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Abstracts o Aecent ArticlesThe following articles have been abstracted by Joan E . Edelstein,R.P.T.,vvho is a Senior Research Scientist, New York University Post-Graduate Medical School, Prosthetics and Orthotics, 317 East 34thStreet, New York, N .Y. 10016.

For this issue of BPR, Joan Edelstein again sought arti-cles in all phases of rehabilitation engineering, from awide number of current journals . Accordingly, you willfind:

Upper limb prosthetics 3 articlesUpper limb orthctiom1Lower limb prosthetics 11Lower limb urthodcm3Spinal orthotics 1Gait 3Environmental control 1Wheelchairs 2

These have been drawn from:

American Journal of Occupational Therapy 1 articlePhysical Therapy 1Orthotics and Prosthetics 3Prosthetics and Orthotics International BJournul ofBimmmuhanics2Journml of Bone and Joint Surgery 2Clinical Orthopaedics 1Archives of Physical Medicine and Rehabilitation 7

Economics of Modular Prostheses : A. Stamu(VetemnaAdministration Prosthetics Center, New York, NewYork), Prosthetics and Orthotics International3:147-149, December 1979.

Definition of modularity is necessary . The crustacean(wood) exoskeletal array was modular in the assemblyprocena, for the fitter assembled a knee-shank, fuwt-an-k!e ' and socket module . It is difficult to replace a majorcomponent in such a system without remaking the wholeprosthesis . The significance of endoskeletal modulardesigns is the speed with which components can be ro-p!aomd, simplifying servicing of prostheses.

Modular hardware does not save time of the prosthe-tist who must cast the patient, fit the socket, and per-form dynamic alignment. Modularity will save techni-cian time because alignment transfer, shaping, andfinishing are not necessary and assembly without gluedjoints is faster . The saving in technician time equals theadditional initial cost of the hardware ; thuo, in the de-veloping world, use of modular hardware would be fi-nancially unsound since labor-intensive methods aruin-dicated for prosthesis production there.

Modularity is primarily advantageous in repair andmaintenance, saving technician and patient time.

The Multiplex system, designed by the United States

Manufacturing Co . in response to a Veterans Adminis-tration stondard ' pnrmitointeruhangninth000meohonkamong different kinds of fluid knee controls and me-ohanioal friction systems . Manufacturers of various unitscooperated in making their controls conform with thestandard geometry of the Multiplex unit . Atria! with ac-tual performance analysis can be done quickly.

Su000uaful experimentation with graphite fibre andepoxy composite materiel achieved weight reduction inthe Multiplex framm, and in a rotator and SACH footkeel.

Modular Assembly Above-Knee Prostheses : J . S . Taylor(National Center for Training and Education in Pros-thetics and Orthotics, Glasgow, Scotland), Prostheticsand Orthotics International 3 :144-146, December 1979.

Modular systems provide functional prosthesesquickly . The ideal system has the possibility of align-ment adjustment through the life of the prosthesis, sim-ple change of components to give prescription flexibil-ity, and easy disassembly for replacement of faultyparts.

The Hosmer and United States Manufacturing sys-tems require the alignment device to be removed afterdynamic alignment . The Blatchford and Otto Bock unitshave the alignment facility as part of the final structureand have been supplied to patients for three years.Modular above-knee prostheses are slightly lighter thanoxonke!*tal ones ; the Blatchford and Bock are lighterthan the American ones . Alignment devices do not nec-essarily reduce proathetiotdnne' but they increase align-ment accuracy . The Bock arrangement has alignmentcapability both below and above the knee . The staticalignment apparatus makes bench alignment very ac-curate . Socket shape has not changed much, but the at-tachment to knee units varies . The Blatchford systemwas designed for metal sockets, hence duralumin struts;that system has an attachment for plastic and woodsockets, but may not allow close access to the knee cen-ter, especially if the amputation limb is too long.

Shape of the cosmetic cover is more important thansoftness, whether one-piece or two-piece ; the former issuitable for a fixed knee, and the latter offers betterfunction and durability for the active amputee . The sys-tem should serve all amputation levels. The child hipdisarticulate cannot be fitted easily . Modular assemblymakes production possible in smaller units, with easierordering and pricing .

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Total Surface Bearing Self-Suspending Above-KneeSockets : R .G . Redhead (Biomechanical Research andDevelopment Unit, London, England), Prosthetics andOrthotics International 3 :126–136, December 1979.

A new socket was devised, based on the assumptionthat the amputation limb had an outer limiting skin en-velope, and oblique pelvic roof, and a central femoralstrut . The shape, but not the volume, of the containedsoft tissue could be altered . A limb in a rigid socket con-forming to its average shape and volume could betreated as a fixed volume hydrostatic system . The pa-tient would be supported on the incompressible volumecontained in the socket, minimizing ischial bearing anddistributing pressure evenly.

Forces act normal to the surface, eliminating shearstress . Support pressure would be related to the area ofthe oblique pelvic wall . The patient sustains fu!l weighton the prosthesis transiently as he shifts support fromone foot to the other ; periods of lower pressure at theinterface permit blood circulation, and the pressure var-iation promotes venous and lymphatic return. Socketretention depends on friction at the interface, voluntarymuscle contraction, and atmospheric praoaure, assum-ing an airtight total contact socket . Diotml stressing in-creases soft tissue stiffness for mke!etal stability ; down-ward movement under axial compression would beprevented by the incompressible limb volume in a rigidsocket. Rotadonal stability is gained by the brim's lock-ing the socket to the limb.

The cast is taken with the patient supine to relax mus-cles and avoid edema . Acaoting board adjustable forheight and flexion are used . An open-ended elasticsleeve stretches the limb distally with 4 .5 kg (equal tothe weight of the prosthesis plus a safety factor) . Withsuch a socket, pressure transducers enabled measure-ment of load distribution and level under axial compres-sion. The socket had total contact, there was no skinmovement, and skin color was uniform . Lowest pres-sures were noted on the proximolateral aspect, andhighest pressures were distolaterally, although onlyabout half of the pressure reported under the ioohioltuberosity in a quadrilateral socket . Small mediolateralalignment changes affected pressure distribution . Thesockets have been issued since 1974 ; patients show noprogressive atrophy.

