An electromyographoic analysis of sumo andconventional style deadlmifts

RAFAEL F. ESCAMILLA, ANTHONY C. FRANCISCO, ANDREW V. KAYES, KEVIN P. SPEER, andCLAUDE T. MOORMAN, III

Michael W. Krzyzewski Huimnan Performiience Labor(atory, Division of Orthopaedic Surgerv, Duke University VedicalCenter, Durham, NC

ABSTRACT

ESCAMIILLA, R. F., A. C. FRANCISCO. A. V. KAYES, K. P. SPEER, and C. T. MOORMAN. 111. An electromyographic analysis

of sumo and conventional style deadlifts. Med. Sci. Sports Exerc., Vol. 34, No. 4. pp. 682-688, 2002. Purpose: Strength athletes often

employ the deadlift in their training or rehabilitatioin regimens. The purpose of this study was to compare muscle activity between] sumoand conventional stvle deadlifts. and between belt and no-belt conditions. Methods: Six cameras collected 60-Hz video d&1ta and

960)-Hz electromyographic data fromi 13 collegiate football players who performed sumo and conventional deadlifts with and .ithout

a lifting belt, employing a 1 2-RM intensity. Variables measured were knee angles and EMG measurements fromn 16 muscles. Muscleactivity were averaged and compared within three 30" knee angle intervals from 9(1 to 0° during the ascent, and three 30' knee angle

intervals from 0 to 900 during the descent. Results: Overall EMG activity from the vastus medialis, vastus lateralis, and tibialis .nteriorwere significantly greater in the sumo deadlift, whereas overall EMG activity fromn the medial gastrocnemius was significantly greaterin the conventional deadlift. Coripared with tlhe no-belt condition, the belt condition produced significantly greater rectus abotlominis

activity and significantly less external oblique activity. For mnost muscles, EMG activity was significantly greater in the knee ex endingintervals compared with the corresponding knee flexing intervals. Quadriceps, tibialis anterior, hip adductor, gluteus maximus, L3 and

112 paraspinal. and middle trapezius activity were significantly greater in higher knee flexion intervals compared with loxwsr kneeflexion intervals, whereas hamstrings, gastrocnetnius. and upper trapezius activity were greater in lower knee flexion in tervalscompared with higher knee flexion intervals. Conclusions: Athletes may choose to employ either the sumo or conventional deadliftstyle, depending on which muscies are considered most important according to their training protocols. Moderate to high co-contractions from the quadriceps, hamstrings, and gastrocnernius imply that the deadlift may be an effective closed kinen 2 chain

exercise for strength athletes to employ during knee rehabilitation. Key Words: EMG, MUSCLE ACTIVITY, WEIGHIT TRAINING,POWERLIFTING, REHABILITATION, STRENGTHI ATHLETE, FOOTBALL.

S trength athletes, such as American football playersand powerlifters, often employ the barbell deadlift intheir weight-training regimen or rehabilitation pro-

gram, such as during the late stages of anterior cruLciateligament (ACL) rehabilitation. These athletes use the dead-lift to enhance hip, thigh, and back strength. The startingposition for the deadlift is with the lifter in a squat positionwith the knees and hips flexed approximately 80-1000,arms straight and pointing down, and an alternating handgrip used to hold a barbell positioned in front of the lifter'sfeet (6). The barbell is then lifted upward in a continuousmotion by extending the knees and hips until the lifter isstanding erect with knees locked and the shoulders thrustback. From this position, the barbell is slowly lowered backto the ground by flexing the knees and hips. This deadliftmotion can be performed using either a coinventional orsumo style. The primary differences between these twostyles are that the feet are positioned further apart and turnedout more in the sumo style, and the arms are positioned

0195-9 13 t/02/3404-0682/$3.0010MEDICINE & SCIENCE IN SPORT S & EXERCISE,Copyright © 2002 by the American College of Sports Medicine

Submitted for publication January 2001.Accepted for publication August 2001.

inside the knees for the sumo style and outside the knees forthe conventional style. Additional kinemat.c comparisonsbetween sumo and conventional deadlifts hbwtve been previ-ously described (6,17).

The efficacy of one deadlift style over antother is utclear.An athlete will choose a deadlift style b,rsed on severalfactors, such as comfort, muscle involvemeit, and personalpreference. For example, an American foohall player withdisproportionately stronger quadriceps relati ve to their ham-strings may choose a deadlift style they believe evokes arelatively greater hamstring involvement :L.nd a relativelyless quadriceps involvement. In addition, oae deadlift stylemay develop the gluteal and hip adductcr muscles to agreater extent than the other deadlift style. Pherefore, mus-cle involvement and development may be (tletermining fac-tors in choosing one technique over anmther. However.electromyographic data, which provides insights inlto mus-cle involvement, are not yet available for sumo and con-ventional deadlifts.

Four studies have compared biomechanical parametersbetween sumo and conventional deadlifts (2,6.7,17).McGtuigan and Wilson (17) performed a kiitiematic analysisduring regional powerlifting competition and reported amore upright trunk, less hip flexion at barh ell liftoff, and agreater shank range of motion in the sunto deadlift com-

682

pared with the conventional deadlift. Cholewicki et al. (2)quantified lumbar loads and hip and knee moments during anational powerlifting championship and found significantlygreater L4-L5 shear forces and moments in the conven-tional group, whereas hip and knee moments were notsignificantly different between the two deadlift styles. Es-camilla et al. (6,7) performed a three dimensional (3-D)kinematic and kinetic analysis during a national masterspowerlifting championship (6) and during the SpecialOlympics World Games (7). Several significant differencesin joint and segment angles, mechanical work, and ankle,knee, and hip moments and moment arms were found be-tween sumo and conventional deadlifts. Ankle dorsiflexormoments were generated in the sumo deadlift, whereasankle plantar flexor moments were generated in the conven-tional deadlifts. Knee extensor moments were significantlygreater in the sumo deadlift, whereas there were no signif-icant differences in hip extensor moments between the sumoand conventional deadlifts.

It was the purpose of this study to compare muscleactivity from leg, thigh, hip, and trunk musculature betweensumo and conventional deadlifts. From deadlift kinetic data(6,7), it was hypothesized that knee extensor and ankledorsiflexor muscle activity would be significantly greater inthe sumo deadlift, ankle plantar flexor activity would besignificantly greater in the conventional deadlift, hip exten-sor activity would not be significanitly different betweensumo and conventional deadlifts, and back extensor activitywouild be significantly greater in the conventional deadlift.

Because strength athletes train the sumo and conventionaldeadlifts both with and without a training belt, it was alsothe purpose of this study to compare muscle activity duringthe deadlift both with and without a training belt. Severalstudies have shown an increase in intra-abdominal pressure(LAP) when using a weight-belt duling lifting movements(9,13,14,16,19), which may affect trunk muscle activity.Differences in trunk musculature have been reported duringlifting between belt and no-belt conditions (14,19). There-fore, it was hypothesized that there would be differences intrunk musculature during the deadlift between belt anidno-belt conditions.

MATERIALS AND METHODS

Subjects. Thirteen Division I-A collegiate footballplayers served as subjects. All subjects were familiar withand had previously performed both the sumo and conven-tional deadlifts in their training regimen. Mean age, bodymass, and body height were 20.1 ± 1.3 yr, 102.8 ± 16.1 kg,and 186.6 ± 7.5 cm, respectively. The mean load lifted was123.1 ± 18.6 kg. Mean foot angle (i.e., mid-foot abduction,defined as 0° with the midline of the foot pointing straightahead in the same direction the subject was facing), stancewidth (inside heel to inside heel), and hand width (insidehand to inside hand) were 25.1 ± 8.70. 64.9 ± .16.9 cm, and25.3 ± 7.7 cm, respectively, for the sumo deadlift, and 7.0± 3.20, 32.7 ± 5.3 cm, and 48.0 ± 8.7 cm, respectively, for

ELECTROMYOGRAPHIC ANALYSIS OF THE DEADLIFT

the conventional deadlift. All subjects signed a human con-sent form before their participation.

Data collection. Spherical plastic balls (3.8 cm in di-ameter) covered with reflective tape were attached to adhe-sives and positioned over the following bony landmarks: a)medial and lateral malleoli of the left foot, b) upper edges ofthe medial and lateral tibial plateaus of the left knee, c)posterior aspect of the greater trochanters of the left andright femurs, d) acromion process of the left shoulder, ande) third metatarsal head of the left foot. Six electronicallysynchronized high-speed charged couple device video cam-eras were strategically positioned around each subject, andcentroid images from the reflective markers were transmit-ted directly into a motion analysis system (Motion AnalysisCorporation, Santa Rosa, CA).

