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RUNNINGRunning' Running requires foot-over-footmovement and causes musculoskeletal stress fromthe impact of landing . Many individuals wearingprostheses can comfortably sprint and run shortdistances ; however, running long distances presentsan entirely different situation . Long-distance run-ning requires a high degree of personal motivation.For those with lower limb amputation, it alsorequires a properly designed prosthesis and a resid-ual limb that is able to withstand the substantialforces generated by the impact of landing.

Over the past decade, the accomplishments ofseveral runners with lower limb amputations haveprovided motivation and inspiration for others.Some have completed ultra-marathons, such asTerry Fox, who at age 19 logged up to 30 miles aday to make a 3,330 mile run across Canada in1980 . In 1985, Steve Fonyo, also 19, ran nearly5,000 miles across Canada . In the same year,21-year-old Jeff Keith ran 3,300 miles across theU.S., wearing the recently developed Seattle Foot.

Not only the young have become outstandingrunners . In 1982, Bart Van Housen, at age 35, ranover 900 miles from the Oregon border to Mexico.Robert Kerrey, Congressional Medal of Honorrecipient (Vietnam) and U .S. Senator from Ne-braska, runs 5 miles a day. Ray Mann, a Vietnamveteran, has run a marathon (26 .2 miles) in under 4hours using the Seattle Foot .

RUNNING IS NOT FOR EVERYONE

Running is a strenuous form of exercise . It cansometimes cause debilitating problems with regardto skin, muscles, ligaments, and tendons in the legs.Therefore, running as exercise should be carefullyconsidered by those with lower limb loss . Factorsthat affect the ability to run are the nature of thesurgery, the level of amputation and the conditionof the residual limb, the prosthetic fitting, thegeneral state of physical fitness, and personalmotivation.

It is recommended that everyone, particularlythose over age 35, consult a physician beforestarting a running or jogging program for fitnessand conditioning. Once medical approval has beenobtained, individuals who have not previously exer-cised should proceed with moderation . Before a newprosthetic leg is built, anyone with lower limbamputation considering running should inform theprosthetist so that he or she can design it with thatin mind. If running or jogging causes any pain orirritation, the prosthetist should be consulted imme-diately.

Most individuals will not be able to run or jogfor extended distances and time without periodicirritation to the residual limb . Alternative aerobicactivities may be better for those who experiencepersistent residual limb irritation . Activities such aswalking, swimming, or bicycling are less traumatiz-ing to the residual limb.

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RRDS Clinical Guide . Physical Fitness: A Guide for Individuals with Lower Limb Loss

RUNNING SURFACE

The running surface substantially affects theability to run . Running on grass does not causestress to the body as much as running on a concreteor asphalt surface . For the runner with lower limbloss, however, grass may be more difficult . Thesurface is not always even ; rocks and holes canthrow a runner off balance, causing irritation to theresidual limb . Running on grass also tends todampen the push-off built into energy-storing feet.Even with these problems, some runners prefer grassbecause it lessens the shock to the body.

In contrast to grass, a concrete surface providesa platform for the spring in the energy-storing footto react with greater intensity, since nothing is lostby the force absorption of the ground reaction .

AP/WIDE WORLD PHOTOSBart Van Housen is shown as he nears the completion of hisrun from the Oregon border to Mexico in 1982 . He made therun to raise funds for the Easter Seal Society.

Thus, a hard, even surface is often preferable tograss because it is a consistent surface, permittingthe runner to land the same way each time.

Many recently constructed running tracks havetartan turf or a hard rubber surface . This may bethe best type of track for disabled runners becausethe material is slightly forgiving, yet it has an evensurface.

Treadmills provide an even surface that absorbssome of the landing impact . The treadmill is alsoexcellent for practicing and improving the foot-over-foot running technique and for cardiovascular train-ing.

ENERGY-STORING FOOT DESIGN

TED KIRK/LINCOLN, NESenator Robert Kerrey is shown on one of his daily 5-mileruns . He uses the same prosthesis for walking and running .

