Functional hallux limitus is a condition in which the big toe joint jams when weight bearing. It is caused by a bone fragment blocking the ability of the first metatarsal phalangeal (MTPJ) joint to move around its axis.
It can be caused by injury or a high impact activity such as running and recreational sports. Your healthcare provider will diagnose the condition by doing a physical exam and x-rays.
Signs
During the propulsive phase of gait, our foot must lift up and support our body weight. This is accomplished by the feet natural windlass mechanism that uses the first metatarsal head to help with this process. This is possible only if the first metatarsal head can move into a wide range of motion. If you have functional hallux limitus, this motion is restricted.
Generally, this condition is a result of a stiffening of the first metatarsal articular joint (MTPJ) with load. The normal range of motion for this joint is 70 degrees in both the nonweight bearing foot and the weight bearing foot. If this range of motion is 70 in the weight bearing foot but not the nonweight bearing foot, it is considered to be functional hallux limitus.
It is important to note that functional hallux limitus will not progress to the much more severe form of hallux rigidus unless it becomes worse or if it is left untreated. This is why early diagnosis and treatment are so critical.
Signs and symptoms include pain, swelling of the big toe joint, and a feeling that your big toe cannot move during walking or other activities. Symptoms can be relieved with icing and nonsteroidal anti-inflammatory drugs (NSAIDs). Changing shoes that put excessive pressure on the big toe joint can also reduce discomfort.
Symptoms
If you are experiencing pain in your big toe joint only when you’re putting weight on the foot (like when walking or stepping) you might have functional hallux limitus. This is when the movement at your big toe joint, called the first metatarsophalangeal (MTP) joint, decreases and eventually becomes stiff and restricted. When you have this condition, your doctor might recommend that you take anti-inflammatory medications or get cortisone injections in your big toe joint. These treatments will relieve your pain and slow down or halt continued deterioration of your big toe joint.
There is no one cause of this condition, but some factors that can increase your risk include: Injury like stubbing or breaking your big toe. Arthritis like rheumatoid arthritis or osteoarthritis, which can change the way you walk and put pressure on your big toe joints. Unusual foot anatomy, like having a first metatarsal joint that is elevated or longer than normal. Wearing shoes that don’t fit well, which can put too much stress on your toes.
If you have this condition, a podiatrist may perform a physical exam and order an x-ray of the big toe. During an x-ray, your doctor will look for narrowing of the MTP joint and/or bone spurs. Your doctor might also recommend over-the-counter or custom-made orthotics for your shoes that will help support your feet and correct an imbalance in your gait.
Diagnosis
Functional hallux limitus is a form of arthritic big toe joint (hallux) restriction in which the first metatarsal bone moves less smoothly than usual. It is a common condition that causes pain and limits the ability to use your big toe. It can be caused by damage to the big toe joint, changes in the way you walk, or other conditions that affect how your foot works. It is most often related to early arthritis. It can become worse over time and lead to a more severe form of arthritis called hallux rigidus.
A Podiatrist can diagnose this condition by a physical exam and x-rays. The x-rays will show how your big toe joint is functioning and if there is any narrowing of the joint space or if you have bone spurs. If you have early signs of this condition you may be able to heal with a few simple treatment strategies. This may include using an ice pack, medications or injections, and changing the activity that you do to reduce pain or injury. Your podiatrist can also fit you with custom orthotics to help your big toe move more normally.
There is another type of hallux limitus that is structural in nature and involves something physically blocking the movement of the big toe joint, such as a bump or bony prominence. Structural hallux limitus can be painful and cause stiffness, a bump on the top of your toe and can lead to a bunion deformity.
Treatment
In order for your feet to be stable and powerful, the big toe must be able to extend up early in the gait cycle (dorsiflexion) when your heel lifts off of the ground and body weight is transferred into the ball of foot. Without this range of motion the big toe is a rigid lever and cannot provide the power required to propel you forward. This can impact your running or walking performance whether recreational or competitive, as well as directional changes and activities that require explosive propulsion like coming off the line in football or racing to the finish line in a marathon.
If you develop pain and a bump on the bottom of your big toe joint, or notice that it is painful to move the big toe, it is important to see a podiatrist. If you leave the condition untreated it will progress to hallux rigidus, in which your big toe becomes stiff and immobile.
There are several biomechanical etiologies that can lead to functional hallux limitus, but the main ones all result in excessive first metatarsophalangeal joint (MPJ) dorsiflexion resistance during late midstance and propulsion. A 2016 study1 found that custom foot orthotics with a first ray cutout, kinetic wedge or Morton’s extension are effective at improving this first MPJ dorsiflexion and reducing pain for people with this condition.