abductor pollicis longus,the extensor pollicis longus,and the extensor pollicis brevis

Opponens Pollicis

Peter lowered his eyes and put his thumb in a downward postion.

It is making the "okay" sign.

Abductor Pollicis Brevis, Flexor Pollicis Brevis, Opponens Pollicis, Abductor Digiti Minimi, Flexor Digiti Minimi, Opponens Digiti Minimi, Adductor Pollicis, Lumbricals, Palmar Interossei, Dorsal Interossei, Abductor Pollicis Longus, Extensor Pollicis Brevis, Extensor Pollicis Longus, Extensor Indicis, Flexor Digitorum Superficialis, Flexor Digitorum Profundus, Palmaris Longus

The muscles that flex your fingers are located on the anterior side of the forearm and hand. The muscles that extend your fingers are located on the posterior side of the forearm and hand.