Electromyography (EMG) was utilized to quantify mus-cle activity. EMG data were quantified with a 16 channelNoraxon Telemyo EMG telemetry unit (Noraxon U.S., Inc.,Scottsdale, AZ). The amplifier bandwidth frequency rangedfrom 16 to 500 Hz, with an input voltage of 12 VDC at 1.5A. The input impedance of the amplifier was 20,000 kfl,and the common-mode rejection ratio was 130 Db. The skinwas prepared by shaving, abrading, and cleaning.

Neuroline (Medicotest Marketin-, Inc., Ballwin, MO)disposable surface electrodes (type 720-00-S) were used tocollect EMG data. These oval shaped electrodes (22 mmwide and 30 mm long) were placed in pairs along thelongitudinal axis of each muscle or muscle group tested,with a center-to-center distance between each electrode of2-3 cm. One electrode pair was placed on each the follow-ing muscles in accordance with procedures from Basmajianand Blumenstein (1) and Cram and Kasman (3): 1) rectusfemoris; 2) vastus lateralis; 3) vastus medialis; 4) lateralhamstring (biceps femoris); 5) medial hamstrings (semiten-dinosus/semimembranosus): 6) lateral gastrocnemius; 7)medial gastrocnemius; 8) tibialis anterior; 9) hip adductors(adductor longus, adductor magnus, and gracilis); 10) glu-teus maximus; 11) L3 paraspinals; 12) T12 paraspinals; 13)middle trapezius; 14) upper trapezius; 15) rectus abdominis;and 16) external obliques. EMG and video data were syn-chronized by the motion analysis system, with EMG datasampled at 960 Hz and video data sampled at 60 Hz.Because bilateral symmetry has been demonstrated duringthe deadlift (6), EMG and video data were collected andanalyzed only on the subject's left side.

During testing, each subject performed four variations ofthe deadlift, each performed in a randomized order: a) sumodeadlift with belt, b) sumo deadlift without belt, c) conven-tional deadlift with belt, and d) conventional deadlift with-out belt. A heavy-duty weight-belt (14) consisting of threelayers of leather 1.0 cm thick and 10.0 cm wide throughoutits length was employed by all subjects and tightened inaccordance to individual preference. Each subject employedthe same weight for each of the four deadlift variations,which was equivalent to their 12-repetition maximum (12RM) weight they currently were using in the hypertrophyphase of a periodization regimen. An 8-12 RM is a commonrepetition scheme for muscle hypertrophy (25) and is also a

Medicine & Science in Sports & Exerciseo 683

comminion repetition scheme during knee rehabilitationi. Astandard 20.5-kg Olympic barbell and Olympic disks wereused during the deadlift. All subjects performed two to threewarm-up sets in preparation for testing. Just before perform-ing each deadlift variation, each subject's stance width andfoot angle (i.e., mid-foot abduction) were measured. Eachsubject performed four repetitions for each exercise varia-tion in a slow and continuous manner (both during theascent and descent), similar to how they performed thedeadlift during their training regimen. Data collection wasinitiated at the end of the first repetition and continuedthroughout the final three repetitions of each set. Therefore,three distinct trials were collected for each deadlift varia-tion. Between each repetition, the subjects were instructedto pause approximately I s to provide a clear separationbetween trials. Each subject rested long enough betweenexercise variations to completely recover from the previousset (approximately 3-4 min). Fatigue was assumed to benegligible due to the submaximal weight lifted, the lowlifting intensity, the low numiber of repetitions anid setscompared with their normal training session, a sufficient restinterval between sets, and the high fittness level of thesubjects. All subjects acknowledged that fatigue did notadversely affect their ability to perform any of the exercisevariations.

Subsequent to exercise testing, EMG data from the mus-cles tested were then collected during maximum voluntaryisometric contractionis (MVIC) to normalize the EMG datacollected during the four deadlift variations (4). MVICswere performed after exercise testing because the mnuscleswere now warmed up but not fatigued. Three 5-s MVICtrials were collected for each muscle group in a randomizedmanner, witlh approximately a 1-min rest interval betweeneach MVIC. Methods and positions used during MVLCs,which are commoni positions used in manual muscle testingto isolate individual muLscles or nuscle grouLps, have previ-ously been described (4,11). Because all the muscle groupswere randomly tested, fatigue was assumed to be minimal.Each highly trained subject acknowledged that fatigue didnot adversely affect their ability to perform maximal -effortMVICs.

