Children Orthotics and Prostheses Devices Designed from Cinematic and Dynamic Considerations

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1 Chlde Othotcs ad Postheses Devces Desged fom Cematc ad Dyamc Cosdeatos C. Colus N. Dumtu M. Ma ad L. Rusu bstact study coceg the chlde locomoto system s eseted though ths eseach. he eseach am s to obta the moto laws develoed by the chlde locomoto system s atculatos ad coecto foces whch ae oduced the stuctue the walkg actvty. hese aametes ae useful fo othotc ad osthetc systems desg fo chlde wth ages betwee 4-7 yeas. he study s based o a exemetal aalyss develoed wth ulta hghseed vdeo equmet o chlde. Fom the exemetal aalyss sgfcat data wll be used fo a huma locomoto system cematc aalyss. Wth these a dyamc aalyss wll be efomed o aalytcal way ode to obta the coecto foces fom the huma locomoto system jots. Data obtaed fom cematc ad dyamc aalyses eesets the ut aametes fo desgg a modula kee othoss mechasm ad a aametezed kee osthess mechacal system whch uses a cam mechasm hs stuctue. Idex ems cematc dyamcs locomoto system othotcs osthess I. INRODUCION HE ma motvato fo these aalyses was gve by the osthess ad othotcs devces develomet estcto fo chlde. It s kow that the estcto s mosed by the fact that chlde ae gowth cotuously esecally betwee 4-7 yeas. Due to ths fact modula othotcs devces ad aametezed osthetcs ca be develoed ode to move the locomoto system ad to satsfy the ablty to move. Fo ths t s ecessay to efom exemetal aalytcal ad desg aalyses ode to ceate databases useful ths eseach decto. It ca be metoed smla eseach wok ths feld by [4] [3] [6] [7] [] [5] ad []. mla dyamc aalyses wth emakable esult ca be foud [] [6] [8] ad [7]. he eseach ma am was to obta the coecto foces fom each huma locomoto system atculato whe the healthy subject wll efom the walkg actvty. hs wll seve as ut data fo dyamc aalyss develoed o aalytcal way. II. EXPERIMENL REERCH akg to accout the exemetal eseach am the motos develoed by the huma locomoto system [] [7] [5] [6] [7] eseted hee wll be evaluated exemetally by usg moto aalyss equmet whch s called CONEMPL. hs has two hgh seed cameas fo catug ad ecodg sequeces ad a DELL otebook fo sequeces aalyss eal tme wth emlo tadad module softwae [3]. he Uvesty of Caova- Faculty of Mechacs ows ths secal equmet whch s used fo the exemetal eseach. hs equmet eables us to deteme the desed ots tajectoes ad satal agula vaatos oto ethe mechacal o bomechacal moble systems though successve detfcatos of the jot cetes ostos the stuctues. he geeal ocedue fo exemetal detematos s show Fg.. Mausct eceved Octobe 9. he eseach wok eoted hee was made ossble by Gat CNCI UEFICU oject umbe PNII RU PD 9 code: 55/8.7.. C. Colus s wth the Faculty of Mechacs Uvesty of Caova. Calea Bucuest steet o. 7. Romaa (coesodg autho to ovde hoe: ; e-mal: cstache3@yahoo.co.uk). N. Dumtu s wth Faculty of Mechacs Uvesty of Caova. Calea Bucuest steet o. 3. Romaa (e-mal: dumtu_c@yahoo.com). M. Ma s wth Faculty of Mechacs Uvesty of Caova. Calea Bucuest steet o. 3. Romaa (e-mal: mh_ma@yahoo.com). L. Rusu s wth Faculty of Educatoal Physcs ad ots Uvesty of Caova. Beste steet. Romaa. (e-mal:usulga@gmal.com). Fg.. CONEMPL Moto equmet ad aalyss scheme hus oe attached makes the otato jots cetes wth a vew to detemg the agula amltude develoed by the huma locomoto system. sequece of the

