The so called touch-down walking exercises is actually one form of
non-weight bearing exercises.

The patient is allowed to touch the ground with the tip of the foot
during walking. He drags the leg along the ground while walking in parallel bar, or in crutches. This kind of walking actually puts less
force across the hip joint than when a patient walks with the affected side off the ground. The reason is that with the leg off the ground, any muscle action across the hip will be multiplited by the leverarm of the whole leg resulting in a big force across the
fracture site. With the leg touching the ground, the leverage action is removed and it had been shown that much less force goes through the hip joint. (Ref. 4)

In practice, however, it is extremely difficult to teach aged patient this kind of exercises and he usually puts partial weight bearing on the affected leg.

http://72.14.253.104/search?q=cache:v1RTByvIA_4J:sunzi1.lib....

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Note added at 1 hr (2007-10-28 04:28:37 GMT)
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触地 may also mean footstrikes（腳接觸到地面）.
http://72.14.253.104/search?q=cache:DbCQ3thjg4AJ:www3.nccu.e...

Foot strike is a term that you may hear bantered about in a running shoe shop, as in, "Are you a heel striker or a forefoot striker?" Most runners tend to be heel strikers who land on the outside of the heel and then roll up to push off the ball of the foot and the toes. A few runners are forefoot strikers and land more on the ball of the foot.

Wear patterns on shoes can tell a lot about foot strike. A forefoot striker (the wear pattern typically results in a smooth area around the ball of the foot) may need a shoe with plenty of forefoot cushioning. An ultraheavy heel striker requires extra cushioning in the heel.
http://72.14.253.104/search?q=cache:vqgy6peR-ccJ:www.comfsm....

Another possibility for 触地练习 is just "footstrke exercise".

http://www.vanguard.edu/faculty/tzeigler/index.aspx?doc_id=3...