Truestride: Knee Recovery

After a knee replacement, the hardest question isn't the pain. It's "am I doing okay?" Your surgeon is finished with you. Your physiotherapist sees you once a fortnight. In between you're on your own, wondering whether what you're feeling is normal. Your iPhone has been measuring how you walk this whole time. Truestride shows you what it recorded, and what those numbers usually look like at your point in recovery. WHAT IT SHOWS YOU • Walking asymmetry — how evenly you're using each leg. This is the number that moves most after surgery. • Walking speed — the most reliably measured of the four, and the clearest signal of overall progress. • Step length — how far each step takes you, which lengthens as you stop guarding the operated side. • Double support — how long both feet are down at once. All four come straight from Apple Health. Your iPhone has been recording them since before your operation, so your history is already there on your first day. Nothing to catch up on, nothing to log. YOUR RECOVERY SO FAR One screen, from your first week to now: pain, daily steps, all four walking measurements and your knee movement — measured from your operation, not from the day you installed the app. MEASURE YOUR KNEE BEND Rest your phone along your thigh, then along your shin. Truestride reads the angle between them — the same thing a physiotherapist measures with a goniometer. Each reading is averaged over three seconds and discarded if the phone moves, so the number is one you can repeat. THE ONE THING YOUR PHONE CAN'T MEASURE Pain takes one tap. Add where it's happening — resting, walking, stairs, at night — and a pattern appears that "pain: 5" never shows. It is compared only with your own earlier readings, never anyone else's. TAKE IT TO YOUR PHYSIOTHERAPIST One page you can email before your next appointment: how you've been walking week by week, your knee measurements, your pain, and a plain explanation of where every number came from. Free, whether or not you buy anything, and made on your iPhone — nothing is sent anywhere until you send it. COMPARED WITH REAL RECOVERIES Truestride compares three of your measurements with published averages from a peer-reviewed study of 686 total knee replacement patients, measured with the same Apple Health metrics your iPhone records. Where a figure is an estimate between published weeks, the app says so. Double support is measured and charted but never ranked: Apple's stated accuracy for it is wider than the whole range of change after a knee replacement, so any comparison would be noise. NO ACCOUNT. NO SERVER. GENUINELY. There is no sign-up and no login, because there is nowhere for your information to go. Truestride has no backend, no analytics, and no tracking of any kind. Your health data is read on your iPhone, used to draw what you see, and never copied, uploaded or sold. Every screen scales with your text size. Nothing flashes red. No streaks to break, no scores to fail, no exercises to fall behind on. You don't need your surgeon's permission, or any particular brand of implant. ONE PAYMENT Your walking numbers are free, always. So is the page you take to your physiotherapist. A single purchase — not a subscription — adds the comparison with published data and your full history since surgery. Nothing renews, and there is nothing to cancel. REQUIREMENTS iPhone 8 or later running iOS 17 or later. Apple's walking measurements need the iPhone carried in a pocket or at the waist, take about a week of walking to appear, and need your height in the Health app. The knee measurement and pain logging work immediately. Truestride is not a medical device and does not provide medical advice. It describes measurements your iPhone already records and compares them with published averages. Talk to your surgeon or physiotherapist about your recovery. Recovery data source: "Stepping beyond Counts in Recovery of Total Knee Arthroplasty", Sensors 2023, 23(12), 5588.