Gait abnormalities in patients with tibial malrotation

170

Abstracts I Gait & Posture 7 (1998) 144-190 Vmiabk Mmisrlml Pelvic Tut Maximum Hip FIeaiat Avmse Hip Adduction

Pqlumt 18.9 (b) 40.40 5.40

I Year Post 13.70(interior) 34.00 3.30

p&e

0.0042 0.0020 0.0064

Table 2: Significant (pCO.OS)deviations in gait due to prekmettcy. Means for each condition and pvalues horn staietieal analyses are presented. Mrusioa Little evidenc=ewas found to support the popular cmttenticm that prgnnnt women exhibit a “waddUi gait”. T&c mutts of this study show that nommlized base of support width. pelvic obliquity-of motion, and foot pmgrrssion angle are all tmekanged during pregnancy. The ehangsain gait duing la%gttency quantified by this study are mild and can be explained by changes in mass distribution about the tnmk, end increases in body mass and pelvic width. The significant inacav in anterior tilt of the pelvis during pregnancy that was obeuved wes p&ably a rcadt of the itmeae in the amount of body mull kated in a low anterior position onth+tmokdwingpregaancy. Aninaasedantetiorloedcntthelowertnmkeotdd~erate a forwzrd rot&g moment tending tn tutate the pelvis anteriorly. Increases in anterior Pelvic tilt generally recult in inuewed tumbv lord&s and may contribute to increased stress on the low back and secmiliac (St) joints during pregnancy.

-.

.‘Y”W

generation for hopping. AKA energy levels for both absorption and generationchanged A-” from less than Niin \mlking to 8reeter in NL in hopping. DISCUSSION: Both emum use similar me&anisms to hon. however. AKA use ho?‘-on a functional rather than recreational basis, aed have learnedto hop wll. This ability is reflected in their greater speedand cadence relative to NL, and in the resulting larger moment and power magnitudes. Experienced hoppers (e.g. track triple jump athletes) optimize energy transfer from the unloadedlimb by swinging it in counterpoint to the active limb (i.e., the unloaded leg is rhythmically swung 10that the hip ip extendedet initial contact and flexed at toe-off). This motion WBSperformed more fluently by the AKA than NL. Also, NL must compensetefor the additional weight of their intact leg versus the AKA residual limb. On the stance side in hopping, NL exhibited depressedpelvic obliquity (allowing the swing side to be lifted) and greater hip abduction relative to walking. Hopping increases loading on the joints of the lower limb and demanda8reater muscle strength then walking. Ankle plenterflexion moment end power demandsare signiticantly increased. The knee remains tlexed approximately 20 degrees in stance, resulting in an extension moment panem and high quadriceps demand for shock absorption end stabilization (Fig. la). Hip abduction moment is doubled (Fig. I b), requiring compensatory (and energy expending) trunk positioning over the stance limb if glutew medius muscle strength is insufficient. In AKA walking, loads are applied asymmetrically and greater than normal loads have ken recorded on the unetTectedside (Lewllen et al., 1986; Engsberget aI./ 1993). Hopping exacerbates this loading. In the short term. AKA hopping requires good bgny altgnment, balance end muscle strength. In the long term, increasedrepetitive lo& may be detrimental ifjoint health (e.g., cartilage integrity) and alignment are not maintained due to associated congenital problems such es lateral femoral hypoplasia. Figure I

The inin body mass during prqpwcy apparently necsspitetedthe increased stance side intemel hip aMwticm moment during etmtce. btemsiingly. small but significant increases in double~anddcasascsinsinslesupporttimesduringprrgMney~tobe compnspfim to minimize the time spent in singk limb e wkn this increased muswkr effort is required to support the increased body mass.

(4

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“IPYWEYI

Compensation for an increased pelvic width during pregnancy apparently occurred in order to avoid walking with a wide bawd, energy-inefficient gait @tern. Hip adduction was increased during the single suppon phaseof gait in order to keep the foot centered under the body and optimize baseof support. Ilerereaen Bullock I.E. etal.. AusfrJfhysiorher, 33:ll-17, 1987. MwreKetal..Proc C~~.~oe.forBiom..Fi~hBienniolConfandSymp., 114-115, 1988. Snijders I.G. et al Digest o/the II” /n&r. Conf on Med and Biol Eng, Ottawa. 1916.

Figure la: Knee extensiotiflexion moment in walking and hopping (NL andAKA). Figure lb: Hip abduction/adductionmoment in walking and hopping (NL and AKA).

RB~EBEtiCES: Engsberg J. R. et al., JPedollhop, 13:169-173, 1993. Lewallen R. et al., J Fed Orrhop, 6:29l-298, 1986. ACKNOWLEDC.MENTS: The authors th& Steve Liou for his help with date reduction.

Posters COMPARISON OF AMBULATlON (WALKING AND HOPPING) IN NORMAL CHILDREN AND CHILDREN WlTH ABOVE-KNEE AMPUTATIONS Anita Be&v. PhD., Jon R Davids, M.D., Theresa Foti, Ph.D Sbriners Hospitals for Children, Greenville, SC 29605 INTRODUCTION: The ability of children with above-knee amputations(AKA) to walk efficiently is a function of residual limb length, underlying bony alignment, muscle strength, and pmstbetic fit end design. Hopping, which is a typical metbud of household ambulation for AKA individuals, may be the principal mode of gait for AKA children in under-served areas of the world. who have improperly fitting pmnheses or lack them altogether. The purpose of this study was to provide kinematic and kinetic pmtiles of these children both walking and hopping, and to compare their abilities to those of children with intact limbs. METHODOLOGY: Thirteen nomml (NL) children (8 female, 5 male; average age 9.4 yrs) end twelve AKA children (4 female, 8 male; average age8.2 yi%) were analyzed with 3D gait analysis (Vicon 370,b camera,2 force plates) during walking and hopping at selfselectedspeeds over level ground. RESULTS: TimUDfstmcc: Both groups exhibited greeter speedin bopping then walking as e result of increwed cadence. NL demonstrated gwater velocity and cadencethan AKA in walking, while AKA demonstrated higher values in hopping. Kinematics At the pelvis, both groups exhibited increased anterior pelvic tilt and decreased pelvic rotation in hopping relative to walking. AKA demonstratedgreeter maximum anterior tilt and se&al plane range of motion than NL in both tasks. In hopping, upwards pelvic obliquity in stance increased for AKA and decreawd for NL (to below neural). Coronal plane renge of motion decreased relative to walking for both groups, hut to a greater extent in NL. At the hip, both groups exhibited less extension endmore internal rotation in hopping than walking. In both tasks AKA demonstrated greater hip flexion than NL and were, on aver&, positiomd in external hip mtation (versus M avenge internal position for NL) during stance. Maximum bitt dduction bweased for AKA end decreaed for NL durina hopping (the movements we& correlated with pelvic obliquity position). At the knee, both pups exhibited more flexion in stance, less flexion in wing, end more intend rotation durhtg k@tg than waking At the ankle, both graqw exhibited increesed dorsifkxion in hopping. For bath lasks, foot pmgressionaaglewesmextemalinAKAtbanNL. Kin&s: At the hip, both groups exhibited bweased bip extension mmnent and power generaion in hopping during swing and initial stance. Power absorption during both swing and stance were innraped (to a greater degas for AKA) as WBSabduction moment. At tk knee. bath groups exbibitcd 8 stansc pbau extension moment pattern and incased powergene&mduringluyping. Powerabsaplionvnwincrascddurbtgbdtialstawsnd decnucdntkendof-. At the adIe, both groups exhibited inaeasd plantar flexion moment, increased energy absorption in early stance (sccntric stretching), and increesed peek and totel energy

Tibial fractera axewmmonly vcpted surgic& by intru&ullary nailing (IM Railing). One complicatbn of tbia procedure is tiblal mebndoa,which presents es a mtnt!onal deformity of thclibiavay1wcishawnboweva.~tbehridcnzoftibial~mtionrftcrIM naihg or the efkcur thir dehmity may kve on mrrcal liutctbm and bcomotbn. Ty@cdly. tibialex~mUIionofgmucrthn!200orintenvlmtationofgnucrt~1S0isco~~ seven enough to wurmt a demtadotml osteo~my. Unfortunately there is no evidence in litem to suppotl thii practice. Tk purpose of this pnlimbmry study was to wantine deviations fmm normal gait patterns in patientswith severe tibial malmtins.

