Functional Electrical Stimulation - Essay Example

Functinl Electricl Stimultin Intrductin Vrbv (1963); Brwn, Ctter, Hudlick & Vrbv (1976); eckhm, Mrtimer & Mrslis (1976); etrfsky & hillis (1983); etrfsky, hillis & Hendersht (1985); etrfsky & Smith (1988, 1991); nd Vn der Meulen (1974) ll exmined the use f electricl stimultin s mens f reversing the trhy f skeletl muscle sscited with rlysis. The ultimte gl f this reserch, including lter wrk n cmuter-ided mvement (Mrslis & Kbetic, 1982; etrfsky, Glser, hillis & Gruner, 1982; etrfsky, hillis & Hendersht, 1985; etrfsky & Smith, 1992) ws t restre lst mtr functin (Guttmn, 1976) nd reverse sme f the secndry medicl rblems sscited with sinl crd injury such s ressure sres, kidney nd bldder infectins, nd bne frctures (Yung, 1982; Fege, 1985). In fct, these secndry medicl rblems re the mst significnt rblems sscited with sinl crd injury in terms f bth cst nd medicl cmlictins. It is nt uncmmn fr rlyzed individul t exend between thusnds nd tens f thusnds f dllrs in medicl csts ech yer (Guttmn, 1976; Burke, 1975; Yung, Burns, Bwen & McClutchen, 1982). ressure sres, fr exmle, hve yerly rte f incidence f ver 30% (Yung, Burns, Bwen & McClutchen, 1982). Freehfer nd Mst (1965) hve shwn tht bne frctures hve n incidence f 9.3%. It is hed tht functinl electricl stimultin (FES) my ffer mens f reversing sme f these secndry medicl rblems thrugh exercising rlyzed muscle nd incresing the bld delivery t the legs. Hwever, questins rise s t the sfety f the technlgy. In wek, stertic bne, cn wered muscle stimultin cuse bne frctures in itself Wht is the incidence f electrde burns with cntinuus FES use Further, the cmlince f tient ultin fr this technlgy must be exmined. This ws the urse f the resent investigtin. Subjects The subjects in these studies were 109 vlunteers. Eighty-three f the subjects in these studies vlunteered t rticite in reserch. These individuls were sked t rticite fr minimum f tw-yer erid. Twenty-six subjects were invlved in brd-bsed clinicl rgrm invlving FES nd cnventinl thery. The verge ge f the reserch gru ws 26 +/- 3 yers, wheres the verge ge f the clinicl gru ws 29 +/- 9 yers. f the reserch gru, 40 were ersns with qudrilegi nd 43 were ersns with rlegi. ll were dignsed s hving cmlete injuries. ll rtcls were shwn t ech subject. ll rcedures were rved by the cmmittee n humn exerimenttin. Methds Fur exercise mdlities were used here s described belw: Weightlifting Uer bdy cnditining f nn-rlyzed muscles (weightlifting) ws ccmlished n secilly designed equiment. Secil hndles nd rm gris were used s tht ersns with qudrilegi culd ccmlish uer bdy weightlifting. FES Weightlifting Functinl Electricl Stimultin (FES) weightlifting invlved electricl stimultin f the rlyzed muscles in the bdy. Electrdes were lied bve the muscle, nd trnscutneus electricl stimultin ws used t excite the mtr nerves t elicit muscle cntrctin. T exercise given muscle, weight ws lied tht wuld resist the mvement f tht muscle thrugh lding f its jint. Electricl stimultin ws then lied with bihsic, squre-wves t ulse width f 350 micrsecnds nd stimultin mlitude, which ws vrible, frm 0 t 150 millims. The frequency f stimultin ws 35 Hz. s current ws incresed thrugh the stimultin electrdes, the muscle cntrcted. Current ws djusted s tht the muscle lifted weight ver erid f three secnds, held the weight fr ne secnd, nd then slwly reduced the munt f frce in the muscle ver nther erid f tw secnds; six secnds were llwed between the cntrctins. The exercise ws cntinued fr 15-minute erids. If exercise culd be mintined fr 15 minutes, then the weight ws incresed by ne und the next dy. In cntrst, if the exercise ftigued the muscle in less thn 10 minutes, ne