Data reduction. Video images for each reflectivemarker were automatically digitized in 3-D space with Mo-tion Analysis EVa software, utilizing the direct linear trans-formation method (4). Testing of the accuracy of the cali-bration system resulted in reflective balls that could belocated in 3-D space with an error less than 1.0 cm. The rawposition data were smoothed with a double-pass fourth-order Butterworth low-pass filter with a cut-off frequency of6 Hz (4). Knee joint angles were calculated throughout thelift using EVa software. Knee angle (KA) was defined as 00

when the knees were filly extended.EMG data for each deadlift trial and the highest I s of

each MVIC trial were rectified and averaiged in a 0.01-smoving window. Data for each muscle tested were normal-ized as a percentage of the subject's highest correspondingMVIC trial over the entire KA range of each deadlift vari-ation. The upward (ascent) phase of the deadlift was divided

684 Official Journal of the American College of Sports Medicine

into three 300 intervals from 90 to O0 KA: u) 90-610, b)60-310, and c) 30-0°. Similarly, the downmard (descent)phase of the deadlift was divided into three 30' intervalsfrom 0 to 90°KA: a) 0330', b) 311-60, and c) 61-90°.Normalized EMG data for each miuscle were hen averagedover each of the three ascent anid three descew KA intervalsfor each of the three repetitions (trials) ancd four deadliftvariations. The three trial average for each muscle and KAinterval was then used in the statistical analysis.

Statistical analysis. A three-factor repe lited measuresanalysis of variance (P < 0.01) was employed to examinethe interaction effect and test for main effe ts of: a) twodeadlift styles (sumo vs conventional); b) tv/o belt condi-tions (belt vs no-belt); and c) six knee angle ntervals (90-610, 60-3l0, 30-00, 0-30°, 31600, and 61-00) Post hoccomparisons were made using the Tukey test (P < 0.013 toevaluate the significance between pairwise co)mparisons.

RESULTS

Each repetition during the sumo and convettional dleadlifttook between 2.50 and 2.75 s to complete (ciscounting theslight pauLse at the end of the ascent before the descent), withsutmio ascent and descent times of 1.24 t 0. I 3 s and 1.32 ±

0.24 s, respectively, and convenitional ascent and descenttimes of 1.30 ± 0.18 s and 1.43 +± 0.21 % respectively.Several small but significant EMG differe ices were ob-served between sumo and conventioInal deadlifts (Table I).Compared with the conventional deadlift, thc sumo deadlifthad significantly greater EMG activity in th vastus latera-lis, vastus medialis, and tibialis anterior but significantlyless EMG activity in the m-nedial gastrocnenius. Comparedwith the belt condition, the no-belt conditirn had signifi-cantly greater EMG activity in the rectus abdominis butsig,nificantly less EMG activity in the ex iernal obliques(Table 1). There were no significant intera tions observedfor all measurements.

For most muscles, EMG activity was signilticantly greaterin the knee extending intervals compared with th-e corre-sponding knee flexing intervals (Table I). ()uadriceps, tib-ialis anterior, hip adductor, gluteus maximus, L3 and T12paraspinal, and middle trapezius activity were significantlygreater in higher knee flexion intervals (61- 900) comparedwith lower knee flexioni intervals (0-30'°). whereas ham-strings, gastroenemius, and upper trapezius activity weregreater in lower knee flexion intervals compi Lred with higherknee flexion intervals (Table 1). Meatn EM G patterns forselect muscles during the deadlift are shownl in Fig. IA andB.

DISCUSSION

Our EMG results are supported by kirietic data fromEscamilla et al. (6,7), who quantified ankic, kn-ee, and hipmoments during the sumo and conventional deadlifts. Theseauthors, who conducted the only known study that quanti-fied ankle moments between conventional and sutl(iO dead-lifts, reported that the sumo deadlift genenrted ankle dorsi-

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flexion moments exclusively throughout the lift, whereasthe conventional deadlift generated plantar flexor momentsexclusively throughout the lift. These kinetic results areconsistent with our EMG findings between sumo and con-ventional deadlifts, in which ankle dorsiflexion activityfrom the tibialis anterior were greater in the sumo deadliftand ankle plantar flexor activity from the medial gastroc-nemius was greater in the conventional deadlift. It can beinferred from these data that the sumo deadlift may be moreeffective overall in recruiting the ankle dorsiflexors,whereas the conventional deadlift may be more effectiveoverall in recruiting the ankle plantar flexors. However, itshould be emphasized that the percent differences in tibialisanterior and medial gastrocnemius activity between sumoand conventional deadlifts were relatively small.

