Conservative treatment
The foot core, core strengthening for the foot muscles
The foot is supported by some twenty short intrinsic muscles that shoe-wearing deconditions. Foot core training gives this musculature back the tone it needs to support the plantar arch, stabilize anchoring to the ground, and counter the collapse promoted by FHL.
Treatments
What is core strengthening for the foot?
Core strengthening for the foot consists of stabilizing anchoring to the ground by toning the intrinsic muscles of the foot. The foot is made up of a so-called “passive” framework of bones, joints, and ligaments that tie the whole together. This structure is supported by an active framework of some twenty short muscles, whose origins and insertions lie within the foot itself — unlike the extrinsic muscles, which arise on the leg.
The muscles responsible for this core support must be fatigue-resistant and able to withstand stress while lengthening. They have no propulsive function strictly speaking, but they contribute to the elastic properties of the plantar arch. When weight-bearing, balance depends on the stability of the foot on the ground and its rapid adaptation to any new situation: the intrinsic muscles potentiate this stability.
Why is it so important?
Wearing shoes in our modern societies deconditions the muscles of the feet: movements are limited and the muscles atrophy from lack of use. The earlier in life shoes are worn, the more the development of these muscles is hindered. Over the years, this accumulated deficit leads to balance disorders that are particularly critical in older adults.
When walking, the plantar arch tends to collapse and the foot to deform under pressure. The intrinsic muscles play a crucial role in preventing this collapse and in maintaining the foot’s dynamic, responsive structure. Single-leg balance and adaptation to uneven ground depend on them.
FHL and the intrinsic foot muscles
Through the tenodesis effect on the flexor hallucis longus tendon, FHL predisposes to collapse of the arch and deformity of the forefoot. To potentiate the results of foot core training, this tenodesis effect must first be released by manipulating the subtalar joint and performing specific stretches to train the gliding of the tendon. This step is a key element in the success of the treatment.
The target muscles of the protocol
The main muscles responsible for active support of the plantar arch are the abductor hallucis, the flexor digitorum brevis, and the quadratus plantae, joined by the dorsal interossei, which are important for keeping the metatarsals in place during weight-bearing.
The three fundamental exercises on video
The exercises are done barefoot, demonstrated here sitting on a chair. They can also be performed standing, on one or both feet, on more or less stable surfaces depending on the level. It is advisable to work only one foot at a time when first learning. No warm-up is required.
The short foot — strengthening the plantar arch without curling the toes
Toes spread out — targeting the dorsal interossei
The snail drawing — training overall foot dexterity
The short foot
Stimulates the abductor hallucis, flexor digitorum brevis, and quadratus plantae. The difficulty is creating a contraction of the arch without any toe-curling movement.
Tips
Slow, controlled contraction
No toe curling
Goal: restore tone to the arch
Toes spread out
Targets the dorsal interosseous muscles, important for keeping the metatarsals in position when the foot bears weight.
Tips
Spread the toes as far as possible
Hold the position for a few seconds
One foot at a time at first
The snail drawing
Targets the adductor hallucis, which works in synergy with the flexor digitorum brevis during the propulsive phase of the stride. Requires an A4 sheet of paper and a pen.
Tips
Pen held by the toes
Slow spiral drawing
Excellent for foot dexterity
Typical program
Six weeks of care, with one to two sessions per week in the clinic and home exercises once or twice a day. Any barefoot activity on a non-traumatic surface is beneficial. The final stage involves sensible, supervised barefoot running or running in minimalist shoes, as poorly adapted practice can cause overuse injuries.
Electrostimulation as a complement
Electrical muscle stimulation aims to strengthen certain foot muscles using electrical impulses: a professional places electrodes on the plantar and medial aspects of the foot to induce a contraction. This method can be combined with exercises on one or both feet, on more or less unstable surfaces depending on the patient’s level. Significant results are achieved by combining the two approaches.
Next pillar
Osteopathy
Releasing the joint blockages induced by FHL, from the pelvis to the thoracolumbar junction.
In practice
Target muscles
intrinsic foot muscles
Program duration
6 weeks
In-clinic frequency
1–2 sessions/week
At home
1–2 times/day
Adjuncts
electrostimulation
Final stage
barefoot running