why does this intransitive verb use が?

Question

For full context: http://www3.nhk.or.jp/news/easy/k10011229751000/k10011229751000.html

The sentence in question: この中には、人と同じように手が動いて、物を持つことができるロボットがあります。

My attempt at translation: "Out of these, there are roboters which can hold things and

Variant A: ...there are hands which can move like human (hands)." Variant B: ...move their hands the same like humans."

I think that Variant B is more likely to be correct than variant A. Variant A makes 人と同じように like a simple attribute to て, which is too far off from the adverbial character this 人と同じように has judging by it's grammatical elements.

However, the problem with Variant B is that I translate "動いて" in a transitive fashion, while 動く is clearly listed as intransitive on jisho http://jisho.org/search/%E3%81%86%E3%81%94%E3%81%8F also, が instead of を suggests an intransitive meaning. If it was a potential verb then I wouldn't mind implying a "transitive" meaning combined with "can (do)", but 動く doesn't have any potential properties by default, does it? I also tried to search for an answer here http://www.guidetojapanese.org/learn/grammar/in-transitive but it wasn't really helpful for this particular case.

EDIT: I think I got a bit closer to resolving the question on my own. I completely overlooked that 動いて is of course also directly connected to ことができる. In this case, 手が動く would fit perfectly well. The only thing which still makes me a bit skeptical is that 動く is intransitive by default. It probably perfectly normal for japanese, but since I usually only encountered transitive verbs being transformed into potential forms, it feels a bit estranging to see an intransitive verb take a pseudo-transitive meaning in a potential construction...^^

Answer 1

Perhaps you're confused by the comma. 「人と同じように手が動いて、物を持つことができる」 as a whole forms a big relative clause and modifies the following noun, ロボット. Remember the usage rule of commas is fairly loose in Japanese.

The main structure of the sentence is:

この中には、ロボットがあります。
Among these, there are robots.

After partially restoring the relative clause:

この中には、人と同じように手が動くロボットがあります。
Among these, there are robots whose arms can move like humans.
Among these, there are robots that can move their arms like humans.

If you're not sure why this relative clause is possible, remember that you can always say 「このロボットは手が動く」 in Japanese, using both は and が. (literally "as for this robot, arms can move" → "this robot can move its arms") Maybe this question will help, too.

この中には、人と同じように手が動いて、物を持つことができるロボットがあります。
Among these, there are robots that can move their arms like humans and hold things.

Finally, as you expect, this sentence can be safely rephrased using 動かす, the transitive version of 動く:

この中には、人と同じように手を動かして物を持つことができるロボットがあります。

Answer 2

人と同じように手が動いて、物を持つことができるロボットがあります。

日本語として説明するべきことが２点あります。

1. 「手」は、「腕 arm」と「手首から先 hand」のいずれの意味でも使います。 質問者が挙げた文では、「手を動かして物を持つ」というときは、「手首から先 hand」を意味していると思います。更に詳細には、操作者が自分の「指を動かす」ことでロボットの指が「物を持つ」のだと思います。

2. 「動いて」と自動詞を使っている理由は、操作者の操作に基づく「ロボットの手（＝指）」の動きを客観的に記述しているからです。
   操作者がロボットの手を操作することで、「ロボットの手（＝指）が動く」、そして「その手（＝指）が物を持つ（＝握る grip）」という一連の事象を記述していますので、自動詞で問題ありません。