2026 · Harvard · Advised by Patrick Slade

Neuromodulation Biomechanics Wearable Systems

Biomechanics · Wearable Systems
Research Methods · Signal Processing

Role: Experimental Design, Signal Processing, Wearable Hardware, Data Analysis

Probing how electrical muscle stimulation reshapes lower limb coordination under dual cognitive and physical load.

This research, conducted at Harvard's SEAS under the supervision of Prof. Slade, investigates whether transcutaneous electrical neuromuscular stimulation (TENS) applied to the calf can modify lower limb coordination during a concurrent cognitive task, and what that reveals about the neural and muscular pathways governing human movement.

The study employed a within-subject dual-task paradigm with four counterbalanced conditions, crossing cognitive load with calf TENS stimulation. Bilateral knee and ankle joint angle time-series were captured via OpenCap and processed to extract three coordination metrics, each normalized to individual participant baselines to account for natural variation.

Methods

Within-subject Design4 Counterbalanced ConditionsDual-task Paradigm

Hardware

TENS / EMS DeviceModular Wearable AttachmentMotion Capture

Software

OpenCapOpenSimPython / MATLAB

Measures

Bilateral Knee AngleAnkle Joint Angle3 Coordination Metrics

Overview

Research Context

Walking is not automatic. Navigating a crowded street, holding a conversation, or performing mental arithmetic while moving imposes measurable cognitive load that degrades gait stability, alters joint kinematics, and elevates autonomic demand, even when walking speed appears unchanged. Yet nearly every lower-limb assistive system in existence operates as if cognition and locomotion are independent. This project proposes otherwise. The study investigates whether real-time, cognitive-load-driven electrical stimulation can restore gait biomechanics during dual-task locomotion without impairing the cognitive performance that triggered the intervention.

Research Design

Experimental Paradigm

4-condition counterbalanced protocol — cognitive load x TENS stimulation

Conditions

Baseline walking (no stimulation, no cognitive task)
Cognitive load only (n-back task during walking)
TENS stimulation only (calf stimulation during walking)
Dual task (cognitive load + TENS stimulation simultaneously)

Signal Processing

Bilateral knee and ankle joint angles extracted from OpenCap video-based markerless capture
Three coordination metrics computed per participant per condition, normalized to individual baseline

Wearable Design

Modular EMS attachment system designed for repeatable placement across participants with varying limb morphology
Personalized stimulation Design: a modular compression sleeve with a pegboard-inspired repositionable electrode system

OpenCap - markerless motion capture

Trial 01 - Walking with VR Game as Cognitive Tasks