Sotirakis H, Patikas DA, Papaxanthis C, Hatzitaki V. Resilience of visually guided weight shifting to a proprioceptive perturbation depends on the complexity of the guidance stimulus.
Gait Posture 2022;
95:22-29. [PMID:
35398706 DOI:
10.1016/j.gaitpost.2022.03.018]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/05/2022] [Accepted: 03/23/2022] [Indexed: 02/02/2023]
Abstract
BACKGROUND
Whole-body tracking of visual motion cues is used in balance training to improve weight shifting ability in old age and sports.
RESEARCH QUESTION
How tracking of a complex (pink noise) and a periodic visual target motion during anteroposterior weight shifting affects postural and muscle responses to unilateral hip vibration.
METHODS
Twenty-six participants performed 160 anteroposterior weight shifting cycles while tracking the vertical motion of a visual target, concurrently receiving Center of Pressure (CoP) feedback. They were randomly divided to groups; (a) the Constant group tracked a visual target motion constructed by 3 sinusoids of different amplitude, and (b) the Pink group tracked a complex visual target motion constructed by a pink noise generation process. Between the 60th and the 120th cycle, vibration was applied to the right gluteus medius, introducing a sideways CoP deviation. CoP displacement and electromyographic (EMG) responses of soleus, tibialis anterior and peroneus longus were recorded and summarized in blocks of 3 cycles.
RESULTS
Sideways CoP deviation induced at the onset/offset of unilateral hip vibration was smaller for the Pink than the Constant group. The Pink group demonstrated greater tibialis anterior and peroneus longus EMG activity around the most anterior sway peak while soleus EMG was similar for the two groups. Both groups successfully coupled weight shifting amplitude to the target motion, but the Pink group tracked the target motion with a greater delay compared to the Constant group.
SIGNIFICANCE
Whole body tracking of complex visual motions evokes perception-based action and increases ankle muscle co-activation making sway more resilient to a proprioceptive perturbation induced by unilateral hip vibration. Complex visual guidance motions should be considered when designing balance rehabilitation regimes, aiming at improving weight shifting ability and dynamic balance control.
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