Two patients (46 and 48 years) were testedjxior to undergoing a demtational osteotomy. A CT scatt was used to masun the severity of the tibial malmtatia~ based on tk technique presentedby l&b et al (1980). Refkctive markers were placal on the pelvis, thigh, leg, and foot to obtain tbne dimensiorul(3D) repreatetbm of tk aagmetttalmovements. Video data were collected at 120 Ii& double tedmion U&III four Falcon Motion Analysis c-. EVa rsonanrttkmarkertflpccaricsin HiRcssoRwnrewrrusutfordur.mllstionuaallasto 3D. Rintrak mftware c&dated joint a+ utd morneete.Joint angles wem cakukted using tk joint coordinate systetn method, ad pia moments wcm cakulated in the rcspccrive segmentcoordhtete rystentr Gmutd reuaiat force data wae cdkacd (1uM Hz) using II Kistkr force plate. Data were colkzted et tlweeB wa!kbt8 speeds:natural walking speed.l.3mlsMdrshaulpoatibk.FivctriLharnecolMedstcrhspeedlndtk~uk were weaged togetkr. Read* Patient one WBSmeasured.clinically, at 20QeaQMl rotation while patient two was measured at 2S” extcmd rot&m. At the rdrk. patient one hada krgc planter tkxion in the beginning ofswcephPaeandpt~~~~~xat~off(Pigu~l).Bothplticnts exhibited a lack of tkrion at the bxe during stawe phase.ka+iig tka knee ettiff until toe Off. Patient one maintaixd a hrll extension angle. WhIk pntient two walked with a constant knee engk of about 15’ of flexan (Figure 2). Moment datafrom both patientswere atypical compared to nomkxl n&e vertkal gmlmd raction forcea Hem.lower than normal especially from mid-to toe-off dcrbg the pmpebion pkak (Figure 3). and produced small moments at each of the lointe..Patient oly demonetmteda rpSe flexor molacnt in tk middle of staxx plmae cap&d to normal gait d&e. Patient two. oitk otkr bend, mai&ned an mewion mom through tlm entire stance pluse ratkr thanchatglng from M extewion mmte.nt to a ma-e t?axor nmtent in tk middle of stance phase (Figure 4). All graphs are of tk affected limb although tk contrakeral limb also had abnomwalpatrerns.

Abstracts

-on These results indicated that tlbml malrotation contributed to abnormal gait patterns. Ihe lack of flexion at the bre during stance suggested that a stiff knee was used to guard against internal buckling of the k”ee due to the severe external rotauo” of the fooL It appears however, that both patientscompe”sated for the deformity in different ways; one by constantly flexing the Imee, the other by locliing it in a neutral position. As well it is comma” that the patients guard the affected limb by not fully loading it. This causes compensation in the wndateraJ Limb. Non-physiological loading in the joints of both the affected limb and the contralateral limb are thought to predispose patients to degenerativej&t disease. specitiially, osteoanbritis. Gait analysis can be a useful and effective tool for identifying patients for surgical interventions. For example. Pmdromos et al. (1985) discovered a significant relation between gait and clinical changes following high tibial osteotomy. Future work. in this study. iovolves identigicatio” of relations tetween degree of tibia1malrotauon and the extent of gait abnormalities.

