Lumbricals

The lumbricals serve as important facilitators of delicate motor control in the digits. In the hand, they enable a unique movement pattern that allows for the simultaneous flexion of the metacarpophalangeal joints while extending the interphalangeal joints. This action is vital for tasks requiring precision grip, such as writing or playing musical instruments. In the foot, the lumbricals play a role in stabilizing the toes during walking and running, contributing to a balanced gait and improving overall foot function. Their ability to coordinate movements between flexors and extensors highlights their importance in fine motor tasks and locomotion, allowing for complex interactions with the environment.

In the hand, the lumbrical muscles originate from the tendons of the flexor digitorum profundus, located on the palmar side. They run parallel to the metacarpals and insert into the extensor expansion on the back of each finger, facilitating their unique muscle function. The hand's lumbrical muscles are positioned in pairs, with each one corresponding to a specific finger. In the foot, the lumbricals are found in the same relative position, originating from the flexor digitorum longus tendons and inserting into the extensor expansions of the toes. Their location allows them to effectively influence movement patterns in both the foot and hand.

• The lumbricals are sometimes referred to as 'worm muscles' due to their worm-like shape.
• The position of the lumbricals allows for a unique combination of flexion and extension, critical for many daily activities.
• Injury or dysfunction of the lumbricals can lead to significant impairments in hand and foot function.
• Each hand contains four lumbricals, while the foot has four lumbricals as well, highlighting their symmetry in function.