und ws remved rir t the next dy's exercise. Cmuter-cntrlled Bicycling Bicycle ergmetry ws ccmlished n mdified Mnrch bicycle ergmeter similr t ne described by etrfsky, Glser hillis nd Gruner (1982) nd etrfsky nd hillis (1983). The bicycle ws mdified with highbck set nd set belts t llw rlyzed individuls, such s the girl t sit cmfrtbly. new bicycle set ws designed becuse cnventinl bicycle set hs t smll set bse t llw sture t be stble in smene with lwer bdy rlysis. dditinlly, the size f cnventinl set bse uts high ressure n the elvic re, n re where ver 50% f ll ressure sres ccur (Yung et l., 1982). Knee stbilizer brs were dded t the sides f the legs s tht exercise culd be ccmlished withut bductin r dductin f the his. digitl cmuter cntrlled the timing f the nset f the electricl stimultin t the qudrices, hmstring nd gluteus mximus muscles. The stimultin ulse width ws 350 micrsecnds, nd bihsic squre-wve stimultin ws used. The current ws djusted t s high s 180 millims t frequency f 35 Hz. t mintin edling seed f 50 rm. If the seed ws belw 50 rm, then the stimultin current ws incresed. In cntrst, if the seed ws t high, the stimultin current ws decresed by the cmuter rgrm. Cmuter-Cntrlled Wlking Sme individuls were invlved in cmuter-cntrlled wlking rgrms. Cmuter-cntrlled wlking (etrfsky, & hillis, 1983; etrfsky, hillis nd Hendersht, 1985; nd etrfsky & Smith, 1991) invlved electricl stimultin f the hmstring, qudrices nd gluteus mximus muscles during wlking in mdified Luisin Stte University recircting git rthsis. Electricl stimultin ws lied t frequency f 30 Hz nd ulse width f 350 micrsecnds t llw mvement f the legs during wlking. The current ws vried t 100 millims, but tyiclly verged but 60 millims during mbultin. rcedures Clerly, there were tw serte grus f individuls in these studies. The reserch gru rticited in lbrtry-bsed series f exeriments. Here nly ne tye f exercise ws dne ver the tw-yer erid nd ll exercise ws dne in the uthr's lbrtry. The clinicl gru ws engged in clinicl rehbilittin rgrm which invlved three nd ne hlf mnths f hysicl thery fllwed by hme rgrm invlving exercise tw dys week fr rximtely tw hurs ech dy. The clinicl gru did ll exercise mdes listed bve but less intensively thn the reserch gru. summry f the rgrms is given belw. Reserch rgrms f the 83 individuls wh rticited in reserch, 40 were ersns with qudrilegi nd 43 were ersns with rlegi. ll individuls were dignsed s hving cmlete sinl crd lesin. f this gru, 22 rticited in weightlifting studies, 28 in bicycling studies, nd 33 in studies invlving cmuter-cntrlled wlking. Fr FES weightlifting studies, individuls exercised their qudrices muscles with FES three times er week, with the weight slwly being rgressed until mximum f 50 unds ws reched. fter tht time, they reduced their rticitin t 2 times er week t mintin muscle mss. This ws the nly exercise this gru ccmlished during tht yer. Fr the individuls invlved in FES bicycling, fllwing fur-week trining erid f the qudrices muscles with FES weightlifting s described bve. FES bicycling ws ccmlished three times er week with ech bicycle sessin lsting 30 minutes. Resistnce ws rgressively incresed s tht individuls ftigued t the end f the 30-minute erid. This exercise ws cntinued fr the reminder f the tw yers. Finlly, the 33 individuls wh were invlved in FES wlking rticited fr ne yer in FES weightlifting nd bicycling rir t wlking. This rtcl invlved ne mnth f FES weight trining f the qudrices, gluteus mximus nd hmstring muscles, s described bve, s tht the strength f the muscles wuld equl r exceed 10 unds f frce during weightlifting. This ws fllwed by FES bicycle trining until they culd edl the bicycle ginst ld f 3/8 K fr 30 minutes. They