I Gait &Posture

7 (1998)144-190

The post-operative nnprovemco~~for Group A pmvide a” indication that soft tissue surgery at theankle is swxessful in improving equbw deviationsin ga” in children and adolescents who are StanISpost TBI. As no signifiiant effects were seenat the knee. seMivisions were created in Group B to fordxr investigate the effects of a rectus fenwris wnsfer on swing phase function in this patientpopulation. Of tie eight sidesexamined. two subdivisions separatingthe “best outcome” and the “worst outcome” patients were defined wtti n=2 in each subgmup. The “best outcome” group was defined by improvements in both rhe magnitudeand the timing of peak knee flexion in swing. The “worst outco”,e” group was defmed by the lack of bnpmvemau in the magnitude andtiming of peak bKe fkxioo in s&g. Tb+ &a four sides in Group B representeda bttemtediary group dtiu showedmixed nswlts in sting phase. The “best outcomes” subgroup exhibited some similar prc-operative chamcteristics such as walking velocities of over 80% of normal, normal cognitive StaNsandhrmiplegic presentations. The “worst outcome” subgroup also exhibited some similar characteristics preoperativeIy. such as poor-to-fair walking spad of 58.73% of normal. maal retardation. and severe. dense. hypertomc, hemipkgk presentationwith upper extremity posmring and trtmk spastiity. However, these characteristics were variably presentin theintermedii subgroup and cannot be accepted as clear predictors for outcome. eitkr positive or negative, of rectus femoris surgery in patients who are status post TBI. Perhapsmost significantly. the “wotst outcome subg~oopshows sagittal knee flexionexten~io” modutioo mat exhibits minimal angularchangetad! pm andpost-operadvely, as seen tn Figure I. This “flat~line” patsm was tmiqoe to thesetwo patients in Oroop B and is consistent with poor results in swing phasefollowing rectus femris surgery. The existence of a dmbtmittg extensor tm dtm sigtdtiantly lbnia dynamic raogeof motion at mCkoee throughot” dK gait cycle may indicatethat theatte”lpt to &dress one r”e&mism of knee flexio” in swing (e.g. with a rec(us feowris transfer) may not lx successful in this patient population.

Referenw Jakob R et al. Journal of Born and Jmnr Surgery, 62B:238-242. 1980. Prodmmos CC et al. Journal ofBone and Joinr Surgery, 67A: 1188.1194. I985

Figure I: Pre- (light line) andpost-operative (heavy line) )n.x ~agittelplane motion for an individual in “worst outcome” subgmop.

ACJUlOWkdW~Ul.5 Special thanks goes out to Stan Ajemian for tech&al assistance. This research was supported by ATCO Ltd., Tra”sCa”ada Pilines, the Alberta Heritage Foundation for Medical F&arch and the Natural Scienie and Engineering Rae&h Council of Canada.

Tk natural history of this patientpopulation’sgait patterns have oat beendrcomcnti. Therefore. we are unable to meclude ii no sorgety m this patientpopoIatioo would have pmluced a decreax in gait function over tim. Fotore stodieswith a comparison to B nonoperative control group are neededm folly interpret the results of this study.

REFERENCES Watms RL eml. Journal of Bone and Joint Surgery, 64.A(2):284-288.1982. Wetem RI. eLal. Journal of Bone and Joint Surgrry, 61.A(6):927-933.1979. Davis RB ctal. In: Human Motion Ann/ysis. Piscataway. NJ: TAB-IEEE, 17-38, 1996

Kinemalic Changes Following Orlhopedic Surgery in Persons Status Post Traumatic Brain Injury Michelle Marks, VT, Sylvia Ounpuu, MSc. Roy B. Davis, PhD, Peter A. DeLuca, MD Connecticut Children’s Medical Center. Hartford, Connecticut 06106 Introduction Orthopecbc surgical uearmentfor gait abnormalitiescausedby muscle imbalancefollowing Traumatic Brain Injury (TBI) is common. ‘llx litemmre pmvid=esstudies that examine surgical prccedwes for adult TBI patie”U for equinus and qdnovarus deformities (Waurs. 1982) and for stiff-legged gait correction (waters. 1979) utilizing gait analysis via clccaomyomphy and electmgoniometers. ‘Dxeeffects of theseor any surgical interventions in children and adolescentswho are status post TBI has“oi yet b&n reported. The porpae of tiis study is to identiry post-operative kinematic changes at the koee andankle in children and adolescentswho are status post TBI. Methodology A total of I2 children andadolescentswho were sWs post TBI and had received onhopedic surgical bttervention welt included in this reoospcctive study. The average ageat the time of TBI was M6 years and dxeaverage ageet the time of surgical intervention was 14*7 years. A computerized gait analysis was perlormed at all subjects pre aed post-operatively and included: I) evaluation of passive joint reogeof motion and muscle sueogdt. 2) video taping, 3) motion analysis with collection of dua dimnsiowd se mrmt andjoint kinanatics and 4) dynamic elecvomyogmphy. A detailed description of mef ads has beenpreviously described (Davis. 19%). To evaluatethe effects of spwitic surgical treamxntr the group was divided into two subgoups: Group A (“=a) including all sides wth ordwpedic surgery at the ankle, and Group B (n=S) including all sides with rcctus fenmris transfer and hamstring surgery. Patients in both groups had other ordmpedic surgeriesdeemed necessary through pre-operative gait analysis. RlWJllS Froup A had a mean ageat TBI of 3i2 yaws noda mea” ageat surgery of IOU years. Of the e&t sides included. six p&n@ had Baker-type gasmxoemios apon~wotic lmgdwoings and two patients had Z teodo-Achilles plasty. Following surgery, kinematic improvements were seenin the ankle position tit initial contact, the slope of aokk angle plot in midsbmce, rmdpeak planter flexion in initial and mid-swing (lhble I). Thsc v&es were statistically significant using a paired Student’s t-test (p-Xl.05). Table I: Postoperative changesat the akle in Omup DFIPF SIOpc mkk wemglc 1°C. midst. r““prr -post twtm p values