Femoral Fractures in Patients with Lower ExtremityAmputations : Erwin G . Gonzales and Mathai M . Ma-thews (Department of Rehabilitation Medicine, Co-lumbia University, College of Physicians and Sur-goono ' New York, New York), Archives of PhysicalMedicine and Rehabilitation 61 :276–280, June 1980.

Eight of a population of 341 lower limb amputees sus-tained fnmoral fracture . The group consisted of five dyu'vaouu!aramputeea (two bilateral below-knee and threeuni!atoral below-knee), two traumatic amputees (a bi!at-oral and a unilateral below-knee), and one individual

who required above-knee amputation following knee in-fection . Fractures were ipui!utenal among those withuni{atorul amputations and on the side of the imbiol am-putation among the bilateral amputees . All but one ofthe fractures were closed. Five fractures were intertro-chanteric or above.

Unilateral amputees with closed fractures had closedreduction and plaster casting . Bilateral amputees hadopen reduction and intarnal fixation . A Cathcart endo-prosthesis was implanted in one patient with hemiple-gia and uni!atoral below-knee amputation . The openfracture was debrided . All fractures healed primarily.Those with proximal fractures had ieohiol weight-bear-ing orthoses with knee locks attached to the patellartendon-bearing prostheses and resumed ambulation anaverage of 20 days after fracture. The others had non-weight-bearing casts and crutches and averaged 54 daysbetween injury and walking.

Fractures occurred an average of nineteen years afteramputation, usually when the patient was not wearinga prosthesis, generally during transfer activity . Patientsneed to be trained in safe transfer with and without theprosthesis . The low incidence of fracture indicates thatmost amputees do not sustain serious falls . The pros-thesis and stump-prosthesis interface absorb torsionaland angular forooa, unlike the intact limb in whichbones and joints absorb stress . Ischia!-bearing orthosesallowed early ambulation, may have encouraged bonydeposition and healing, and avoided atrophy whichwould have necessitated socket alteration . Those whohad non-weight-bearing treatment delayed prostheticreturn, but all ultimately returned to previous functionallevels.

Rehabilitation of Blind Patients with Lower-ExtremityAmputations : Peter C. Altner, Joseph J . Rusin, andArlin DeBoer (Division of Orthopaedic Surgery, TheChicago Medical School at Veterans AdministrationW1*dioo! Center, North Chicago, Illinois), Archives ofPhysical Medicine and Rehabilitation 81 :82–85 ' Feb-ruary 1980.

During a 7-year period, 12 of 650 new amputees wereblind . These geriatric amputees were followed for anaverage of nearly four years . Uncorrected visual acuityin both eyes was 20/200 or worse or the central visualfield was 20 degrees or !*oo, because of cataracts, glau-coma, retinopathy, trauma, or various etiologic combi-nations. Eleven were diabetic and all required amputa-tion because of gangrene . Blindness precededamputation in nine cases.

All received prostheses 6 months postoperatively orsooner . Most below-knee prostheses were patellar-ten-don-bearing with soft insert, although one was a train-ing prosthesis and another had supracondylar-supra-patellar suspension . Syme's prostheses had medialopenings . Above-knee prostheses had quadrilateralauokotn, pelvic suspension, safety kneon, and SACH feet .

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All patients reached ambulatory status on an outpatientbasis, requiring an average of 11 weeks training . Extratime was needed to teach donning, including countingthe number of holes on straps and feeling for sockthickness and seam pooidon, as well as manual inspec-tion of the amputation limb . Ambulation progressedfrom parallel bars to regular cane or walker, first in fa'mi!iar ' then new areas, following verbol cues . The as-sistive device always served as both blind stick andweightbearing aid.

Nine (one bilateral Symu'o, six uni!aioral below -knee,and two bilateral below-knee) amputees walked 2 yearsafter amputation. The other three (one bi!atorol below-knee, one unilateral above-knee, and one above-knee/below-knee) amputees used prostheses for cosmesisand transfer only. Outpatient care reduced the amountof adjustment required to complete training, and savedexpense . None of the patients complained of phantompain, attributed to the early fitting policy.

System of Reporting and Comparing Influence of Am-bulatory Aids on Gait : Gary L. Smicband M. A. Mom'mono (College of Medicine, University of Iowa, IowaCity, Iowa 52242), Physical Therapy 00 :551–558 ' May1980.

Anew automated gait analysis system enabled mea-surements of the gaits of 25 nornoal young adults . Thesystem included triexial eooe!ovomotom, foot nwitohoa,signal-amplification unit, and computer which nnoa-ouradtempora} and distance factors and body acceler-ation . Subjects walked at various velocities and withnine gait patterns utilizing canes or crutches : two-pointonntra!atmral cane (right hand/left foot) ; two point uon-tra!aterel cane; two point oontna!uterul crutch ; two pointipsilateral cane ; three point crutch; delayed two pointcnntro!otnral cane; delayed three point crutch ; four pointcrutch ; and delayed five point walker.

Walking speed with ambulatory aids was much slowerthan self-selected unaided velocity ; using the walkerproduced the slowest locomotion . Patterns involvingfour counts were slower than those involving two orthree counts . Swing/time and stance/time ratios wereuymmetriuul for all gait patterns, but step length wasnot, especially with three-count and five-count gaits.The lead step was longer . Step time for three-countgaits was also asymmetrical, the lead limb being fasterby 60 to 100 percent.

Vortioml accelerations were greatly inoreaoed, inas-much as assistive devices tend to increase the verticalloading on body structures even though the device re-duces force on one limb . Consequently, potential long-term effects on other body parts of excessive loadingshould be monitored .

The Role of the Ankle Plantar Flexors in Normal Walk-ing : David H . Sutherland, Les Cooper, and Dale Daniel(Children's Hospital and Health Center, San Diego,California), Journal of Bone and Joint Surgery 62-A :354–363, April 1980.

