Last week, I went to the gym with a friend. After the fitness test, the coach called him into a small room alone. He flipped through the fitness test sheet, frowned: "Your posture issues are too serious. Rounded shoulders, anterior pelvic tilt, leg length discrepancy."

The friend was stunned: "Leg length discrepancy? I don't feel it myself."
The coach said: "Of course you can't feel it. When you walk, does the sole of your left shoe wear out faster than the right?"
The friend looked down at his shoes. The left sole was indeed worn down faster.
The coach continued: "Leg length discrepancy can lead to scoliosis, then high and low shoulders, and eventually your face will tilt."
The friend's face turned pale. He immediately paid 8,000 yuan and bought forty correction classes.
He came back and told me, "I feel something's off, but I can't quite put my finger on what."
I told him to go see a rehabilitation specialist.
He went. The doctor asked him to take off his shoes, stand, squat, stand up, and walk a few steps. Then he had him lie on the bed, pinch his ankles.
Afterward, he took off his reading glasses and said, "You don't have leg length discrepancy. Your two feet are the same length."
He was anxious: "Then why is one side of my shoe's sole higher than the other?"
The doctor said: "Drive a car, an automatic. Your right foot controls the accelerator and brake, and your left foot stays still. The right foot wears out more, so the soles are different. It has nothing to do with your legs."
The friend stood in the consultation room for a long time. Then he asked, "So, does my posture have any problems?"
The doctor didn't even lift his head: "Your biggest posture problem is sitting too long. Just stand up and walk a few steps."
He walked out, clutching that fitness test sheet. In the corridor, he ran into a girl who had just come out of the coach's room, her eyes red, clutching a contract.
He told her, "Go get a registration."
She was stunned for a moment. He left.
And you? Have you ever paid for those explanations that sound very reasonable but you never thought about who invented them?
Did you figure it out later?