YOU SAID:

The best part of him ran down his mother's legs.

INTO JAPANESE

彼の一番上の部分は母親の足で駆け落ちした。

BACK INTO ENGLISH

The top part of him ran off with his mother's feet.

INTO JAPANESE

彼の上の部分は母親の足で逃げた。

BACK INTO ENGLISH

The upper part of him ran away with his mother's feet.

INTO JAPANESE

彼の上半身は母親の足で逃げた。

BACK INTO ENGLISH

His upper body ran away on his mother's feet.

INTO JAPANESE

彼の上半身は母親の足で逃げた。

BACK INTO ENGLISH

His upper body ran away on his mother's feet.