Five nonnal adults consented to a left tibial nerveblock, paralyzing thaguotroonemiuo .00!auo.flexor ha!'!ucio ionguo,flexor digitorum !ongun ' unddbia!iupos-terior, and anesthetizing the sole. The investigators thendetermined joint motions, phasic muscle auiivity, dura-tion of single-limb stance, step and stride lengths, ve-!ooity, vertioal force, fore-aft shear, center of pressure,extrinsic and intrinsic ankle torques, extrinsic kneetorque, ankle-movement deceleration and acceleration,and energy output during and after the block.

Normally, plantar flexor activity begins at 12 percentin the gait cycle, decelerating and resisting dorsiflexionand thereby stabilizing the knee . 8y41 percent in thecycle, plantar flexors reverse dorsiflexion, and cease ac-tivity at 50 percent, coinciding with ipoi!utoral single-limb support . Flexors thus adjust limb length, lessen thefall of the center of mass, and stabilize the ankle . Withnerve block, subjects could not lean forward on the ip-ni!etoral forefoot without having the nonparalyzed footon the floor . Pressure concentrated beneath the left an-kle, rather than the normal location beneath the meta-tarsal heads . Single-limb stance reduced . The paralyzedfoot did not thrust downward during the latter part ofsingle-limb support . Contralateral step length reduceddnastioo!!y, walking velocity fell, and four subjects in-creased work output markedly.

Increased left dorsiflexion was due to lack of suffi-cient intrinsic torque to counteract extrinsic ankle torque;the left knee remained flexed because of the dorsiflex-ion, necessitating more quadriceps activity . Compensa-tory oontra!ateral knee flexion and ankle dorsiflexionduring late stance was due to lack of ankle restraint;that foot contacted the floor prematurely to check thefa!l and the knee flexed to absorb impact, disturbingsmooth weight transfer. Orthotic substitution for plantarflexor function should increase opposite-step length andreduce energy output.

Polyurethane Foam Wheelchair Cushions : Retention ofSupportive Properties : Gary M . McFadyen and DavidL. Stoner (Department of Industrial Engineering, TexasA&M University, College Station, Texas), Archives ofPhysical Medicine and Rehabilitation 61 :234–237, May1980.

Indentation load deflection OLD) due to steady load-ing and to cyclic loading were studied separately in fivecushions of various polyether and polyester foams indifferent densities . Cushions should hovna high ILD toprevent rapid bottoming out . A thick cushion has a highILD but might upset patient stability. Too high an ILDwould result in a cushion that feels stiff . A dense cush-

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ion would retain ILD values after repeated loading, butits heaviness would decrease handling ease . High vooi'!i*noe ' such as common in wheelchair cushions, resistspermanent deformation.

Cushions were subjected to static fatigue testing byprolonged loading, dynamic cyclic fatigue testing, andto combination loading . Most of the ILD loss occurredwithin the first three hours of static testing, and after200 cycles of dynamic testing ; ILD loss due to dynamicloading was less than that due to static loading . Poly-urethane foam recovered 80 percent of its supportiveproperties after 24 hours rest . Patient weight and dura-tion of sustained loading thus have the greatest effecton cushion life. Consequently, alternating use of cush-ions might prolong the usefulness of both cushions.Change in surface properties of statically loaded foamis less at cold temperatures than at room or hot tem-peratures ; the change in bulk properties is greater ateither extreme than at room temperature.

Cushions should be prestressed statically before pre-scription at 75 percent deflection for 3-hours ; a 4-inchfoam would be compressed to 1 inch by placing thefoam between two boards bolted together . The cushionshould be tested for pressure distribution under the pe-tientaoon after.

Orthoses and Ambulation in Hemiplegia : A 10 Year Ret-rospective Stwdy: Reuven Ofirond Heiner Sell (Insti-tute of Rehabilitation Medicine, New York University),Archives of Physical Medicine and Rehabilitation61 :216-220 . May 1980.

Charts of 843 hemiplegics due to rerebrmvaoou!arac-cident admittedforoctive rehabilitation were reviewed.Approximately equal numbers of men and women, andright and left hemiplegics were studied . The mean agewas 64 years . The average time from onset of stroke torehabilitation admission was 65 days for the first 6years studied, then was 50 days for the succeeding 4years . The average stay was 78 days for the first 6years; more recent stays were 64 days on average . Ofthose admitted as nonambulators, a third remainednonambulatory ; 20 percent became functional ambula-tors, walking independently at home, but may haveneeded supervision outdoors; 42 percent became par-tially functional, walking with supervision at home andshort distances outdoors. Two-thirds of those who wereinitially partially ambulatory advanced to functionalambulation.

No knee-ankle-foot orthoses were prescribed after1976. Plastic ankle-foot orthoses were introduced in1908. especially the posterior solid ankle, and in 1970the first opirol posterior leaf spring and solid ankle-footorthoses were used . By 1973 ' no metal orthoses wereprescribed and only 43 percent of patients received anyorthooeo.

The most common orthoses are now hemispiral, pos-terior leaf spring, and hemiposterior leaf-spring ankle-

foot orthoses . While prescription considerations remainunchanged, performance expectations for the spiral andsolid ankle orthoses have changed . The opiral is un-suited for hemiplegics who exhibit strong inversion anddoroif!oxion . The prime indication for solid ankle or-thoses is strong equinus or equinovarus, yet immobili-zation of a spastic limb may increase spasticity . Manypatients benefitted more by use of lateral heel flares orlateral heol and sole f!oroo, sometimes with he*l eleva-tions, accommodating equinus, preventing pain frompressure sites, and increasing the lateral base ofsupport.

A Prosthesis for Very Short Below -Knee Stumps : R . Se-liktar and others (Julius Silver Institute of BiomedicalEngineering Sciences, Technion-lsrael Institute ofTechnology, Haifa, Israel), Orthotics and Prosthetics34:25-35, March 1980.

