The knuckles are the joints of the fingers which are brought into prominence when the hand is clenched and a fist is made. The Knuckle diseases like arthritis and extensor tendon injuries make the knuckle joint stiff and restrict its normal movements. The Dyna Dynamic Knuckle Bender Splint helps in flexing the stiff metacarpophalangeal joints of the hand. It also helps to retain the normal movements of the joints.