SUMMARY: Are you starting to feel pain in your ankle, knee, or hip from running? That might be a hallux limitus! Read on to know how the big toe causes injuries in runners.
Even though it is not a common topic among runners, a lot of people know that a hallux limitus – “stiff big toe” in layman’s term – is one of the usual causes of knee, hip, or ankle pain.
Understanding the Movement of the Big Toe
When you are running and one of your feet is about to hit the ground, that foot is pulled back (dorsiflexed) a bit as it prepares for the initial contact with the ground. The big toe or the hallux is also pulled back at this point. But since your foot has not hit the ground yet, the dorsiflexion of the big toe is insignificant.
However, as soon as the foot touches the ground and begins to support the weight of your body, the position of the big toe becomes significant. As the body passes over the foot that supports your weight, the hip, knee and ankle stop bending and start to straighten. The extension or straightening of the ankle is known as plantar flexion.
The normal movement of the joint involves the bone behind the big toe to flex. The head of the bone slides and climbs onto the two small bones under it. This movement allows the big toe to dorsiflex and stabilize the foot. If the slide and climb motion is restricted, the big toe will not dorsiflex sufficiently. The foot then looks for alternatives, which over time can cause discomfort and even degenerative arthritis.
Functional VS Structural Hallux Limitus
The limited movement of the joint is known as hallux limitus. The limited movement comes from two different sources: functional and structural.
In functional hallux limitus, movement is limited, but this is not caused by joint degeneration. Upon examination, toes are able to move freely while there’s no weight on it. The limited movement is caused by “jamming” of the big toe and first metatarsal, the bone found behind the big toe. Although the exact cause of hallux limitus is still unclear, wearing tight shoes and high-heeled shoes can lead to the condition. Running on one’s toes and trauma can also cause hallux limitus.
There are several ways to treat hallux limitus without having surgery, so it’s important to deal with the condition immediately. If you don’t, it can become totally restricted.
Structural hallux limitus is known to be the late stage of a functional hallux limitus. However, it can also be due to trauma. The repeated jamming in functional hallux limitus can cause the joint cartilage to wear down and eventually suffer from degenerative arthritis.
In structural hallux limitus, movement may be restricted even if you are not weight bearing. If it is not treated, structural hallux limitus can affect movement, until there is no movement at all (hallux rigidus).
How the Body Compensates
Both hallux limitus and rigidus can cause severe pain, which is why the brain looks for an alternative way to get that foot off the ground. However, this compensation pattern does not eliminate the force that the foot experiences when it hits the ground. The force merely shifts to another part of the body.
The body compensates by shifting the pain from the foot to the lower leg. The calves shorten and tighten with every stride, changing the dynamics and causing pain in the lower leg, calf, and Achilles tendon. And since the body is a chain where anything that happens to a joint will affect another, the knee will bend early when there is insufficient ankle dorsiflexion. This in turn can disrupt the gait cycle and lead to knee pain.
Reduced ankle dorsiflexion means that the heel will be off the ground for a longer time, resulting in a decrease in hip extension. This in turn forces the front of the hip to work harder. This can manifest as hip pain or lower back pain. The big toe needs adequate mobility in order to avoid injuries, pain, and other problems. If you have any of the symptoms mentioned above, it’s important that you see a doctor immediately.