Runners with leg amputations have run foryears prior to the development of energy-storing

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Activities for Fitness and Skill : Running

THE WINKLEY CATALOGRunning foot-over-foot using conventional prostheses of thelate 1940s and early 1950s was possible for short dis-tances but not very comfortable.

feet . But because their prostheses provided no springand lift, running was painful and induced greattrauma to their residual limbs and throughout theirbodies . Energy-storing feet provide comfort as wellas improved performance . They have helped tomake it possible for an athlete such as DennisOehler to run the 100-meter dash in 11 .73 seconds atthe 1988 Paralympics in Seoul, Korea, and for JimMacLaren to complete the 1988 New York Mara-thon in 3 1/2 hours, the fastest recorded time for amarathon runner with an amputation.

The Seattle Foot and the Carbon Copy II Footare energy-storing feet that are particularly wellsuited to running because of their responsiveness,light weight, and adaptability to many conventionalprostheses . The Flex-Foot is excellent for distancerunning as well as sprinting . It represents themaximum in energy storage potential . 2 The Flex-Foot is one of the lightest weight prosthetic feetavailable. The Springlite Foot and the Carbon CopySystem III are recently developed energy-storing feetthat are made of carbon fiber material .

BELOW-KNEE PROSTHETIC ADAPTATIONS

The weight of the entire BK running prosthesisshould not exceed 3 pounds . Components fabricatedfrom Kevlar, fiberglass, Spectralon epoxy, andacrylic resins, as well as from plastics, graphite, ortitanium can provide for strong, lightweight limbsthat weigh from 2 to 2 1 /2 pounds . Improvements insuspension methods help lighten the sensation ofweight of the prosthesis . For example, a cuff strapcan be enhanced by adding a neoprene suspensionsleeve over it or by adding a waistbelt . A latexrubber or neoprene sleeve by itself can also be addedas an auxiliary suspension to a supracondylarprosthesis or patellar tendon-bearing (PTB)-style BKprosthesis . The 3S silicone suction socket andIcelandic Roll-on Suction Socket (IceRoss) are newmethods of BK suspension which use no straps,belts, or sleeves.

To help protect the residual limb while running,a nickleplast liner with selectively placed siliconegel, 3 a complete silicone gel liner with horsehide, 4injection-molded silicone liner, 5 or the PM Linerhelp reduce the shear forces associated with skinbreakdown . Silicone end pads also help absorbimpact and prevent possible injury to the distal endof the residual limb.

Because there is great impact on the limbs asthey land on the ground, weight must be distributedevenly through the socket of the artificial limb . Indesigning a socket for a potential runner, the use ofmultiple, clear diagnostic sockets and alginate im-pression material helps to ensure a total contact fitfor even distribution of pressure . 6 Some may findthat they need to add side joints and a thigh lacer tofurther reduce forces on the residual limb by sometransfer of weight to the thigh . This also may helpprevent skin breakdown. Some runners, however,will find these additional components restrictive andcumbersome. Once the socket is constructed, therunner should exercise on it and slowly increase therunning distance covered . Any problems should beresolved prior to making the finished prosthesis.

Anterior Distal Tibia Problems

A common problem among runners with BKamputations is excess pressure on and possible skinbreakdown over the distal anterior portion of thetibia. The tibia is the larger of the two major bones

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RRDS Clinical Guide . Physical Fitness : A Guide for Individuals with Lower Limb Loss

MARATHON PHOTOSJim MacLaren crosses the finish line of the 1988 New York marathon . In addition tobreaking records in running, he holds records in triathlon events.

in the leg. In a person with a BK amputation, theanterior distal portion is the lower front section ofthe tibia in the residual limb.

Jogging is usually characterized by a gaitpattern that extends the knee so that the foot landsfirst on the heel. However, running patterns showthat people usually land on their forefoot whensprinting . The forces that control the knee from heelstrike to foot flat result in the residual limbextending into the socket as the knee is flexing inorder to control the prosthesis . Thus, there is greater

danger of developing pressure and possible skinbreakdown when landing heel first . A foot thatprovides plantar flexion will help control the kneeand greatly lessen the forces on the anterior distaltibia . However, landing on the forefoot is usuallybest .

Socket Fit and Suspension . One way to helpprevent skin breakdown at the tip of the tibia is toensure a comfortably fitted and accurately con-toured socket . A loose-fitting and ill-contouredsocket with incorrect suspension can result in fric-

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TIMOTHY B . STAATS, PhD, CP/UCLA PROSTHETICS-ORTHOTICSEDUCATIONAL PROGRAM

Alginate is used inside of the clear diagnostic check socketto create a total contact fitting for a below-knee residuallimb.