then entered wlking rgrm fter cmleting the weight trining nd bicycling rgrms nd 3 mnths f stnding in stnding frme ne hur dy, three dys week. Wlking invlved tw mnths f trining n hw t wlk in the Luisin Stte University recircting git rthsis. nce brce trining ws cmlete, FES wlking ws begun. This invlved using cmbintin f electricl stimultin nd mbultin in the RG. Wlking invlved mbultin in the brces while stimultin ws lied t the qudrices, hmstring nd gluteus mximus muscles t rvide mvement f the legs. Individuls in this gru wlked fr minimum f 1 mile er week nd ls exercised twice week n the FES bicycle ergmeter. Clinicl rgrm The clinicl rgrm ws cnducted t the etrfsky Centers fr Rehbilittin nd Reserch in Irvine, Clifrni. The clinicl rgrm required medicl screening exmintin which ws cnducted rir t the dmissin f n individul int the rgrm. Screening included ulmnry functin test, ECG nd ECG stress tests, clinicl chemistry rfile, cmlete hysicl exmintin, neurlgicl evlutin, MRI's nd X-Rys. Individuls then begn the rgrm with tw weeks f ssive hysicl thery (rnge f mtin nd stretching) nd ne hur dy stnding in the stnding frme. Rnge f mtin nd stnding frme cntinued fr the first tw mnths f the rgrm. Hwever, fter tw weeks, electricl stimultin ws strted n the qudrices, hmstring, gluteus mximus, gstrcnemius nd tibilis nterir muscles in the rlegic grus. Qudrilegic grus underwent the sme rgrm f electricl stimultin. In dditin, they received stimultin f the deltids, bices, nd trices, finger flexrs nd finger extensrs. FES weightlifting ws cntinued fr the first tw mnths f the rgrm. During the third mnth, FES bicycling ws strted. fter 3-1/2 mnths in the rgrm, individuls rticited in git trining in the FES wlking system (etrfsky nd Smith, 1991). fter 4-1/2 mnths frm the beginning f the rgrm, individuls grduted frm the full-time rgrm nd begn hme rgrm. The hme rgrm invlved functinl electricl stimultin with hme cmuter-cntrlled stimultr f the qudrices, hmstring nd gluteus mximus muscles, s well s cmuter-cntrlled wlking. Weightlifting ws ccmlished ginst lds f 10 unds n ech f the muscle grus listed bve tw times er week. This hme exercise regime required rximtely 2 t 2-1/2 hurs er dy n ech f the exercise dys. Every six mnths individuls returned bck t the min rgrm fr hysicl evlutin t ssure tht the rgress ws stisfctry nd t see hw they were cmlying with the rgrm. Cmlince The cmlince f the subjects in the tw rgrms is shwn in Tble 1. The number f ele wh strted in ech rgrm is shwn s well s the number f ele remining in the rgrm t ne mnth, three mnths, ne yer nd tw yers lter. Fr the clinicl gru, very few ele left the rgrm. fter tw yers, rximtely 90% f the ele wh strted remined. In cntrst, f the 83 ele wh strted with the reserch gru, nly 42% f the ele remined in the rgrm. COMPLIANCE IN FES PROGRAM , Table 1 TIME FROM START RESEARCH GROUP CLINICAL GROUP START 83 26 1 MONTH 81 24 3 MONTHS 80 24 1 YEAR 71 24 2 YEARS 35 23 Interestingly enugh, in this gru, the mjrity f the ele wh dred ut were the ersns with rlegi nd nt the ersns with qudrilegi. Mst ersns with qudrilegi in the reserch gru (83%) remined thrughut the entire length f the study. Injuries sscited with Functinl Electricl Stimultin ver the tw-yer erid tht functinl electricl stimultin ws used, injury recrds were ket f bne frctures nd electrde burns. Tble 2 shws the incidence f electrde burns. In the clinicl gru, nly ne electrde burn ws fund in the first mnth f the study. N electrde burns were seen fter this time. In the reserch gru, three burns were fund in the first mnth, ne burn in the secnd, nd n dditinl burn in the third mnth f the study, nd n burns therefter. ELECTRODE BURNS, Table 2. TIME FROM START RESEARCH GROUP CLINICAL