They also provide motor innervation to quadratus plantae, abductor digiti minimi, flexor digiti minimi brevis, lateral three lumbricals, adductor hallucis, and the dorsal and plantar interossei.
In some individuals, the lumbricals can be dragged into the carpal tunnel with flexor digitorum profundus contraction.
As the wrist flexes, the flexor digitorum profundus contracts in a proximal direction, drawing the lumbricals along with it.
The lumbricals attach in part to the flexor digitorum profundus tendons.
Exercises to strengthen lumbricals, strengthen flexion in the metacarpophalangeal joint, and extension in the interphalangeal joints are beneficial.
Beneficial exercise will be any that strengthens the interosseous muscles and lumbricals.
As it crosses the deep part of the hand, it innervates all the interosseous muscles and the third and fourth lumbricals.