| Namespace | MPheno.ontology | Obsolete | false |
| description | any structural anomaly of the T-shaped protein complex that links an outer microtubule doublet of the sperm flagellum axoneme with the sheath that surrounds the central pair of microtubules; it is composed of a stalk that attaches to each doublet microtubule and a globular structure (spoke head) that projects toward the central pair of microtubules |