柔韧性评分计算器 — 公式

## How the Sit-and-Reach Test Works

### Procedure

1. Sit on the floor with legs straight and feet flat against a sit-and-reach box.
2. Reach forward as far as possible, keeping knees straight.
3. The box is set so that the feet are at the 26 cm mark. Reaching the toes = 26 cm.

### Benchmarks (Male 18-30)

| Rating | Distance |
|--------|----------|
| Excellent | >34 cm |
| Good | 28-34 cm |
| Average | 20-27 cm |
| Below avg | 15-19 cm |
| Poor | <15 cm |

### Why Flexibility Matters

Good hamstring and lower-back flexibility reduces injury risk, improves posture, and enhances athletic performance. It tends to decrease with age without regular stretching.