In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: OBJECTIVE : Conventional treatment methods of lumbusacral radiculopathy are physical therapy , epidural steroid injections , oral medications , and spinal manipulative therapy .
### Output Text:
OBJECTIVE : Conventional treatment methods of lumbusacral radiculopathy are physical therapy , epidural <span class="chemical">steroid</span> injections , oral medications , and spinal manipulative therapy . 