Palmaris longus muscle

The palmaris longus is a muscle visible as a small tendon located between the flexor carpi radialis and the flexor carpi ulnaris, although it is not always present. Reviews report rates of absence in the general population ranging from 10–20%; however, the rate varies in different ethnic groups. Absence of the palmaris longus does not have an effect on grip strength. The palmaris longus muscle can be observed by touching the pads of the fourth finger and thumb and flexing the wrist. The tendon, if present, will be visible in the midline of the anterior wrist. It is one of the five muscles that make up the so-called "flexor-pronator mass". (Wikipedia)