GROUP START 83 26 1 MONTH 3 1 3 MONTHS 1 0 1 YEAR 0 0 2 YEARS 0 0 During the tw-yer erid tht these studies were being ccmlished, there were three dcumented bne frctures in the reserch gru. ne ws directly relted t the ctul FES reserch. The ther tw frctures were cused by ccidents utside f the lbrtry envirnment. In the clinicl gru, ne dcumented frcture ws fund ut f the 26 ele wh were exmined in these studies. This frcture ccurred during FES weightlifting. Strength nd Endurnce Individuls wh rticited in the reserch studies shwed drmtic increse in endurnce nd strength. In the reserch bicycle gru, fr exmle, individuls wh culd nly edl bicycle ergmeter t the nset f the studies fr erid f few secnds were ble t edl the bicycle ergmeter fr n hur t ld f u t 1 k t the end f the tw-yer erid. Fr the verge qudrilegic nd rlegic, the endurnce incresed frm 15 +/- 11 nd 11 +/- 7 sec n the first dy f bicycling ginst ld f zer k t 27 +/- 4 min. nd 29 +/- 3 min. t ld f 0.7 +/- 0.1 NS 0.8 +/- 0.2 k fr the tw resective grus. With the clinicl gru, lthugh trining ws nly 3 mnths lng, bicycling endurnce incresed frm few secnds t the bility t wrk ginst lds f 0.3 +/-.04 nd 0.3 +/- 0.05 k fr 28 +/- 3 nd 29 +/- 4 min. in the qudrilegic nd rlegic grus resectively. In similr mnner, muscle strength incresed in bth reserch nd clinicl grus. t the end f the tw-yer erid, the led dt f the reserch gru shwed tht the verge subject in the reserch gru ws ble t lift 35.6 +/- 11.1 lbs with the qudrices muscles sustined fr the 15-minute exercise regimes described bve, wheres the verge ersn in the clinicl gru culd nly lift 12.3 +/- 1.4 lbs. fr 15-minute exercise erid. These differences were sttisticlly significnt () when cmring dt n the rlegic reserch gru t tht f the rlegic clinicl gru r cmring the dt n the clinicl nd reserch qudrilegic grus. Helth Cre Benefits In bth the reserch gru nd clinicl gru, helth cre benefits were exmined. During the yer befre individuls rticited in these studies, the number f bne frctures, ressure sres, nd kidney nd bldder infectins were recrded. The sme rmeters were mesured during the tw-yer study erid. Dt n individuls wh dred ut f the rgrm were nt used in this sttisticl dt bse. Discussin Individuls engged in either reserch r clinicl rgrms, shwed high cmlince in mintining the rgrm thrugh erid f tw yers. The individuls wh engged in clinicl rgrms hd much higher cmlince thn thse in the reserch rgrms. The resn this rbbly ccurred is tht the clinicl rgrm ws nly f 3-4 mnths durtin, fllwed by hme rgrm. In cntrst, the reserch rgrm required 24 mnths f lbrtry rticitin, mking it hrder t be subject in since it required individuls wh rticited t sty t the lbrtry ech week fr tw-yer erid. Further, the clinicl rgrm hd better blnce in terms f ding exercise n ll the mjr muscle grus in the bdy thn the reserch rgrm where nly ne tye f exercise ws dne fr tw yers. This vribility f llwing ele t d different things ech dy mde the rgrm much mre interesting, ccrding t the rticints. FES exercise ered t be firly sfe t ccmlish. In bth grus f reserch nd clinicl subjects, the incidence f bne frctures ws lwer thn the ntinl verge f ele nt engged in ny tye f rehbilittin. Further, the incidence f electrde burns ws nt nly lw, but fter the first few mnths when ele were better cquinted with the equiment nd hw t use electrdes nd electrde ste, electrde burns were n lnger rblem fr this gru f ver 100 individuls. Since ressure sres ccunt fr tw-thirds f ll medicl csts sscited with sinl crd injury in individuls wh hve been injured fr tw r mre yers, nything tht will reduce the incidence f ressure sres is very imrtnt t ccmlish (Yung 1982). The Ntinl Trnsrttin Sfety Brd cmmissined the Ntinl Reserch