2 exemetal aalyss usg ths equmet s show Fg. Fg. 3 Fg. 4 ad Fg. 5. I ths sequece chlde have to efom 3 stes fo walkg actvty. Fo ths exemetal eseach a umbe of chlde wth ages betwee 4-7 yeas wee used. Makes have bee attached o huma locomoto system s atculatos cetes ode to deteme tajectoes ad agula amltudes. hese moto laws foms a database whch cossts a umbe of 4 segmets each segmet cossts 5 healthy chlde wth the same age. Fg. 4. Exemetal aalyss sequece fo kee jot agula amltude Fg.. Exemetal aalyss sequece fo jots tajectoes (4 yeas old chld case) Fg. 5. Exemetal aalyss sequece fo akle jot agula amltude Fg. 3. Exemetal aalyss sequece fo h jot agula amltude lso the heght teval fo all the aalyzed chlde was: cm. Weght of these subjects was betwee -36 klogams. I each segmet was gl ad the est of the subjects wee boys. he cameas ecod smultaeously the makes tajectoes ad agula amltudes fo each lowe lmb. s a examle of the fal esults oe esets the moto laws fo the aalyzed atculatos dagams fom Fg. 6 Fg.7 Fg.8 ad Fg.9. Fg. 6. Locomoto system s agula amltudes aveage fo chlde at 4 yeas fo walkg actvty he agula amltude of each jot s a fuctoal agle fo lowe lmb jots meas useful agle fo develos movemet fom DL scale (actvty daly lvg scale) eset by the tajectoes of the jots. he aveage agula amltudes dug the gat cycle o the examed chlde segmets ae eseted able whee: IC-Ital Cotact LR-Loadg Resose Mt-Mdtace temal tace Pw-Pewg Iw-Ital wg MwMdwg w-emal wg.

3 Fg. 7. Locomoto system s agula amltudes aveage fo chlde at 5 yeas fo walkg actvty III. HUMN LOCOMOION YEM CINEMIC NLYI he method used hee has a flexble chaacte ad assues a teface fo dyamc aalyss esecally fo fte elemet modelg of satal ad laa moble mechacal systems [5] [] [] [5] [6] [7] ad [8]. he geeal method s eseted bellow. Fo obtag the geeal mathematc model t wll be cosdeed a cematc elemet ealzed fom sold gd bodes coected togethe though - cematc as (Fg. ). Fg. 8. Locomoto system s agula amltudes aveage fo chlde at 6 yeas fo walkg actvty Fg.. Cematc elemet ealzed fom sold gd bodes coected togethe though - cematc as Fg. 9. Locomoto system s agula amltudes aveage fo chlde at 7 yeas fo walkg actvty BLE I VERGE NGULR MPLIUDE FROM NLYZED HUMN UBJEC egmet wth 4 yeas age egmet wth 5 yeas Jots Gat hase H Kee kle H Kee kle IC LR Mst st Pw Iw Mw w egmet 3 wth 6 yeas age egmet 4 wth 7 yeas age IC LR Mst st Pw Iw Mw w Fo ths cematc elemet we make the followg x y z eesets the efeece coodate otatos: system attached to elemet havg the W j k vesos base wth ; x y z eesets the W j k vesos base; global efeece system wth eesets the elatve taslato vecto betwee - ad elemets deedg wth ted f exsts a taslato jot betwee - ad ( ); eesets the osto vecto whch deeds wth efeece ' system agast wth O I ot whe the elatve taslato stats ( ); eeset the osto vecto of the M deedg wth attached to elemet. Fo deteme the osto vecto of M ot aot wth the global efeece system s gve by the elato: M Whee: O M W () () W (3)

4 z y x W (4) We toduce the tasfomato coodates matx fo cossg fom a efeece coodate system to aothe: W W (5) We cosde the followg coecto ode: he () (3) ad (4) elato wll be: W W (6) W W (7) W W (8) By toducg the (6) (7) (8) () we obta: W M O M (9) he seed calculus wll be obtaed by dffeetatg the (9) deedg o tme. Cosdeg the coodates tasfomato matx as a quadatc oe the followg elato wll be wtte: I () By dffeetatg the () elato aot wth tme we obta: () () We obseve that - tem s a o symmetc matx: (3) By multlyg the (3) elato wth t wll obta: (4) Dffeetatg (9) elato aot wth tme we obta: W M (5) We obta the followg o symmetc matx: x y x z y z (6) Whee: k j z y x (7) Fo each vecto ad ( ) a o symmetc matx ca be attached as has bee doe (6). he used tems (5) the followg fom ca be wtte: (8) (9) () z y x o () I ths case the (5) elato ca be wtte: W W V M ()

