Toes Hurt and Go Numb While Running

Question

I've been running for 11 weeks doing the Couch to 10K program, with 8-9 weeks of that being in Vibram FiveFingers Bikila LS. As I've steadily increased the amount of running in my workout, I've started experiencing toward the end of my workout (last 10 minutes or so) a semi-painful almost numbing sensation from slightly behind the base of my toes to the ends of the two toes nearest my big toe on my left foot only.

^{Bottom of Foot Diagram from Bottom of Foot Pain}

The toes hurt in the area right around where the above image is marked "Toe cramps" and feel more numb and less painful toward the ends of the toes. Changing the distribution of weight on my foot as I run doesn't seem to help any with the pain once it starts. The pain goes away just a few minutes after my workout is completed and I've taken a short break.

Is this a result of the minimalist running shoes, am I possibly landing wrong on my foot, or is it something that will work itself out with enough time?

Answer 1

It sounds like metatarsalgia to me. If you check out the symptoms section that article they match what you described. Running and jumping increase the risk of metatarsalgia, and anything that increases impact on your feet makes it worse. The article lists wearing shoes without appropriate padding as a risk factor, so your vibram's lack of padding may be contributing to the problem. Being overweight also increases impact, which contributes to the problem (I don't know if this is an issue for you or not). I imagine that running on high-impact surfaces like concrete would also increase your risk (grass and asphalt have more give).

Distributing more weight into the ball of the foot also makes it worse. According to Arnheim's Principles of Athletic Training:

One of the causes of metatarsalgia is restricted extensibility of the gastrocnemius-soleus complex. Because of this restriction, the athlete shortens the midstance phase of the gait and emphasizes the toe-off phase, causing excessive pressure under the forefoot.

Translation: if your calves are tight, you run in a way that puts more pressure on the ball of your foot. This might be an issue for you. One of the benefits of barefoot running is that it strengthens your ankles by strengthening the lower legs muscles that support them. The problem is, if you don't stretch those muscles regularly they can get tight. Metatarsalgia can also be caused by a fallen metatarsal arch (the arch that goes across the ball of the foot).

If tight calves are suspected contributors, Arnheim suggests stretching the calves several times a day (see the right column of the Gastrocnemius and Soleus sections on ExRx for some stretches). If you have a fallen arch cauaed by weakness, you should also do foot-strengthening exercises. In addition, both sources I mentioned suggest metatarsal pads, which sit behind the balls of the feet to help with support and shock absorption.