TIMOTHY B. STAATS, PhD, CP/UCLA PROSTHETICS-ORTHOTICSEDUCATIONAL PROGRAM

A clear diagnostic check socket is used with atmospheric

suspension .

tion and, if not corrected, cause skin breakdown.Two ways to correct the problem are by: 1)providing adequate relief over the distal end of thetibia; and, 2) loading either side of the tibial bonewith increased pressure in the socket to keep the tipof the bone from hitting against the socket . Makingthe posterior walls of the socket high keeps pressurecounter-balanced on the anterior distal tibia as it isextended in the socket . This will prevent the tibiafrom cantilevering between heel strike and foot flat,which could cause the anterior distal tibia to bedriven into the front wall of the socket.

Another way to prevent anterior distal tibiaproblems is by changing the materials used in thesocket . A flexible inner socket material, such asstress-relieved polyethylene, can be used with rigidouter socket material, such as polypropylene . Whenthe outer rigid socket is cut out over the distal endof the tibia, leaving the flexible insert exposed,pressure is relieved . This concept may be used forflexibility in other areas of the socket as well, solong as the socket structure is not weakened.

A prosthetic nylon sheath can be placed under-neath the sock to help reduce friction . This allowsthe prosthetic socket to slide over the sheath ratherthan over the skin, which can sometimes lead to skinbreakdown . Some runners use two or three sheathsat a time to help reduce shear forces on the skin andhelp to "wick" off perspiration. Also, runners whoknow that their skin breaks down in the same placeeach time they run should use skin care pads orSecond Skin (among other products) as a preventivemeasure by putting them over these areas beforethey run.

Gait Patterns/Prosthesis Design and Align-ment . Landing on the heel rather than the ball of thefoot is often caused by the alignment of the artificiallimb . For someone with BK amputation, a heel-toegait is not harmful in walking, but in running orjogging it causes excessive force on the anteriordistal portion of the tibia. Anterior distal tibiaproblems caused by a heel-toe gait can be alleviatedby using a prosthetic foot that allows for easyplantar flexion . At heel strike the foot should dropquickly toward the ground . This prevents the needfor knee flexion to control the leg from heel strike tofoot flat . The addition of the Endolite MultiFlexAnkle or the Seattle Ankle MultiAxial Rotation(MARS) unit is excellent to accommodate therunning pattern .

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The Solid Ankle Cushion Heel (SACH) foot,with a soft heel cushion, is a single-axis foot thatprovides for plantar flexion . It was designed to helpstabilize the knee and make walking smooth andnatural . Unfortunately, it is not good for runningsince it is not energy-storing . The Flex-Foot issimilar in reaction to a single-axis type of foot whenthe softer heel is chosen for the runner's weight andfor the distance run.

Most energy-storing feet do not have a truesingle-axis design, but some, when combined withadditional ankle components, can provide an activeform of plantar flexion . The Seattle Foot, CarbonCopy II Foot, SAFE Foot, STEN Foot, and OttoBock Dynamic Foot are energy-storing or havedynamic elastic response and can be combined witha compatible ankle unit . The use of Endolite'sMultiflex Ankle or the MARS unit on any of thesefeet will enhance their multi-axis function forrunning . The Seattle Ankle, when added to any ofthese feet, also provides a degree of active plantarflexion, which helps reduce anterior distal tibialpressure. (In this case, plantar flexion is the act oflowering the foot from heel strike to foot flat .)

The DAS (Dual Ankle Spring) Foot develops itsenergy storage release from the compression of ananterior spring and offers ease of plantar flexionfrom the posterior spring compressing .' The com-bined anterior/posterior spring also offers a multi-axis function . It is excellent for sprinting off the toesection because the keel extends to the end of thefoot, thus enhancing running speed.

Because anterior distal tibial problems canoccur from jogging when a person lands with anextended knee at heel strike, it is preferable to landon the ball of the prosthetic foot or on the toes (as arunner or sprinter does) . Thus, many joggers natu-rally take on this pattern of running with kneeflexion to land on the toe section as a self-protectivemechanism, in order to prevent pain resulting fromexcess pressure on the anterior distal tibia . Althoughjogging with a flexed knee may not look as nice asrunning with long strides, it may be the only way forsome individuals to run long distances withoutcausing problems to the anterior distal tibia.

