Impact of Combined Core Stability Training, Blood Flow Restriction, and Tai Chi on Muscle Physiology and Functional Characteristics Among Adults With Low Back Pain

Core muscle activation by root mean square(RMS)

时间窗: Baseline (1st week), 6th week, and 12th week

Root Mean Square (RMS) is a vector used to analyze the properties of electrical signal fluctuations, and the size of the RMS value represents the level of activity of a certain muscle(Abdelouahad et al., 2018). Absolute RMS demonstrated the highest overall dependability (ICC: 0.66-0.98) across activities (ICC: 0.66-0.98)(Van Helden et al., 2022).

Core muscle fatigue by mean frequency (MF)

时间窗: Baseline (1st week), 6th week, and 12th week

Mean Frequency (MF) is a frequency-domain index that represents the midpoint of muscle fiber discharge frequency during skeletal muscle contraction. It is widely assumed that it is connected to the proportion of fast and slow fibers in muscle tissue. The multifidus muscle demonstrated good to outstanding reproducibility of initial MF and MF fatigue changes during Trunk Holding Tests (ICCwithindays =82%; ICCbetweendays =78%) (Ng \& Richardson, 1996).

Abdominal drawing-in maneuver by the pressure biofeedback unit (PBU)

时间窗: Baseline (1st week), 6th week, and 12th week

The Pressure Biofeedback Unit (PBU) device consists of a pressure transducer with three airbags, a catheter, and a sphygmomanometer (with a range of 0 to 200 mmHg). It will be applied to evaluate abdominal drawing-in movements objectively (Grooms et al., 2013b). It is a trustworthy clinical instrument for assessing deep abdominal muscle function, with moderate to good (ICC = 0.47-0.82) and acceptable construct validity (ICC = 0.48-0.90) (P. O. D. P. Lima et al., 2011).

Back Extensor Strength by a push-pull dynamometer

时间窗: Baseline (1st week), 6th week, and 12th week

A push-pull dynamometer will be applied to assess back extensor strength in the prone position. Because of its acceptable reliability (ICC=0.93), validity (r=0.54), and measurement errors, maximal isometric back extensor strength assessment in a prone posture can be applied to individuals with varying levels of back strength and may be the most useful for ranking back extensor strength in clinical and epidemiological studies (Yang et al., 2020).

Postural sway by the mobile app APECS

时间窗: Baseline (1st week), 6th week, and 12th week

The application of a mobile app could represent a quick, safe, and accurate method for researchers and clinicians to evaluate general posture quantitatively. Adopting a movable and affordable tool for postural assessment could benefit the primary prevention of musculoskeletal disorders of the spine. The mobile app APECS-AI Posture Evaluation and Correction System® (New Body Technologies SAS, Grenoble, France) (APECS app) will be applied to evaluate the subject's postural sway in this study. The evaluation index is the maximum angle of the torso wobbles. According to a recommendation from a study, clinicians should consider APECS's worth as an auxiliary posture evaluation tool with (ICC \> 0.60) (Trovato et al., 2022).

Balance by Y-Balance Test

时间窗: Baseline (1st week), 6th week, and 12th week

The Y-Balance Test Kit will be applied to measure balance in this study. The device includes a single central plastic plate and three attached tubes positioned anteriorly, posteromedially, and posterolaterally. A measurement with a 0.5 cm spacing is placed on each of the tubes. A study found that the Y-Balance Test has high inter-rater reliability and validity for assessing dynamic balance in the CLBP group (Alshehre et al., 2021).

Lumbar proprioception by joint repositioning error(JRE)

时间窗: Baseline (1st week), 6th week, and 12th week

The primary result of proprioception was a joint repositioning error(JRE). The absolute error, constant error, and variable error can all be used to describe repositioning errors. We picked absolute error since it affects accuracy(Strimpakos et al., 2006), reflects the magnitude of the inaccuracy (Sheeran et al., 2012), and is the most widely used measurement (Tong et al., 2017). The proprioception test had great inter-rater reliability(ICC=0.61-0.76)(Petersen \& Rundquist, 2009).

Gait speed by the 10-meter walk test.

时间窗: Baseline (1st week), 6th week, and 12th week

The gait speed is measured using the 10-Meter Walk Test. The gait speed test is the most commonly used outcome measure to assess functional limitations of the lower limbs (Muñoz-Mendoza et al., n.d.). With ICC values ranging from 0.96 to 0.98, 10m gait speed measurement shows outstanding test-retest reliability(Peters et al., 2013).

Fear avoidance belief by the Chinese version of the Fear-avoidance Beliefs. Questionnaire (FABQ-CHI)

时间窗: Baseline (1st week), 6th week, and 12th week

The Chinese version of the Fear-avoidance Beliefs Questionnaire (FABQ-CHI) is a relatively basic, easy-to-understand, easy-to-use, low-cost, and comprehensive LBP evaluation tool. The FABQ-CHI was shown to have adequate factor structure, internal consistency, test-retest reliability, and construct validity. (Pei et al., 2010). The maximum possible score for each question is 6, the lowest possible score is 0, and the total score is 96. The higher the score, the greater the severity of the perceived fear-avoidance belief.

Pain by visual analogue scale (VAS)

时间窗: Baseline (1st week), 6th week, and 12th week

Visual Analogue Scale (VAS) is a 10 cm horizontal strip with numbers ranging from 0 to 10 (the most severe pain possible). This is one of the most dependable quantitative scales that is commonly utilized in research (Scrimshaw \& Maher, 2001). VAS has proven to be trustworthy and valid (ICC=0.49-0.83) (Crossley et al., 2004).