About Tai Chi Coach

Tai Chi Coach checks your tai chi and qigong stances and slow movements from your camera against clear, measurable rules. Holds bank good-form seconds only while every rule passes. Movements count only when they are complete and slow. Every mistake gets one named hint within about a second. One person at a time. Nothing ever leaves your device.

Safety first

• Clear the space around you. You need room to step forward and sideways and to spread your arms, with nothing to trip over and a non-slip floor.
• This supplements an instructor; it does not replace one. Learn the movements from a qualified tai chi or qigong instructor, then use this app to practise them at home.
• Check with a doctor first if you have knee, hip, back or other joint problems, balance problems, are pregnant, or are recovering from an injury or surgery.
• Never force a stance. Sink only as low as feels comfortable; the app's "Come up a little" hint exists for a reason. Stop if anything hurts or you feel dizzy, and keep a chair nearby if your balance is unsteady.

How it works

• The app tracks your body joints (shoulders, wrists, hips, knees, ankles, nose) with the MediaPipe Pose Landmarker, running entirely in your browser at about 30 frames per second. No video is sent anywhere.
• Set your standing position first. Stand tall facing the camera, arms relaxed at your sides, for 2 seconds. The app measures your shoulder width, torso length and leg length and scales every rule to your body and your distance from the camera.
• Two camera views. Standing post, horse stance, commencement and cloud hands use the FRONT view: face the camera. Bow stance, empty stance and ward-off, rollback, press use the SIDE view: turn so the camera sees you from the side, because only the side view shows which leg carries your weight front to back.
• Weight distribution is read from where your hips sit between your feet: 0% means right over one foot, 100% right over the other.
• Feedback is one named hint at a time: the first rule that fails, in a fixed order, so you fix one thing at a time.
• The camera is only on while you are in a lesson. It turns off when you go back to the practice list, press Turn off, or switch to another tab.

The rules

• Standing post (hug the tree), front view: feet 0.7 to 1.6 shoulder widths apart ("Bring your feet to shoulder width"); hips no more than 15% of leg length below standing ("Come up a little"); both wrists at chest height, from 10% of torso length above to 60% below the shoulders, and 0.5 to 2.4 shoulder widths apart ("Raise your arms to chest height, as if hugging a tree"); weight 40% to 60% ("Center your weight between your feet"); shoulders within 15% of torso length of the hips sideways ("Keep your back upright").
• Horse stance, front view: feet at least 1.8 shoulder widths apart ("Step your feet wider"); hips sunk at least 10% of leg length ("Sink a little lower") but no more than 45% ("Come up a little"); weight 40% to 60% ("Center your weight between your feet"); upright ("Keep your back upright").
• Bow stance, side view: feet at least 60% of leg length apart front to back ("Lengthen your stance"); weight at least 60% toward the front foot ("Shift your weight onto your front leg"); front knee 140 degrees or less ("Bend your front knee"); back knee 150 degrees or more ("Straighten your back leg"); front knee no more than 15% of leg length past the front ankle ("Keep your front knee over your ankle"); shoulders within 25% of torso length of the hips front to back ("Keep your back upright").
• Empty stance, side view: feet 20% to 80% of leg length apart ("Bring your front foot closer" or "Lengthen your stance"); at most 35% of your weight toward the front foot ("Sit back onto your back leg"); hips sunk at least 6% of leg length ("Sink a little lower"); upright.
• Slow movement, all movements: hand speed, measured over half a second, at most 1.5 torso lengths per second. Faster than that: "Slow down, let the movement flow".
• Commencement, front view: arms down, then both wrists up to shoulder height, then down again, the whole cycle taking at least 4 seconds. Arms that never reach shoulder height: "Raise your arms to shoulder height". Rushed: "Slow down, let the movement flow".
• Cloud hands, front view: feet at least 1.4 shoulder widths apart. One pass is your weight moving from one side (38% or less) across to the other (62% or more) in at least 1.5 seconds, with your hands following your waist (hands at least 0.3 shoulder widths toward the weight side). Hands left behind: "Let your hands follow your waist". Turning back halfway: "Shift your weight further across". Rushed: "Slow down, let the movement flow".
• Ward-off, rollback, press, side view: in order, each change taking at least 1 second. Ward-off: weight 60% or more forward with one arm rounded at chest height in front. Rollback: weight 40% or less, hands drawn back toward the waist. Press: weight forward again, both hands together at chest height. Pressing without the rollback: "Roll back: sit back onto your back leg before you press". Dropping the hands before the press: "Finish with the press". Rushed: "Slow down, let the movement flow".
• Not seen, not counted: if the app cannot see your hands, hips and feet clearly, it says so instead of guessing.

