Effective Date: April 30, 2026 · Version 1.1
3D Medical LLC ("we," "our," or "us") operates The Knee App. This Privacy Policy explains how we collect, use, and protect your information when you use our mobile application.
Account Information: When you create an account, we collect your name and email address.
Exercise Data: We store your saved workouts and exercise completion history to provide personalized recommendations and track your progress.
Usage Data: We collect anonymous analytics about how you use the app to improve our service.
Interactive Guidance Responses: If you use our Interactive Guidance feature, your questionnaire responses are processed to provide personalized program recommendations.
Assessment Photos and Measurements: When you complete the Postural Assessment or Movement Assessment, we capture and store a photo of you, the position of markers you place on that photo, and biometric measurements derived from those markers (such as joint angles and alignment ratios). This data is stored on DigitalOcean Spaces, accessible only to you and authorized 3D Medical staff, and is retained as part of your personal program record.
We use the following third-party services:
If you are invited and choose to enroll as a beta tester, additional information from your assessments may be shared with the 3D Medical team to help us improve marker placement instructions and detection accuracy. This data may include:
Beta program enrollment requires a separate opt-in beyond accepting this Privacy Policy. You can opt out of beta data sharing at any time in Settings, and you can request deletion of your beta-shared data at any point. Beta-specific data is automatically removed from our systems after 90 days, regardless of opt-out status.
Opting into the beta program does not affect your normal use of the app, and opting out does not affect your existing program or assessment history.
We implement industry-standard security measures to protect your personal information. Your data is encrypted in transit and at rest. Assessment photos are stored in private, access-controlled storage with signed-URL access that expires after a short window.
You can delete your account at any time from the Profile screen in the app. When you delete your account, all your personal data — including saved workouts, progress history, assessment photos, marker positions, measurements, and findings — is permanently removed from our servers within 30 days.
If you participate in the beta program and wish to remove only your beta-shared data while keeping your account active, you can do so from the Beta settings in your Profile. This removes data shared exclusively for beta program purposes (such as raw pose detection data and your beta-shared photos), while preserving your own program history and assessment results.
The Knee App is not intended for children under 13. We do not knowingly collect personal information from children under 13.
We may update this Privacy Policy from time to time. When we make material changes, you will be asked to review and accept the updated policy before continuing to use the app. We will also update the effective date at the top of this document.
When you create an account or accept an updated version of this Privacy Policy, we record the version you accepted and the date and time of acceptance. This record is retained for our compliance records, and is anonymized if you later delete your account.
If you have questions about this Privacy Policy, please contact us at: