According to the Nicholas Institute of Sports Medicine and Athletic Trauma, an ankle sprain is most often caused by turning your foot the wrong way, which can happen when you are walking or running on an uneven surface. Although a treadmill provides an even surface to walk on compared with most outdoor surfaces, you can still sprain your ankle on a treadmill.
Ankle Sprain
An ankle sprain occurs when you overstretch or tear a ligament, which is a fibrous band that connects two bones, in your ankle joint. A mild, or grade-one, ankle sprain is a mild tear or stretching of the ligament. If you partially tear the ligament, this is a grade-two ankle sprain, and if you completely rupture the ligament, this is a grade-three ankle sprain. All ankle sprains can cause pain, bruising and discoloration.
Moving Belt
The most common cause of an ankle sprain is turning your foot in an unnatural position. If you step on an uneven surface, you may roll your foot, causing the sole to turn inward. This places increased pressure on the ligaments on the outer portion of your ankle.
The built-in programs on many treadmills offer a convenient way for you to work out; the treadmill automatically changes the belt speed and the ramp incline for you. However, the moving belt can pose a risk if you are not prepared for it to change speed. Although many treadmills alert you before a speed change, if you miss the warning, the sudden change of speed may cause you to stumble and turn your foot wrong.
Side Rails
If you keep the treadmill belt clean, it provides a smooth, level surface to run or walk on. A treadmill belt is only 18 to 22 inches wide. On each side of the belt is a small gap and then the plastic rails. If you accidentally shift to one side and step on a rail, this will cause you to lose your balance and you could sprain your ankle.
Precautions
Use the safety key found on most motorized treadmills. The key attaches to a piece of rope. Insert the key in the console and hook the clip, which is on the other end of the rope, to your clothing. If you trip or lose your balance, the rope pulls the key out of the console, which automatically stops the running belt, preventing further injury.
If you are not used to running on a treadmill, use the handrails to keep your feet centered on the running belt. Don't grasp the handrails, but allow your hands to lightly touch them. This helps you maintain your sense of balance and space.
