As we transition, we are recruiting and utilizing muscles in our feet that we haven’t used in years. These are the intrinsic muscles. The intrinsic muscles perform the functions of flexing and extending toes, abducting and adducting the digits, and stabilizing the joints of the toes or the metatarsophalangeal joints (MPJs.) We discussed calf pain in a previous post that is due to eccentric contractions and delayed onset muscle soreness. The same scenario is occurring with the foot musculature.
Let’s review the muscles to better understand the reason for the location of the pain.
The extensor digitorum / hallucis brevis muscle belly originates on the lateral or side of the foot. The muscle belly commonly swells and enlarges after activity.
It is Common to experience pain in this muscle belly.
The dorsal and plantar interossei are located between the metatarsal bones and help to stabilize the MPJs as well as splay the toes. It is the hypertrophying of these muscles that leads to the “splaying” we may see after wearing FiveFingers over several months to years.
Pain to the forefoot area that is “pinpoint” over the metatarsal bones, and close to the toe, could represent a stress fracture. Xrays need to be performed if this pain persists.
Pain to the plantar aspect (bottom) of the foot over the metatarsal heads is common secondary to the repetitive pounding but should resolve as you adapt and learn to land softly.
Remember, most muscular pain will worsen upon arising in the am as the muscle is cold, and then will ease up as we move around and “warm up” the muscles. If it does not improve, see your physician for radiographs.