If only I knew…
The Infamous Hallux Brothers
An overview of foot conditions affecting the big toe.
By Marie-Catherine Bruno, BScPT, Cped(C).
When I first started writing my column in ONA I was lecturing at the School of Rehab in Montreal and working part time as a physiotherapist. I have since then moved to Beautiful British-Columbia and I have obtained a specialty in feet! (I was certified Pedorthist in May of 2003). In my practice I see a lot of experienced runners dealing with toe injuries. You would think that a simple toe injury would not affect your life too much, but when you realize how much time you actually spend on your feet everyday and how important your toes are, you also realize that maybe you should treat your feet with a lot more care from now on.
The foot is a very complex piece of anatomy with 28 bones, over 100 ligaments and 32 muscles and tendons. To make the architecture even more complicated, the foot has 2 separate structures called arches: a longitudinal arch (the most commonly known) - see figure 1- and a transverse arch – figure 2. Both arches help support and maintain the structure of your foot. They also contribute greatly in shock absorption and improve the stability of the structure (you architects and engineers out there will know what I am talking about! – an arch is a very strong and stable structure) so you have a rigid platform to push off the ground with. The foot also plays a very important role in balance, especially the toes. Together they send a lot of information to the brain about the ground (how soft, how hard, tilted or not, bumps…) and all different changes that can occur so you can readjust with your muscles.
When healthy, the foot is a little marvel and requires only minimal care (how many of you get regular foot massages and pedicures?). However, our feet (well, our entire body) were originally designed to function for no more than 30 years. So what happens after 30? Well, a slow but unstoppable degeneration process begins. It is the beginning of a condition called Osteo-Arthritis (OA in the medical field). OA simply means that joints are suffering from excessive wear and tear. There are various degrees of OA, and the worse case scenario usually leads to foot surgery (joint fusion, bone grafts, you name it). So before you get there, let’s take a look at some common easily avoidable mistakes and defects that lead to early degeneration of the foot.
I mentioned earlier that the foot serves two main functions: shock absorption and propulsion off the ground. That is only possible because the longitudinal arch has the capacity to unlock and therefore allow for shock absorption as the foot reaches the ground. Let’s look at the normal sequence from the moment your heel hits the ground to the moment your foot takes off:
- Heel strike: your heel hits the ground slightly on the outside. The foot is still rigid.
- Foot Flat Phase: the rigid foot slowly comes down to meet the ground. As the ball of the foot touches the ground, the longitudinal arch unlocks and your foot becomes almost flat on the ground. During that phase, the foot is soft, flaccid.
- Resupination: the soft foot slowly rotates up and the arch rebuilds, making the foot rigid again in preparation for take off.
- Heel off: you begin lifting off the heel, ready to take off, the arch is now rigid again so that you can efficiently push off the ground.
- Toe off: the heel clears the ground and your weight rolls toward the front of the foot where you take off through the middle of your foot and your big toe.
In an ideal world, all feet would religiously follow that sequence and everybody would be happy.
Unfortunately, in my practice, I see only a minority of feet following the ideal sequence: most patients have trouble in the shock absorption phase where the arch does not slow down the weight of the body enough so the foot goes directly to the Foot Flat Phase. Then the foot lies inert on the ground, unable to regroup and pick up the arch. This makes it very difficult to lift off the heel as the foot remains in its soft flaccid phase. So most people will compensate by turning the foot out a bit (Duck feet) and they end up rolling off the big toe. The big toe all of a sudden becomes the sole supporter of the entire body weight (remember, your other foot is still up in the air). It is a very small limb to support some 150 pounds (and as you gain weight, your big toes do not grow accordingly… ouch!). So this is usually how most big toe problems begin. Factors other than poor mechanics can also aggravate the normal wear and tear of your big toe: poor footwear (refer to ONA January 2003 for choosing proper footwear), old injuries (this could include any joint up to your hips), genetics (some people are born more prone to foot injuries because of the anatomy of their foot) and abuse of your feet (running on hard surfaces with worn out shoes, orienteering…). No matter what the trigger is, you could end up with a big toe injury. The most common ones are Hallux valgus, Hallux limitus and Hallux rigidus (that I call the Hallux Brothers).
Probably the most common of toe injuries/problems. It is easily recognized by the deformity that it causes (figure 3): the big toe starts migrating towards the rest of the foot, making the foot look pointy. It is normal to have an angle of up to 10-15 degrees from a straight line at the big toe, but anything beyond 20 degrees is considered a Hallux valgus. In worst cases, the bone on the outside of the foot (called the metatarso-phalangeal joint – MTP) becomes so irritated by the increased pressure caused by the shoe and the constant bending that it becomes red, swollen and hot. This is the beginning of a bunion. A bunion is simply a reaction from your body to try to protect the joint by developing a cushion (called bursa) on top of the joint. Unfortunately, this cushion makes the foot even wider and usually simply increases the pressure on the MTP, causing a vicious circle that only stops when people take care of the problem.
