Network Analysis of Bodywide Coordination Supporting Suprapostural Dexterity

Summary

Prevailing understandings of movement disorders characterize "broken" movements in a piecewise fashion, for instance, focusing on motor control, muscle tone, posture, or cognition independently of each other. These fractured approaches to movement coordination are blind to the body's functional integrity. Consequently, rehabilitative interventions target the limb or body parts most affected by the disorder, seeking to support the whole body by mending the broken part. However, dexterity is global, functional coordination spanning the whole body. In other words, task completion draws on fundamental interactivity, allowing the body to coordinate various anatomical parts. This coordination may be more vital to healthy movement than individual anatomical parts. Understanding this interactivity is thus paramount to developing novel rehabilitative interventions to prevent falls and improve the quality of life in pathological populations. Studying bodywide coordination for suprapostural dexterity requires innovation in experimental setup and analytical techniques. This project integrates a customizable life-size Trail Making Test with posturography, whole-body movement tracking, eye tracking, and state-of-the-art cascade modeling and network analysis methods to assess functional coordination across the whole body. The experimenters will leverage causal network analyses of multiplicative interactions instrumental in previous studies of whole-body exploratory motor behavior but not yet utilized in studying suprapostural dexterity. Aim 1 will investigate how multiplicative interactions among movement-system components support suprapostural dexterity. The experimenters hypothesize that maintaining an upright stance would produce a functional network of multiplicative interactions among movement-system components. The experimenters also hypothesize that participating in the Trail Making Test would produce a succession of distinct, modular networks of multiplicative interactions among movement-system components. Aims 2 will investigate how multiplicative interactions among movement-system components support suprapostural dexterity in the face of postural instability. The experimenters hypothesize that destabilizing contact with the ground surface when maintaining an upright stance will produce modular networks of multiplicative interactions with increased connectivity among these modules compared to stable standing. The experimenters also hypothesize that destabilizing contact with the ground surface in the Trail Making Test would produce a succession of distinct, modular networks of multiplicative interactions with increased connectivity among these modules compared to stable standing. This modeling framework offers a new way to understand suprapostural dexterity and its breakdown in various movement disorders in light of recent theoretical developments in cascade modeling and network physiology.

Conditions

• Trail Making Task
• Balance Board

Interventions

BEHAVIORAL

Trail Making Task

Participants will perform a modified, life-size version of the Trail Making Test (TMT) while standing upright, either on a stable (force plates) or unstable (balance board) surface. The task involves visually searching for and tracing a sequential path through spatially randomized numerical targets projected onto a large screen using a laser pointer. This dual-task condition simultaneously engages cognitive, visual, and motor planning systems while requiring continuous postural control. The task is designed to elicit suprapostural coordination, capturing the dynamic interplay between postural stability and goal-directed behavior.

BEHAVIORAL

Balance board

Participants will maintain an upright stance on a commercially available balance board positioned atop dual force plates. The unstable surface introduces controlled postural instability, requiring continuous sensorimotor adaptation to preserve balance without external support. This condition is administered alone and in combination with the Trail Making Task to simulate dual-task challenges that more closely resemble real-world balance demands.

Sponsors & Collaborators

• University of Nebraska

  lead OTHER

Study Design

Allocation

NON_RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

19 Years

Max Age

35 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2023-08-01

Primary Completion

2024-07-31

Completion

2024-07-31

Countries

• United States

Study Locations