iPad gait analysis debuts at AAHKS with dynamic-static alignment divergence

At the AAHKS meeting, Dr. Jeffrey Geller of Columbia Orthopedics presented an iPad-based gait analysis study to a packed room: 55 patients with primary knee disease, 110 knees total, comparing standing X-rays (static HKAA) against dynamic measurement during walking (D-HKAA).

Confirmed

Data was labeled from real clinical visits: every knee was measured on a surgeon's order during actual care with documented clinical reasons, with paired follow-up from pre-op to 3 months post-op
Quantified results: walking measurements were more neutral than standing X-rays; D-HKAA averaged 2.5° lower than S-HKAA in varus knees
Correlation: static and dynamic HKAA were only moderately correlated; 28% of knees showed inconsistent alignment between standing and walking, with valgus knees at 5.4 times the risk of inconsistency versus varus knees
Conclusion: dynamic coronal alignment is an independent biomechanical measure that may be useful for TKA preoperative planning

Why it matters

Author @zawthet noted the data strategy differentiates itself from public movement datasets: public data mostly consists of single studio recordings of healthy volunteers, whereas this study's data comes from paired pre-/post-op measurements during real clinical visits across multiple departments—better suited for training medical AI models
If dynamic alignment is widely adopted, traditional preoperative planning that relies solely on standing X-rays may need re-evaluation, especially for valgus knee patients

2026-11-12 ~ 2026-11-12 · 6 related posts

Primary sources

iPad-based gait analysis presented at AAHKS: 110 knees, standing X-ray vs walking alignment — zawthet · 2026-11-12 01:31 (UTC+08:00)
Walking alignment measured 2.5-3.1° more neutral than X-ray, iPad gait study finds — zawthet · 2026-11-12 01:31 (UTC+08:00)
28% of knees discordant between static and dynamic HKAA, valgus knees at 5.4x odds — zawthet · 2026-11-12 01:31 (UTC+08:00)

[source] iPad-based gait analysis presented at AAHKS: 110 knees, standing X-ray vs walking alignment — zawthet · 2026-11-12
[source] 28% of knees discordant between static and dynamic HKAA, valgus knees at 5.4x odds — zawthet · 2026-11-12
[source] Walking alignment measured 2.5-3.1° more neutral than X-ray, iPad gait study finds — zawthet · 2026-11-12
Dynamic coronal alignment is a biomechanically distinct measure, may aid TKA planning — zawthet · 2026-11-12
Gait dataset labeled by encounter, spanning pre-op to 3 months post-TKA — zawthet · 2026-11-12
Clinical pre/post-surgery video motion data trains one model across neurology, spine, senior care — zawthet · 2026-11-12