Color Blindness and Trail Blazes

a properly painted North Country Trail blaze

excerpted from the Finger Lakes Trail e-group, Sept 7,8, 2009

Recently, on the Finger Lakes Trail e-group there was a discussion about trying to follow trails if one is color blind. Some of the branch trails of the FLT system are blazed in orange, and these blazes are nearly invisible to those who are red-green color blind. The problem primarily affects men, with somewhere between 5 and 7% of the population being unable to discern red and green. Other, much less common problems with color perception occur. About one-half of one percent of women are red-green color blind.

Many trails are marked with colors that contain large amounts of red or green pigment, so in the discussion that followed several people offered suggestions for how to see trail blazes when there are problems discerning colors. Three different fellows in the group admitted that they have difficulties with this, so the situation does come up.

Someone said that it is a problem for him to tell the FLT white-blazed main trail from the blue-blazed side trails. At a junction he’s never sure if he’s continuing on the main trail or headed for a campsite or water source.

Another person mentioned that in Europe sometimes blazes have stripes so that the colors can be seen. That doesn’t seem like a very good solution. It’s often hard enough to get trail maintainers who will keep a trail blazed with one color, let alone coming back when the paint is dry to add a stripe!

Another man said that he always hikes with a non-color blind friend.

Lynda Rummel, the Finger Lakes Trail Conference Director of Trail Quality offered several good ideas. First she identified two parts of the challenge: “picking out the manmade blazes from the natural blobs on the trees, and secondly, identifying the color of the blaze, once the blaze has been seen”

She offered an interesting aid for color blind hikers. She suggests getting several pieces of vinyl siding (or something similar), and cutting them into 2x6" rectangles, which is the size of an FLT, or North Country Trail, or Buckeye Trail blaze. Then paint each one with the official colors of the blazes in the areas where you hike. The local trail maintainer should be able to help you with this. When these dry, write on each one with a permanent marker what color it is.

When you are hiking you can hold these color swatches up to a blaze to see which shade is the better match.

Linda also suggested using other clues, which are good advice for anyone:

• At junctions, ask yourself, "Which trail has more use?" The main trail is likely to be well worn, where a side trail will be narrower and less compacted.
• If the blazes are not the precise rectangles they are supposed to be, is there some similarity between the wrong-ness of the blazes. Perhaps they tend to trail off down the tree. Noting such details can help a person tell a blaze from a blob.
• Become familiar with GPS and use it

On the other hand, trail maintainers can help by

• making sure that blazes have crisp corners (a rectangle is not a normal shape in the woods so it can be spotted)
• touching up often so the blazes are fresh and bright.
• Bbeing sure to paint over blazes on abandoned trail sections with black, gray or camo paint so that they really are gone.
• adding reassurance markers following junctions which may be disks, emblems or whatever symbol is preferred by the trail manager.

See Guide to Painting Trail Blazes

Natural Repellant Found as Effective as Deet

Ixodes scapularis, the black-legged or deer tick (photo from Michigan State University)

a news release of the Entomological Society of America

Isolongifolenone, a natural compound found in the Tauroniro tree, also known as Bastard Bulletwood, of South America, has been found to effectively deter biting of mosquitoes and to repel ticks, both of which are known spreaders of diseases such as malaria, West Nile virus, and Lyme disease.

Derivatives of isolongifolenone have been widely and safely used as fragrances in cosmetics, perfumes, deodorants, and paper products, and new processing methods may make it as cheap to produce as DEET.

The authors found that isolongifolenone deters the biting of two kinds of mosquitoes more effectively than the widely used synthetic chemical repellent DEET (N,N-diethyl-3-methyl benzamide) in laboratory bioassays. Furthermore, it repelled blacklegged ticks and lone star ticks as effectively as DEET. The two species most repelled are Aedes aegypti (L.) and Anopheles stephensi Liston.

Since “isolongifolenone is easily synthesized from inexpensive turpentine oil feedstock,” the authors write, “we are therefore confident that the compound has significant potential as an inexpensive and safe repellent for protection of large human populations against blood-feeding arthropods.”

In addition, a new, patented method developed by the authors to efficiently produce isolongifolenone would make it even more cost effective.

The results of this research are presented in the latest issue of Journal of Medical Entomology in an article by Aijun Zhang et. al titled “Isolongifolenone: A Novel Sesquiterpene Repellent of Ticks and Mosquitoes.”

The full text of the article is available at The Entomological Society of America, with a subscription.
See Big Mosquitoes are Safer Mosquitoes
See Researchers Put the Bite on Mosquitoes

Heel Pain of Plantar Fasciitis Can Be Eliminated

a news release of the Radiological Society of North America

Combining an ultrasound-guided technique with steroid injection is 95 percent effective at relieving the common and painful foot problem called plantar fasciitis, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA).

"There is no widely accepted therapy or standard of care for patients when first-line treatments fail to relieve the pain of plantar fasciitis," said the study's lead author, Luca M. Sconfienza, M.D., from Italy's University of Genoa. "Our new technique is an effective, one-time outpatient procedure."

Plantar fasciitis, the most common cause of heel pain, is an inflammation of the connective tissue called the plantar fascia that runs along the bottom of the foot, from the heel to the ball of the foot. The condition accounts for 11 percent to 15 percent of all foot symptoms requiring professional care and affects one million people annually in the U.S.

Conservative treatments, which may take up to a year to be effective, include rest, exercises to stretch the fascia, night splints and arch supports.

When the condition does not respond to conservative treatments, patients may opt for shockwave therapy, in which sound waves are directed at the area of heel pain to stimulate healing. Shockwave therapy is painful, requires multiple treatments and is not always effective. Complications may include bruising, swelling, pain, numbness or tingling and rupture of the plantar fascia. In the most severe cases of plantar fasciitis, patients may undergo invasive surgery to detach the fascia from the heel bone.

For this study, Dr. Sconfienza and colleagues used a new ultrasound-guided technique, along with steroid injection, on 44 patients with plantar fasciitis that was unresponsive to conservative treatments.

After injection of a small amount of anesthesia, the anesthetic needle is used to repeatedly puncture the site where the patient feels the pain. This technique is known as dry-needling. Dry-needling creates a small amount of local bleeding that helps to heal the fasciitis. Lastly, a steroid is injected around the fascia to eliminate the inflammation and pain. The technique is performed with ultrasound guidance to improve accuracy and to avoid injecting the steroids directly into the plantar fascia, which could result in rupture.

After the 15-minute procedure, symptoms disappeared for 42 of the study's 44 patients (95 percent) within three weeks.

"This therapy is quicker, easier, less painful and less expensive than shockwave therapy," Dr. Sconfienza said. "In cases of mild plantar fasciitis, patients should first try noninvasive solutions before any other treatments. But when pain becomes annoying and affects the activities of daily living, dry-needling with steroid injection is a viable option."