Hard miles on the road and in the pool can add up before you know it. The foot and ankle take the brunt of the load from weight bearing. Not only do the foot and ankle experience a significant amount of stress, but they also dictate the amount of stress placed on our bodies. The balance of muscular strength from right to left, the architecture of the joint, and mobility of the joints all factor into how we handle the stress of road running, biking, and even the propulsive force of kicking during the swim. Subtle deficits of any of these can magnify and add up to cause problems that are sometimes obvious, but occasionally are a bit cryptic and slow to show their faces.
Our ankles are stabilized in the front by the anterior tibialis muscle/tendon unit, with its tendon inserting on the top/middle of the foot. The posterior part of the ankle is stabilized by the calf/soleus muscle complex with the Achilles tendon attaching on the back of the heel. If these stabilizing muscle/tendon units are not strong enough to handle the stress that they are put under, they can become acutely inflamed and over the longer term, can become damaged from the inside (a degenerative process called tendinopathy). When this happens, either the front of your lower leg or your lower calf muscle/tendon becomes painful.
Recovery depends on what prompted the injury and how long it has been present. It may be as simple as unloading the foot/ankle with relative rest such as taking a break from running and swimming an focusing on biking. However, if not responding to unloading the ankle, you should consider obtaining an evaluation by a sports medicine professional with expertise in treating triathletes. He or she may recommend therapeutic exercises, medications, bracing, further imaging (perhaps via an in office musculoskeletal ultrasound) or possibly an injection in recalcitrant cases.
In similar fashion, the posterior tibial muscle tendon unit (PTT) covers the inside part of your ankle. It helps you come up on your toes and push off while running. It also acts to stabilize your ankle preventing it from collapsing inward while running and it supports your arch. On the outside, your peroneal muscle tendon unit works similar to the PTT. It keeps your ankle from rolling outwards and works to turn your foot outward.
With repetitive pounding, the PTT can become inflamed and cause pain in the arch of your foot or on the inside of your leg. Stress levels that exceed one’s ability to recover become additive, and when this happens along the top part of the PTT unit along the inside part of the shin, it contributes to the development of shin splints. The outside part of the leg faces similar issues with overuse that can occur with high levels of trail running or side-to-side activities. It also is susceptible to injury as part of a lateral ankle sprain. Treatment of the tendons on the inside and outside of the ankle is similar to treatment of the anterior and posterior tendons.
Ultimately, when the soft tissue stabilizers of the ankle don’t do their jobs or if the balance is not right, high levels of stress/shock/force can get transmitted to bone and lead to stress fractures of the tibia (shin), fibula (outside of ankle) and in the talus (the mortise bone of the ankle). Less common but more insidious are stress injuries in the small bones of your foot or the metatarsals. While most stress fractures are considered “low risk” and respond to unloading by relative rest, some stress fractures in the foot/ankle are “high risk” and need further treatment with either immobilization or in rare situations even surgery. Your sports medicine physician can help properly diagnose the severity of the stress injury and prescribe appropriate treatment specific to which bone is injured.
While most foot/ankle injuries experienced by triathletes are from cumulative load, they are not immune to acute injuries such as strains or other direct trauma. A sudden side-to-side stress to the ankle can injure not only the outside part of the joint (typical ankle sprain), but also the inside part as well. If the stress goes ever further and the foot twists out as well, the sprain can extend up the leg as a high ankle sprain. In the foot, ligament injuries can affect the joints between the small bones of the mid-foot as well as the joints between the toes and metatarsals. The big toe especially can get injured with overuse stress to not only the ligaments and joint capsule, but also to several small bones underneath the big toe joint called sesamoids. Treatment for ligament injuries depend on which ligament(s) are injured and the severity of the injury.
With so many areas of potential injury, how does one avoid all these pitfalls? What most good coaches and trainers will tell you is to stay within your limit and avoid prolonged or repetitive visits to excessive training zones so your body can adapt. Recovery can be as important as training. They should also stress the importance of muscular strength, as subtle areas of weakness get magnified over the course of many miles and imbalances can add up. When these strategies are not enough, a good sports medicine professional should be able to help.
Dr. Hunt is a Primary Care Sports Medicine physician from the Chicago area. He served as Medical Director for USA Triathlon for 12 years, and has also served as Team Physician for multiple local high schools and Division I and III universities. He is currently Team Physician for USA Hockey, and practices with TRIA Orthopedic Center in Minneapolis, Minnesota.