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Estudio Transversal Sind Banda Iliotibial

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  • 8/12/2019 Estudio Transversal Sind Banda Iliotibial



    Assessment of Strength, Flexibility, and Running Mechanics in Males with Iliotibial BandSyndrome

    Brian Noehren, P, Ph!"

    Anne Schmit#, Ph!"

    Ross $em%el, BS


    &arolyn 'estla(e, MS"

    'illiam Blac(, M!)

    "!i*ision of Physical hera%y, +ni*ersity of entuc(y, -exington, ., +SA)!e%artment of S%orts Medicine, +ni*ersity of entuc(y, -exington, ., +SA

    here are no funding sources to disclose/ he study %rotocol was a%%ro*ed by theInstitutional Re*iew Board at the +ni*ersity of entuc(y/

    Address corres%ondence to Brian Noehren, )01! 'ethington Building, 200 South-imestone Street, -exington, . 10345/ 67mail8 b/noehren9u(y/edu/



    mailto:[email protected]:[email protected]
  • 8/12/2019 Estudio Transversal Sind Banda Iliotibial



    Study Design8 &ross7sectional laboratory study/

    Objectives8 o assess differences in hi% strength, iliotibial band length, and hi% and

    (nee mechanics during running between male runners with iliotibial band syndrome and

    healthy controls/

    Background8 Flexibility, strength, and running mechanics are commonly assessed in

    %atients with iliotibial band syndrome :IBS;/ $owe*er, these *ariables ha*e not been

    e*aluated concurrently in this %o%ulation/

    Methods8 hirty7four males %artici%ated :"< healthy, "< IBS;/ $i% strength was

    measured with a hand held dynamometer and iliotibial band flexibility was assessed

    using an inclinometer while %erforming the =ber>s test/ inetic and three7dimensional

    (inematic data were obtained during running/ inematic *ariables of interest included

    frontal and trans*erse %lane hi% and (nee ?oint angles during early stance/ Inde%endent

    sam%le t7tests as well as effect si#es were used to assess grou% differences/

    Results8 &om%ared to the control grou%, %ersons with IBS had a significantly lower

    =ber>s measurement :"/)@;, wea(er hi% external rotators :"/) Nm(g;, greater hi%

    internal rotation :4/

  • 8/12/2019 Estudio Transversal Sind Banda Iliotibial



    %o%ulation/4) !es%ite its high %re*alence, little is (nown about the etiology of this

    condition/ !e*elo%ment of IBS is thought to include extrinsic factors :e/g/ training

    *olume, shoe wear; as well as intrinsic factors :e/g/ flexibility, strength, running

    mechanics, etc/;/

    Physical thera%y %rograms ty%ically focus on addressing the intrinsic factors that

    contribute to IBS/ 'hile there ha*e been limited re%orts on the role of these intrinsic

    factors indi*idually, there has been no com%rehensi*e analysis of these factors within

    the same grou%/ Moreo*er, %re*ious studies ha*e consisted of males and females, or

    females only/ &onsidering males with IBS as a se%arate grou% may be im%ortant as

    %re*ious research has shown that men and women differ in terms of muscular strength

    and running mechanics// In addition, establishing an in?ury %rofile in men with IBS is

    im%ortant since males com%rise 30 to C" of those suffering from IBS/ 4)

    $i% strength and iliotibial band :IB; flexibility are commonly assessed as %art of

    the e*aluation of an in?ured runner with IBS/ For exam%le, hi% abductor wea(ness has

    been demonstrated in trac( athletes with IBS/")$owe*er, this is in contrast to more

    recent research in which no differences in hi% abductor strength in %ersons with IBS

    were re%orted/"1 he conflicting results between %re*ious studies could be the result of

    different testing %rocedures :isometric *ersus iso(inetic assessment of muscle strength;

    and grou% demogra%hics :high le*el athletes *ersus recreational runners;/

    'hile there ha*e been a limited number of re%orts on hi% abductor strength in

    runners with IBS, there ha*e been no studies e*aluating hi% external rotation strength

    in this %o%ulation/ $i% external rotation strength %lays an im%ortant role in %ro*iding

    rotary control of the hi% and wea(ness of the external rotators may contribute to greater



  • 8/12/2019 Estudio Transversal Sind Banda Iliotibial



    strain on the IB/"-astly, while the =ber>s test is commonly used as an indicator of IB

    flexibility, the authors are not aware of any %ublished re%orts e*aluating whether runners

    with sym%tomatic IBS exhibit diminished IB length/

    Abnormal running (inematics, s%ecifically excessi*e motions of the hi% and (nee

    in the frontal and trans*erse %lanes, are often cited as im%ortant contributing factors

    with res%ect to the de*elo%ment of IBS/ he attachment sites of the IB ma(e this

    structure %articularly *ulnerable to altered secondary %lane running mechanics/

    Proximally, the IB is attached to the %el*is through both the tensor fascia latae and

    gluteal muscles/ !istally, its insertion includes the lateral femoral e%icondyle and

    Derdy>s tubercle/ herefore, greater hi% and (nee adduction, as well as greater hi% and

    (nee rotation may increase the tensile strain in the IB/

    $amill et al/ ha*e confirmed that runners with sym%toms do ex%erience greater

    IB strain rates during the early stance %hase of running/"3 $owe*er, %re*ious

    in*estigations e*aluating the (inematic *ariables that may contribute to the de*elo%ment

    of IBS ha*e been mixed/ For instance, one study of women with IBS found greater

    %ea( hi% adduction and (nee internal rotation whereas another study using a mixed

    sam%le of males and female runners with IBS found no differences in hi% or (nee

    (inematics/ he lac( of consensus among studies suggests that males with IBS may

    ha*e a different (inematic %rofile when com%ared to females/

    he %ur%ose of the current study was to assess differences in hi% abduction and

    external rotation strength, IB length :=ber>s test;, as well as frontal and trans*erse

    %lane (inematics at the hi% and (nee in males with and without IBS/ Based on what is

    (nown about the intrinsic factors that may contribute to IBS, it was hy%othesi#ed that



  • 8/12/2019 Estudio Transversal Sind Banda Iliotibial



    male runners with IBS would ha*e significantly wea(er hi% abductor and external

    rotators, diminished length of the IB, increased hi% and (nee adduction, and increased

    hi% internal and (nee external rotation angles com%ared to a %ain7free control grou%/


    A total of 41 male runners between the ages of "C713 %artici%ated in this study

    :"< with IBS and "< %ain7free controls;/ he control and IBS grou%s were similar in

    terms of age, distance run %er wee(, mass, and height :able ";/ he number of

    sub?ects was chosen to detect a moderate effect si#e :&ohen>s d of 0/3; with reasonable

    statistical %ower :E0/C;/

    he study was a%%ro*ed by the Institutional Re*iew Board of the +ni*ersity of

    entuc(y/ Sub?ects were recruited from local races, %osted flyers, and %hysician offices/

    Prior to %artici%ation, all sub?ects %ro*ided written informed consent/ o be considered

    for the study, sub?ects in both the IBS and control grou%s had to re%ort running at least

    "5 (ilometers %er wee(/ In addition, %ersons with IBS had to re%ort being free from any

    other lower extremity in?ury other than IBS for the %ast 5 months/ Similarly, the control

    grou% had to be in?ury free for the %ast 5 months/

    Indi*iduals with IBS were e*aluated by a %hysical thera%ist to determine if they

    Gualified for the study/ Runners in the IBS grou% had to re%ort an insidious onset

    lateral (nee %ain while running during the %ast ) months/ Partici%ants were included in

    the IBS grou% if they had re%orted %ain of at least 4 out of "0 on the numeric rating

    scale during running/ he re%eatability and *alidity of this scale %re*iously has been

    re%orted :I&& 0/2470/23;/","s tubercle or the



  • 8/12/2019 Estudio Transversal Sind Banda Iliotibial



    lateral femoral e%icondyle, or re%ort %ain during the Noble com%ression test which has

    been re%orted to ha*e acce%table inter7rater reliability/5 As %art of the e*aluation,

    %ossible ligamentous :*arus stress test; and meniscus in?uries :McMurray test; were

    ruled out/"C

    6ach sub?ect>s hi% strength was measured with a hand held dynamometer

    :-afayette Instruments, -afayette, IN; using %re*iously re%orted %rocedures that ha*e

    been shown to be reliable/ o measure hi% abduction strength of the in*ol*ed leg, the

    sub?ect was %ositioned in sidelying :non7in*ol*ed side; and %ushed into the

    dynamometer using the in*ol*ed leg/ he dynamometer was secured 3 cm %roximal to

    the tibiofemoral ?oint line with a stabili#ation stra% around the dynamometer and the

    testing table/ $i% external rotation strength was measured in a seated %osition, with the

    dynamometer %laced on the inside of the in*ol*ed leg 3 cm su%erior to the an(le ?oint

    and held in %lace with a stabili#ation stra%/ "5For both strength tests, the %artici%ants

    were instructed to gradually increase how much they %ushed o*er 4 seconds and then

    to hold their maximum effort for the next ) seconds/

    All indi*iduals %erformed ) %ractice trials followed by 4 testing trials/ he

    maximum efforts attained during the 4 testing trials were then a*eraged for each

    sub?ect/ he raw force *alues were multi%lied by femur length to %ro*ide a torGue *alue,

    normali#ed by mass to account for body si#e, and then multi%lied by "00/ Femur length

    was measured as the distance from the greater trochanter to the medial tibiofemoral

    ?oint line/ A %ost7hoc analysis demonstrated that the normali#ed torGue *alues were not

    correlated with mass or height, thus confirming the effecti*eness of the normali#ation

    strategy to minimi#e the influence of sub?ect si#e/)



  • 8/12/2019 Estudio Transversal Sind Banda Iliotibial



    he length of the IB was assessed using the =ber>s test using %re*iously

    established %rocedures/ he indi*idual was %laced in sidelying with the examiner

    standing %osteriorly/ he in*estigator>s (nee was %laced on the sub?ect>s bac( for

    stabili#ation and to %re*ent the s%ine from rolling bac(wards during the e*aluation/

    'hile maintaining the (nee in a slightly flexed %osition :"07"[email protected];, the sub?ect>s u%%er

    thigh was then brought into hi% extension and adduction until the %el*is started to tilt or

    when there was no additional hi% adduction mo*ement/ his techniGue has been

    %re*iously shown to be reliable :I&& 0/20;/)

  • 8/12/2019 Estudio Transversal Sind Banda Iliotibial



    tra?ectories were recorded at )00$# with a "3 camera motion analysis system :Motion

    Analysis &or%, Santa Rosa, +SA;/ Force data was collected at ")00 $#/

    Hisual 4! software :&7motion, Dermantown, M!, +SA; was used to filter the

    data, identify the functional hi% ?oint center, and calculate ?oint angles for 3 running

    cycles/ Mar(er tra?ectory data was filtered at C $# and force data was filtered at 43 $#

    using a 1th order Butterworth low %ass filter with #ero lag/ he cutoff freGuencies were

    selected using the results of a residual analysis of the data/45$eel stri(e and toe off for

    a running cycle occurred when the *ertical ground reaction force was 40 N/

    oint coordinate systems were defined in the Hisual 4! software using %re*iously

    %ublished %rocedures/)1he %el*is coordinate system was %laced at the mid%oint of the

    line connecting the iliac crests, the J7axis was oriented along the line connecting the

    mid%oint of the iliac crests and the mid%oint of the greater trochanters, and the KJ7%lane

    was established through a %lane best fit to the iliac crests and greater trochanters *ia

    least7sGuares/ A segment fixed coordinate system for the femur was %laced at the

    functional hi% ?oint center)Cwith the J7axis defined along a line connecting the hi% ?oint

    center and the mid%oint of the femoral e%icondyles and the KJ7%lane established by the

    e%icondyles and greater trochanter/ he shan( coordinate system was %ositioned at the

    mid%oint of the tibial %lateaus, the J7axis was oriented along a line connecting the origin

    and mid%oint of the malleoli, and the KJ7%lane was established by minimi#ing the sum

    of sGuares distance between e%icondyles, malleoli, and a %lane/ For all segments, the

    .7axis was oriented forward and %er%endicular to the frontal :KJ; %lane and the K7axis

    as the cross7%roduct of the J and .7axes/



  • 8/12/2019 Estudio Transversal Sind Banda Iliotibial



    oint angles were determined using a &ardan rotation seGuence of flexion,

    adduction, and internal rotation, referencing the distal segment to the %roximal segment/

    A custom -ab*iew code :National instruments, Austin, exas; was used to extract frontal

    and trans*erse %lane hi% and (nee ?oint angles at the time of the initial im%act %ea( for

    each trial/ Halues were then a*eraged across the 3 trials for each sub?ect/ oint angles

    were obtained during early stance since IBS sym%toms ha*e been re%orted to occur

    during this %eriod of time/

    Means and standard de*iations of the following *ariables of interest were

    calculated for each grou%8 hi% strength, IB length, and frontal and trans*erse %lane hi%

    and (nee ?oint angles at the time of the im%act force %ea(/ o assess grou% differences

    between these *ariables, inde%endent t7tests were %erformed using SPSS *ersion "C/0

    :IBM SPSS, &hicago, Illinois;/ he in?ured limb in the IBS sub?ect was com%ared to the

    same limb in the matched control %artici%ant/ !ifferences were considered significant if


    If a *ariable was shown to be statistically significant, clinical rele*ance was

    established using the effect si#e and M!&/ 6ffect si#es were calculated in DPower/

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