Nothing brings runners enjoying their blissful weekend runs or intense race training schedules to a grinding halt like big toe or hallux pain. It seems impossible to mentally tough out big toe pain and finish the race (not a wise idea) because there is no way to compensate and run without using the big toe joint (1st MTP). It is a joint we take for granted when all is working well, but runners need 50-60 degrees of motion at the big toe in order to run properly, and when that motion becomes limited or painful, it discourages physical activity.
Bunions affect 64 Million Americans and 35% of women over the age of 65. This abnormal joint growth leads to painful running and walking, and although it can be corrected with surgery, about 15% of bunions return after surgery and pain relief is often limited.
The best way to treat a bunion is to ensure you never get one in the first place, so knowing what causes bunions and who is at risk is important. If you have noticed that your big toe is starting to drift towards your small toe and the joint is getting larger, it is extremely important to start getting treatment in order to slow down the progression of the bunion.
So, what causes a bunion? Let’s talk about how the foot should work before we talk about how things can go wrong…
It is useful to think of the foot as a truss, or a triangular frame. The calcaneus (heel) and the metatarsals create the upright supports, while the plantar fascia connects the calcaneus to the metatarsal heads and first phalanx to provide the bottom support. The weight of the body on the foot compresses the metatarsals and places a tensile strain along the plantar fascia, which helps provide support to the foot. While walking or running, dorsiflexion of the first phalanx pulls the plantar fascia around the MTP joint and helps provide a rigid foot so that the big toe can act as a fulcrum for forward propulsion. This is called the Windlass mechanism.
There are also many muscles within the foot and the calf that help support this mechanism, and a bunion develops when the foot is not properly supported causing rotation of the big toe joint and abnormal lateral stress on the joint due to external forces and muscle imbalance. Narrow shoe boxes, high heels, and improper running mechanics are all factors that increase the lateral stress of the 1st MTP joint and increase the risk of bunions include, but genetics also play a role in bunion development. One of the biggest factors that can lead to bunion formation is over-pronation of the foot. Pronation occurs when the calcaneus everts while the forefoot abducts (moves laterally) and dorsiflexes (moves upwards).
Pronation of the foot causes the first metatarsal to adduct and internally rotation, and the big toe to abduct (shift laterally). Once in this position, the 1st MTP joint no longer aligns with the normal plane of the foot, which means muscles that move the joint are now in a shortened or lengthened position and cannot provide a strong contraction or support. They also pull in the wrong direction leading to worsening of the deformity. Having the axis of the big toe turned more towards the transverse plane also means weight is placed on the medial side of the big toe, which pushes it laterally and further exacerbates the problem.
A recent article in the Journal of Orthopedic and Sports Physical Therapy found that there are five muscles, three in the foot and two in the calf, that can help support the arch and keep it from rolling inward. By strengthening these five muscles, the foot can have better support which will increase proper big toe mobility and help reduce pain while running or walking. These five muscles include abductor halluces, adductor halluces, flexor halluces brevis, tibialis posterior, and fibularis longus.
The article also included three exercises, which when done properly, will help strengthen these five muscles and help prevent or reduce the progress of bunions. These three exercises should be done daily for as many reps as possible until fatigue, and progressed from sitting to standing to balancing on one leg.
Exercises for Foot Strengthening
#1. The Short Foot
The short foot exercises recruits the intrinsic muscles of the foot (abductor halluces, flexor halluces brevis, and adductor halluces oblique head) and is performed by keeping the heel and forefoot on the ground, and without curling the toes into the floor, shorten the foot so the base of the toe moves back towards the heel. The toes should be off the floor and you should visibly see an increase in the medial arch of the foot. Hold for 5 seconds and repeat until fatigue.
#2. The Toe-Spread
For the toe-spread out exercise, lift and spread out the toes while keeping the heel and forefoot on the floor. Next, push the little toe downward and out while simultaneously pushing the big toe downward and towards the inside of the foot. Hold for 5 seconds and repeat until fatigue. This exercise is able to target the abductor halluces more specifically.
#3. The Heel Raise
The last exercise is the heel-raise, which works the calf musculature, but also tibialis posterior and fibularis longus, which help support the mid-foot arch and prevent pronation of the foot. For this exercise, knees should be slightly bent and then raise your heel off the floor placing most of the weight towards the inside ball of your foot or at the base of the big toe. Make sure the heel of your foot is turned inward and try not to lean forward any more than is necessary to maintain balance. Hold for 5 seconds and repeat until fatigue.
It is difficult for many people to voluntarily contract these muscles; therefore, it may be helpful to have the guidance of a physical therapist to properly instruct these exercises. Here at Competitive Edge Physical therapy, we treat many runners with bunions due to foot pronation and high running miles. We have been very successful at teaching these foot exercises and utilizing EMG feedback to help clients learn quicker. If you are interested in learning more about foot mechanics or how we can help you reduce pain and improve bunion mobility, email, call, or visit our clinic in San Jose, CA.