Understanding Gait Analysis & RTM Billing
Clinical evidence, billing guidance, and practical implementation for clinicians and health systems.
Walking Speed as the Sixth Vital Sign
A landmark 2011 JAMA study of 34,485 community-dwelling adults (Studenski et al.) found that walking speed was as predictive of survival as age, chronic conditions, smoking history, blood pressure, body mass index, and hospitalization history. Individuals walking faster than 1.0 m/s had survival rates exceeding age-matched norms; those below 0.6 m/s had markedly reduced 10-year survival.
Walking speed integrates the functional state of the neurological, cardiovascular, musculoskeletal, and pulmonary systems into a single measurable number — making it uniquely valuable as a longitudinal health indicator. The NIH Toolbox includes 4-Meter Walk Speed as a standard assessment for this reason. Apple Watch Series 6 and later measures walking speed passively and continuously, generating a clinically meaningful data stream at zero patient burden.
RTM Billing: Codes, Requirements, and Revenue
CMS finalized Remote Therapeutic Monitoring (RTM) codes in the 2022 Physician Fee Schedule. Unlike Remote Patient Monitoring (RPM), RTM covers non-physiologic data including musculoskeletal function, respiratory function, and therapy adherence — making it directly applicable to gait monitoring. The five core codes are 98975 (setup, once per episode), 98976 (device supply, 30-day), 98977 (respiratory device), 98980 (first 20 min clinical time), and 98981 (additional 20 min).
A patient generating 16+ days of gait data in a calendar month qualifies for the device supply codes. Combined with 20 minutes of physician review and patient communication, the monthly reimbursement per patient ranges from $94 to $170 depending on the payer. At 50 active RTM patients, this represents $4,700–$8,500 in monthly recurring revenue from data that your patients are already generating passively. SurgeonValue's RTM billing agent automates the documentation and billing workflow.
Gait Changes as Early Disease Markers
Multiple studies have identified gait changes as early markers for conditions that appear clinically years later. A 2012 Neurology study found that slower walking speed and shorter stride length precede clinical Alzheimer's disease diagnosis by 5–7 years. Gait variability (inconsistency in step timing) is a sensitive marker for Parkinson's disease progression that outperforms clinical motor scoring on some measures.
For post-surgical patients, gait speed recovery curves are the strongest predictor of 90-day readmission risk in total joint replacement — directly relevant to CJR-X bundled payment program performance. A patient whose walking speed at 14 days post-discharge has not returned to 50% of baseline is at significantly elevated readmission risk. FallRisks home assessment pairs with HealthGait to complete the fall-risk picture.
Apple HealthKit: The Passive Gait Data Stream
Apple Watch Series 4 and later measures six validated gait metrics using the device's accelerometer and gyroscope: walking speed, step length, step cadence, walking asymmetry, double support time, and stair ascent/descent speed. Apple's validation studies compare these measurements against research-grade motion capture systems with high agreement (ICC > 0.90 for walking speed).
These metrics are stored in Apple Health as HKQuantityType samples and are accessible via the HealthKit API with user consent. HealthGait pulls this data through the SolvingHealth MCP connector, analyzes 30-day trends, flags clinically significant changes, and generates a physician-ready RTM report. The physician attests via ClinicalSwipe in under 3 minutes.
Integrating Gait Monitoring with Home Care
Gait monitoring is most impactful when embedded in a care coordination framework. A clinician who identifies gait deterioration in isolation has limited ability to act; a care team that includes a home caregiver, physician, and family coordinator can respond to early warning signals with concrete interventions — medication review, physical therapy referral, or home environment assessment.
co-op.care companion caregivers perform structured gait observations during home visits using the same metrics HealthGait tracks remotely, providing a ground-truth check on passive sensor data. CaresCircle family coordination ensures that gait trend alerts reach the right family member immediately, not at the next scheduled call.
Gait data: Apple HealthKit. RTM billing: CMS Physician Fee Schedule 2022. Clinical evidence: JAMA 2011 (Studenski et al.), Neurology 2012. Not a substitute for medical advice. Content reviewed by Josh Emdur, DO, April 2026.
