inward curve

There should be a slight inward curve in your lower back, an outward curve in your upper back, and another inward curve at your neck.

这时你下背部应该是一条略微内凹的曲线，上背部是一条略微外凸的曲线，脖子则是另一条内凹的曲线。

The lateral inward tilting, as of a motor vehicle or an aircraft negotiating a curve.

飞机水平行飞了一会儿, 然后开始倾斜并转弯.

The legs curve inward until they unite in a single tapered tower.

四条腿内侧则呈弧线,逐渐交汇,形成锥形塔身.

This is an inward curve.

这是一条向里弯曲的曲线。

Allowing the thigh to point down at an angle may make it easier to maintain an inward curve in your lower back, which is suggested to reduce low back stress.

让大腿以某个角度向下倾，可以更容易地让下背保持向内弯曲的姿态，据说这样能缓解下背部压力。