Running with the knee slightly flexed helps oneland on the ball of the foot . However, if the quad-riceps muscles are weak, it can be difficult to landon the ball of the foot with a flexed knee . In thiscase, a cuff strap that holds the knee in flexion helps

maintain the leg in the desired degree of flexion . Thecuff strap may be combined with a suspension sleevefor additional support . A suspension sleeve alonedoes not hold the leg in flexion while running, but itwill be adequate for those with strong knees andquadriceps muscles . The addition of side joint andlacer may also be needed for some individuals.

Summary . Each person's residual limb isunique and each prosthesis may require special adap-tations . An artificial leg used for walking may neverresult in anterior distal tibia problems. The walkingalignment often can also be used for running, butsome individuals will require a special leg with arunning alignment . Two common changes made fora running leg alignment are increased toe-out tocompensate for greater internal rotation at the hip,and a longer toe lever on energy-storing feet toprovide a stiffer spring rate for an increased push attoe-off. Some prosthetic legs aligned just for run-ning force the runner to land on the ball of the foot.

Options to consider to help prevent anteriordistal tibia pressure are summarized below:

a well-fitting BK socket/total contact/surface-bearing socket (non-prominent patellar bar, ifany);socks with no more than 5-ply thickness;sheaths to reduce shear force;an even load on both sides of the tibia on themedial flare and pre-tibial compartment alongwith a posterior wall high enough to preventcantilevering;a flexible socket liner and a rigid outer framecut out over the crest of the tibia or otherpressure areas;full gel liner or selectively placed gel over distaltibia;a prosthetic foot and ankle that will provideplantar flexion from heel strike to foot flat;flexed knee gait (optional cuff suspension forlanding on the forefoot);preventive skin care using Spenco TM 2nd Skin""and Spenco TM Skin Care Pads or Johnson &Johnson Bioclusive® Pads.

ABOVE-KNEE PROSTHETIC ADAPTATIONS

Two main characteristics of running that makeit different from walking present a challenge for

1.

2.3.4.

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Activities for Fitness and Skill: Running

G . MENSCH AND P .E . ELLIS/'RUNNING PATTERNS OFTRANSFEMORAL AMPUTEES : A CLINICAL ANALYSIS,'

PROSTHETICS AND ORTHOTICS INTERNATIONAL, V . 10,129-134, 1986 . REPRINTED WITH PERMISSION

Schematic representation of "normal" foot-over-foot running cycle.

people with AK amputation. First, the increase invelocity causes the stance phase to make up only 30percent of the gait cycle, while the swing phaseaccounts for 70 percent . Second, in normal foot-over-foot running, both feet are off the groundsimultaneously for a short period of time.

Foot-Over-Foot Versus Hop-Skip Running

Individuals with AK amputations have hadgreat difficulty running in a normal foot-over-footfashion because the impact at heel strike must beabsorbed by knee flexion . Conventional AK pros-thetic components do not provide a great deal ofknee flexion . Without knee flexion, one must use ahop-skip method of running . 8 In the hop-skip

method, both legs cannot be off the ground simulta-neously. A double-stance phase takes place when thesound leg makes the second hop . The extra secondhop gives the time needed to get the prosthesis out infront. The hop-skip method causes the legs to beclose together at heel strike, which lessens theimpact when landing on the prosthesis and decreasesthe knee flexion moment . The hip is also in a betterposition to extend the residual limb to furthercontrol the tendency for increased flexion of theknee .

The hop-skip pattern was used by Terry Foxduring his 1980 run across Canada to raise funds forresearch of cancer, the disease which caused him tolose his leg. His original idea to use a spring toabsorb the shock was developed after his death . A

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G. MENSCH AND P.E . ELLIS/'RUNNING PATTERNS OFTRANSFEMORAL AMPUTEES : A CLINICAL ANALYSIS,'

PROSTHETICS AND ORTHOTICS INTERNATIONAL, V . 10, 1 29-134, 1986 . REPRINTED WITH PERMISSION

Schematic representation of the hop-skip cycle.

prosthesis using the spring idea was designed to helpmany people with AK leg loss by alleviating groundimpact and allowing for comfortable foot-over-footrunning . It is called the Terry Fox Running Prosthe-sis, and can be combined with a conventionalquadrilateral socket .'

