The pain often feels worst when running downhill or walking down stairs, and the knee is often stiff and sore after sitting down for long periods.

在下山跑或下楼梯的时候疼痛加剧，长时间坐了之后膝盖会感到僵硬和疼痛。

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When walking downhill, the ants carried fragments at a significantly shallower angle.

BBC: Earth News - Ant's head balancing act revealed by video

Activities play off the environment: dune trekking--somewhere between hiking and barefoot beach walking, with a whiff of snowboarding as you slide downhill--camel rides, archery, and dune bashing in SUVs driven (by staff) at high speed over the hills.

FORBES: Magazine Article