There are several muscles involved in flexing the hand.

- Palmaris longus (flexes hand)

- Flexor carpi radialis (flexes and abducts hand)

- Flexor carpi ulnaris (flexes and adducts hand)

- Flexor digitorum superficialis (flexes proximal and middle phalanges, flexes hand)

- Flexor digitorum profundus (flexes phalanges and hand)

- Flexor pollicis longus (flexes thumb and hand)

- Flexor pollicis brevis (flexes thumb)

There are also a few more I did not include that flex specific digits of the hand

It plantar flexes the foot at the ankle and flexes the leg at the knee.

The gastronemius muscle is one of the calf muscles and it plantar flexes the foot or flexes the knee.

its a joint that flexes

Plantar flexes the foot. (: