Mar-09
Study Examines Shoelace Patterns On Running Shoes
By Brian McCurdy, Senior Editor
Before hitting the track, runners must take various factors into account to streamline their performance. A recent study in the Journal of Sports Medicine explores how different shoelace patterns can affect the biomechanics of runners.
According to the study, researchers evaluated 20 experienced runners and the influence of shoelace tightness and the number of laced eyelets upon foot pronation during contact, tibial acceleration and plantar pressure distribution.
Researchers found that running shoes with the tightest and highest lacing conditions exhibited reduced loading rates and pronation velocities. The seven-eyelet lacing pattern facilitated the lowest peak pressures under the heel and lateral midfoot, according to the study authors. Researchers concluded that a firm foot-to-shoe coupling with higher lacing facilitates a more effective use of running shoes, and may reduce the risk of lower limb injury.
David Levine, DPM, CPed, says the study’s conclusion is logical as the tighter the shoelaces are, the more support the runner has and the better the foot will stay in place.
“Lacing can be subjective as can the fit of shoes but the bottom line is that the shoe needs to be tied tight. Now there is data to support that,” says Dr. Levine, who is in private practice in Frederick, Md.
Doug Richie Jr., DPM, agrees that a tightly laced shoe seems to enhance performance. He attributes this to either the enhanced “coupling” of the foot to the shoe as the researchers suggest or an enhanced proprioceptive mechanism that gives the athlete a better “feel” for the sport surface.
Richard Bouché, DPM, usually recommends that athletes use all seven laces, which ensures good coupling of the foot and shoe. When athletes combine this lacing with a textured insole and an appropriate shoe for their specific foot type, it can be helpful in preventing injuries, notes Dr. Bouché, a Fellow of the American Academy of Podiatric Sports Medicine.
When Tight Lacing Is Problematic
Dr. Richie sees more frequent injuries from shoes laced too tightly than from loose laces. He says injuries arising from too tight laces commonly include tendinopathy in the extensor tendons and in the anterior tibial tendon. Since there is little intrinsic protective tissue over the dorsum, Dr. Richie notes that shoelaces can impinge and injure tendons that are actively working during the contact phase of gait.
“These injuries, once they occur, are extremely difficult to resolve. I would much rather advocate a comfortable, medium tension lace adjustment rather than a tight lace for most athletes,” says Dr. Richie, an Adjunct Associate Professor in the Department of Applied Biomechanics at the California School of Podiatric Medicine at Samuel Merritt College.
Dr. Bouché notes that if the quarter of the shoe is too high, the ALL7 lacing pattern can cause irritation on the ankle bones (fibular more than tibial) “because it snugs up the topline of the shoe opening.”
Dr. Levine says there are several variables (including foot structure and bony prominences) that one should consider. He says runners might skip a pair of eyelets if they have bony prominences. Dr. Levine also points out that it can be impractical in some situations to lace a shoe tightly due to spurs or a high instep as this could cause dorsal nerve compression.
In his practice, Dr. Bouché offers different lacing patterns for various types of patients. In addition to the high instep that Dr. Levine points out, Dr. Bouché says runners with a wide foot, narrow foot, pronated foot or supinated foot may require different lacing techniques. For example, he will employ a forefoot lacing pattern for patients with recurrent great toe problems to lessen excessive pressure that will help to prevent subungual hematomas.
Abstract: Apligraf Effective For Diabetic Heel Ulcers
By Lauren Grant, Editorial Assistant
A new study abstract, submitted for the Symposium on Advanced Wound Care (SAWC) in April, explores the healing effects of Apligraf (Organogenesis) on diabetic heel ulcers.
The study, conducted over a year and a half, assessed wound care treatments for diabetic heel ulcers in 34 patients. Of the 34 patients, 21 patients with an average wound size of 16.3 cm2 were treated with Apligraf while 13 patients with an average wound size of 24 cm2 were treated with other wound care products such as Duoderm gel (Convatec).
Out of the 21 ulcers treated with Apligraf, 10 reached complete closure by the 12th week while no wounds from the other group healed in the same time. In the Apligraf group, the wound area decreased an average of 72 percent while patients treated with other products had a 56 percent average reduction of wound size. Researchers also note that of the 13 patients who did not receive Apligraf, two underwent major amputations within the 12-week period while a third patient had a severe infection.
“Apligraf is an active product which provides keratinocytes, fibroblasts, growth factors and cytokines. These stimulate the chronic wounds and help to ‘revitalize’ the cells in the wounds to improve healing,” says Hau Pham, DPM, the lead author of the abstract and an Attending Physician at Boston Medical Center.
While this study was conducted with a larger sample, Dr. Pham feels the use of Apligraf in heel ulcers was important to highlight, given that heel ulcers are often difficult to heal.
Dr. Pham, an Assistant Professor of Surgery at the Boston University School of Medicine, concedes that the average ulcer size between the two treatment groups at the beginning of the study was “significantly different.” However, Dr. Pham notes that “some of the ulcers in the ‘non-Apligraf’ group with small size still did not achieve healing.” He also points out that the healing rate of the ulcers in the Apligraf group that did not heal in 12 weeks was “significantly better” than the rate for the non-Apligraf group.
The SAWC will be held from April 26 to 29 at the Gaylord Texan Hotel and Convention Center in Dallas. For more information, visit www.sawc.net. n
Editor’s note: For a related article, see “A Closer Look At The Research On Bilayered Living Cell Therapy” in the July 2008 issue of Podiatry Today.
Can Wound Fluid Components Predict DFU Healing?
By Brian McCurdy, Senior Editor
Given the sometimes dire complications of diabetic foot ulcers, having methods of predicting poor healing is vital. A recent study in Diabetes Care looks at how matrix metalloproteinase-9 (MMP-9), tissue inhibitors of matrix metalloproteinases (TIMP) and transforming growth factor-b1 (TGF-b1) can predict healing.
The study focused on 62 ulcers, 56 of which were diabetic. Researchers cleansed the ulcers, removed exudates and collected wound fluids to analyze MMP-9, TIMP-1 and TGF-b1. The study found that MMP-9 and the ratio of MMP-9 to TIMP-1 were both lower in the 23 patients who achieved healing at 12 weeks in comparison to the 39 patients who did not complete healing. Furthermore, the pro-MMP-9 concentration was predictive of healing at 12 weeks, according to the study.
The study authors conclude that a high MMP-9 may indicate poor wound healing and inflammation. They also note that measuring MMP-9, TIMP-1 and TGF-b in wound fluids may help predict ulcers that are at high risk of poor healing.
Khurram Khan, DPM, says any indicators of wound healing are advantageous as they add to the armamentarium of wound care physicians. However, he does question the practicality of measuring MMPs and whether one can “transfer (this) bench work to the bedside.” To measure MMPs, Dr. Khan says one must perform a gelatin zymography and TIMP and TGF measurements require an Elisa study. He notes these tests are out of the realm of average practitioners. He adds that the MMP test may not be cost effective as one must transport the MMPs at -20ºC.
In regard to further research, Dr. Khan suggests concentrating not only on the products one can use to reduce MMPs but to what degree. He questions whether one should reduce the MMP load to zero or if there is an optimum level. Dr. Khan also suggests researching a way to convert the information in the study into a practical “litmus test” by which one can measure MMPs, TIMP and TGF.
“If this can be achieved, then the ability to take this information and make it useful in terms of everyday clinical experience will be increased by tenfold,” says Dr. Khan, an Assistant Professor in the Department of Medical Sciences at the New York College of Podiatric Medicine.
In Brief
John (Jack) Nelson, DPM, has been appointed as Interim Dean of the School of Podiatric Medicine at Barry University. A member of the Barry community since 1988, Dr. Nelson will be replacing Chet A. Evans, DPM, who served as the dean for 22 years, according to the school.