Hallux valgus is thought to be mainly due to poor foot mechanics like described above (by turning the feet out – Duck feet – and rolling off the big toe, it constantly pushes the toe towards the inside of the foot, eventually creating a permanent deformity). Other possible causes include systemic diseases like rheumatoid arthritis, the prolonged wear of very narrow and pointy shoes (it keeps the foot in that pointy position) and the prolonged wear of high heels (increases dramatically the pressure on the big toe).
If the problem comes from the mechanical aspect, this can be corrected by custom made orthotics (orthoses in Canada) that will increase the support in the arch and take the weight off the big toe. Choosing running shoes that offer extra support on the inside of the shoe (called Motion Control shoes) is also a wise decision. Eliminating the cause early enough can insure complete recovery of the big toe. However if your foot has reached a more advanced stage (significant deformity and presence of a bunion), slowing down further degeneration of the limb and pain control will be your main goals. Surgery to remove the bunion and realign the big toe is also possible, but why let your foot get that bad?!
Hallux limitus is very often underdiagnosed as it does not always cause any pain, especially in the early stages. People will more often complain of clicking in the joint (MTP) and stiffness upon activity (walking, running, cross-country skiing). Later on the pain will develop. Since pain is usually what triggers the alarm, this is normally when I see people in my office. Fortunately at that stage you can still improve things significantly. Hallux limitus means that the big toe is limited in range of motion. It is an early stage of the Hallux rigidus that we will describe later. Your big toe should bend (called flexion) and extend (dorsiflexion). At the MTP joint, it can also move in towards other toes and out, and even do circles because the joint is shaped like a ball and a socket. Hallux limitus is described as having less than the required 60 degrees of dorsiflexion for normal walking at the MTP joint.
Like its half brother Hallux valgus, Hallux limitus is usually caused by poor foot mechanics. The increased weight on the big toe causes early degeneration of the joint (OA) and the joint becomes stiff and sometimes painful. Corrective custom made orthotics will help decrease the load on the joint and improve the mechanics, preventing further degeneration. At this stage, mobilization of the joint by a physical therapist is crucial: the stiffened joint usually has not reached yet a severe state of degeneration so the joint’s health can be improved (even fully recovered if caught early enough) with proper care and maintenance. Motion control running shoes are also a wise decision in the case of Hallux limitus.
Other causes include mainly the prolonged wear of high heel shoes and abuse of your feet.
Hallux rigidus is Hallux limitus’ bigger and meaner brother. It is exactly the same as above, except that the joint has now reached a severe state of degeneration and the range of motion is now limited to only a few degrees of motion. At that stage, the cartilage that lines the joint becomes eroded and sometimes little pieces can even chip off and float freely in the joint. The joint is extremely painful to move and does not tolerate weight bearing very well. Physical therapy can help ease the pain and gain some movement back, but usually at this stage a lot of the damage is irreversible. Corrective orthotics and physiotherapy might help, but very often the only thing that really brings relief at this point is to immobilize and protect the joint. Shoes that have a rocker bottom (like clogs) so that you don’t have to bend at the toes when walking become very helpful. For regular shoes, you can insert a plate of carbon designed to give that rocking motion to a normal shoe and therefore reduce the bending stress on the joint. Such a plate is called a rocker. The very last resort for such a condition is a surgery (arthrodesis) where they fuse the joint using a bone graft.
Investing in your foot health
The best way to avoid the mean Hallux Brothers is to keep your feet healthy. Make sure the mechanics are proper (you can refer to ONA January 2003 to assess your own feet) or ask your health specialist. Change your running shoes regularly (this is not a good place to cheap out) and if you usually run 2 days in a row, make sure you own a second pair as the sole can take up to 24 hours to recover from a training session. Choose shoes that fit your feet properly without creating pressure points and avoid seams in the front of the shoe as much as possible, especially seams that run directly over the bunion (such shoes are called toe plain). If you already have a big bunion, do not hesitate to ask a cobbler to stretch the shoe right where the bunion is, using a ball and ring device (seams make it almost impossible though).
Dress shoes and sport shoes should be fairly flexible where the toes bend and bend following the same angle as your toes (a mild diagonal pattern, not a straight line). Avoid heels (the difference between the front and the back of the shoe that is) higher than ¾ of an inch.
If you run regularly (or hike or do any sport where your feet take a bit of abuse), do not hesitate to make maintenance appointment for your feet with a physical therapist or a registered massage therapist, at least twice a year. If you notice callous and/or corns, consult with a podiatrist to get them removed (and make sure you find out the cause of them so you can eliminate it).
Never forget that you cannot possibly walk (let alone orienteer) without putting weight on your feet, so you’d better keep them in good shape! Happy trails!