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Lydia Knutson
Stephanie Sullivan
Fred Langeneggar
Jennifer Massa
Emily Drake
Kate Hayes
Martha Herbert


Long-COVID, Post-Viral Syndrome, Post-Acute Covid-19 Syndrome


Purpose: To prototype the procedural steps, assessment methodologies, and participant response to care in a long-COVID research study conducted within a chiropractic practice.

Methods: Following a single-arm trial design, participants experiencing protracted COVID-19 symptoms for greater than 90 days were recruited through healthcare referrals, social media, and emails to existing patients of the participating chiropractor. Participants received 8 to12 weeks of Axial Stability Method (ASM) chiropractic care and participated in 4 assessment time points. Participant response to care and baseline assessments included participant self-reports, CareTaker Medical physiologic responses, spirometry, and balance.

Results: Recruitment resulted in 30 individuals indicating interest in the study; most individuals responded to recruitment efforts following implementation of Facebook advertisements (n=21). Seven participants were enrolled in the study. Five of the 7 participants were female and the average age was 46. Study procedures were tolerated well within the clinic, excepting spirometry. All participants either agreed or strongly agreed that the study organization, processes, staff, knowledge, and overall experience were appropriate. Overwhelmingly, participants experienced improvement in fatigue, long-Covid symptoms, and quality of life. For example, participant T-scores for the Functional Assessment of Chronic Illness Therapy – Fatigue Scale (FACIT-Fatigue) initially demonstrated that study participants were on average more fatigued than 76% (76th percentile) of the United States population, while at the end of the study participants were scoring in the 25th percentile. CareTaker Medical physiologic responses were consistent with previous chiropractic research. Unique physiologic response patterns based on initial presentation were observed for systolic blood pressure and heart rate variability (HRV) analysis using distribution entropy. Time domain analysis of HRV (root mean square of successive differences) demonstrated increased HRV response baseline to immediate post with a decrease in HRV over the course of care for most participants. Balance results were mixed.

Conclusion: Implementation of the study protocol was successful. Investigators accounted for challenges with recruitment, staffing, and scheduling. Participants reported improvement and often resolution of long-COVID symptoms, and physiologic marker responses to care were consistent with previous chiropractic research. Study design and small sample size limit response to care generalizability; findings need to be confirmed with properly powered clinical trial design.


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