5 Fo the acceleato calculus t ca be obtaed by dffeetatg the () deedg o tme. Fo ths aalyss the cematc model eseted Fg. wll be cosdeed. he cematc aalyss wll be efomed fo walkg; oly oe gat whe a foot s fxed wth the goud ad the othe efom the desed moto. he cematc aametes vaato laws wee obtaed by ocessg wth the MPLE softwae ad the mathematcal models whch ae defg the huma locomoto system exemetally cematc aalyss. Fom a stuctual vewot the cematc cha t cossts 6 otato jots. he R O vecto has the followg exesso: O R (3) tasfomato matces) oe the elato (5) to (4) t wll be obtaed W O ; W ; W ; W 3 ; W 4 ; W 5 ; W 8 ; W 7 ; W 8 ; W 9 ; W ; W ; W ; W 3 ; W 4 ; W 5 ; W W OW O; W W O W O; W 3 3W O3W O; W 4 34W 3 O4W O; W 5 45W 4 O5W O; W 6 56W 5 O6W O; W 7 67W 6 O7 W O; W 8 78W 7 O8W O; W 9 89W 8 O9W O; W 9W 9 OW O; W W O WO W W O WO W3 3 W O3 WO W4 34 W3 O4 WO W5 45 W4 O5 WO W6 56 W5 O6 WO W7 67 W6 O7 WO 6 (4) (5) (6) (7) (8) (9) (3) (3) (3) (33) (34) (35) (36) (37) (38) (39) (4) (4) ; ; ; ; ; ;. Fg.. Huma locomoto system cematc model he coectvty ode wll be: O Posto calculus he osto vectos ae gve by elato (4). Chagg the vesos base at cossg fom a efeece coodate system to aothe (toducg the coodate By aalyzg 5) to (4) we obseve that: O O; O3 3 O; O4 34 O3; O5 45 O4; O6 56 O5; O7 67 O6; O8 78 O7; O9 89 O8; O 9 O9; O O; O O; O3 3 O; O4 34 O3; O4 45 O3; ;. O5 56 O4 O6 67 O5 (4)

6 Based o (4) we detfy the coodates tasfomato matces fo each cematc jots wth 9 ad 6. Pot: B C D E F G H I J K L M N O P ad R ostos aot wth O coodate system bouded to the left foot wll be detfed though the (43) to (5). mlaly we obta the dslacemets of othe jot cete ots. he dslacemet fo R ot s gve by (5). W ; O (43) O O B W O OW O ; (44) O C W W W ; 3 O D O O O O W W O O 3 O W O 4 3O W O; O E W O OW O W W 3 O W ; 5 O F 34 O 3 O 4 O O 3 O W W O O 3 O W O 4 3 O W O O W O O W O; O W W G 3 O W O 4 3 O W O O W O W 6 O O W ; O O H W O O W O 3 O W O 4 3 O W O O W O O W O W O O W ; 8 O O O O O 3 O O O R W O O W O 3 O W O 4 3 O W O O W O O W O O W O W W O O O O O 56 O (45) (46) (47) (48) (49) (5) (5) B. eed calculus We follow to deteme the R ot seed deedg wth O efeece system. Fo ths we dffeetate successvely (43) to (5) but fo acheve ths calculus s ecessay to buld the at symmetc matces fo each jot lke the fom fom (5). Cx Fo ths: O O3 O5 O7 O9 O O3 O5 O7 Cx Cxj Cx Cxj Cx Cx O O O 3 O3 O4 45 O5 O6 67 O7 O8 89 O9 O O O 3 O3 O4 45 O5 O6 67 O7. ; ; ; ; ; ; ; ; ; ; wth j 6. (5) ; ; 34 ; ; 56 O O4 O6 O8 O O O3 ; ; O6 (53) By dffeetatg (43) to (5) fo each jot cete ot we obta the seed equatos. Fo B ad C we wll obta the seed (54) (55) ad (56). mlaly we obta the veloctes of othe jot cete ots. he velocty fo R ot s gve by (57). v O ; (54) O v B O O W O; (55) v O C W W ; O O O O O 3 O vr O OW O 3 W W O W W W W W. O5 5 O O 4 O 34 4 O O4 56 O 3 45 O O6 O O 5 6 O 5 O 45 (56) (57)

