Employee had knelt down to check the temp on a bearing and felt a stabbing pain in EE's back. EE got self using guarding to climb onto a concrete curb. EE walked took about 3 steps, and when EE went to step off the curb, EE tripped and fell forward. EE latched onto the guarding to break EE's fall and when EE did, EE's back twisted, causing a tingling sensation in EE's buttocks.