Biomechanical Differences: Male and Female Marathon Runner

Bio robotic Differences Male and Fe antheral Marathon RunnerMore than by brain size or tool-making major power, the human species was set apart from its ancestors by the ability to jog mile after lung-stabbing mile with greater endurance than any other primate.The introductory quotation (Hotz, 2004) simply, yet vividly, expresses the results of a recent study ideal by 2 Ameri bath scientists, Dennis Bramble and Daniel Lieberman, and released in the journal Nature(2004). Bramble and Lieberman contend that the ability to run coherent outdistances was the driving force shaping the modern human anatomy.Hotzs characterization of early humans as marathon hands and wo custody from the tips of their differentively short toes and long Achilles tendons to the tops of their biomechanically balanced heads (emphasis added) sets the screendrop for this essayan exploration of the biomechanical differences among male and female marathon runners.After a few additional historical comwork forc ets, this essay opens with a presentation of anatomical differences betwixt men and women with ad hoc reference to runway then continues with definitions and descriptions of the term marathon, as a appoint of organized running maneuver, and definitions for the term biomechanics in preparation for a banter of how the report of biomechanics is applied to running. With this in varietyation as a foundation, the objective and scope will be articulated followed by presentation of previous methods and findings revealed from a search of the belles-lettres on the emergence of biomechanical differences surrounded by male and female marathon runners and closely-related topics. These findings will be discussed and conclusions drawn. Finally, recommendations for further inquiry will be presented.To re tress briefly to the research findings of Bramble, a paleontologist and biomechanics expert, and Lieberman, a physical anthropologist, to continue setting the backdrop for the essay, Bra mble states Running made us human, at least in an anatomical sense. We weigh running is one of the roughly transforming events in human history (Chui, 2004). Endurance running is an activity that is reserved for humans in the primate world and non common in other mammals with the exception of dogs, horses and a few others. Bramble and Lieberman contend that running permitted humans to scavenge and hunt for food over significant distances and that the uplifted protein food they secured was instrumental in developing larger brains (Wilford, 2004).To facilitate running, humans developed several traits including large buttocks with strong musclemans which connect the femur to the physical structure of the clay preventing the luggage compartment from over-balancing with each step. In addition, humans lose a lengthy arm-swinging stride and long ligaments and tendonsincluding the Achilles tendonwhich serve as springs that store and release mechanical energy during running.(Hotz, 2 004).Brambles reference to todays running in the evolutionary context he and Lieberman established provides an appropriate introduction to the exploration of the biomechanical differences between male and female marathon runners (Wilford, 2004) Today, endurance running is primarily a form of exercise and recreation, but its roots may be as antediluvian as the origin of the human genus.The description of anatomical differences between men and women,which is foc economic consumptiond on anatomical signs that are involved in running,begins with a sexual urge-neutral discussion to establish a foundation for the more gender-specific entropy.Rossi (2003) emphasizes the complexity of walking, a precursor torunning. He writes that half of the 650 muscles and tendons in thehuman body are involved in what almost people consider to be the simpleact of walking. He suggests that, in the evolution of the human body,there were hundreds of adaptations that had to take place,adaptations that r equired repositioning of everything in the bodyover several million years. Rossi writesThe arms, no seven-day needed for branch swinging, became shorter, thelegs longer, the pelvis wider, the shoulders qualifyer, the neck longerand more slender, the spine changed from C-shape to S-shape. Majorchanges were required in the hip, knee and ankle junctions. Hundreds ofmuscles, tendons, ligaments and joints gradually shifted in position,size and function. And of course, the new posture and stride requiredimportant changes in the size and position of all the organs of thechest and abdomen.Rossi suggests that near of these changes were extremely significantfrom a biomechanical perspective. For instance, he calls attention tothe blood pumping requirement of the upright human form Daily in eachindividual, nearly 74,000 quarts of blood must travel through one C,000 miles of blood vessels from the brain to the feet and legs in acircular pattern. Rossi emphasizes the human engineering chall engethat was required to design a body that would counteract the effectuateof gravity in moving blood vertically in this manner. Rossis commentsare particularly important in the context of the current discoursebecause they provide some insight into the current state of relevantanatomical features of todays runners and how those features werederived.The anatomy of humans, unlike that of other living creatures,provides for speed and endurance. The unique characteristics related torunning include (Science in Africa, 2005, citing University of universal time Public Relations, 2004) Skull features. These features, which include sweating from the scalp and face, cool the blood. A balanced head. This shape of head with a relatively flat face,small teeth, and short snout moves the total of the mass backwardwhich dish ups to counter the effects of moving upward and downward duringrunning. A ligament running from the rear of the skill and neck downward tothe thoracic vertebrae. This f eature serves as a shock absorber thataids the arms and shoulders in counterbalancing the head during runningactivity. Shoulders decoupled from the head and neck. This feature allowsrotation of the body while the head faces forward during running. A tall body. This feature, which includes a narrow trunk, waistand pelvis, provides for increased skin surface allowing for enhancedbody cooling and permits the upper and set about body segments to moveindependently. Short forearms. This feature permits the upper body to act as acounterbalance to the lower body during running activity while reducingthe muscle power required for maintaining flexed arms. stupendous vertebrae and disks. This feature permits the human back to accepted heavier loads when runners impact the ground. Large, strong conjunction between the pelvis and the spine. Thisfeature supports more stability and shock absorbing capacity duringrunning activity. Large buttocks. This feature, and the muscles that form it, stabilize the body during running activity. The connection of thesemuscles to the femur prevents the body from rake forward. Long legs. This feature allows humans to take large strides duringrunning activity. The tendons and ligaments permit the legs to belighter and less muscular thereby requiring a smaller amount of energyto propel them while running. Large hip, knee, and ankle joint surface areas. These featuresprovide enhanced shock absorption by reducing the impact in any onespecific area. Arrangement of bone ups in the backside. This feature provides for a morerigid foot by creating a stable arch, allowing runners to push off in amore efficient manner and to use ligaments located on the bottom of thefeet as springs. Large heel bone, short toes, and a big toe. These features providefor enhanced shock absorption and increased capacity to push off duringrunning activity.With the running-related anatomical features applicable to allhumans as a foundation, the focus now turn s to the differences inanatomical features between men and women, specifically those featuresthat are involved in running activity. Holschen (2004) writes that,until puberty, males and females are equal in terms of strength,aerobic power, content size, and weight they also concur similar amountsof body fat.Starting at puberty, according to Holschen (2004), male and female sexhormones begin affecting bone and lean body mass, circulation, andmetabolism in different ways. A female typically has a wider pelvis,femoral anteversion (inward twisting of the femur), genu valgum (kneestouch but ankles are separated), and external tibial torsion (feet donot line up in a straight manner because of out-toeing from outwardrotation of the large calf bone). Center of gravity differences betweenmen and women are minimal, correlating more by body type and heightthan with gender. (Atwater, 1985, cited in Holschen, 2004). Whencompared with males, females typically have smaller bones accompaniedby sma ller articular surfaces. They also have proportionately shorterlegs with resulting decreased potential force in certain maneuvers.(Holschen, 2004).At puberty, girls hand both fat and lean muscle mass due to theinfluence of female hormones boys lose body fat and add muscle massdue to the influence of male hormones (Holschen, 2004). Women inadulthood have about ten portion more body fat than do their malecounterparts (Greydanus, D. and Patel, D., 2002, cited in Holschen,2004). The basal metabolic rate is approximately ten percent lower inwomen than in men. The presence of female hormones mandates that womenrely more on fat metabolism at any given exercise level when comparedto men. In addition, glycogen uptake, storage, and use are increased.(Holschen, 2004, citing Bonekat, H. W. et al., 1987 Dombovy, M. L. etal., 1987 Frankovich, R. J. and Lebrun, C. M., 2000 Nicklas, B. J. etal., 1989 Tarnopolsky, L. J., 1990) Cureton and associates (1988,cited in Holschen, 2004) attribute the di fferences in muscle strengthbetween men and woman to skeletal and cardiac muscular hypertrophy andmuscle mass percentage they contend that muscle mass in men is fortypercent compared to twenty-three percent in women.Changes in body composition and circulatory capacity beginning atpuberty result in approximately twenty percent highercardio-respiratory capacity in men. Men also have comparatively higheroxygen-carrying capacity, larger heart and lung mass, a higher strokevolume, and higher maximal cardiac output which result in greatereffectiveness in aerobic and anaerobic activities, although trainingcan overcome the inherent differences (Williford, H. N. et al., 1993,cited in Holschen, 2004).The results of the current research point to fundamental anatomicaldifferences between men and woman, differences that largely begin toappear during puberty and which have some bearing on runningcapability.The term running can be defined as moving swiftly on foot sothat both feet leave the ground during each stride (American HeritageDictionary of the side Language, 2000). The research by Bramble andLieberman (2004, cited in Nature, 2004), which was presented earlier,seems to indicate that running has been part of human being sinceits beginnings and, in fact, contributed significantly to developmentof human life today. Humans no longer require running for survival, atleast in their normal affairs that is, typically, humans do not haveto run from danger or run in pursuit of animals to kill for food. Inmodern times, running has taken on a new formcompetition foot hotfoot.This competition racing can be against oneself to achieve ones ownpersonal best or with others. Racing against others can take manyforms ranging from informal competitions between ii young friendsracing against one another on a playground to very formal competitionssuch as those in the quadrennial Olympics. The more formal runningcompetitions are typically sort out by the length of the run 100,200, 400, 80 0, 1500, 5000, and 10000 meters as well as marathons(Dollman, 2003).There are many terms that refer to specific forms of foot racing run,dash, sprint, relay, meet, competitive trial of speed, foot rush, andmarathon (Websters New World Thesaurus, 1997). Of these, the termsdash and sprint are typically used interchangeably to describe ashort, fast run or race (Websters New World Dictionary, 1988) or ashort, swift movement (Websters New World Thesaurus, 1997). Organizeddashes and sprints are commonly of 50 meters, 100 meters, 200 meters,50 yards, 100 yards, and 200 yards in length (Websters New WorldThesaurus, 1997). Marathons are a form of long-distance running, whichare on- and off-the-track competitions of more than 3000 meters (Hlus,1997). Specifically, a marathon is a footrace of 42 kilometers, 195meters (26 miles, 385 yards) run over an open course, or anylong-distance or endurance contest People who compete in marathons arecalled marathoners (Websters New World Dictionary, 1998) .Physiologically, there is a fundamental difference between a sprint ordash and a marathon. According to Pritchard (1994), A sprinter canexert maximum force passim the run, but this is not possible forlonger runs, where propelling force must be reduced to match energyavailability.Historically, marathons are not new events. According to legend, thename marathon is derived from the Greek city, Marathon, to commemoratePheidippidess run from that city to capital of Greece to announce Greek victoryover the Persians. The marathon was introduced to the Olympics in 1896and todays official distance was established in 1908. (Hlus, 1997 TheColumbia Encyclopedia, 2005) Today, in addition to marathon races inthe Olympics, many cities throughout the world serve as sites forannual or other periodic marathons (The Columbia Encyclopedia, 2005).A new form of marathon race has recently taken formthe ultramarathon,which is any organized footrace extending beyond the standard marathonrunning distance o f 42 kilometers, 195 metersthey typically begin at 50 kilometers and extend to enormous distances (Blaikie, n. d.).Standard distances for ultramarathons are 50 and 100 kilometers and 50and 100 miles (Meyers, 2002) with the longest certified race being theSri Chinmoy, a 2092 kilometer race held annually in New York (Blaikie,n. d.).The research produced numerous and varied definitions for the termbiomechanics. The following are representative of the findings The study of the mechanics of a living body, especially of theforces exerted by muscles and gravity on the skeletal structure. (TheAmerican Heritage Dictionary of the English Language, 2000). The application of mechanical engineering principles andtechniques in the field of medicine and surgery, studying naturalstructures to improve those produced by humans (The HutchinsonEncyclopedia, 2003). A science examining the forces acting upon and within a biologicalstructure, and the effects produced by those forces (The University of Calgary, n. d.). The science that deals with forces and their effects, applied to biological systems (Freivalds, 2004). The application of the principles and techniques of mechanics to the human body in motion (Snowden, 2001). Biomechanics is a specific field which evaluates the motion of aliving beingnessand the actions of forces on that organismacombination of several different areas of study including anatomy andphysiology, kinematics (the study of motion without regard to itscauses), kinesiology (the study of human movement) and kinetics (thestudy of forces acting on a system) (National Endurance SportsTrainers Association, 2005).In furni clamberg a definition for biomechanics, the Quintic ConsultancyLtd. (2005) provides some additional insight into the origin anddetails of the term, stating that the name is derived from the Greekbios meaning life and mekhaniki meaning mechanics, adding that theseindividual terms are combine to mean the mechanics of life forms.The biomecha nics discipline includes research into various life formsincluding plants, insects, reptiles, birds, fish, humans, and others.Within the human specialty, topics include mechanics of bone, tooth,muscle, tendon, ligament, cartilage, skin, prostheses, blood flow, airflow, eye movement, joint movement and social unit body movement (TheQuintic Consultancy Ltd., 2005).Historically, according to Knudson (2003), the study of humanbiomechanics has alternated between emphasizing each of its twocomponentsthe biological and the mechanical. Atwater (1980, cited inKnudson, 2003) claims that, during the first half of the twentiethcentury, scholars emphasized medicine and anatomy under the termkinesiology. The distinct field of biomechanics was born from the workof biomechanists in the 1960s and 1970s. From that point the fieldbegan to emphasize mechanics over biology. Today, the competing forcesto move the discipline every toward a biological emphasis or toward amechanical emphasis continue (Knud son, 2003).The field of biomechanics, already narrowed in a previous sectionfrom consideration of all life forms to only humans for the purpose ofthis essay, can be cogitate even further to a sub-field called sportsbiomechanics (The Quintic Consultancy Ltd., 2005)Sports biomechanics uses the scientific methods of mechanics tostudy the effects of various forces on the sports performer. It isconcerned, in particular, with the forces that act on the humanneuromusculoskeletal system, velocities, accelerations, torque,momentum, and inertia. It also considers aspects of the manner ofsports implements, footwear and surfaces where these affect athletic exploit or injury ginmill. Sports biomechanics can be divided upinto two sections performance improvement and injury prevention.The Australian Sports Commission (n. d.) furnishes additionaldescriptive information on the application of biomechanics to sports,using a term the Commission calls applied sports biomechanics whichincorporates tec hniques from physics, human anatomy, mathematics,computing and engineering to analyse technique to prevent injury andimprove performance. The Commissions division of sports biomechanicsinto two categoriesperformance improvement and injurypreventionechoes the classifications offered by The QuinticConsultancy Ltd.Williams (2003) describes how biomechanics can help runnerperformance, specifically that of the marathoner. Leading into hisrecommendations, he describes how marathon runners use a simplebiomechanical strategy known as compose off another runner whenrunning into the wind to reduce the adverse effects of air resistanceand reduce oxygen consumption for the latter part of the race. HewritesThe goal of the sport biomechanist is to improve movement efficiency,mainly by maximizing propulsive forces and minimizing resistive forces,and thus provide the athlete with a mechanical edge. using high-speedcinematography, the biomechanist can analyze a runners form and detectproblems in r unning form that may be inefficient, such as overstriding,and that may waste energy. Although most elite and experiencedmarathoners have developed efficient running styles, even a smallimprovement in running efficiency may make a significant differenceover the duration of a marathon.In addition to the strategy of drafting off another runner,Williams offers several other biomechanical strategies includingselecting the proper sportswear (i.e. uniform and shoes) and optimizingbody weight and composition.Thus far the topics of anatomical differences between men and womenwith specific reference to running definitions and descriptions of theterms marathon (as an organized, competitive form of running) andbiomechanics and the application of biomechanics to running have beenpresented and discussed. With this as a foundation, the focus of thediscourse now turns to the topic of biomechanical differences betweenmale and female marathon runners and closely-related topics.The objective of this p ortion of the essay will be to explore thebiomechanical differences between male and female marathon runnersthrough a review and depth psychology of selected literature on the topic andrelated issues.The scope of the literature review will include marathon running withspecific reference to available information on the differences betweenmales and females. Although running of shorter distances (e.g. sprintsand dashes) and longer distances (e.g. ultramarathons) as well as othersports activities are excluded from the specific scope of this essay,references will be made to these activities when they related tomarathon running. Performance improvement and injury prevention werementioned as the two primary areas addressed by applied sportsbiomechanics. Gender-specific issues in each of these areas will beexplored briefly as well. REVIEW OF EXISTING RESEARCH ON METHODS AND FINDINGSOne researcher who has studied gender differences in enduranceperformance, including marathon running, is Step hen Seiler (1996) ofThe Institute for Sport, Agder College in Kristianstad, Norway. Hewrites Some years ago it was proposed by some that women wouldactually perform break dance than men at ultra-endurance type activities.This theory has been disproved in the laboratory and in practice. Aslong as women are women, I dont think they will surpass men, statesNorways repeated marathon winner Grete Waitz (quoted in Holden,2004). The anatomical differences between females and their malecounterparts, specifically those that affect running, were presented inthe introduction. Now an attempt will be made to show that the generalanatomical differences between men and women extend to biomechanicaldifferences that affect marathon running performance and injury.Holschen (2004) writes that The female athlete remains less wellunderstood and less well studied compared with male athletes,especially in the areas of performance factors, repetitive stress, andacute injuries. She continues Logical reasons for this include (a)a limited two-generation span of the high-profile elite female (b)fewer females involved in coaching, research, and sports medicine and(c) limited areas of female youth sports historically (gymnastics,swimming, dance). The humankind of Holschens findings proved to be truein the current research activity. There were remarkably few availablesources on the biomechanics involved in womens marathon running. Mostof the research either applied to males or did not identify the gender.Results from a review of selected research literature will be presentedin this section beginning with gender-differentiated research resultson running performance. chase this, results of research into thetwo applied sports biomechanics specialties will be presented with afocus on studies concerning footwear and injuries.Holden (2004) writes about performance in running with specialattention to female runners. She quotes physiologist Henrik Larsen ofthe Copenhagen Muscle Research Centre in explaining womens marathonperformance vis--vis men Women had not developed long distancethats why the improvement is much greater on the marathon. Larsen,who seems to attribute the performance improvements of femalemarathoners to focused training instead of anatomic factors, claimsthat we dont see any higher oxidative capacity in women. Holdenalso offers comments by exercise physiologist Timothy Noakes of theUniversity of mantel Town, South Africa who agrees with Larsensassessment A smaller body frame gives women an edge on endurancebutmen can run 10% faster even when the difference in body size iscontrolled for.Stephen Seiler (1996), who was quoted at the start of this sectionstating that the proposal that women could perform better inultra-endurance activities has been disproved, confirms that there aresome physiological differences between the sexes that impactperformance in females independent of age. He notes that there is aten percent difference in marathon times between me n and women, addingthat this difference is the selfsame(prenominal) across the distance runningperformance spectrum. He attributes this difference, not to adifference in training, but to physiological differences. He studiedmaximal oxygen consumption, the lactate threshold, and efficiency toanalyze the differences between men and women as these factors mightaffect long-distance running performance Maximal Oxygen Consumption. There is a 43 percent differencebetween men and women with men possessing a VO2 max (oxygen-deliveringcapacity measure) of 3.5 liters per minute and women with a capacity of2.0 liters per minute. Seiler attributes this in part to male size menare larger. But, even when size is factored in, male oxygen consumptioncapacity is still fifteen to twenty percent higher. Males have agreater capacity to deliver oxygen to their muscles and organs. The Lactate Threshold. This is the point at which lactic acidbegins to accumulate at higher than normal levels in the blood streamindicating an exercise intensity boundary at which the level ofintensity can be maintained over a long period and that which willresult in quick fatigue. Seiler does not believe that lactatethresholds are different for men and women as a percentage of their VO2max. Efficiency. After finding conflicting information comparing theefficiency of males and femalesrevealing that females are lessefficient, more efficient, or the same as males in terms ofefficiencySeiler believes that differences in efficiency do notaccount for the differences in endurance performance.Seiler concludes with his finale that the ten percentperformance difference between men and women in endurance running canbe attributed to the first of the three physiological factors hestudiedmaximal oxygen consumption.Another researcher who explored gender differences in athletics,and especially in endurance events, is Dollman (2003). Citing Shepard(2000), Dollman writes that there is consistent evidence, based onobs ervations, that males possess larger measures of the following(quoted) Heart volume, even when corrected for stature. Haematocrit, which gives males a 13 percent greater oxygen-carrying capacity than females. Plasma volume. Total muscle mass, which means that females perform the sameabsolute task at a higher percentage of maximum voluntary contraction,with tender vascular impedance limiting cardiac ejection and peakcardiac output.In addition, male skeletal muscles may have a higher succinatedehydrogenase (an integral membrane protein) minginess (Dollman,2003, citing Costill, et al., 1987). Males may produce bettermechanical efficiency during running (Dollman, 2003, citing Miura,1997) although this is arguable as it may be rooted in cultural origins(Dollman, 2003, citing Shepard, 2000).Now attention will turn briefly to a review of selected researchinto the two primary application areas addressed by applied sportsbiomechanics running performance and injuries. Regarding performa nce,footwear will be discussed followed by a presentation of selectedfindings on research into injuries. Gender issues will be introduced.Lipsky (2001, citing Hennig, 2001) presented research findings ongender-specific requirements for athletic footwear designed forrunning. The research experiment involved fifteen women and seventeenmen of the same body weights, heights, and ages. Each subject wore thesame shoe size and each tested five types of shoes which included threestyles of mens shoes and two styles for women. Using Kistler forceplatforms at a set velocity, ground force reactions, tibialacceleration, angular foot motion, and plantar pressures at eightstrategic locations on the foot were measured. According to Lipsky, theexperiment revealed that none of the variables demonstrated asignificant fundamental interaction among gender and footwear type meaning, Lipskycontends, that women had the same biomechanical dilemmas in mensshoes as they did in their own footwear. Despite simi larity in thetest subjects weight and other factors, men exhibited higher pressurerates in all regions of the foot. Men had significantly higher heelloads, but less midfoot loads, indicating that the arches of women donot support the middle of their feet. According to Lipsky, theseresults support the conclusions that women have a stronger buckle ofthe longitudinal archduring weight bearing and have an increasedtendency of pronation and the smaller amount of pressure to theground. The recommendation from this study is that women should selectrunning shoes that protect against overpronation. This, according toLipsky, will help prevent knee injuries.Bartold (2004) adds to the literature on the differences inrequirements for athletic shoes for men and women. He claims thatrunning footwear is largely designed and manufactured for malerunners, making little recognition that women have significant injuryissues compared to men. Although Bartold acknowledges that reasons forinjuries are no t scientifically established, he indicates thatproposals have been made that known differences in structure maypredispose female athletes to differences in running mechanics, andthese differences may lead to specific injuries, continuing by statingthat anecdotally, we have excellent evidence that the particularbiomechanics of female athletes and the way they run predisposes themto specific injury patterns.With regard to injuries, Parfit (1994) compared running injuries ofmiddle distance runners and marathon runners, concluding that thelatter incur more injuries when compared to the former (approximatelyeighty-two percent for middle distance runners compared to ninety-sevenpercent for marathoners). Acknowledging validity questions due to smallrunner populations studied and lack of injury definitions, Parfit foundthat whilst marathon runners suffered from back problems and hipailments, middle distance runners were more susceptible to kneeproblems, stress fractures, and shin splints.Ce rtain types of knee, shoulder and back injuries are more commonin females and can in part be attributed to differences in body shapeand biomechanics, reports Glasgow, Scotlands Daily Record (2004).Taunton et al. (2002) found that there were significant differencesbetween running injuries incurred by men and women. According to thisstudy, knee injuries seemed to be the most common injury in both sexeswith men experiencing higher incidences of the following injuries (thefirst percentage shown in parenthesis is for men the second forwomen) plantar fasciitis, an injury to the splasher connective tissue on the bottom of the foot (54%/46%) meniscal injury, a condition in the knee cartilage that acts ascushion between the thigh bone (femur) and shin bone (tibia) (69%/31%) patellar tendinopathy, a rupture in the tendon that connects the kneecap to the tibia (57%/43%) Achilles tendinopathy, tendon agony or dysfunction in the muscle that connects the calf to the heel of the foot (58%/42 %) gastrocnemius injury, a condition in the largest, most prominentmuscle in the calf which allows for extending the foot and bending theknee (70%/30%) adductor injury, a condition, such as a tear, in the muscle in the inner thigh (68%/32%) and osteoarthritis of the knee, a degenerative joint diseasecharacterized by breakdown of the articular cartilage in the joint(71%/29%).The study by Taunton et al. (2002) revealed that women experiencedhigher incidences of the following running injuries (the firstpercentage shown in parenthesis is for women the second for men) PFPS, or patellofemoral pain syndrome, a pain behind the kneesometimes known as runners knee (62%/32%, does not add to 100%) ITBFS, or iliotibial band attrition syndrome, a conditioncharacterized by injury to the thick band of fibrous tissue that runsdown the outside of the leg beginning at the hip and extending to theouter side of the shin bone just below the knee joint (62%/32%, doesnot ad