Balance declines silently for decades before a fall happens. Stela uses your phone's motion sensors to measure postural stability in 5 minutes — and gives you a single number that actually means something.
Like VO₂ max or bone density age, BalanceAge™ translates your raw performance into years — the age at which a typical person balances exactly the way you do.
BalanceAge™ compares your measured sway velocity across all 8 tests against population normative curves stratified by age and sex. The result is a composite biological age for your postural system.
It stabilizes after 3 sessions and updates with each new assessment — so you can track whether your training, your habits, or the passage of time is moving the number in the right direction.
Your phone has the resolution to detect postural sway at clinically meaningful precision. No wearables. No force plates. No appointment.
Hold your phone flat with one or both hands, arms comfortably against body. Screen faces up. No calibration required.
Eight stances, 20–30 seconds each. Each isolates a different subsystem: vestibular, proprioceptive, visual, reactive, and cognitive-motor. The app guides you through every position.
Scores compute immediately after each session. After 3 sessions, a rolling median gives you a stable baseline to track as you train and improve.
The composite BalanceAge™ gives you the headline. Each of the 8 tests tells you exactly where your balance system is strong — and where it needs work.
Your baseline. Feet shoulder-width apart, eyes open. Establishes visual contribution to postural control.
Visual systemSame stance, eyes removed. Romberg ratio isolates vestibular and proprioceptive function independent of vision.
Vestibular · ProprioceptiveReduced base of support, eyes closed. Maximizes proprioceptive challenge without equipment.
ProprioceptiveRhythmic head rotation on cue. Measures vestibulo-ocular reflex and reactive postural adjustment.
Reactive · VestibularBipedal stance, eyes open. At an unexpected moment an audio will cue to close eyes. Measures reactive postural control.
Reactive balanceHead pitched 30° forward. Measures cervical proprioception impact on postural stability.
Proprioceptive · DynamicSerial subtraction while standing. Measures prefrontal cognitive load on postural control.
Dual-task · CognitiveCategory word naming while standing. Cross-validates cognitive-motor interference with a second modality.
Dual-task · CognitiveResearch identifies three inflection points where the rate of balance decline sharply increases. Most people are completely unaware any of this is happening — until a fall makes it impossible to ignore.
Muscle mass and proprioceptive sensitivity begin declining. Gradual, easy to miss — and the highest-leverage window for prevention.
Vestibular hair cell loss and reduced CNS processing speed compound the proprioceptive deficit. Fall risk begins rising steeply.
Steep decline. Falls become the leading cause of injury-related mortality. Intervention shifts from performance to fall prevention.
Stela is a measurement tool. The architecture reflects that from the ground up.
Assessment data lives in a local database on your phone. Name, sex, and date of birth are never transmitted or stored off device.
We do not sell, license, or share your balance data with advertisers or data brokers.
Contribute to the population dataset. Only anonymized data. Your name, sex, and DOB is never included.
No account required for the core assessment features.
The full 8-test battery and BalanceAge™ trend tracking are free. Clinical features for coordinators and research organizations are available via provisioning.
Everything you need to measure and track your balance health.
For physical therapists, coordinators, and research teams.
Five minutes. Your phone. No equipment. Free.