A war veteran was amputed bilaterally at equal levels,5 cm below the knee . High sockets caused painfulcompression of the posterior vva!l against the ham-strings during knee flexion . A thigh corset with sidebars was not used because incongruity between sidebar axis and natural knee would limit function . A usualpatellar tendon bearing prosthesis is spherical when theamputation limb is short, reducing the efficiency of themoment transfer mechanism . To reduce socket spher -icity, a supracondylar suspension was used with an ex-tra long posterior vxa)l which limited knee flexion . Sit-ting pressure was a combination of hamstring wedgingpressing obliquely against the brim and soft tissuebulging in the popliteal region . Three alternatives wereoutlined:

1. A sliding posterior wall with translation limited to25 mm;

2. Concentric sockets with relative axial movementbetween them ; the posterior support provided by theouter socket is augmented by anterior and mediolateralsupport from the inner one ; excessive flexion would un-\noh1he inner socket from the outer, relieving pressure;and

3. A stabilized socket attached above a four-barmechanism ; at a predetermined degree of knee flexion,the socket unlocks and rotates with respect to the shank,so the amputee can sit with his knee extended while theshank is vertical.

The solution for each prosthesis involved concentricsockets with posterior extensions and supracondylarsuspension . A section of the posterior wall was cut fromthe inner socket and glued to the outer one . A guidingmechanism with self-locking was fitted between thesockets . Normally the mechanism was locked, holdingthe sockets tightly . When hamstrings compressed theunlocking lever, the inner socket ejects with the aid ofa compression spring . Ejection exposes the posteriorrecess, relieving hamstring pressure . The mechanismallowed adequate knee flexion during gait, full flexion

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in sitting, and sufficient support for stable ambulation.During a 9 month wear period, the patient's gait asmeasured by force plate dynamometers was satisfac-tory and pressure sores in the hamstrings and poplitealregion disappeared.

Recreational Activities of Lower-Extremity Amputees:A Survey : Bernice Kegel, Jeffrey Webster, and ErnestM . Burgess (Prosthetics Research Study, Seattle,Washington), Archives of Physical Medicine and Re-habilitation 61 :258-264, June 1980.

One hundred amputees responded to a questionnairesent to 450 lower-limb amputees ; 10 therapists and 6prosthetists also replied . Forty of the 60 amputees whowere recreationally active wear a prosthesis when par-ticipating in sports, but only 3 wear a specifically de-signed sports prosthesis . Two-thirds use a SACH foot,and one out of four uses a hydraulic knee . Very fewhave waterproof prostheses, rotators, or a Greissingerfoot. Prosthetists had fabricated limbs for swimming,football, snowshoeing, basketball, fishing, waterskiing,and flying an airplane. In most cases, insurance com-panies did not pay for the sports limb.

Fishing was the most popular activity, followed byswimming, bowling, hunting, golf, baseball, horsebackriding, and basketball, all of which were reported by atleast 20 percent . Volleyball, waterskiing, snowskiing,tennis, football, and jogging had fewer devotees . Skiersused either outriggers or conventional ski poles.

Many active amputees swim often . Some doffed theprosthesis at water's edge, others removed it andhopped to the water, a few used crutches, some crawled,and four had waterproof prostheses to get to the water;two used them (or fins) in the water.

Inactive amputees noted pain, disinterest, fear of in-jury, lack of a waterproof prosthesis, family overprotec-tion, embarrassment, lack of sports training, and lack ofsports organization as reasons for nonparticipation . Mosttherapists did not teach sports skills . Active amputeesdid not want allowance made for their disability ; theywere usually informed about sports by prosthetists.Amputees requested better impact-absorbing legs, bet-ter foot and ankle mobility, limb rotators, lightweightlimbs, ventilation, more comfortable sockets, better sus-pension, and better knee units.

Wheelchair Cushion Effect on Skin Temperature, HeatFlux, and Relative Humidity : S .F .C . Stewart, VincentPalmierei, and George Van B . Cochran (Helen HayesHospital, West Haverstraw, New York), Archives ofPhysical Medicine and Rehabilitation 61 :229-233, May1980.

A normal man set for one hour on each of 24 com-mercially available cushions, with its original cover.Skin temperature, heat flux, and relative humidity were

measured under the Ischia . Room environment wasmonitored.

Foam and viscoelastic foam cushions caused signifi-cant temperature rise, reduced heat flux, and little hu-midity increase. They tend to be hot because foam andentrapped air are poor heat absorbers and heat conduc-tors. Humidity is stable if the cover is porous, becausethe open-cell structure provides a pathway throughwhich moisture can diffuse . A vinyl cover increases hu-midity . Increased skin temperature is undesirable be-cause the accompanying metabolic increase compelstissues, already suffering from poor circulation due topressure, to use more oxygen. Temperature rise alsoaggravates risk of infection and sweating and decreasesskin tensile strength . On gel cushions, temperature re-mained constant while heat flux and humidity increasedmarkedly, probably due to the relatively high specificheat of gel and to its nonporous nature . Water floata-tion pads caused significant temperature drop, in-creased heat flux, and slight humidity rise due to thehigh specific heat of water combined with its good con-duction and mechanical circulation; its nonporous na-ture accounts for the humidity elevation . The styrofoambead-filled cushion produced temperature and humidityrise and low heat flux, as did the balloon cushion.

A layered combination cushion may improve opti-mum thermal and mechanical performance . The mois-ture control properties of gels could be improved by aseparate top layer of porous foam, with the cushion en-cased by a porous cover.

Ballistic Walking : Simon Mochon and Thomas A.McMahon (Division of Applied Sciences, Harvard Uni-versity, Cambridge, Massachusetts), Journal of Bio-mechanics 13 :49-57, 1980.

A ballistic model of swing phase assumes that muscleaction during double support establishes a set of initialconditions and velocities for both stance and swinglegs, and assumes also that in the rest of swing limbsmove under the influence of gravity, that total energy isconstant during ballistic swing, and that zero musculartorques act during swing . The swing leg moves like apure pendulum. Most muscles of the swing leg are in-active, except at the beginning and end . The mathe-matical model includes hip flexion and knee flexion ofthe swing leg, the most important determinants of nor-mal walking . The model has one link representing thestance leg and two for the thigh and shank of the swingleg, the foot being rigidly attached. The moment of in-ertia and location of the center of mass of each link aretaken from anthropometric data . In stiff-legged walking,the swing leg will hit the ground during swing, if onedoes not plantarflex the stance ankle or tilt the pelvis.If the knee locks before heel strike, the vertical forcedips due to pulling down of the center of mass of thebody produced by the centripetal acceleration of theswing leg at midswing . The impulsive moment at the

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knee stops shank swing and locks it with the thigh, re-ducing backward thigh movement because if no mo-ment were applied to the knee, the thigh would havecontinued to swing . Knee locking keeps the thigh flexedfor hool strike. Equations are provided for stiff-leggedgait, ballistic walking with knee flexion, and swing timesfor various angles as related to various velocities . Basicaooumpdono, such as constant step length and prohi-bition of toe drag, would not change if the model weremore complex.

The assumption that muscles do not act during ballis-tic swing is not justified at very low or high speeds.Horizontol and vnrCioel forces and joint angles of a sim-ple inverted pendulum all execute trajectories close tothe model, but swing time is prolonged . The model cou-ples ad inverted pendulum for the stance leg and acompound pendulum for the swing leg as the simplestrepresentation of walking which has a natural periodwith accurate ground reaction forces.

For Accelerated Postamputation Rehabilitation—ZorocIntermediate Prostheses : J . M . Leal and others (Vet-erans Administration K4odioa! Center, Tucson, Ari-zona), Orthotics and Prosthetics 34 :3-12, March 1880.

A new technique for construction of removable inter-mediate prostheses uses Zoroc resin-impregnated plas-ter. The !ightmoight, durable prosthesis can be fabri-cated in 2 hours and ready for patient use in 1 day . Thetechnique uses predesigned shapes such as the quad-rilateral brim, sometimes with a medial window forknee disarticulates.

Above-knee and knee disarticulation prostheses re-quire a polyethylene brim, polypropylene pelvic jointwith pelvic band, below-knee immediate postoperativeprosthesis belt, and above-knee postsurgical pylon orOHC polycentric hydraulic knee. The below-knee pros-thesis has postsurgical felt relief pads and below-kneewaist suspension belt and pylon. All prostheses also . in-clude SACH feet, Zoroc plaster, elastic plaster, and othersupplies. The below-knee socket is constructed on theseated patient ; the above-knee and knee disarticulationsockets are molded on the supine patient.

Normally a temporary plastic prosthesis is provided2 or 3 days after romovul of the final immediate post-operative prosthesis by staff prosthetists . Outside facil-ities delayed provision of the temporary prosthesis 2 to4vveeku. Use ofZoroo prostheses in 19 patients (includ-ing below-knee, knee disarticulation, and above-kneecases) reduced hositalization and enhanced maturity ofthe amputation limb . Zoroc does not replace a plastictemporary prosthesis, but serves as an inexpensive in-terim device . Patient acceptance has been excellent .

Bilateral Shoulder Disarticulation : Equipment Used toFacilitate Independence : Janet Poole and M . MarthaParkinson (Towers Unit, University of Virginia Hospi-tal, Charlottesville, Virginia), American Jnurnol of Oc-cupational Therapy 34:397-389.June 1980.

Independent living skills were developed for a 24-year-old man who acquired bilateral traumatic shoulderdisarticulation . He used his teeth and feet for simpletasks, but could not feed, dress, toilet, or bathe . Twobattery-powered prostheses aided feeding, communi-cation, and some hygiene activities . The prostheseswere too limited in range of motion for dressing,bathing, and toileting . Their passive shoulder jointscould not achieve full range of motion in any direction.Equipment was designed for tasks in which prostheseswere not functional . Alternative methods in communi-cation and hygiene were implemented during periods ofskin breakdown and mechnnioal problems with theprostheses.

Dressing was accomplished with a frame chair usedas the base for attaching devices . A double hookclamped to the back of the chair assisted the patient indonning trousers. Using feet, he maneuvered the pantsup his thighs . He then stood and hooked a belt loopover the double hook to stabilize his pants . The hookalso enabled him to engage the zipper with the aid ofa zipper ring . An attachment mounted to the chair'sfront legs was for donning adapted socks . Two over-head bars bracketed to the chair aided shirt donning ; abutton hook was also clamped to the chair.

For bathing, two long-handled sponges were clampedto each end of a vertical grab bar . Wearing Soep'on'a-ropmaround his neck, the patient lathered the sponges,then moved his body against them . He scrubbed with ahairbrush suctioned to the shower wall, and dried him-self by wearing a bag-type robe and rubbing against thewall . Two goosenecks aided tooth brushing, shaving,and hair combing.

A commercially available BeOK deluxe toilet aid wasattached to a conventional removable toilet side rail forperional cleansing . Another aid for doffing clothing forurination was suitable for use away from home . Amouthpiece with interchangeable end pieces aided typ-ing ' wridng . page turning, and telephone dialing . Lowerbody agility may be a prerequisite for efficient use ofsome of the equipment.

Tibial Torsion—A Simple Clinical Apparatus for itsMeasurement, and its Application to a Normal AdultPopulation : Saeed Malekafzali and Michael B . Wood(Division of Orthopaedic Surgery, Medical College ofOhio, Toledo, Ohio), Clinical Orthopaedics141 :154-157, November-December 1979.

Tibial torsion implies a fixed rotary deformation ofthe tibia along its !ongitudinal axis, with either exces-sive anterior or posterior displacement of the medialmalleolus relative to the !aterml malleolus . !nternal tor-

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sion is nonnal in utero ; at birth no torsional deformityexists ; a progressive oxtornal torsion occurs to an av-erage 23 degrees in adulthood . Pathologic torsion usu-ally causes out-toeing or in-toeing . Tomionul deformi-ties may be congenital, developmental or traumatic.Roentgenographic measurements require trained por-eonnel and are not applicable to the incompletely de-veloped osseous structures of the child ; goneometricapparatuses are cumbersome for routine office use.Clinical assessment by estimation of the angle formedby the transmalleolar axis with the axis of the knee ispossible, but grossly inaccurate.

The new apparatus has been applied to 500 adult ti-bias . It consists of a goniometer to the movable limb towhich are attached two parallel hinged rods. Rubberizedmalleolar cups are placed equidistant from the hingedportion of the rods . The movable limb is placed paralleland in congruity with the axis of rotation of the kneewith the knee flexed 90 degrees . The malleolar cupscontact the malleoli, while maintaining para!!nl relation-ship of the rods and equidistance of the cups from themovable limb . The angle described by the goniometeris the same as that between the transmalleolar axis andthe transcondylar axis.

