional study involving 44 children aged 9 months to 10 years.
- Electromyographic (EMG) activity of key postural muscles (gastrocnemius, hamstrings, paraspinals, tibialis anterior, quadriceps, abdominals) was measured.
- Center-of-pressure (COP) adjustments and peak joint torques (ankle, knee, hip) were analyzed during reactive balance tasks on a movable platform.
Main Results:
- Significant relationships were found between postural muscle activity, lower limb torque, and COP adjustments.
- Increased and more coordinated postural muscle activity correlated with higher peak torques and faster, shorter COP readjustments.
- Developmental level grouping revealed more significant differences in balance control compared to chronological age grouping.
Conclusions:
- Developmental level is a more effective predictor of balance improvement than chronological age in children.
- Specific muscles (gastrocnemius, hamstrings, paraspinals) play key roles in the balance synergy for correcting forward sway.
- Improved muscle synergy and strength are critical for efficient reactive balance recovery.
Abstract:
This cross-sectional study examined electromyographic (EMG) and kinetic variables during reactive balance responses in children grouped according to developmental level as compared with chronological age. Purposes were to explore relationships between the two types of variables and the effectiveness of the two grouping methods. Forty-four children between 9 months and 10 years old were tested for reactive balance control on a moveable platform. Surface electrodes measured EMG activity in the gastrocnemius (GA), hamstrings (HA), paraspinals (PS), tibialis anterior (TA), quadriceps (QA), and abdominal (AB) muscles. Timing and distance of center-of-pressure (COP) movements and peak muscle torques at the ankle, knee, and hip were also examined. Significant relationships and group differences were found between postural muscle activity and both the torque generated in the lower limbs and the timing and distance of COP adjustments employed to restabilize balance. As postural muscle activity increased and became more coordinated in timing, peak torque at the ankle and hip also increased, while the distance of and time to complete COP readjustments decreased. Children in younger/developmentally lower groups had smaller-magnitude and less-synergic muscle activity, lower peak torques, longer times to restabilize the COP, and greater COP paths than older/higher developmental groupings. Grouping by developmental level produced more statistical differences than did grouping by age. The correspondence of GA, HA, and PS muscle activity with COP measures and joint peak torques confirms that these muscles are key contributors to the balance synergy correcting for induced forward sway. Additionally, developmental level appears to be a much better predictor of balance improvement than chronological age.
