RESUMO
INTRODUCTION: The sensory strategies of postural control in adult haemophilic arthropathy patients are still poorly understood. AIM: To determine sensorial posture-control strategies through postural sway frequency analysis when in a bipedal quiet stance with and without visual stimulus deprivation in healthy subjects and patients with haemophilic arthropathy. Secondarily, to determine the irregularity of postural balance control through sample entropy (SampEn). METHODS: A triaxial accelerometer attached at the L3 level determined the displacement and acceleration of the centre of mass (DCoM and ACoM, respectively) under open- and closed-eyes conditions. Sensorial strategies were studied by spectral analysis of the DCoM signal, divided into low, medium and high frequencies for visual/vestibular, cerebellum and somatosensory strategies respectively. DCoM irregularity was also analysed by SampEn. RESULTS: Fifteen young, healthy subjects and fifteen young, haemophilia patients were included. The mediolateal DCoM and anteroposterior ACoM differed between groups. During the open-eyes condition, haemophiliacs presented limited high and medium frequencies, and more low frequency bands as compared to non-haemophiliacs (P<.05). In the closed-eyes condition, haemophiliacs had a minor percentage of high frequencies but an elevated percentage of low frequencies as compared to non-haemophiliacs (P<.05). Non-haemophiliacs had higher SampEn than haemophiliacs in the mediolateral axis with open- and closed-eyes (P<.05 and <.001, respectively). CONCLUSIONS: The presented results indicate that patients with haemophilic arthropathy, as compared to healthy subjects, have less postural control irregularity and poor somatosensory system contributions that are compensated by more vestibular inputs.