Roentgenographic confirmation of measurements withthe apparatus was obtained on one hundred tibias ; allmeasurements were within three degrees.

A Polycentric Knee-Ankle Mechanism for Above-KneeProstheses : A. Cappouzo' T Leo, and S . SandroliniCortesi (Istituto de Fisiologia Umana, Universitadag!iStudi ' Roma, Italy), Journal of Biomechanics13:231–238 .188O.

Priority in a new prosthetic design was given to sta-bility with minimum muscular effort, smooth passagefrom stability to knee flexion, and dorsiflexion in swingphase . Substantial muscular effort is always required atthe beginning and end of stance or both . Strain on ex-tensors during weightbearing, or on flexors at push-off,depends on the position of the instantaneous center ofrotation of the shank with respect to the socket. Am-putees rarely oontrol the rate of knee f!exion, which re-sults in unaesthetic appearance and sudden weighttransfer to the contralateral limb . The prosthesis has asimple adjustment device for changing the degree ofvoluntary control ; swing-phase dynamics were not dealtwith.

The rationale of the new design is based upon anal-ysis of the prosthesis as a kinetic chain, the proximalend of which is the femoral head and the distal end thefoot link subjected to forces and torques due to groundreactions. Single-axis and polycentric four-bar-linkageprostheses have their centers of rotation lying in a sec-tor bounded by a straight line from the hip to the heeland another line from the hip to the ba!l of the foot . Inthis sector, the minimum control moment required atthe beginning of stance decreases when the rotational

center gets closer to the line from hip to heel, while theuontvol moment required to flex the knee at the end ofweightbearing decreases by moving the center towardthe line from hip to forefoot . These moments are bothreduced by raising the center . Polycentric mechanismshave higher controllability than single axis, but nonepermits reducing the control moment as much as onewould wish . Prosthetic stability increases from hoolstrike to ton-off, in contradiction to the normal require-ment of highest stability at beginning of stance and de-crease going toward push-off to allow effortless kneeflexion. For this raquirement, the shank and foot werelinked.

A prototype knee-ankle linkage prosthesis was man-ufactured. A computer program for calculating the rel-ative controllability of the prosthesis was developed,and the p rototype was fitted on two middle-aged pa-tients. Qualitative results were onooumging, and quan-titative gait analyses are in progress.

The Use of Plastic Jackets in the Non-OperativeTreatment of Idiopathic Scoliosis : William P.Bunnell, G . Dean K4aoEwen ' andShenmugaJayakumar (Department of Orthopaedic Surgery,Upstate K8odica! Center, Syracuse, New York),Journal of Bone and Joint Surgery 62--A :31–38,January 1980.

Prior to fabrication of an Orthoplast body jacket, thepatient haaa Risser or Cotrel cast with an average 27-kg longitudinal traction . A roentgenogram shows theamount of realignment . The cast is removed, and a pos-itive mold is made and modified to relieve pressurepoints . Plastic is molded to the model . Trim lines are atthe level of the pubic symphysis and greater trochan-ters and high in the axillae . The jacket opens in front.Fabrication time and cost are about half of that for theMilwaukee brace.

The jacket suits flexible immature curves less than 40degrees with the apex below the seventh thoracic ver-tebra . A significant rib hump or respiratory insufficiencycontraindicate it . The jacket is worn 23 hours daily untilthe spine is stable . Then the patient is out of it for 2hours daily for 2 to 3 months . If the curve remains sta-ble on X'ray, time out is 4 hours daily. After another 2months with curve stability, time out is 8 hours, then 12hours after another 2 months . Patients wear it nightlyfor 2 years . All correction is achieved with the originalmold ; no structural adjustments are made.

Exercise within the total-contact orthosis are impon'oib!o ' but pelvic tilt and sit up exercises to avoid por-aopinal and abdominol atrophy are done with it off.Tumbling, trampoline, and gymnastics are restricted;swimming without the jacket is encouraged . Fivehundred children have been treated with the orthosis.The average age of application was 11 years, 10 months;weaning started at 14 years and 3 months and the pro-gram was completed at 16 years and 9 months . Thaav'

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erage reduction was 62 percent at all curve levels.Of patients older than 16 years who had been without

the jacket for at least 6 months, half the curves wereunchanged, a third improved, and only 6 progressedmore than 5dmgr000 beyond the initial curve . Vital ca-pacity with the jacket was reduced 18 percent, but wasnormol when the jacket was removed . Patients pre-ferred it to a Milwaukee brace because of the absenceof neck ring . More durable plastics, Vitrathene or poly-propylene, decreases frequency of replacement . Prefab-ricated versions are being tested.

The VAPC Functional EHbmxvOrthmsm : Kenneth P.LaBlanc and Carl P. Mason (Veterans AdministrationProsthetics Center, New York, New York), Orthoticsand Proothedoo34 :13–24 ' March 1980.

Conventional elbow orthoses for ambulatory patientsusually have an elbow lock and cable ; they requirestrong shoulder muscles and are bulky, heavy, and dif-ficult to operate . The oxperimantal orthosis uses apneumatic device to assist elbow flexion . It has a shoul-der cap, wrist cuff, and five-bar elbow linkage ; a pneu-matic-spring cylinder flexes the elbow . Minimal force isneeded to initiate f!oxion, and increase in flexion pro-duces non-linear force increase . The user requires someextension activity because the force needed to extendthe system exceeds that needed for flexion . Counter-balance is produced between forces used to extend thecylinder during flexion and compress it during exten-sion, permitting the system to be stabilized against theweight of the forearm. After the elbow is flexed mod-erately, the wearer can hold objects weighing up to onepound. The unit continues to flex until the triceps retardflexion or stop it . Slight elbow extension is required tomaintain full extension . Three different cylinders pro-vide 200 ' 300, or 400 newtons of force . The system islightweight, functional, and cosmetic, although patientsneed help in donning and doffing it.