Impact at heel strike is alleviated by the TerryFox Running Prosthesis through the spring shaft,which compresses and cushions the impact to the re-sidual limb . From heel strike through mid-stance thespring is compressed to shorten the prosthesis slight-ly and lower the center of gravity. As the runner rollsover the toe, the spring is released, weight is takenoff of it, and energy is released at toe-off, whichmoves the prosthesis forward into swing phase.

Socket Design and Other Components

Socket fit is the most critical feature of the AKprosthesis for a runner . As with socket design for

BK prostheses, clear diagnostic sockets with alginateimpression material helps to ensure a total contactfit for even distribution of pressure . Injection-molded silicone gel in selected locations of thesocket reduces shear forces and provides additionalshock absorption, particularly for the quadrilateralsocket wearer . 10

Foot-over-foot running is improved throughcombining CAT/CAM or Narrow M/I_, sockets andStance and Swing Phase knee units with energy-storing feet . Components designed for foot-over-foot running are made of lightweight plastics,graphite-epoxy composite, and titanium . A flexiblebrim socket adds comfort by providing a moreforgiving material on heel-strike impact.

New socket designs providing ischial contain-ment also enable foot-over-foot running . In thesenew designs, the ischial tuberosity is contained in thesocket instead of resting on a posterior shelf as in

THE CITIZEN/OTTAWA, ONTARIO, CANADA

Terry Fox is seen on his famous run across Canada.

Airborne

AirborneStance StanceSwing Stance,lr Stance

Support

Support Support

Stance

Swing

Double DoubleDouble

Left leg

Right leg

i 4 ISwing Stance

Airborne70% 30%

Left leg

Right leg

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GERTRUDE MENSCH, RPT/HAMILTON, ONTARIO, CANADAThe Terry Fox Spring Shank Running Leg.

the quadrilateral socket . This reduces shock forceson the ischial tuberosity at heel-strike, which is par-ticularly important since running produces groundreaction forces that amount to three to five times thebody weight . " A conventional prosthesis with quad-rilateral socket design will not allow the individualto withstand forces so great while running.

A socket with ischial containment also providesalignment stability and control of the femur thatsurpasses that of the quadrilateral socket . There areseveral names for sockets based on these principlesof design: the Narrow M/L or Normal ShapeNormal Alignment (NSNA) socket, the CAT/CAMsocket, and the Ischial Ramal Containment (IRC)socket, as well as several derivatives.

Hydraulic knees that feature stance and swingcontrol, such as the Mauch SNS Knee Unit, provide

TIL iYNAMC, SEATTLE, WAFront view of the CAT/CAM Flexible Brim socket . Apolypropylene retainer socket is connected to the EndoliteStabilized StanceFlex (Bouncy) Knee unit.

the stability and knee flexion control at midstanceneeded by AK runners . The Mauch SNS Knee Unitis excellent for running when enhanced with theEndolite Stabilized StanceFlex (Bouncy) Knee.When these two units are combined, they provide aform of cushioning from the rubber torsionalelement . This reduces the forces on the residual limband results in increased comfort, adding to theforward propulsion of the limb during the laterstages of the stance phase . 12

There is also a need to accelerate the lowershank portion of the leg fast enough to get it out infront of the runner . A device designed for foot-over-foot running, the OKC Running System, does this.The system extends the lower portion of the leg

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DALE TILLY/VAMC, SEATTLE, WAThe Endolite Stabilized StanceFlex (Bouncy) Knee supportsweight at mid-stance for runners with single-limb sound-ness . Also shown is a flexible brim CAT/CAM suction socketand a Mauch Swing Phase Hydraulik Knee Unit, which isused for cadence control while running .

DALE TILLY/VAMC, SEATTLE, WAThe Endolite Stabilized StanceFlex (Bouncy) Knee is at-tached between the above-knee socket and the knee unit.The rubber torsional element provides impact cushioningwhile running.

quickly enough to maintain the rhythm of foot-over-foot running. The system allows for hip flexionwhile tension is drawn on a cable which attaches toand extends the lower shank section of the AKprosthesis . When the lower portion of the leg is notextended quickly enough, a hop-skip pattern willallow the prosthetic leg to "catch up." 13 A constantfriction knee can be used with the OKC RunningSystem, acting as a stabilizer during the stance phasebecause it keeps the leg extended until toe off.