7 C. cceleato calculus hese wll be obtaed by dffeetatg successvely the seed equatos. Fo ad B we wll obta the acceleatos (58) ad (59). mlaly we obta the acceleatos of othe jot cete ots. he acceleato fo R ot s gve by (6). a O ; (58) a O B O W W. O O O O O O a R O O W O W W O W W O O W W... O 3 W W O 4 45 (59) W W W 7 W. O O O O O O O O O O O 3 O O O O O O 5 O O O O 3 O 6 (6) Fg.. Geealzed coodate moto law equvalet wth the h jot fo walkg actvty the case of a 4 yea old chld: a-left lowe lmb; b- ght lowe lmb. D. Numecal ocessg Fo cematc aalyss the geometcal elemets ae kow. he comutg algothm was elaboated wth the MPLE ad. he geometcal elemets dmesos ae mllmetes: L O =7; L =65; L =65; L 3 =; L 4 =5; L 5 =5; L 6 =5; L 7 =5; L 8 =; L 9 =5; L =5; L =5; L =5; L 3 =; L 4 =65; L 5 =65; L 6 =7. he geealzed coodate system vaatos fo the equvalet locomoto system actve jots walkg actvty s case ae eseted Fg. Fg. Fg. 3 Fg. 4 Fg. 5 ad Fg.6. hese wee ocessed a 4 ad 7 yeas old chlde. he agula amltudes of these moto laws wee valdated by cosultg secalty lteatue data ad eesets a sgle gat fo walkg [8] [9] [] [7]. he 4 yeas old chlde segmet eesets the lowe lmt fo the desed desg aametes ad the 7 yeas old chlde segmet eesets the ue lmt. Fg.. Geealzed coodate moto law equvalet wth the kee jot fo walkg actvty the case of a 4 yea old chld: a-left lowe lmb; b- ght lowe lmb.

8 Fg. 3. Geealzed coodate moto law equvalet wth the akle jot fo walkg actvty the case of a 4 yea old chld: a-left lowe lmb; b- ght lowe lmb. Fg. 5. Geealzed coodate moto law equvalet wth the kee jot fo walkg actvty the case of a 7 yea old chld: a-left lowe lmb; b- ght lowe lmb. Fg. 4. Geealzed coodate moto law equvalet wth the h jot fo walkg actvty the case of a 7 yea old chld: a-left lowe lmb; b- ght lowe lmb. Fg. 6. Geealzed coodate moto law equvalet wth the akle jot fo walkg actvty the case of a 7 yea old chld: a-left lowe lmb; b- ght lowe lmb.

9 IV. CHILDREN LOCOMOION YEM DYNMIC NLYI he dyamc aalyss am s to detfy the coecto foces vaato laws deedg o tme. Mathematcal models adoted wee desged so that we ca develo a teface wth fte elemet method. hs teface wll allow exctato of each jot omal oeatg codtos o ctcal oes aoate wth those exstet ealty. he coect falty of ths objectve s guaateed by the desg of the tegated dyamc model - exemet fte elemet modelg ad smulatos. mathematcal model used fo vese dyamc aalyss of the huma lowe lmb wll be elaboated by takg accout the goud cotact. hs dyamc model stats fom the cematc scheme eseted Fg.. mla aalyss ad ocedues ca be foud [] [4] [6] [7] [] [4] [6] ad [6]. Iut data: Fo a vese dyamc aalyss oe cosde kow the geometc elemets (L O L L L6) ad geealzed coodates vaato laws fom cematc jots: q q q 3 q 6 obtaed fom cematc aalyss. calculus algothm was elaboated wth MPLE softwae s ad. Outut data: It wll be followed to obta the coecto foces comoets whch wll aea the walkg actvty fo a gat cycle at the each jot level fom the mathematcal model stuctue whch s equvalet to huma locomoto system. he costat equatos ae: ( q t). (6) q - Geealzed coodates vecto cosdeed whe the elemets ae gd oes; t- tme. O customzg fo elemets we obta: q cx C ; (6) cx cx cx cx C X C Y C Z C ; (63) Wll make the followg otatos: X cx ; cx ; cx X C Y Y C Z Z C ; (64) X cx X C cx Y Y C Y cx Y C (65) Fom whee shall obta: cx x C Ex y cx C Ey z cx C Ez wth: 6. (66) By dffeetatg elato (6) deedg o tme wll be obtaed: J q q t (67) O elatos (66): cx x cx C X C t cx y cx C Y C. t cx z cx C Z C t (68) We dffeetate elato (67) deedg o tme ad we obta: J q q J q q q J q q q t (69) By dffeetatg elatos o (68) aot wth tme we obta: cx x C Ex t cx y C Ey t cx z C Ez t (7) Equatos o (67) ad (69) ca be wtte a comact fom by toducg the otatos: J q q v t (7) Jq q J q q Jq q q a q t (7) he mechacal wok of mass foces s: L... cx C cx C 6 G G 6 G cx C 6 cx C... G he moto equato has the followg fom: M Jq J q q Qa. a (73) (74) Whee: M eesets the mass matx wth:

