Dose-effect Relationship of Tai Chi on Health Promotion in Different Age Groups

Pittsburgh Sleep Quality Index

Time Frame: This study was a cross-sectional study. Each subject was measured only once from the day of randomization to the first assessment, assessed up to 3 months

With subscale scores ranging from 0 to 3, the PSQI assesses subjective sleep quality in the previous month and consists of seven items (sleep duration, sleep latency, sleeping medications, sleep disturbance, daytime dysfunction, sleep quality, and sleep efficiency). The total score of the PSQI, ranging from 0 to 21, is the sum of subscale scores, and the higher the scores, the lower the subjective quality of sleep.

Heart rate variability (HRV)

Time Frame: This study was a cross-sectional study. Each subject was measured only once from the day of randomization to the first assessment, assessed up to 3 months

HRV, a non-invasive method used to evaluate the autonomic nervous system modulation on the cardiac sinus node, describes the oscillations between consecutive electrocardiogram R-R intervals. High levels of HRV indices are generally signs of efficient autonomic mechanisms that characterise a healthy individual, while low or reduced HRV often show an autonomic nervous system malfunction and may imply health impairment.

Cardiac Output (CO)

Time Frame: This study was a cross-sectional study. Each subject was measured only once from the day of randomization to the first assessment, assessed up to 3 months

Cardiac Output (CO) is a key indicator in echocardiographic examinations, used to measure the total volume of blood pumped by the heart per minute. This parameter reflects the efficiency of the heart's pumping action and the status of systemic blood circulation. The measurement of Cardiac Output is based on the volume of blood ejected by the heart with each beat (stroke volume) and the number of heartbeats per minute. Cardiac Output is typically expressed in liters per minute (L/min).

The Berg Balance Scale（BBS）

Time Frame: This study was a cross-sectional study. Each subject was measured only once from the day of randomization to the first assessment, assessed up to 3 months

The BBS scale evaluates an individual's ability to maintain their balance while performing functional activities. It includes 14 items and each section is scored between 0 (worst) and 4 (best), and measures level of dependence/independence in positions such as standing from sitting, standing with feet together, standing in full balance position, balancing on one leg, as well as ability to change positions. High BBS score indicates good balance. Participants are classifed based on BBS score as high fall risk, balance disorder (0-20 points), moderate fall risk, acceptable balance (21-40 points), and low fall risk, good balance (41-56 points)

The 30-s Chair Stand Test

Time Frame: This study was a cross-sectional study. Each subject was measured only once from the day of randomization to the first assessment, assessed up to 3 months

In the 30-s CST, which assesses dynamic balance and physical ftness, the individual sits in the middle of a chair with seat height of 43 cm, with a straight back, feet fat on the foor, and arms crossed over the chest with hands at shoulder level. The test starts with the subject in this position at the "go" command. The number of times the patient rises to a full standing position without assistance in 30 s is recorded as the test score. A score of 5 indicates strength and 10 indicates both strength and endurance

Lower limb muscle strength test

Time Frame: This study was a cross-sectional study. Each subject was measured only once from the day of randomization to the first assessment, assessed up to 3 months

Using the micro FET3 (HOGGAN, USA) to test lower limb muscle strength. The main muscles tested include the tibialis anterior, triceps surae, quadriceps femoris, hamstrings, and iliopsoas. Each muscle is tested twice, and the maximum value is recorded

Flow-mediated dilation (FMD)

Time Frame: This study was a cross-sectional study. Each subject was measured only once from the day of randomization to the first assessment, assessed up to 3 months

Flow-mediated dilation (FMD) can assess endothelium-dependent vasodilation, evaluating vascular elasticity and dilation function. Its mechanism involves inducing reactive hyperemia, increasing arterial blood flow, leading to elevated shear stress on the vessel wall, prompting endothelial cells to release NO, resulting in vasodilation. A normal FMD value is ≥7%; values \<4% indicate endothelial dysfunction.

Intima-Media Thickness (IMT)

Time Frame: This study was a cross-sectional study. Each subject was measured only once from the day of randomization to the first assessment, assessed up to 3 months

Intima-Media Thickness (IMT) is a significant indicator measured through carotid ultrasound examination, used to assess the thickness of the carotid artery wall. The measurement of IMT focuses on the distance between the intima and media layers of the carotid artery, serving as a key indicator of early changes in atherosclerosis.