Adverbials of source and direction are normally used with verbs of motion and dynamic verbs that allow a direction meaning:
Cóng jiā zǒudào xuéxiào zhǐ xū shí fēnzhōng.
(It only takes ten minutes to walk to school from home.)
Qiánmian díshì bīng yóu chē shang tiàoxià，bǎ cìdāo ānshàng.
(The soldiers in front jumped down from the truck, and attached their bayonets to their guns.)
Yī duì duì de qiúfànyóu wàimian yáng sì de bèi gǎn jìnlai.
(File after file of prisoners were driven in like sheep from outside.)
Cháng Jiāng yóu xī wǎng dōng liú.
(The Yangtze River flows from the west to the east.)
The adverbials of source ‘cóng jiā’ (from home), ‘yóu chē shang’ (from the truck), ‘yóu wàimian’ (from the outside), etc., all express the origin or point of departure of an action. In the real world, an action and a motion start from the source or point of departure. Therefore, in accordance with the PTS, adverbials of origin and source precede the verb.
 Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.