3 sentences

1. 医生发现他的腰椎有轻微的错位。

   yī​shēng fā​xiàn tā de yāo​zhuī yǒu qīng​wēi de cuò​wèi.

   The doctor found a slight misalignment in his lumbar vertebrae.

   Source: Dong Chinese Dictionary

2. 长时间保持不正确的坐姿容易损伤腰椎。

   cháng​shí​jiān bǎo​chí bù zhèng​què de zuò​zī róng​yì sǔn​shāng yāo​zhuī.

   Maintaining an incorrect sitting posture for a long time can easily damage the lumbar spine.

   Source: Dong Chinese Dictionary

3. 医生建议他久坐后要起身直立行走几分钟，以缓解腰椎压力。

   yī​shēng jiàn​yì tā jiǔ zuò hòu yào qǐ​shēn zhí​lì xíng​zǒu jǐ fēn​zhōng, yǐ huǎn​jiě yāo​zhuī yā​lì.

   The doctor advised him to stand up and walk for a few minutes after sitting for long periods to relieve pressure on his lumbar spine.

   Source: Dong Chinese Dictionary