10 M= dag (m J ); 6. (75) 9.845N he vecto of actve foces: - mq - mq... Qa (76) q q - m5 - m6 mathematcal elato betwee mass matx ad the actve foces vecto s gve by: M q J q Q a (77) We obta the Lagage s multles ae: J Q M q q a. (78) Fg. 7. Coecto foce comoet o Y decto fo kee atculato (I-jot) [Newto] vs. tme [sec] fo 4 yeas chlde segmet 8.98N he moto laws ae kow: q (t) q (t) ad q (t) fom the cematc aalyss. Fom (78) we deteme λ Lagage s multles wth the ad of a ogammg algothm accomlshed MPLE softwae. Wth these t wll be ocess a vese dyamc aalyss fom t wee obtaed jot coecto foces. hese foces wee detemed by takg to accout the Lagage multles: F "( j) [R " ] j) ( o (79) Based o the elaboated algothm the coecto foces fo each jot wee obtaed. he jots ae fom the model eseted above ad the coecto foces comoets ae oeted o 3 dectos fo a xyz coodate system. he foce comoets fo kee jot ae eseted Fg. 7 ad Fg. 8 ad ae used to desg othotc ad osthetc mechasms esecally fo chlde o 4-7 yeas age. he hgh values ad hgh oscllatos oto these dagams ae fom the foot wth goud cotact whe the aalyzed subjects ae the st ad sw gat hases. he kee coecto foce value case of a 4 yea old chld s 9.845N o swg hase. I case of a 7 yea old chld the kee coecto foce s 8.98N o swg hase. hs data hel us to desg othotcs ad osthess mechasms. I ode to valdate these mechasms s ecessay to smulate wth Dyamc Module fom MC dams evomet. Fg. 8. Coecto foce comoet o Y decto fo kee atculato (I-jot) [Newto] vs. tme [sec] fo 7 yeas chlde segmet V. ORHOIC ND PROHEI DEIGN BED ON DYNMIC CONIDERION Based o the dyamc aalyss eseted hee the obtaed esults ae useful fo desg a kee modula othoss fo 4-7 yeas old chlde ad a aametezed kee osthess whch has a cam mechasm hs stuctue. he vtual models ae eseted Fg. 9 ad Fg. 3. Fo vtual smulatos the kee modula othoss was moted MC dams Evomet by ceatg a exot teface fom oldwoks. wo vtual models wee ceated oe fo a 4 yeas old chld ad othe fo 7 yeas old as t show Fg 9 - a b. s a dyamc vewot fo kee modula othotcs though vtual smulatos t wats to be detemate the cable foces fo both cases. Fo ths the coecto foces comoets fom Fg. 7 ad Fg. 8 wee aled o kee othotcs fal module. he coecto foce fom fgue 7 was aled case of the modula kee othoss fom Fg. 9-a ad the othe coecto foce fom Fg. 8 fo the vtual model fom Fg. 9-b.