Fabrication requires casting the shoulder and upperarm and the forearm, modifying the casts, and laminat-ing (or vacuum-forming or drape-molding) low-densitypolyethylene . The shoulder and wrist sections are linedwith Pelite . Cross-chest and upper-arm straps supportthe device. The pneumatic unit is screwed to the shoul-der and wrist cuff . The orthosis has been fitted toa polio patient, one with brachial plexus avulsion whohas used it successfully for nearly two years, and onewith another neuropathy.

Environmental and Typewriter Control Systems forHigh-Level Quadriplegic Patients : Evaluation andPrescription : G . Heiner Sell and others (Instituteof Rehabilitation Medicine, New York UniversityK8odiou! Center, New York), Archives of PhysicalMedicine and Rehabilitation 60 :246–252, June 1979.

Testing of commercial environmental control units,

self-contained telephone, and typewriter systems wasdone in the occupational therapy laboratory, bedside,and home with 52 patients . None were respiratory-de–pendent ; most lesions were C4,5 (although levels rangedfrom C2 to C6, 7).

Of envirnnmental controls, Fidelity Comfort and Com-munication was preferred initially, but was ultimatelyrejected because of unreliability . The bulk and error-prone dialing mode of Possum Selector were disliked.Nu-Life was too slow . Remote Operation by Oral Trig-gering (ROBOT) has an exhausting operation mode . En-vironmental Control Unit ECU-1 was preferred, althoughPrentke Romich ECU-2 was not, due to lack of a sepa-rate display. Genie was annoying with its constantlyscanning display . Touch Operated Selector Control(TOSC-2) lacked viouul numarioal telephone dialing dis-play . Prentke Romich Automatic Dialing Telephone (ADT-5A) was most popular due to its total digit dial capabil-ity and easy operation.

Typewriter systems were no better than mouth-stickand balanced forearm orthosis control of an electrictypewriter . The PMV Printer had a demanding mode ofoperation . Possum Scanner was better, but only onepatient preferred scanning over other typing methods.Possum Hi-Speed gained five advocates ; others dislikedits complicated random-access method . PMV Minimumwas easy to operate.

Training for all patients for all units required a singleexplanation . All, except one with periodic cyanosis, couldoperate all pneumatic interfaces easily . None could op-erate the ROBOT by either audio or manual input.

ECU'2 ' Nu-Life, ROBOT, and TOSC-2 were mainte-nance-free . All typewriting systems required repair. Costare compared. C2-4 patients use pneumatic interfacesbest ; C4-5 often used pneumatic and pressure controls;C5-6 used only pressure.

ECU-1 and ADT-5A demonstrated exceptional patientacceptance and reliability.

Skin Problems of the Leg Amputee : S. William Levy(Department of Dermatology and BiomechanicsLaboratory, University of California, San Francisco),Prosthetics and Orthotics International 4 :37–44,April 1980.

A snug socket prevents free air circulation and trapsperspiration . Uneven loading stresses !ooal areas . !nu*r-mittentotutching of skin and friction against the socketedge and interior also abuse skin . A thigh corset mayobstruct venous and lymphatic drainage . Minute lesionsmay initiate extensive disorder with mental, social, andeconomic disaster . Poor hygiene produces infections,nonupooifioeozomudzanion ' intertriginous dermatitis, andepidermoid cysts, as well as maceration and malodor.Cleansing with bland soap or detergent nightly, anddaily wear of a clean sock, are necesary.

Initially a suction socket causes reactive hyperemia,reddish-brown pigmentation resulting from capillary

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hemorrhage; elastic bandaging reduces this innocuouscondition . An edematous end may strangulate, ulcerate,or become gangrenous . Socket choking, poor fit andalignment, and excessive negative pressure must beeliminated, and distal tissues supported . Varnishes, lac-quers, p!aodoo, oemento, and resins (especially incom-pletely cured epoxy) may cause contact dermatitis ; theirritant must be removed . Nonspecific eczematizationmay be secondary to faulty fit or alignment or to edema.Epidermoid cysts on the proximomadial thigh resultafter much prosthetic friction ; surgery, topioal medica-tions, and socks such as an adductor rim sock, may bebeneficial . Follicultis and furuncles, especially amongthose with hairy, oily skin, may ensue from poor hy-giene . Fungus usually appears only on skin enclosed bythe socket and generally responds to fungicides . Inter-triginous dermatitis occurs in the inguinal and cruralfolds and at the invaginated scar ; it requires cleansingand powdering apposing skin . Chronic ulcers from bac-terial infection, poor cutaneous nutrition, or !ooal pres-sure may progress to malignant ulcers . Benign and ma-lignant 1umom, verrucose hyperplasia which respondsto distal contact, acne, seborrheic dermatitis, psoriasis,and lichen planus may also occur; treatment proce-dures are suggested.

Toileting Self-Care Methods for Bilateral High LevelUpper-Limb Amputees : L . Friedman (PaediatricOccupational Therapy Department, Institute ofRehabilitation Medicine, New York, New York),Prosthetics and Orthotics International 4 :29-36, April1980.

Toileting is of greatest concern for the bi!atoral highlevel amputee. Inability to cleanse oneself eliminatesschool attendance, independent travel, or employment.It is destructive of self-confidence to have toileting care.The principles are the same with children with congen-ital or acquired amputation and with adults, althoughtheir range of lower-limb motion is generally restricted.

Individual assessment of limb length, motion, strength,and agility is oruoial prior to a triel of methods and de-vices . Juvenile motivation reflects parental wishes.

Before toileting, clothing and underclothing must beremoved; adaptations, especially for adolescents, shouldbe inconspicuous. Few special devices should be used,so that travelling is not unduly hampered . Loose cloth-ing without elastic eases doffing and donning . Proce-dures for disrobing for urination and defecation are de-tailed . A wrist flexion unit aids manipulating zippersand some can use the prosthetic hook for wiping. Aclothing hook on the wall facilitates dressing . Varioustypes of forked rod aid in pushing trousers down andpulling them up . An "S" shaped dressing hook benefitspatients with upper phoconnelia and normal legs.

The child with short uppe r limbs with adequate graspmay use one of the several custom or commerciallyavailable limb extenders (illustrated) for clothing doff-

ing and holding toilet paper . Patients with upper ex-tremities with inadequate grasp and limited lower-limbmobility do best by placing toilet paper on the seat orother stationery object and rocking against it. Patientswith no hand function can manage with well-developedfoot function.