Escamilla et al. (6,7) reported significantly greater kneeextensor moments during the sumo deadlift compared to theconventional deadlift during a 3-D analysis of the deadlift.These kinetic results are consistent with our EMG findings.The significantly greater vasti activity in the sumo deadliftcompared to the conventional deadlift support our originalhypothesis that knee extensor activity would be greater inthe sumo deadlift. It can be inferred from these data that thesumo deadlift may be more effective than the conventionaldeadlift in recruiting the vasti muscles. In contrast, no signif-icant knee moments were found by Cholewicki et al. (2)between sumo and conventional deadlifts. However, the kneemoments reported by Cholewicki et al. (2) were calculatedfrom a two dimensional (2-D) sagittal plane analysis. Although

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ELECTROMYOGRAPHIC ANALYSIS OF THE DEADLIFT

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a 2-D analysis has been shown to be adequate for the conven-tional deadlift (6), significant differences in knee moments andmoment arms have been demonstrated in the sumo deadliftbetween 2-D and 3-D analyses (6,7). Because in th-e sumodeadlift the knees move out of a sagittal plane zind into a frontalplane as the stance widens and the feet turn out, a 2-D analysiswill produce erroneous knee momnents and moment arms. The65 ± 17 cm stance width and 25 + 9 mid-ifoot bductioncluring the sumo deadlift are similar but slightly less than the 70± 11 cm stance width and 42 + 8° mid-foot abduction pre-viously reported by Escamilla et aL (6).

No significant differences in hip extensor moments havebeen previously reported betwveen sumo and conventionaldeadlifts (2,6). These data are consistent with our EMGfindings, in which there were generally no significant dif-ferences in lateral hamstring, medial hamstring, and gluteusmaximus activity between sumo and conventional deadlifts.

Cholewicki et al. (2) conducted the only known study thatcompared back extensor moments between sumo and con-ventional deadlifts. These authors reported a significantlygreater L4/L5 back extensor momernt in the con ventionaldeadlift compared with the sumo deadlift. Our EMG data donot suipport these findings, because no significant differ-ences were found in L3 and TI2 paraspinal activity duringthe ascent, which implies that the sumo deadlift may be aseffective as the conventional deadlift in recruiting theparaspinal muscles.

Tibialis anterior, hip adductor, gluteus maximus, and L3and T1 2 paraspinal activity were significantly greater duringthe final 30° of the descent (i.e., 61-90'KA) compared withthe other knee angle intervals. These miuscles may fire moretoward the end of the descent to enhance stability during thisportion of the lift as the lifter decelerates the weight towardthe end of the lift.

High lumbar compressive ad shear forces have beenreported during the deadlift (2,8). Thiese compressive andshear forces can be decreased by wealing a weight-trainingbelt (14). A tightly worn weight-belt can help to pressurizethe abdominial cavity, enabling it to bear up to 50% of theload normally placed on the spinal columnl and associatedstructures (12). Several liting studies have shown an in-crease in lAP from 13 to 40% when a weight-belt was used(9,13,14,16), thus unloading the spine and decreasing shearand compressive forces. Employinc, a lifting belt can alsoa-ffect muscle activity (Table 1). In the current study, therectus abdominis and external obliqu es were the only mus-cles affected by wearing a belt during the deadlift. Thegreater external oblique iactivity in the belt condition coim-pared to the no-belt condition is in agreemiient with data fromLander et al. (14) during the barbell squat, which is per-formed in a similar maanner as the barbell deadlift. Greaterexternal oblique activity without wearing a belt may beneeded to enhance trunk stabilization and rigidity, whi'chnormally is enhanced by the belt due to increased IAP (14).Although increased IAP generates a force that resists spinaltlexion, thus unloading the spine and decreasing paraspinalactivity, we did not find a significa'nt difference in paraspi-nal activity between the two belt conditions. The greater

686 Official Journal of the American College of Sports Medicine

rectus abdomiinis activity with a belt compared, to without abelt is in agreement with lifting data from Miyamoto et al.(19). The greater rectus abdominis activity withi the belt mayoccur because the belt works as a resistance against thecontraction of the rectus abdominiis, tlhus allcfwing a moreintense voluntary contraction than- without a belt (19).

