Idea
Real-time clinical joint angle extraction platform from smartphone video for accessible movement analysis.
Research Paper
Core Innovation
This paper introduces a direct extraction method for clinical joint angles from parametric body model rotation matrices without inverse kinematics or musculoskeletal model fitting. It uses a small calibration table to map rotation matrices to clinical angles, enabling real-time, accurate joint angle estimation from single-camera smartphone video without additional inputs.
Why It Matters
Quantitative joint angle data is rarely available in routine care due to costly, slow, or lab-confined tools. This method simplifies and speeds up joint angle measurement using only smartphone video, eliminating complex inputs and enabling scalable, decentralized movement analysis for clinical and remote rehabilitation applications.
Market Size (TAM)
$2–10B TAM for digital movement analysis and rehabilitation tools; $500M–$1B SAM from clinics, telehealth, and sports medicine. Driven by increasing demand for remote patient monitoring and scalable biomechanical assessment.
Potential Customers & Pain Points
- Clinics – Need fast low-cost joint angle measurement
- Telehealth providers – Require remote movement assessment
- Rehabilitation centers – Seek scalable patient monitoring
- Sports medicine – Demand real-time biomechanical feedback
- Research institutions – Need large-scale decentralized data collection.
Business Model
Subscription-based SaaS platform offering real-time joint angle analysis via smartphone app and API access for clinics, rehabilitation providers, and researchers.
Competitive Landscape
- OpenCap Monocular
- Vicon
- Xsens
- Noraxon
Implementation Challenges
- Integration with existing clinical workflows
- Validation across diverse populations and movement types
- User training and adoption in non-laboratory settings
Validation Strategy
- Conduct clinical trials comparing accuracy against gold-standard motion capture
- Pilot deployments in rehabilitation centers and telehealth programs
- Collect user feedback to optimize usability and integration
Research Paper Overview
Direct Clinical Joint Angle Extraction from Parametric Body Model Rotation Matrices
Summary
This paper presents a method to extract clinical joint angles directly from per-segment rotation matrices of parametric body models without inverse kinematics or musculoskeletal fitting. Using single-smartphone video and a small calibration table, it achieves accuracy comparable to existing methods but with a simpler, real-time pipeline requiring no additional inputs. This enables practical movement analysis in diverse settings including clinics, homes, and large-scale studies.