The sesamoid bones in your feet are tiny pea-size structures, but the pain they cause when they become inflamed can be enormous. In this article, we delve into what they are, what they do, what goes wrong, and what you can do about it when it does.
The name sesamoid is derived from the Latin for sesame seed so, yes, they’re small, but what makes these bones unique in the human body is the fact that they are embedded in a tendon and are therefore free floating rather than forming a joint with another bone.
The kneecap is a sesamoid bone, the largest in the body, and others can be found in a variety of locations including your hand, but for the purposes of this article we’re going to focus on the two sesamoid bones located in each foot.
The sesamoid bones in the foot are positioned side-by-side under your big toe joint in the ball of your foot, one on each side of the metatarsal bone (the long bones in your foot that each connect to a toe).
Interestingly, not everyone has two sesamoid bones in the foot and it’s possible to have just one, but the function remains the same.
Embedded in the tendon connecting the metatarsal to the big toe (hallux), each sesamoid bone acts as pulley, helping you to raise your big toe and move it through its normal range, and giving the leverage required to push off the ground when you’re running.
The sesamoids also provide a weightbearing surface for the metatarsal bone, absorbing the weight that’s put onto the ball of your foot as you bound along in a gazelle-like fashion in your daily run… well, maybe not always, but even if you’re more hippo than gazelle, the sesamoids take the strain in all walking, running and jumping movements.
As the name suggests, sesamoiditis is inflammation of the sesamoid bones. It’s an overuse injury and could also be described as tendonitis due to the tendon in which the bone is embedded also becoming inflamed.
Let’s take a look at the causes, symptoms and treatment.
The cause of sesamoiditis is essentially increased pressure on the sesamoid bones. As a runner, common causes are a rapid increase in mileage or in training intensity, with hill intervals, speedwork, or running up steps most likely to get you running on your toes and thereby putting more pressure on the balls of your feet.
Biomechanical issues such as high arches will also lead to running on your toes, and simply having bony feet with little padding on the underside can lead to sesamoid damage in repetitive, high-impact activities.
Sesamoiditis is distinguished by its gradual onset. If you have it, you’ll most probably feel a mild ache in the ball of your foot as you begin your run, one of those it’ll-wear-off-when-I-get-going sort of niggles, but it doesn’t. The more you do, the more it aches, and the mild ache manifests into a pain that’s screaming at you to stop.
The pain or throbbing sensation experienced can make you feel that you’ve bruised the ball of your foot, but there are rarely any external signs such as redness or bruising to explain the discomfort.
In the acute stage, it goes without saying that rest will be required. We’re not claiming to be medical experts, but if something is causing you pain, you need to stop doing that something.
As with any inflammation, ice treatment and anti-inflammatory drugs will help reduce the pain, but it’s also recommended that ice treatments continue once you’re back into running. Applying a cold pack for 10 minutes after each session will help to limit the potential for further inflammation and pain, but it’s important to avoid aggravation by building up the workload gradually.
If symptoms persist, a trip to your doctor, a podiatrist or a sports therapist is recommended, and shoe insoles to relieve the pressure on the sesamoids are often prescribed. Other treatments include taping or strapping to immobilise the big toe, thereby allowing the area around the sesamoids to heal.
Candy Lamb has a fantastic video over on her YouTube Channel that discusses her experience as a sesamoiditis patien and covers some of the treatment options that she’s tried.
Check it out:
Symptoms of sesamoiditis should clear in around four to six weeks, but if symptoms are on-going, further intervention in the form of a removable walking cast and/or steroid injections may be required – then you’ll be sorry you didn’t rest when you should have done!
If you’ve suffered the pain of sesamoiditis, you’ll be keen to avoid ever suffering it again, but what can you do? Well, prevention is always better than cure and in this case, new running shoes or orthotic insoles may be the answer.
Continuing to run in inappropriate shoes will only lead to recurring overuse injuries if your biomechanics or running style are the source of the extra pressure being placed on your bones and joints. A trip to a specialist running shop to have your gait analysed is a great starting point in terms of finding the best running shoes for you.
To avoid sesamoiditis, podiatrists advise a mid-foot strike when you run, using your knees and ankles to propel you forwards rather than pushing off from your toes alone. With the best will in the world, making changes to your running style is not an overnight process and not something everyone can hope to achieve, but, making corrections to your overall posture as you stand and walk in everyday life will go a long way towards keeping the pressure off your sesamoids as you spread your weight evenly across your feet.
Oh, and whether you’re a gazelle or a hippo, too much time spent in high-heeled shoes is never a good thing!