Influence of sex, leg dominance and anthropometric data in postural control and proprioception

INTRODUCTION: The postural control includes a wide set of neural input by nervous system, essential to keep a static or dynamic balance. The concept of proprioception, defined as the ability to sense position of a joint in the space, is strictly related to postural control. Both are the key factors for balance, joint stability, coordination and injury prevention. The aim of this study was to evaluate the influence of sex, leg dominance and anthropometric data in postural control and proprioception, using Delos Postural Proprioceptive System (DPPS; Delos, Turin, Italy). METHODS: A cohort of 24 healthy subjects (24.3±2.6 years), 12 women and 12 men, were involved in the study. Postural control and proprioception were evaluated through Static Riva test and Dynamic Riva test by mean of DPPS. Static Riva test was performed during single stance on a static board and included 2 tasks with open eyes and 4 tasks with closed eyes. Dynamic Riva test was performed during single stance on a rocking board and included 4 trials without upper limbs restriction and 4 trials with upper limbs restriction. Parameters considered for these tests were Stability Index (SI) and Dynamic Stability Index (DSI), both as a percentage score (0-100%), where 100% is a theorical task performed with maximum stability. Leg dominance and sex differences were evaluated through t-test. The influence of height and weight was first considered using Pearson’s correlation coefficient, then by normalizing the raw data. RESULTS: No significant differences were found in terms of dominant and non-dominant limbs. Thus, the analysis was performed on the average results of two limbs. Women scores were higher than men in all parameters, significant differences were found on SI open eyes task (92.5% vs 89.3%; p=0.02) and on DSI with restriction (67.9% vs 55.9%; p=0.01). An inverse correlation was found between DPPS indices and both height and weight. Normalizing data by height, the gap between women and men reduced for all the scores except for SI open eyes, in which men had significantly higher scores (50.7% vs 71.8%; p=0.03). Normalizing data by weight, women scores were lower than men in all parameters, significant differences were in SI open eyes (27.8% vs 61.5%; p=0.0002) and SI closed eyes (35.3% vs 60.2%; p=0.010). CONCLUSION: According to scientific literature, this study did not show any differences between lower limbs during single stance test when performed in static or dynamic condition. A raw analysis of result showed a greater proprioceptive and postural control in female subject. When normalizing, it is clear how anthropometric data influenced and often inverted the first results, thus confirming their crucial role in postural control and proprioception. The role of sex differences remains still unclear and needs further analyses. Future studies could include other assessment instrument (e.g. electromyography, force plates) in order to have a global approach to the topic