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Paresthesias Can Be a Pain for Backpackers By Christine Dobrowolski, DPM It's a clear, crisp morning and the scenery is breath-taking. Your legs feel solid as you begin to hike on your annual backpacking trip with old college friends. All the running after work, weight lifting at the gym, and hiking on the weekends has paid off, as the miles slip by. All of the sudden there's a sharp, bizarre pain in your right foot. Climbing up the switchbacks is grueling enough without this burning and numbness. It's like nothing you've felt before. The First Aid kit you so carefully pieced together seems useless now. The burning worsens with each step, and electrical pain shoots from the ankle to the toes. As you sit down to yank off the hiking boot, pull the sock, and free the confined toes, a feeling of anxiety comes over you. What is this pain? Will it worsen if I continue? Will I be able to make it through the rest of the trip? A study in The Journal of Wilderness & Environmental Medicine found 34% of backpackers hiking seven or more days experience "paresthesias", yet many backpackers are unaware of the warning signs of this fairly common problem. A paresthesia is an abnormal sensation that occurs in the extremities. Paresthesias are described as tingling, burning or prickling sensations. Numbness commonly accompanies these sensations and sharp electrical pain can be experienced as well. There are many causes of paresthesias including diabetes, under active thyroid, vitamin B12 deficiency, stroke or even certain medications, but paresthesias in backpackers typically result from nerve damage due to excess pressure on nerves. The pack can place pressure on a nerve and over an extended period of time the pressure will irritate and damage the nerve, eliciting numbness or a burning sensation. Continued hiking up and down uneven and steep terrain places excessive pressure on nerves, also causing irritation and resulting in burning or tingling sensations. In the study, 81% of the backpackers experienced numbness. Their greatest risk factor for the development of paresthesias was a distance of over 2000 miles. Another contributing factor was the duration of the daily hike. Those backpackers who hiked for longer hours each day were more likely to develop paresthesias. Surprisingly, backpack weight, initial body weight, multivitamin use and the types of shoes or boots worn were not significant factors in the development of paresthesias. Should you be worried? If weakness or paralysis of the extremity, associated confusion, loss of consciousness, slurred speech or vision changes accompany the numbness and burning, then this may present a true medical emergency. Most likely, these symptoms will not accompany the paresthesias. In The Journal of Wilderness & Environmental Medicine study, 98% of the backpackers who experienced paresthesias had complete resolution of their symptoms in 30 days after their backpacking trip was complete. If you do experience these symptoms, you need to first assess why you have developed the sensations. Is the backpack pinching one of the nerves? Adjusting the backpack may help relieve some of these symptoms. You can relieve burning and tingling sensations in the leg by resting, removing the shoe and massaging the calf and the foot. Anti-inflammatory medications (like ibuprofen) may help. If you experience these symptoms, it is recommended that you decrease your daily mileage. If the symptoms persist, you may need to shorten the overall trip. In most cases, paresthesias are transient and self-limiting. By altering your pack, your shoes or your mileage, the paresthesias will resolve on their own. If you continue to experience the paresthesias after the backpacking trip, your should visit your doctor. A persistent burning pain on the bottom of your foot could represent tarsal tunnel syndrome. Although only 6% of backpackers with paresthesias had tarsal tunnel syndrome, this problem may be more likely to persist after the trip. Similar to carpal tunnel syndrome in the wrist, tarsal tunnel syndrome is pressure on the nerve that supplies the bottom of the foot. This may be due to rotation in your feet and in some cases can be controlled by orthotics and may be preventable for future backpacking trips. Christine Dobrowolski is a podiatrist, runner, and author of "Those Aching Feet: Your Guide To Diagnosis and Treatment of Common Foot Problems," available via her publisher, SKI Publishing, and at Barnes & Noble and Amazon.com. Articles by Dr. Christine Dobrowolski, DPM Recommended Products at Northcoast Footcare.com Superfeet Orthotics Deluxe Heel Pain Kit