Cuncil t write study, "Injury in meric" in 1985. The Ntinl Reserch Cuncil identified reserch n ressure sres t be f gretest imrtnce in reltin t victims f ut ccidents becuse f their significnt medicl nd finncil imlictins with ll sects f rlysis. The drmtic reductin in ressure sres sscited with the functinl electricl stimultin trining rgrm my be cused by number f different things. First f ll, they my be cused by chnges in lifestyle. ressure sres re cmmnly cused by inctivity. Individuls engged in these tyes f exercise rgrms begin t get ut mre in the cmmunity, tke n mre ctive rle in life, such s ging bck t their eductin, nd jbs. dditinlly, the increse in eriherl bld flw nd the resultnt delivery f xygen t the limbs, must hve telling effect. Since 50% f ll ressure sres ccur in the elvic re, the increse in muscle mss nd muscle girth sscited with functinl electricl stimultin in itself wuld dd dding t bny rminences. The cmbintin f n increse in bld flw nd incresed muscle mss my be significnt fctr in reducing the incidence f ressure sres. The results f this study suggest tht functinl electricl stimultin cn be well tlerted by rlyzed individuls. In clinicl rgrms, the cmlince is very high. Exercise cn be dne sfely nd results in sitive helth cre benefits t the tient. Hwever, it must be emhsized tht these studies were nly cnducted n limited number f individuls nd ver erid f tw yers. Further study is wrrnted. References 1. Brwn, M.D., Ctter, M.., Hudlick, . nd Vrbv, G. (1976). The effects f different tterns f muscle ctivity n cillry density, mechnicl rerties nd structure f slw nd fst rbbit muscles. fluegers rch., 36,241. 2. Burke, D.C., nd Murry, D.D. (1975). Hndbk f sinl crd medicine. Lndn: McMilln ress, Ltd. 3. Freehfer, H.., nd Mst. W.. (1965). Lwer extremity frctures in tients with sinl crd injuries. J. Bne Jint Surg., 47:683-694. 4. Guttmn, L. (1976). Sinl crd injuries: Cmrehensive mngement nd reserch. xfrd: Blckwell Scientific ublishers, 226-227. 5. Mrslis, E.B., nd Kbetic, R. (1982). Functinl wlking f rlyzed tients by mens f electricl stimultin. rceedings f the Fifth nnul Cnference n Rehbilittin Engineering, 60, Hustn, ugust 22-26, 1982. 6. eckhm, .H., Mrtimer, J.T., nd Mrslis, E.B. (1976). ltertin in the frce nd ftigbility f skeletl muscle in qudrilegic humns fllwing exercise induced by chrnic electricl stimultin. Clin. rth., 114:326. etrfsky, J.S., Glser, R.E., hillis, C.., nd Gruner, J. (1982). The effect f electriclly induced bicycle ergmetry n bld ressure nd hert rte. The hysil, 25:253. 7. etrfsky, J.S., nd hillis, C.. (1983). ctive hysicl thery - mdern rch t rehbilittin thery. J. Neur. rth. Surgery, 4:165-173. 8. etrfsky, J.S., hillis, C.., nd Hendersht, D. (1985). Crdivsculr resnses f rlyzed individuls during electriclly induced iskinetic exercise. J. rth. nd Neur. Surg., 6:230-241. 9. etrfsky, J.S., nd Smith, J. (1988). Cmuter-ided rehbilittin. vitin Sce Envirn. Med. 59:670-679. 10. etrfsky, J.S., nd Smith, J. (1991 ). hysilgicl csts f cmuter cntrlled wlking in rlegi in ersns with n R60. J. Clin. Eng. 16:505-512. 11. Rck, .M.H., nd Westbury, D.R. (1969). The effects f length nd stimulus rte n tensin in the ismetric ct sleus muscle. J. hysil., 204:443-460. 12. Vrbv, G. (1963). The effect f mtr neurns ctivity n the seed f cntrctin f strite muscle. J. hysil, 169:513-526. 13. Yung, J.S., Burns, .E., Bwen, .M., nd McClutchen, R. (1982). Sinl crd injury sttistics: Exerience f reginl sinl crd injury systems. henix, Z: Gd Smritn Medicl Center. 14. Vn derMeulen, J.., eckhm, .H., nd Mrtimer, J.T. (1974). Trhic functins f the neurn. Three mechnisms f neurtrhic interctins. Use nd disuse f muscle. nn. N. Y. cd. Sci., 280(0):177-189. Read More