The effects of repetitive haemarthrosis on postural balance in children with haemophilia.

Sensory information from visual, vestibular and proprioceptive systems is necessary to control posture and balance. Impairment in proprioception due to repetitive joints bleeding may lead to a deficit in postural balance which, in turn, leads to high joint stress and risk of bleeding recurrence. Despite the increase in attention in this field during the past few years, the data concerning to how bleeds can affect postural control in children with haemophilia (CWH) remain scarce. This study aimed to evaluate the postural balance in CWH. Twenty CWH Haemophilia Group (HG) and 20 age-matched children Control Group (CG) were recruited to this study. A force plate was used to record centre of pressure (COP) displacement under four different postural conditions during quiet standing: eyes open on firm surface, eyes open on foam surface, eyes closed on firm surface and eyes closed on a foam surface. Variables of COP as sway area and mean velocity and in anterior-posterior (y) medio-lateral (x) direction were processed and for each variable sensory, quotients were calculated and compared between groups. No differences were found in visual and vestibular quotients variables between groups. A higher value was found in sway area variable on proprioception quotient in the HG when compared with CG (P = 0.042). CWH with repetitive joint bleed on lower limbs showed differences in postural balance when compared with non-haemophiliac children. The identification of early balance impairments in CWH can help us understand better the effects of bleeds inside joints on postural control and plan a more effective preventive and rehabilitative treatment.

Postural adjustment after an unexpected perturbation in children with haemophilia.

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.