Limited Interaction Between Vision and Proprioception on Centre of Pressure, Pelvis and Head Positions During Ankle or Neck Vibration in Walking: An Experimental Study.

Background: By stimulating proprioceptive receptors, muscle vibration helps understand the crucial role of proprioception in gait control. From the literature, variability in responses during the stance phase across studies may be due to protocol differences, such as lighting conditions that affect visual information. This study aimed to investigate the interaction between vision and proprioceptive information from ankle and neck muscles over the gait cycle during treadmill walking.

Methods: Twenty-five healthy participants (aged 30 ± 5 years) walked on an instrumented treadmill under three visual conditions (eyes open, dim light and eyes closed) and three vibration conditions (no vibration, neck muscles and ankle plantar flexor muscles) in a randomised order. The centre of pressure (COP), pelvis and head positions were measured and analysed across three gait cycle phases (heel contact, midstance and toe-off). A mixed-effects model on ranks was used for analysis, with post-hoc Tukey corrections for significant interactions.

Results: No significant interaction was found between vibration conditions, different visual conditions, and the gait cycle on the COP, pelvis and head positions (p > 0.42). Neck muscle vibration caused a forward shift in the COP at heel contact (p = 0.0006) and midstance (p < 0.0001) and in pelvis and head positions throughout the gait cycle (p < 0.0001). Ankle muscle vibration had no significant effects (p > 0.4). Eye closure led to more pronounced gait reactions compared to eyes open or dim light at heel contact and toe-off (p = 0.0001).

Discussion: This study investigated the influence of vision and proprioception during walking by manipulating visual information (eyes open, dim light and eyes closed) and proprioceptive information (neck and ankle vibration). Under these specific experimental conditions, no clear interactive effects between vision and proprioception were observed. Instead, their contributions appeared at distinct moments of the stance phase: both modalities influenced gait control at heel contact, neck proprioception effects were more pronounced at midstance, and vision contributed more strongly at toe-off. These findings enhance understanding of sensory contributions during walking and support further exploration of vibration application protocols.