Cardiovascular response to postural perturbations of different intensities in healthy young adults.
Level 2 - randomized trial
Randomized crossover physiological experiment in humans
PubMed 35531916 · doi:10.14814/phy2.15299
What was done
Twenty healthy young adults completed a randomized crossover protocol testing cardiovascular responses to three intensities (low, medium, high) of balance perturbations. Each condition included 25 brief posteriorly-directed perturbations delivered 8–10 s apart in random order. Beat-to-beat heart rate (HR), systolic blood pressure (SBP), and cardiac baroreflex sensitivity (cBRS) were measured during perturbations and across 5-min quiet stance baseline and recovery periods.
What was found
Post-perturbation analysis showed immediate HR acceleration for 1–2 s, followed by elevated SBP 4–5 s post-perturbation. HR increases were significantly greater in medium (p = 0.035) and high (p = 0.012) intensity conditions compared with low intensity. SBP changes were not intensity-dependent. cBRS was not intensity-dependent (p = 0.402), but when all perturbation conditions were combined, cBRS was significantly elevated compared to Baseline (p = 0.046). Baseline cBRS stability across quiet standing conditions was high (ICC = 0.896).
Why it matters
This study shows that acute balance disruptions engage rapid autonomic cardiovascular adjustments, with heart rate acceleration scaling directly to disturbance intensity. Understanding these dynamics provides a baseline for evaluating how autonomic dysfunction may impair fall recovery in clinical or older populations.
Limits
The study had a small sample size (n = 20) limited entirely to healthy young adults. Perturbations were exclusively brief, posteriorly directed, and laboratory-induced, which may not capture multidirectional real-world balance loss. Absolute cardiovascular metrics (e.g., baseline HR, baseline SBP) were omitted from the abstract.
Cited by
- partial Adding manual perturbation feedback, such as having a partner tap you during a balance exercise, instantly raises heart rate by 20%.