Walking on a treadmill can cause swelling of the ankles. The main causes for this type of inflammation are usually due to the repetitive nature of treadmill walking and the aggravation of previous injuries. Improper form and over-extending yourself can also lead to bio-mechanical injuries that will leave your ankles sore and swollen.
Equinus
According to clinical editor, Nicholas Sol, DPM, CPed, for "Podiatry Today," when interval training or using the treadmill at an incline, it is possible to develop Equinus. This condition affects the dorsiflexion or upward movement of the foot from the ankle joint. Exercising for long hours or failing to stretch properly before training are the leading causes of Equinus while on a treadmill. Before you begin exercising on the treadmill, stand next to a wall or flat surface and stretch your calf muscles by doing a few toe lifts. If you have a history of Equinus, you should take stress off your Achilles tendons by wearing lifts in your sneakers.
Swelling from Ankle Sprain
According to the Nicholas Institute of Sports Medicine and Athletic Trauma (NISMAT), sprained ankles are the most common type of ankle injury. Walking on a treadmill can lead to a sprained ankle, especially if your weight is not evenly distributed over the foot. This causes the ankle to undergo inversion, which is commonly called "rolling the ankle." This type of injury is rare on a treadmill because the surface is smooth and even. However, spraining your ankle while walking on a treadmill will lead to swelling. The best prevention is to wear the proper shoes during your treadmill exercises. Make sure the laces are tight enough and you have plenty of ankle support.
Swelling from Achilles Tendinitis
The largest tendon in the body is the Achilles tendon, located on the back of your ankle. You can't walk, run or jump without it. It is particularly vulnerable to sports-related injuries and swelling. Achilles tendinitis occurs when the tendon is overworked or damaged. Swelling can occur across the middle of the tendon or over the lower portion of the tendon, near the heel bone. Due to the repetitive nature of treadmill walking, you should avoid pushing your workout to the extreme. The overuse of the Achilles tendon leads to inflammation, pain and swelling that can be avoided by simply pacing yourself properly.
Unlikely and Overlooked Causes
According to a study published in a 2007 issue of the "Journal of Applied Physiology," problems with visual perception can lead to an altered running gait while on a treadmill. The study found that subjects walking on a treadmill receive different optic inputs than when walking on the ground. This visual confusion leads to a loss of stability and balance. Therefore, you're more likely to roll your ankle and experience other bio-mechanical injuries. Also, walking on a treadmill leads to a spike in the number of steps you take in a given day, which can alter your body's natural walking cadence. This can lead to muscle confusion, limited range of motion and consequently, swelling of the ankles.
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Writer Bio
Frederick S. Blackmon's love for fiction and theater eventually led to a career writing screenplays for the film and television industry. While living in Florida, Blackmon began exploring issues on global warming, health and environmental science. He spent two years as a Parkour and free-running instructor as well. Now he writes everything from how-to blogs to horror films.