Use your stomach muscles, not your shoulders or your head, to lift yourself off the floor. Remember to breathe out on the way up and in on the way down.

你的腹部肌肉使劲，不要用你的肩膀或者头部。

youdao

You can sense temperature variations, proprioception (position of your muscles), and the force of gravity (you do this by knowing at what Angle your head is in while your eyes are shut).

你可以体会到温度变化，本体感受(体会到你每块肌肉的方位)和重力感(通过闭上眼睛时头部的角度来感知)。

youdao

However, it is important to ensure that your pillow is not too high or too low, as this can strain the muscles and nerves in the neck, leading to head and neck pain in the morning.

不过，确保你的枕头高度恰当十分重要，因为过高或过低都会使背部肌肉和神经紧张，导致早上起床后头部和背部疼痛。

youdao

They also can become weak, expel material from the stomach, and suffer pain in the head or muscles.

VOA: special.2010.04.20

They also can interfere with mental ability,make muscles weak and cause pain in the head.

VOA: special.2010.07.27

And the muscles in their neck, that on Earth work all day to support the head, are weak, so they can easily sprain their neck by looking to the side, too quickly.

FORBES: What's It Like Experiencing Gravity After Being In Space For 6 Months?

The small dog came bounding through the grass, all tight muscles and yap, went for the shed, braked, stuck its head in the door and snarled, small body rigid with excitement.

NPR: Excerpt: 'The Broken Shore'