https://github.com/ariabehroozi/landingtask_emg_fz_analysis
MATLAB pipeline for detecting EMG onset/offset and vertical ground reaction force (Fz) contact during landing tasks. Includes feedforward (pre-activation) and feedback (post-activation) timing analysis.
https://github.com/ariabehroozi/landingtask_emg_fz_analysis
acl biomechanics emg feedback feedforward forceplate landing matlab neuromuscular-control
Last synced: 9 months ago
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MATLAB pipeline for detecting EMG onset/offset and vertical ground reaction force (Fz) contact during landing tasks. Includes feedforward (pre-activation) and feedback (post-activation) timing analysis.
- Host: GitHub
- URL: https://github.com/ariabehroozi/landingtask_emg_fz_analysis
- Owner: AriaBehroozi
- License: mit
- Created: 2025-09-27T14:33:54.000Z (9 months ago)
- Default Branch: main
- Last Pushed: 2025-09-27T14:55:28.000Z (9 months ago)
- Last Synced: 2025-09-27T16:23:02.822Z (9 months ago)
- Topics: acl, biomechanics, emg, feedback, feedforward, forceplate, landing, matlab, neuromuscular-control
- Language: MATLAB
- Homepage:
- Size: 1.34 MB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Landing Task EMG & Force Plate Analysis (MATLAB)
This repository provides a fully transparent and research-oriented MATLAB pipeline for analyzing **landing biomechanics** — combining **vertical ground reaction force (Fz)** and **surface EMG signals** to identify **muscle activation patterns** during landing.
---
🧠 Overview
Landing tasks are widely used in sports biomechanics to evaluate **neuromuscular control** and **injury risk** (especially for ACL-related research).
This code automates the detection of:
- **Force plate events:** contact onset & offset (based on 10% body weight threshold)
- **EMG preprocessing:** baseline correction, band-pass filtering (20–400 Hz), rectification, and envelope creation
- **Onset and offset detection:** using mean + SD thresholds and a **stability rule** (≥ 25–50 ms)
- **Feedforward (pre-activation)** and **Feedback (post-activation)** timing relative to ground contact
All calculations follow protocols supported by published research on neuromuscular activation during landing【1】【2】【3】.
---
🚀 Features
- 🔹 Automated **body weight detection** from stable standing phase
- 🔹 **Butterworth filtering** for both force and EMG
- 🔹 Baseline mean + 3SD thresholding for EMG onset
- 🔹 Dual-threshold hysteresis (3SD for onset, 1.5SD for offset)
- 🔹 **Feedforward (pre-activation)** vs **reactive activation** classification
- 🔹 Visualizations for each phase: raw vs filtered, envelope, onset/offset events
---
🧩 How It Works
1. **Input:** Excel file (`.xlsx`) with
- Column 2: EMG signal
- Column 11: Fz (vertical ground reaction force)
2. **Output:**
- Detected **contact onset & offset** (force plate)
- **EMG onset & offset** with thresholds
- Printed report showing feedforward / feedback timings
- Figures illustrating all processing steps
---
🧪 Example Output
Feedforward (Pre-activation): 0.706 s before contact
Post-activation: 0.221 s after contact ended
> Typical literature reports pre-activation ≈ 0.05–0.15 s before contact and post-activation ≈ 0.15–0.25 s after contact【1】【2】.
---
📊 Applications
- ACL reconstruction research
- Landing mechanics and neuromuscular control
- Injury prevention studies
- Skill-based jump-landing assessments
---
📦 Requirements
- MATLAB R2021a or newer
- Signal Processing Toolbox
- Input file: Excel (`.xlsx`) with columns as specified
---
⚙️ Usage
```matlab
% Place your Excel file (e.g., adinevand.land2.xlsx) in the same folder
run('Landing_EMG_Fz_Analysis.m')
🔗 References
【1】Santello, M. (2005). Feedforward control of hand posture and force during grip–load force coordination. J. Neurophysiol.
【2】Cowling, E. J., & Steele, J. R. (2001). The effect of gender and task on neuromuscular control during landing. J. Electromyogr. Kinesiol.
【3】McNair, P. J., & Marshall, R. N. (1994). Landing characteristics in subjects with normal and anterior cruciate ligament-deficient knees. Arch. Phys. Med. Rehabil.
👨💻 Author
Aria Behroozi
MSc Candidate – Sport Biomechanics
University of Tehran
📫 LinkedIn : www.linkedin.com/in/aria-behroozi-1996
If this code helps your research, please ⭐ star the repo and cite it in your work.