11 Pmay module Itemedate module Fal module Cable o. Cable o. a Cable o. Pmay module b Fg.. sects egadg the aled foce laws (a-case of a 7 yeas old chld; b-case of a 4 yeas old chld). Cable o. Fal module Fg. 9. Kee modula othoss vtual model wth comoets detfcato (a-case of a 7 yeas old chld; b-case of a 4 yeas old chld). I Fg. ad Fg. a asect of vtual models the MC dams evomet s show (alyg the foce laws ad kee moto defto). he foces fom cables ae eseted Fg. ad Fg. 3. It ca be obseve that the maxmum value s.5n fo a 7 yeas old chld whch meas that the cable dametes ae coectly choose. he damete ths case s a.75 mllmetes staless steel. I the 4 yeas old chld case ths was smalle ad the obtaed value was 68.75N (Fg. 3). I the kee aametezed osthess case eseted Fg. 4 the comoet detfcato s: -femu comoet -cldcal jot 3- cam followe 4- cam 5- tba comoet 6-FEO shock absobe 7-adtoal shock absobe mechasm. Fo ths though VsualNasta smulatos dyamc esose was detemed. Dyamc esose was eeseted though vo Msses stess dslacemets ad defomatos of the kee osthess mechasm. hese esults wee obtaed a dyamc mode by alyg the coecto foces fom fgue 8 oto femu elemet ad the kee moto law fom fgue 5 was aled oto the dve elemet fo a sgle gat. he dve elemet was the Festo shock absobe. he foot elemet was cosdeed as fxed oe ad at kee jot level as t show Fg. 5 Fg.. Defg the modula othoss moto case of a 7 yeas old chld. Fg.. Foce vaato dagam fo cable o. of the kee modula othoss a 7 yeas old chld case. he esults ae show Fg. 6 Fg. 7 ad Fg. 8. Vo Msses stess aveage value was MPa dslacemets wee.34mlmetes ad total defomatos wee.6. lso the vaato dagams of these esults ae show Fg. 9 Fg. 3 ad Fg. 3.

12 hese values wee obtaed fo alumum alloys whch cofe a small weght ad ca be easy to wea fo the chlde wth oe amutated leg. Fg. 3. Foce vaato dagam fo cable o. of the kee modula othoss a 4 yeas old chld case. Fg. 6. Vo Msses stess of the aametezed kee osthess Fg. 4. Paametezed kee osthess fo 4-7 yeas old chlde wth comoet detfcato Fg. 7. Dslacemets of the aametezed kee osthess lyg the vaable foce DOF o foot. Ux=Uy=Uz= Fg. 8. Defomatos of the aametezed kee osthess Fg. 5. lyg loads ad establshg the DOF codtos fo the aametezed kee osthess fo 4-7 yeas old chlde

13 stess [MPa] kee mechasm vo Mses stess tme [sec] Fg. 9. Vo Msses stess of the aametezed kee osthess vaato dug oe gat deedg o tme.5e-4 kee mechasm vo Mses defomatos vo Mses defomatos [mm/mm] dslacemet [mm].e-4.5e-4.e-4 5.E-5.E tme [sec] Fg. 3. Defomatos of the aametezed kee osthess vaato dug oe gat deedg o tme kee mechasm dslacemet Fg. 3. Pototye exemetal eseach case of a 4 yeas old chld he exemetal tests of both kee modula othoss ae valdated by testg these o chlde wth locomoto dsabltes. hese ototyes wee tested o two chlde oe of a 4 yeas old ad othe of a 7 yeas old. he acqusto data used ths case was the CONEMPL Moto alyss equmet. he esults ae eseted dagams fom Fg. 37 ad Fg. 38. I these dagams oe t ca be obseved that the moto vaato law s almost the same as case of a healthy chld. he agula amltudes ad lowe lmb segmets dmesos ae used as ety data fo dyamc aalyss. lso the agula amltudes eeset the moto laws whch dctate the osthetc ad othotc devces motos secally desged fo chlde tme [sec] Fg. 3. Dslacemets of the aametezed kee osthess vaato dug oe gat deedg o tme VI. CONCLUION s fal coclusos t ca be metoed that ths tye of aalyss has a ogal aoach because t was stated by ceatg a database fom a exemetal eseach ad fally to obta coecto foces dagams used fo othotcs ad osthess desg. Wth these t ca be eseted hee eal models of a modula kee othotc devce (Fg. 3 Fg. 33 Fg. 34 Fg. 35 ad Fg. 36) ad aametezed kee osthess (Fg. 39 ad Fg. 4). he moto laws develoed though the exemetal eseach ca be useful to jot actuatos ogam ad cotol fom a exoskeleto stuctue secally desged fo chlde wth temoal locomoto dsabltes accodg wth bomechacal featues of chlde. Fg. 33. Pototye exemetal eseach case of a 7 yeas old chld If we aalyzed the jots values movemet dug the gat cycle we ca obseve dffeece betwee gou of age ad ths s motat fo desg the assstve devces accodg wth bomechacal featues of chlde.