-2M10 -23 0%

0.22M.zs 0.19zto.34 0.003

A following gastmcncmius sorgery. t% initial swing

Ta;k mid swing

-26fl4 -6f13 -16i5 0.005

-18ilZ 3fll 4f5 0.001

showed w in knee slgle at i&al contact peak knee flexion at loading response. and peat knee extension in midstam. However. noneof these improvements were statistically significant w.05).

lntnlimb

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Introduction Inhumanwrlling,p~nnd~umcy~tionainthclimbs,limb~andthoraxMd withelagesin pelvis haw heal found to show noo-eqoilihriomphMe tlocomotor v&&y and cao be used to desoribeand rawdyzeplualo&d @it (van Emmerik ctal,l9%,Dicdrichat~..1996).ThsMhueofhn~~cowdimtionhnbssnstudisd modeling the limhsBScoopIed oscinnws that al&it mode locking (Van Hoist, 1969). Von Hoist deserihed diffemn cowditutian modesthat can be observed in relative pbax and f?eqwney couplings betweentwo biologically carpled oxillatom: relative and absohrte coordination In absolute coordination, the oscillators are perf&tly entraioedand move in a I.1 locking mode, domionted by one osoilluor In r&in coordination h&h osoillators tend teamaintain their intrinsic Iiqmey but through their carplii, varying phue and frcsuency relations CM occur This distinction heccmes important wha lo&kg et stahilii and adaptabilityof difTere”t coordbution patterns Syxtem dynamics that exhibit absolute coordimtion will be more stable(resistant to pertorbations) yet less adapt&k System dynamics that exhibit relative coordiion are on the other handmore adaptablebut less stabk Stahilitv Md ada~abiitv are determioedhv the variahilitv of the coordination patterns The kahilii o; vari&lii of syslrrn co&dinatiw i&ted by eriticdl fluctuations is a key element when modeling tmositions between two loconmtor mode8 as nonequilibrium phase transitions. (Diedrich et al, 1996) I” the walk to roe transitioh these critical fluctoatioos are hypothesized to he an indication of systnn instability and preceed a bifurcation to a more stablemode of coordination. This study was designedto more closelv investigatethe stability and variability of iotralimb and iotetiimb coordination around the transition region (around I 6 to 2 I m/s) betweenwalking and running Metbodolqy Fourteen college age subjects were required to both walk and run on a treadmiUat 1 34. I 52, I 70. 1.88. 2.06.2.23. and 2 41 m/s High speedkinanatic data @&&etlex.. Owlvas Inc ) were colkoted et 60 Hz in the s&al pi?“e’from refleaive mprkm placed o” ihe + metatarsal,ankle, knee, hip, shoulderand elbow. Heel contacts were recorded using a foot switch Discrete Relative Phase(DRP) relations were calculatedat maximum exteosion ankles of thiah. lep. foot and ueeer arm for 20 consecutive *rides oer velaitv fn& wu1 En&rik et al., 1996). The Sd bf the DRP was calculatedatw& thigh nod-fdot (DRPTHF), thigh and Icg (DRP-THL), thigh and upper arm (DRP-THUA) and foot end upper arro (DRP-FUA) as a measure of variability Results Figures la and lb show for interlimb coordination that the SD ofDRF-TM

as well as