Here the body becomes a workforce that has had enough. The speaker lists what is failing: a left eye "as poor as a cog," a heart made to "sing an impossible part," an ear that takes in the voices of the mad, and "no-good hips." Each organ is treated like a worker pushed past its limits, and the strike is a collective refusal to keep performing.
The tone is wry but tired. Calling the eye a cog suggests something worn and mechanical, while the heart's "impossible part" sounds like a singer handed music beyond their range. The "we" is interesting, since it can mean the parts of the body together, or the speaker and the body as a group.
The final line shifts everything. "What faction lit up the mind" imagines the mind as the thing set ablaze by some rival group, as if the trouble began with an uprising there. It leaves the poem on an open, uneasy question. The mood is a mix of aching humor, exhaustion, and a slight sense of unrest that no one has settled.