Forms, tests and points

• Stances: standing post, horse, bow and empty stance (open, 20 good-form seconds each), and a long horse stance (60 seconds, unlocks at 150 points).
• Slow movements: commencement, cloud hands, ward-off, rollback, press.
• Short forms: Stance circuit (each stance for 15 good-form seconds), Short form (commencement, 4 cloud hands passes, ward-off, rollback, press, closing standing post; unlocks at 50 points), Flowing practice (unlocks at 150 points).
• Tests: hold each stance to standard, unbroken: the clock restarts on any fault. Stance test (all four stances, 10 unbroken seconds each), Horse stance test (30 unbroken seconds), Slow movement test (3 cloud hands passes and 1 ward-off, rollback, press).
• Points: +1 per good-form second, +10 per clean slow movement, +15 for a finished form, +20 for a passed test. Levels: Rooted Seedling, Still Water (50), Flowing Cloud (150), Mountain Stance (300). Badges: First Root, First Flow, Steady Horse, Cloud Walker, Form Complete, Test Passed, 7-Day Streak. Gentle chimes and confetti celebrate wins; both can be turned off in Settings.

What it cannot see

• The app sees joint positions, not intention, breath, relaxation, the feeling of rootedness, or where your attention is. Those are the heart of tai chi and qigong and need a teacher.
• It cannot see foot angles, toe direction, or whether a knee is twisting. Keep your knees pointing the same way as your toes.
• Loose clothing, poor light, a cluttered background, or another person in frame can confuse the pose tracker. From the wrong camera view a stance cannot be judged.
• Pose tracking is approximate. A hold the app accepts may not be perfect, and one it rejects may have been fine. Styles differ too: your teacher's version of a stance is the one to follow.
• Instructor review sought: we are seeking review of these rules by qualified tai chi and qigong instructors, in parallel with release. Corrections will be folded in as they arrive.

Resources: find an instructor

For real instruction, learn from a qualified tai chi or qigong instructor: a community centre, a senior centre, a hospital wellness programme or a local school. This app is a practice aid, not a replacement.

These links open other websites in a new tab. Tai Chi Coach is not affiliated with any of them and sends them nothing.

Privacy

• Your video never leaves your device. It is analysed in your browser frame by frame and immediately discarded. Nothing is recorded, uploaded or shared.
• No accounts, ads, cookies, analytics or trackers. The app loads nothing from other websites, and a security policy blocks connections anywhere else.
• Stored on your device only: which items you have done, your points, badges, practice days and settings, your standing-position calibration, and whether you have read the safety check, in your browser's local storage. Clear it any time in Settings → Clear progress, with the Offline proof → Delete all my data button, or by clearing this site's data in your browser.
• Offline copy: after your first visit, your browser keeps a copy of the app so it works offline. Clearing site data removes it.
• Hosting: like any website, the server that delivers the app's files may keep standard technical logs (such as IP addresses) of those downloads. The app itself sends nothing.

Disclaimer

• This is a home practice tool, not a teacher, therapist or safety device. Everything runs on your device: no video, audio or images are sent anywhere. Feedback is automatic and can be wrong. For real instruction, learn from a qualified tai chi or qigong instructor, linked on the Resources page.
• Not medical advice and not a treatment. Check with a doctor before starting if you have joint, balance or heart problems, are pregnant, or are recovering from an injury. Stop if anything hurts or you feel dizzy.
• The app is provided "as is", without warranty of any kind.

Accessibility

• Everything works with a keyboard. Hints are announced to screen readers, and animations follow your device's "reduce motion" setting. Sound and confetti can be turned off in Settings.
• Seated practice is not checked by the rules yet; the descriptions and resources still work on their own.

Credits

• Pose tracking: MediaPipe Pose Landmarker (lite), Apache 2.0, bundled with the app. See THIRD_PARTY_NOTICES.md.
• The stance and movement rules are original to this app and documented above.
• Built with the on-device coach pattern from the PE Rep Counter and Little Hands apps.

Tai Chi Coach version 1.0.0