Extensor pollicis brevis tendon can hyperextend thumb interphalangeal joint in absence of extensor pollicis longus: Case report and review of the literature

Figure 1 Patient demonstrating full thumb MP and IP extension using only extensor pollicis brevis tendon.

Figure 2 Examiner’s finger pointing to extensor pollicis brevis tendon which is extending thumb at MP and IP joints.

Figure 3 Patient demonstrating thumb MP and IP flexion.

Figure 4 Extensor pollicis brevis tendon extending thumb (Video core tip 1).