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Updated: May 24, 2026
Experimental Methods to Study Human Postural Control
Published on: September 11, 2019
Postural adjustment after an unexpected perturbation in children with haemophilia
F M B De Souza1, R P Pereira, N P Minuque
1Department of Physical Therapy, Communication Disorders and Occupational Therapy. University of São Paulo, São Paulo, Brazil.
Insights
Children with haemophilia show impaired postural balance adjustments after unexpected disturbances. This suggests a higher risk of falls and potential bleeding events in these individuals.
Area of Science:
- Pediatric Physical Therapy
- Neuromuscular Control
- Bleeding Disorders
Background:
- Children with haemophilia (blood clotting disorder) frequently experience joint and muscle bleeds.
- Impaired postural adjustments can hinder balance control during daily activities.
- Difficulty in recovering balance may increase the risk of bleeding episodes.
Purpose of the Study:
- To investigate if children with haemophilia have deficits in postural adjustment following unexpected perturbations.
- To compare postural control between children with haemophilia and healthy children.
Main Methods:
- Twenty children with haemophilia (HG) and 20 healthy controls (CG) participated.
- Subjects stood on a force plate and experienced a sudden release of weight applied to their trunk.
- Centre of Pressure (COP) displacement was measured to assess postural adjustments.
Main Results:
- No significant differences in initial response (t1) between groups.
- The haemophilic group showed significantly greater COP displacement at 1 second (t2) post-perturbation compared to controls.
- No inter-group differences were found in subsequent intervals (t3-t8).
Conclusions:
- Children with haemophilia exhibit altered postural adjustments to unexpected balance challenges.
- These findings highlight potential underlying neuromuscular control differences in pediatric haemophilia.
- Further research is warranted to explore the clinical implications for fall risk and bleeding prevention.
Abstract:
Children with haemophilia often bleed inside joints and muscles, which may impair postural adjustments. These postural adjustments are necessary to control postural balance during daily activities. The inability to quickly recover postural balance could elevate the risk of bleeding. To determine whether children with haemophilia have impaired postural adjustment after an unexpected perturbation compared with healthy children. Twenty children with haemophilia comprised the haemophilic group (HG), and 20 healthy, age-paired children comprised the control group (CG). Subjects stood on a force plate, and 4% of the subjects' body weight was applied via a pulley system to a belt around the subjects' trunks. The centre of pressure (COP) displacement was measured after the weight was unexpectedly released to produce a controlled postural perturbation followed by postural adjustment to recover balance. The subjects' postural adjustments in eight subsequent intervals of 1 s (t1-t8), beginning with the moment of weight removal, were compared among intervals and between groups. The applied perturbation magnitudes were the same for both groups, and no difference was observed between the groups in t1. However, the COP displacement in t2 in the HG was significantly higher than in the CG. No differences were observed between the groups in the other intervals. Within-group analysis showed that the COP was higher in t2 than in t4 (P = 0.016), t5 (P = 0.001) and t8 (P = 0.050) in the HG. No differences were observed among intervals in the CG. Children with haemophilia demonstrated differences in postural adjustment while undergoing unexpected balance perturbations when compared with healthily children.
