Flexor Pollicis Brevis

The flexor pollicis brevis is a thenar muscle located within the hand. It forms the medial aspect of the thenar eminence and is described as having a superficial and deep part (although the deep component is variable in size).

• Attachments: Originates from the tubercle of the trapezium and from the associated flexor retinaculum. Attaches to the base of the proximal phalanx of the thumb.
• Actions: Flexes the metacarpophalangeal joint of the thumb.
• Innervation: Median nerve (recurrent branch). The deep head is innervated by the deep branch of the ulnar nerve.
• Blood supply: Superficial palmar arch

By TeachMeSeries Ltd (2025)

Figure 1
Palmar view of the thenar muscles.