14 Fg. 36. sect egadg the kee modula othoss commad ad cotol moto he database that we ty to ceate begg fom healthy eole ths eseach hel us to desg the assstve devces fo chlde wth euomoto athology deedg of age ad athoometc featues that meas a movemet ad develomet of fast ad well ehabltato ogam. Fg. 34. Pototye exemetal eseach case of a 4 yeas old chld Fg. 37. gula amltude case of a 4 yeas old chld Fg. 38. gula amltude case of a 7 yeas old chld Fg. 35. Pototye exemetal eseach case of a 7 yeas old chld alyzed of jots kematcs fo each hase of gat hel us fo desg the costucto of assstve devces ad movemet the moto cotol fo each jot accodg wth bomechacal ules. hat meas to move the movemet ad stablty of jot wthout decease the ole of dyamc stablty volved by muscle system. Much moe s ossble to tegate the movemet atte of chld omal atte of gat ad to move the balace dug gat. alyzg the foces fom Fg. 8 ad Fg. 9 t hel us to tag the muscle gou close to omal atte of gat because the assstve devces ca volve a omal atte of gat. o s ossble to estoe o to move the omal cetal evous system actvty the stuatos o ceebal alsy. he system of assessmet the gat hase usg

15 bomechacal assessmet ca hel to motog the ehabltato ogam ad to develo the sklls fo each hase of gat at each jot. Femu comoet dtoal shock absobe mechasm Cam followe Cam elemet ccodg wth the exemetal tests ad the lteatue data [5] [7] ths value cetfcate the aametezed kee osthess ototye. he majo oblem fo kee osthess mechacal system s the fabcato ocedues whch ae exesve. I the kee othoss case the oblems cossts ts sze whch s bgge tha some chlde kee atculato sze. O the futue the eseach eseted hee wll be cotued ode to cease the mechacal systems efomaces. CKNOWLEDGMEN hs wok was suoted by the stategc gat PODRU/89/.5//6968 Poject ID6968 (9) cofaced by the Euoea ocal Fud wth the ectoal Oeatoal Pogam Huma Resouces Develomet 7-3. FEO shock absobe Fg. 39. Real model of aametezed kee osthess fo chlde (exloded vew) Fg. 4. Real model of aametezed kee osthess fo chlde he kee agula amltude obtaed o exemetal tests by a 7-yeas old chld wth a amutated leg s 63degees fo oe gat (Fg. 4). Fg. 4. he ew kee osthess flexo/exteso agula dslacemet vaato deedg o tme. REFERENCE [] F. mouche Comutatoal methods multbody dyamcs. Petce-Hall Publshg House. 99. [] R. M. Kss L. Kocss ad Z. Koll Jot kematcs ad satal temoal aametes of gat measued by a ultasoud-based system. J. Med. Eg. Phys. vol. 6: [3] G.. ohl ad J. E. Bobow Recusve Multbody Dyamcs ad estvty lgothm fo Bached Kematc Chas. ME J. Dy. yst. Meas. Cotol 3_3: [4] F. C. deso ad M. G. Pady Dyamc Otmzato of Huma Walkg. J. Bomech. Eg. 3_5: [5] C. Colus N. Dumtu. Mage. "Modula Kee Othoss FEM alyss fom Kematc Cosdeatos". New eds Mechasm ad Mache cece Mechasms ad Mache cece. Vol [6] C. Colus M. Ma L. Rusu I. Geoea "Desg Cosdeatos egadg a New Kee Othoss" Joual of led Mechacs ad Mateals Vol. 6.. Ole avalable sce /Ma/7 at [7] C. Colus M. Ma N. Dumtu L. Rusu "Locomoto ystem Dyamc alyss wth lcato o Chlde Othotcs ad Postheses Devces". Lectue Notes Egeeg ad Comute cece: Wold Cogess o Egeeg. Vol. III [8] C. Colus " Desg of a New Kee Modula Othotc Devce fom Cematc Cosdeatos". Lectue Notes Egeeg ad Comute cece: Wold Cogess o Egeeg. Vol. III [9] C. Colus N. Dumtu M. Ma L. Rusu Huma Lowe Lmb Kematc alyss wth lcato o Posthess Mechacal ystems. 3th Wold Cogess Mechasm ad Mache cece Guaajuato Méxco. IMD-3. IfOMM-. Pae ID: IBN [] C. Colus M. Ma L. Rusu New Kee Posthess Desg Based o Huma Lowe Lmb Cematc alyss Lectue Notes Egeeg ad Comute cece: Wold Cogess o Egeeg Vol. III [] C. Coluş N. Dumtu L. Rusu M. Ma Cam Mechasm Kematc alyss used a Huma kle Posthess tuctue. Lectue Notes Egeeg ad Comute cece: Wold Cogess o Egeeg. Vol. II [] C. Colus Reseaches egadg some mechacal systems alcable medce. PhD. hess Faculty of Mechacs Uvesty of Caova. Romaa. 9. [3] CONEMPL Moto Equmet. Use Maual. valable: htt:// [4] N. Dumtu C. Colus M. Ma L. Rusu. Huma Lowe Lmb Dyamc alyss wth lcatos to Othoedc Imlats. Mechasms ad Mache cece New eds Mechasm cece. alyss ad Desg. ge Bel Hedelbeg Publshg house. Vol. V [5] N.Dumtu C. Coluş. Zuha. Dyamc Modelg of a Moble Mechacal ystem wth Defomable Elemets. Lectue Notes Egeeg ad Comute cece: Wold Cogess o Egeeg. 9. Vol. II

