HQ BaselineBalance testing
Objective mBESS and tandem gait, scored by the phone.
The modified Balance Error Scoring System (mBESS) and tandem gait test are validated, widely-used sport concussion assessments. HQ scores both with the phone's built-in motion sensors — no human sway-counting, no harness.
mBESS asks athletes to hold three stances — double-leg, single-leg, and tandem — for twenty seconds each on a firm surface. Sway errors (hands leaving hips, eyes opening, stepping out of stance) have traditionally been counted by a proctor with a clipboard. HQ replaces that with motion sensing.
How the motion scoring works
The athlete places the phone against their sternum or holds it between their hands at chest height. The accelerometer samples torso acceleration at 50 Hz, and the gyroscope captures angular velocity. Our model detects sway amplitude, frequency content, and abrupt corrections — the biomechanical fingerprint of a BESS error.
Unlike visual scoring, it’s reproducible: two proctors will disagree about whether an error occurred on frame 14, but the motion trace is the motion trace. It’s also more sensitive to subtle sway changes that are easy to miss by eye.
Tandem gait
Tandem gait is a three-meter heel-to-toe walk. The athlete sets their phone against their sternum, walks the line, turns, and walks back. HQ detects motion onset, steady-state walking, the turn, and the return-to-origin — then reports the total time and variability across three trials.
What you see in the dashboard
- Per-stance sway amplitude and frequency profile
- Error counts using standard mBESS scoring conventions
- Three-trial tandem gait times with variability
- Side-by-side comparison to personal baseline after injury
Why it matters
Vestibular and balance dysfunction is one of the four concussion subtypes, and balance problems often persist longer than symptom reports. Objective balance data gives clinicians a defensible metric for clearance — and catches athletes who are rushing back.