Several modifications for menstrual cleanliness aredescribed.

Patients with quadrimambmral involvement need var-ious dressing devices ; a bidet is generally required forperineul cleansing.

Controlled Environment Treatment (CET) : I . M . Troup(Limb Fitting Centre, Dundee, Scotland), Prostheticsand Orthotics International 4 :15-28, April 1980.

Clinical impressions are the basis of the report of 100cases. Wound healing depends on phyoival environ-ment, including the degree of pressure on tissues andits variation in level and time . A conventionally dressedwound is warm, moist, and not sterile, allowing bacteriato thrive. The CET Steriehie!d o bag has an intornal prox-imal apron which forms a partial seal, and is suspendedby shoulder harness and hemipa!vio band . Automaticcycling of pressure level and time imposes a vascularpump, promoting lymphatic and venous return . Pres-sure is uniform, avoiding a tourniquet effect . Air or gashumidity and temperature can be controlled . All casestreated preoperatively, from three to nine days, hadedema eradicated or diminished . Most treated postop-eratively had edema controlled, but infection (whichmay have been due to ischemia) was not always con-trolled; a third of these patients had pain . Most hadabout 2 weeks of treatment with CET . Compared with arigid dressing, CET controls edema better, althoughplaster may uonuol pain better. Many of those withnonhealing were aided by CET . CET also benefitted var-icose ulceration, diabetic foot lesions, and nondiabeticinfection . The doctor is involved in critical assessmentof case suitability, daily observation, and instruction ofparamedical staff . Nurses must be familiar with patientmunagoment, including moving patient with machine.The physiotherapist can mobilize the patient within alimited area and can move the joint within the Steri-shield ; the patient may be frustrated, however, seeingothers more mobile.

The apparatus is self-managing ; air filters are changedmonthly, and bactorial filters yearly . No aW!l of appli-cation is required, the extremity can be observed duringCET treatment, and no bandaging is needed . Reducingporiphorol vascular statis with CET is especially import-tant in varicose ulceration and in the diabetic foot ; thelatter also requires radioal surgery .

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Gait Training for the Below-Knee Amputee: C . VanGriethuysen (Bioengineering Unit, University ofStrathclyde, Glasgow, Scotland), Prosthetics andOrthotics International 3 :163–165, December 1979.

The therapist usually deals with older dysvascularamputees who have diabetes, hypertension, or cerebro-vascular accidents . Preoperative treatment is directed tomuscle reinforcement and joint mobility ; the patientbalances on one foot and transfers . Postoperative carebegins when the patient's condition permits, withstrengthening and preventing of contractures . If there isno rigid dveouing, the patient should press his amputa-tion limb manually, preparing him for prosthetic toler-ance acceptance of it as a part of his body . Stand-ing in parallel bars is started with or without aprosthesis . He learns to flex and extend his knee towork the amputation limb in the socket and bring weightover the prosthesis . He must bring full weight over theprosthesis before starting walking . A mirror helps cor-rect posture. Once he needs only slight support fromthe bars, walking starts . He first raises each knee alter-nately. Then, with the prosthetic foot slightly ahead ofthe sound one, he flexes his knee with progressivelymore weight on it, until the prosthetic foot is flat on thefloor. He does the reverse, extending the knee fullywhile bringing weight back to the sound leg . Then hebrings the prosthetic foot forward and steps with thenormal foot while extending the knee on the amputatedside. These exercises prepare him for free walking inthe parallel bars.

When he can walk confidently in the bars, he startswalking with crutches or canes, first with one aid and abar, then with two aids inside the bars, using the four-point gait . He learns to rise from his wheelchair andfrom a straight chair. Walking exercises are progressedto nutdouru, walking with one cane, clearing obstacles,and climbing inclines and stairs, usually with prosthesisand sound leg alternating . Young patients also run,jump, and practice equilibrium exercises on a beam.

The gait should have foot flatness at midstance, !at-orul knee stability, controlled knee use, smoothness,minimal lateral trunk bending—and even step !ength,timing, and arm swing . Causes of stance and swing de-viations are noted.

Ideas on Sensory Feedback in Hand Prostheses:P. Horbortoond L . Korner (Department ofOrthopaedic Surgery, University of G~teborg,Sweden), Prosthetics and Orthotics International3157–162 ' December 1979.

Myoelectrically controlled systems have developedrapidly, with some clinical success in spite of the lackof feedback which mandates vinuul control . Patient per-formance is close to that with cable-operated prostheses.

A hand prosthesis replaces prehension and some sen-sation. Sensory feedback enables comparison of output

to input to increase control accuracy . Proprioceptivefeedback, information about position, movement, andforce in prosthetic joints, and somatosensory feedback,concerned with grip force and a !ippa ge, are needed;most systems convey the latter . Systems usually havevibratory or electrical stimulation . Rejection has beendue to fragility, control interference, and bulk.

Systems using physiological mechanisms have greateracceptance than entire artificial ones . Position senseprobably has its neural basis in muscle spindles and theoentrol nervous system, not in joint and skin afferents.The bo!ow+e!bovvomputee retains some hand muscles.In the Boston arm, effort sensing accompanies musclework at the myoelectric oontrol site ; a negative feed-back oignol proportionol to the force resisting move-ment augments the myoelectric signal . Prosthetic con-trol should be related to physiologic movements, ratherthan to single-muscle action—which is unphysiological.Pattern recognition for hand prostheses should permitproportionol uontrol of effort and force, through inte-gration of signals from several muscles relevant to amovement.

Most acquired amputees easily move the perceivedphantom and foel how it moved . The neural basis ofperception of phantom movement probably is muscleafferents from the diotal amputation limb . Pattern-rec-ognition onnt/ol requires that specified phantom move-ments result in corresponding prosthetic movements.Extended physiological proprioception refers to theability to translate movements and positions of the am-putation limb to the prosthesis proportionally ; the brainadapts to prosthesis length just as a golfer adapts to thelength of his club.

Patient acceptance depends on psychological and so-cioeconomic analysis and prosthesis reliability, easyuse, and inconspicuousness ; thus self-containment andself-suspension are vital .