16 [6] N. Dumtu G. Nau D. Vtlă Mechasms ad mechacal tasmssos. Mode ad classcal desg techques. Ddactc tg house IBN Buchaest. 8. [7] N. Dumtu M. Checu Z. lthalab heoetcal ad Exemetal Modellg of the Dyamc Resose of the Mechasms wth Defomable Kematcs Elemets. Poceedgs of IFoMM Besaco Face. Pae [8] N. Dumtu. Mage. Modelg bases mechacal egeeg. Uvestaa tg house. Caova. Romaa [9] L. Guou C. Batau P. Rdeu Numecal modellg ad smulato bomechacs. Uvestaa Ptg House Caova. 5. [] C-Y. E. Wag J. E. Bobow Dyamc Moto Plag fo the Desg of Robotc Gat Rehabltato J. of Bomech. Eg [] C-Y. E. Wag J. E. Bobow ad D. J. Rekesmeye wgg fom the H: Use of Dyamc Moto Otmzato the Desg of Robotc Gat Rehabltato. IEEE It. Cofeece o Robotcs ad utomato [] K. Hashmoto Y. ugahaa. Ohta H. uazuka Realzato of table Bed Walkg o Publc Road wth New Bed Foot ystem datable to Ueve ea. BoRob 6. [3] D. Hooma M. Bgtte Jolles et. al. Estmato ad Vsualzato of agttal Kematcs of Lowe Lmbs Oetato Usg Body-Fxed esos. IEEE asactos o Bomedcal Egeeg. Vol. 53. No [4]. Hey R. E. Mayagota. V. Nee ad P. H. Veltk he kematcs of the swg hase obtaed fom acceleomete ad gyoscoe measuemets. Poceedgs of the 8th It. Cof. IEEE Egeeg Medce ad Bology ocety [5]. amee Itellget Robotcs Fo Rehabltato Robotc Lowe Lmb fo bove Kee Posthess. Gat tye (83/ECE/) Deatmet of Electocs ad Commucato Egeeg Ida. 4. [6]. Vuca M. Hudec Kematcs ad foces the above kee osthess dug the sta clmbg. cetfc ae MOR Bosa 5. [7] M. Wllams Bomechacs of huma moto. W.B. audes Co. Phladelha ad Lodo. 996.