The OKC Running System is excellent forteaching people with AK amputation to run becausethe cable does the work for them and they can haveimmediate success . If desired, the system can beremoved from the leg when the user learns how to

run. However, many users prefer to keep it attachedto the leg because it insures placement of the leg infront of them when running.

Flexible sockets, stance-controlled knees, andenergy-storing feet, combined with training andpractice, now enable people with AK amputation torun if they wish. However, running foot-over-foot ismost common for shorter distances and limited timeperiods . The majority of runners still run longdistances using the hop-skip step method . To date,there has not been a runner with AK amputationwho has completed an ultra-marathon or cross-country event running foot-over-foot . However, it isundoubtedly only a matter of time .

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Activities for Fitness and Skill: Running

SAaUuun p&nCENTER, OKLAHOMA CITY, OKThe OKC Running Cable is attached to an exoskeletalprosthesis with a flexible brim CAT/CAM socket, constantfriction knee, and SAFE Foot . This system allows forfoot-over-foot running .

NEWS/SUN-SENTINEL, FT . LAUDERDALE, FLAfter swimming 1 mile and cycling 25 miles, RichardHughes runs 10 kilometers to finish atdmtho!on .

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RRDS Clinical Guide . Physical Fitness: A Guide for Individuals with Lower Limb Loss

SABOLICH P&O CENTER, OKLAHOMA CITY, OKRoger Charter, thought to be the first person with bilateral above-kneeamputation to run foot-over-foot, is shown running with the energy-storingSabolich Feet and CustomFlex Sockets TM

NOTES

1. B. Kegel, E .M. Burgess, J .C . Webster, "Recreational Activ-ities of Lower Extremity Amputees: A Survey ." Archives ofPhysical Medicine and Rehabilitation, 61(6), 1980, pp . 258-264.

2. J . Michael, "Energy Storing Feet : A Clinical Comparison ."Clinical Prosthetics and Orthotics, 11(3), 1987, pp . 154-168.

3. J .H . Graves, "The Selectively Placed Silicone-Gel LinerSystem for PTB Prosthesis ." Orthotics and Prosthetics, 34(2),1980, pp . 21-24 .

4. University of Michigan Medical Center, BK Gel InsertFabrication Technique With Latex Suspension Sleeve . AnnArbor: University of Michigan Medical Center Release, 1976.

5. W . Koniuk, The Silicone Injection Molded Liner . Continu-ing Education Series, No . 1 . Chicago : American Academy ofOrthotics and Prosthetics, 1988.

6. T.B . Staats and J . Lundt, "The UCLA Total SurfaceBearing Suction Below-Knee Prosthesis ." Clinical Prostheticsand Orthotics, 11(3), 1987, pp . 118-130 .

205


7. J .P. Voisin, "Dual-Ankle Springs (D .A.S .) Foot-Ankle

System ." Orthotics and Prosthetics, 41(1), 1987, pp . 27-36.

8. G. Mensch and P.E . Ellis, "Running Patterns of

Transfemoral Amputees : A Clinical Analysis ." Prosthetics and

Orthotics International, 10, 1986, pp . 129-134.

9. G. Martel, "The Terry Fox Running Prosthesis ." In Pro-ceedings of the 1985 National Sports Prosthetics/OrthoticsSymposium, UCLA, Santa Monica, CA, Oct . 31, 1985.

10. W. Koniuk, The Silicone Injection Molded Liner . Continu-

ing Education Series, No. 1 . Chicago: American Academy of

Orthotics and Prosthetics, 1988 .

11. A.H. Payne, E . Asmussen, K . Jorgensen, A Comparison ofGround Reaction Forces in Race Walking With Those inNormal Walking and Running, Biomechanics VI. Baltimore:University Park Press, 1978, p . 293.

12. J .J . Shorter, "A New Design for the Knee Mechanism of aLight-Weight Modular System . " In Proceedings of the InterborCongress, Spain . Hampshire, England : Chas . A. Blatchford &Sons, 1987, pp . 24-27.

13. J . Sabolich, "The O .K.C. Above-Knee Running System ."Clinical Prosthetics and Orthotics, 11(3), 1987, pp . 169-172 .

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