The Effects of the Yi Jin Jing on the Muscles and Bones of Adults

Appendicular Skeletal Muscle Index (ASMI) = appendicular lean mass (kg) / height² (m²). It reflects muscle mass, used for sarcopenia diagnosis. Lower values indicate muscle loss, linked to aging, malnutrition, or disease.

Handgrip strength (HGS) = maximum force (kg) measured by a dynamometer. It reflects overall muscle function, predicts disability, morbidity, and mortality. Low HGS indicates sarcopenia, frailty, or poor nutritional status.

Mini Nutritional Assessment - Short Form (MNA-SF) consists of 6 items:

• Appetite and food intake - assesses whether food intake has decreased over the past 3 months.
• Weight loss - records recent unintentional weight loss.
• Mobility - determines whether the person can walk independently or is bedridden.
• Acute disease or psychological stress - checks for stressful events in the past 3 months.
• Neuropsychological problems - identifies dementia, depression, or other mental disorders that affect eating.
• Body mass index (BMI) or calf circumference - reflects body fat reserves and muscle mass.

Each item scores 0-3 points. A total score ≤11 indicates a risk of malnutrition. It is commonly used for nutritional screening in elderly populations.

Fried Frailty Phenotype = a 5-item scale assessing unintentional weight loss, exhaustion, low grip strength, slow walking speed, and low physical activity. item ≥3 = frail; 1-2 = prefrail; 0 = robust. Predicts falls, disability, and mortality.

FRAIL Scale = a 5-item questionnaire: Fatigue, Resistance (climb stairs), Ambulation (walk), Illness (≥5 chronic conditions), and Loss of weight (≥5%). Score 0 = robust, 1-2 = prefrail, 3-5 = frail. Quick screening for frailty in community settings.

Short Physical Performance Battery (SPPB) = a 3-component test: standing balance (0-4), 4-meter gait speed (0-4), and 5-repetition chair stand (0-4). Total score 0-12; ≤8 indicates poor physical function, predicts disability, falls, and mortality in older adults.

Ultrasound-based measurements of peripheral skeletal muscles offer a practical, non-invasive, and radiation-free approach for assessing muscle mass in clinical and research settings. In accordance with previously established cut-off values, the following parameters are employed to identify a tendency toward reduced muscle mass:

• Biceps brachii cross-sectional area (CSA) - a male-specific indicator, with a value < 7.1 cm² suggesting reduced muscle mass;
• Tibialis anterior muscle thickness (MT) - a female-specific indicator, with a value < 2.3 cm suggesting reduced muscle mass;
• Rectus femoris muscle thickness (MT) - a gender-neutral rapid screening index, with a value < 1.3 cm serving as a universal cut-off for both men and women, indicating a tendency toward low muscle mass.

These ultrasonographic parameters are intended for initial screening and may assist in the early identification of individuals at risk for sarcopenia, particularly when access to dual-energy X-ray abs