The magnitudes and patterns of quadriceps activity in thecurrent study have also been observed duririg the barbellsquat (4,5,27-29). Both the vastus medialis auid vastus late-ralis produced approximately the same amouat of activity,which is in agreement with vasti data from several squatstudies (4,5,18,24,27). The lower activity observed in therectus femoris compared to the vasti muscles nay be due toits biarticular function as both a hip flexor and knee exten-sor. Increased activity from the rectus fem(ris wouild in-crease hip flexor torque, with a con'nomitant ucrease in theamount of hip extensor torque needed from the hamstrings,gluteu s maximus, and adductor magnus (is hial fibers) toextend the hip. Employing the same 12 RM Uifting intensityas the current study, Escamilla et al. (4) and NVilk et al. (27)reported similar peak hamstring activity (30-80 % of aMVIC) during the squat as observed in the current study. Inaddition, numerous sqtuat studies (4,l0,20,26,27) have re-ported that peak hamstring activity occurs between 10 and60°KA, which is in agreement with our h imstring data,which were hiahest between 0 and 60°KA.

The significantly greater medial gastrocuemius activitywith the more narrow stance conventional deadlift com-pared with the wider stance sumo deadlift ii in agreementwith data from Escamillt et al. (5), who reported signifi-'antly greater gastrocnemius activity durilig the narrowstance squat compared to the wide stance squat. In addition,both Escamilla et al. (5) and McCaw and Melrose (1 5)reported no significant differences in rectus femoris andhamstring ac'tivity between narrow and wide stance squats,which are similar to the results found betwee.n the conven-tion1al and sumo deadlifts. In contrast, althoun-h vasti activityhas not been shown to be different between n rrow and widestance squats (5,15), the wider stance surnio deadlift didshow g'reater vasti activity than the more narrow stanceconventional deadlift. Interestingly, the 29-cm narrowstance width and 57-cm wide stance wid&h reported byEscamilla et al. (5) during the squat are very similar to the33- m stance width for the conventional deadlift and 65-cmstance width for the sumo deadlift. It can bh inferred fromthese data that gastrocnemius recruitment may be moreeffective with a narrow lifting stance, whereas performingthe deadlift with a wider stance may be ml;re effective invasti recruitment. These results may have clinical implica-tions, because vasti activity is very important in knee reha-bilitation programs, especially the vastus mnedialis. More-over, because the deadlift is considered ) closed kineticchain exercise (22), it may be appropriate during kneerehabilitation, such as after ACL reconstiuction. This isespecially true for strength athletes (e.g., Amtierican footballplayers) who already employ the deadlift n their trainingregimen. Closed chain exercises, like the sqtiat and deadlift,elicit moderate to high co-contraction fron knee muscula-

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ture (quadriceps, hamstrings, and gastrocnemius) and havebeen shown to minimize ACL strain (21,23,26,3 1). Becausethe deadlift is performed in a similar manner as the squat,the deadlift may provide similar benefits during ACL reha-bilitation. Additional studies are needed to test this hypoth-esis. Moderate to high hamstring activity has been reportedduring the conventional straight leg deadlift (30), whichmay help protect the ACL during knee rehabilitation.

CONCLUSION

From our EMG findings, the sumo deadlift may be moreeffective overall than the conventional deadlift in recruitingthe vastus medialis, vastus lateralis, and tibialis anterior,whereas the conventional deadlift may be more effectiveoverall than the sumo deadlift in recruiting the medial gas-trocnemius. The primary effect of wearing a belt is that therewas greater rectus abdominis activity and less externaloblique activity. Therefore, wearing a belt during submaxi-mal training does not appear to alter muscle activationpatterns, except in abdominal musculature. Strength athletes

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We would like to extend a special thanks to Coach WilliamStephens and Coach Sonny Falcone at Duke University, for all theirassistance in recruiting the subjects and helping during data collec-tion. We would also like to thank Morena Newton and Tracy Lowryfor their help in organizing and preparing the data.

Address for correspondence: Rafael Escamilla, Ph.D., P.T.,C.S.C.S., Duke University Medical Center, P.O. Box 3435, Durham,NC 27710; E-mail: rescamil©duke.edu.

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TITLE: An electromyographic analysis of sumo and conventionalstyle deadlifts

SOURCE: Medicine and Science in Sports and Exercise 34 no4 Ap2002

WN: 0209101727019

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