Pronator teres muscle
The pronator teres is a muscle of the human body (located mainly in the forearm) that, along with the Pronator quadratus, serves to pronate the forearm (turning it so that the palm faces posteriorly when from the anatomical position).
Flexor carpi ulnaris muscle
The flexor carpi ulnaris muscle is a muscle of the human forearm that acts to flex and adduct (medial deviation) the hand.
Flexor carpi radialis muscle
In anatomy, flexor carpi radialis is a muscle of the human forearm that acts to flex and (radial) abduct the hand. The Latin carpus means wrist, and carpi "of the wrist." Hence flexor carpi is a flexor of the wrist.
Palmaris longus muscle
The palmaris longus is seen as a small tendon between the flexor carpi radialis and the flexor carpi ulnaris, although it is not always present. The muscle is absent in about 14 percent of the population; however, this number varies greatly in African, Asian, and Native American populations. Absence of this muscle does not have an effect on grip strength.