Sprained Ankle
Ankle sprains result from a twisting force, where the foot rolls to the inside under the leg. If that's not how it happened, it may NOT be a simple "sprain."
Ankle sprains result from a twisting force, where the foot rolls to the inside under the leg. If that's not how it happened, it may NOT be a simple "sprain."
Scenario:
Most ankle sprains occur, not while crashing, but when stepping off the bike or walking alongside the bike. In adults, the sprain occurs when the foot lands on a log or rock, and the foot tips inward.

In children, ankle sprains occur when riding a bike that's too big. As the child tries to step off, the bike must tilt far to the side before the foot can touch down. (The child's body also travels sideways as the bike tips.) This lateral motion causes the ankle to pull under when the foot touches the road.

Description:
A sprain is a stretching injury to ligaments (the bands of tough tissue that control which direction joints can bend). A minor sprain may swell slightly, but does not significantly interfere with using the injured part. Bruising in the area of the sprain indicates tearing of ligament tissue. Sprains can be serious if the ligament is ruptured.
Serious ankle sprain, caused by stepping on a rock while walking the bike up a steep hill. Note the swelling on the outer side of the left ankle.
Serious ankle sprain, caused by stepping on a rock while walking the bike up a steep hill. Note the swelling on the outer side of the left ankle.
Swelling in front of the outer ankle bone from a sprain.
Swelling in front of the outer ankle bone from a sprain.
Here we see the typical swelling of an "inversion" sprain of the ankle. Most of the swelling is just in front and slightly below the bony bump on the outer side of the ankle. The back of the bone isn't tender. Typically, any swelling from a minor sprain will be in front of the bony prominence on the outer side of the ankle, and takes a while to show up. An immediate bulge of swelling suggests bleeding from a torn ligament.
If some ligament fibers have been torn, a bluish discoloration may appear in the swollen area. This is blood. Bruising indicates tearing of deeper tissues. This means a more serious injury, and a longer rehabilitation time.
Vague blue color beneath the swelling, early after a twisted ankle.
Vague blue color beneath the swelling, early after a twisted ankle.
Here we see bruising appearing on the INNER side of the ankle -- the blood came from the outer side of the ankle, crossing over behind the achilles tendon.
Here we see bruising appearing on the INNER side of the ankle -- the blood came from the outer side of the ankle, crossing over behind the achilles tendon.
After a few days, the area may appear more intensely bruised. The bruising can cross behind the achilles tendon to appear on the inner side of the ankle and heel. It can even travel down to the toes. Bruising indicates a more severe ligament injury.
Concerns:
A serious sprain can take a long time to heal. It can leave the ankle weak. If there are signs of serious injury, you should have the doctor help you. Even if there's no fracture, you may need physical therapy, special exercises, and precautions while the ankle heals.

See the doctor if:
    there's deformity or severe swelling
    the ankle can't be walked on after an hour of rest
    you can't move the joint fully
    there's continued severe pain
    there's numbness or weakness below the injured area.

One week after this serious sprain, the entire foot remains bruised and swollen. Note the "pit" in the swelling created by pressure.
One week after this serious sprain, the entire foot remains bruised and swollen. Note the "pit" in the swelling created by pressure.
Immediate care:
The treatment of a sprain is "RICE:" Rest, Ice, Compress, and Elevate. Immediately elevate the injured part and apply an ice bag. Once the area is thoroughly cooled, apply an elastic wrap to compress the injury. Coban wrap is a light, efficient wrap that you can carry in your biking backpack. It compresses and stabilizes sprains, and can hold a dressing over cuts and scrapes while you ride your bike back to civilization.
Ice and elevation and compression applied to a sprain.
Ice and elevation and compression applied to a sprain.
Ankle brace.
Ankle brace.
Ongoing care:
For the first 48 hours, repeat ice and elevation 1/4 of the time (for example, 30 minutes of ice every two hours). As the pain subsides, return to activities. The rule is: "If it hurts, don't do it." You can usually stop using the elastic wrap after 2 to 3 days. If the ankle seems weak, wobbly, or painful in routine use, go to the doctor.

If you need support while an ankle sprain heals, there are a variety of ankle braces, ranging from a simple pull-on elastic sock, to strong braces like the one at left. The worse the sprain and the harder your activities, the more protection you need.

Ankle rehab:
After about a week, start strengthening the muscles on the front and side of the lower leg. Continue the exercises for up to six months, until the ankle seems fully strong and secure.

Strength and tightening: Pull your foot up (towards your face) against resistance. A two-pound dumbell taped to the toe of a shoe works great as an ankle-exercise machine. Lift about 20 times, twice a day.
Balance and control: Stand on the injured foot. Raise the heel up, standing on the ball of your foot. Start the ankle shaking side-to-side. Go slowly up and down, while looking straight ahead. Keep your balance while raising and lowering your body as the ankle shakes, for a total of 1 minute twice a day.

Contrast baths. An option to improve blood flow during healing.
Contrast baths. An option to improve blood flow during healing.

Restoration of mobility:
If the ankle remains stiff and swollen, try contrast baths. Soak the ankle in warm water for 10 to 15 minutes, then begin gentle range of motion. Stretch 30 seconds up, then 30 seconds down. Repeat this 10 times. Now soak the ankle in cold water for 10 minutes, followed by elevation while your ankle rewarms.

Watch for:
If the injured area doesn't improve promptly, see the doctor.