Review Article
LUNGEOM ETRY- GEOM ETRICAL INVESTIGATION OF LUNGE
R.Vinodh Rajkumar.
Founder: PALEOLITHICX, Physiot herapist & Funct ional Fit ness Training Inst ruct or (Freelance), Bangalore, India.
Physiot herapist s m ust lear n t he biom echanics of lunge in det ail t o clear ly underst and it s signif icance in hum an life and im plem ent eff ect ive t raining m easures t o overcom e t he lim it ing fact ors of proper lunge of t heir client ele. To understand the biomechanical value of every m ovem ent , int eresting experim ental learning m ethods m ust be em ployed t o kindle t he Physiot herapist s t o act ively t ake part in research act ivit ies fr om t he under-graduat e level onw ards. Lungeom et ry is a novel, sim ple and inexpensive experim ent al invest igat ion of lunge, applying basic geom et rical m et hods t aking near norm al low er lim b lengt h dim ensions and rat ionale approaches int o consider at ion. Lungeom et ry can give a foundat ion t o learn ot her for m s of lunges like f orw ar d lunge, w eight ed lunges, lat eral lunges. This m odel of learning biom echanics of movement s using fundam ent al geom et ry t echniques is expect ed t o st rongly connect w it h any fut urist ic Physiot herapy curr icular st ruct ure.
KEYW ORDS: Lungeom et ry, Vert ical Lunge, Leg-split stance.
ABSTRACT
INTRODUCTION
Address for correspondence: R.Vinodh Rajkumar, # 638, 1st Floor, Jakkuramma Building, Behind
Eswara Temple, 1st Cross, 1st M ain, M at hikere, Bangalore-560054. India. M obile: +919008424632
E-M ail: dreamofkalam@rediffmail.com
Int J Physiother Res 2015, Vol 3(1):855-62. ISSN 2321-1822 DOI: 10.16965/ ijpr.2014.703
Low er lim b m ovem ent s of hum ans are very specialized enough t o produce t r em endous muscular forces in closed kinet ic chain (CKC) t o derive efficient ground react ion forces not ably ut ilizing leg-split st ance t o support and m ove t he mass of HAT (Head, Arm & Trunk) interact-ing w it h or w it hout any ext ernal loads durinteract-ing a w ide range of maneuvers compat ible t o basic act ivit ies of daily living, sport s, occupat ional labors and sur vival com pet ency skills. The o v er al l f i t n ess, esp ecial l y t h e l o w er li m b muscular st rengt h levels should be prevent ed from premature det erioration as a consequence of prolonged sedent ary life st yle accompanied by unfavorable changes in t he body mass (ex-cess fat percent age, inadequat e muscle mass),
culminating in (1) rest rict ed locomotor funct ions (2) low ered healt h and fit ness compet ence (3) painf ul life span harboring incurable healt h disorders. Therefore, basic and advanced cus-t omized exercises used in ficus-t ness cus-t raining and rehabilitat ion must emphasize on improving t he efficiency of closed-kinet ic chain low er lim b m o vem ent s li ke sq u at s, l u n ges, f o r w ar d bending, st air climb, get t ing up from t he floor t o st anding et c, on t he basis of healt h-fit ness screening of t he individuals. Paul Chek described seven m o v em en t p at t er n s; squ at , l u nge, upper-body pull, upper-body push, bending, t w ist ing and gait [1]. It has become com mon now adays t o see a large number of people at even very early st ages of life demonstrating very poor levels of m ovem ent capabilit ies w hen t est ed on t he basis of t hese seven movement
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International Journal of Physiotherapy and Research
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DOI: 10.16965/ ijpr.2014.703
Received: 24-11-2014 Peer Review : 24-11-2014 Revised: None
pat t erns as t hey part icularly st ruggle t o squat , lunge, bend, w alk and run. Every individual must regularly engage in st ruct ured physical act ivit y and preserve all t hese biomechanically efficient movement pat t erns as long as t hey live. Preser-vat ion of physical funct ion is a grow ing concern and decr eases in ph ysi cal capab ili t ies ar e associat ed wit h loss of funct ional independence; how ever, t hese decreases are often att ributable t o inact ivit y and not t o underlying pat hologies [2]. Act ivit ies incorporat ing full range of CKC m ot ions are alm ost com plet ely fading in t he modern life st yle of quit e a lot of people and it is not at all a surprise for exercise profession-als if t hese people succumb t o various muscu-loskelet al disorders and deform it ies of low er limbs. Lunge is very indispensable CKC move-ment t hat basically enables us t o get up from t he floor from a lying or sitt ing posit ion t o stand-ing posit ion usstand-ing a leg-split st ance biomechan-ics. Inabilit y t o lunge correct ly can be equat ed t o a massive st rengt h deficit in low er limbs. In fact , in t he domains of musculoskelet al reha-bilit at ion and goal-specific exercise regimens, lunge t est can be t he best indicat or of essent ial low er limb m uscular st rengt h part icularly t he Quadriceps of t he rear ext remit y. Rect us femo-ris in t he rear leg w as found t o be more st rained during t he lunge but st ill t he muscle forces, joint cont act forces and joint moment s are virt ually unknow n for nearly all st rengt h t raining exer-cises and t heir various execut ions [3].It is w ell know n, t hat st rengt h t raining prevent s muscle atrophy (St one, St one, & Sands, 2007), enhances st rengt h and improves t he general healt h, t he body mineral densit y, t he lean body mass, t he endurance performance, t he insulin sensit ivit y and ot her basal met abolism (Wilmore, Cost ill, & Kenney, 2008) [4,5].
Lunge and it s variat ions are one of t he most preferred low er body st rengt hening exercises. The lunge act ivat ed m ost of t he low er lim b muscles great er t han t he squat and it is an ideal act ivit y t o t rain at hlet es [6]. St rengt h t raining of specific muscle groups is also done t act ically t o prevent abnormal configurat ion of musculoske-letal system and injuries. Training hip muscles increases low er ext remit y alignment , improves landing t echnique, and decreases risk of ACL injury by reducing valgus force t o t he knee [7].
Gender specific differences in t he kinet ics may creat e a problem in t he st rengt h t raining and rehabilit at ion.Great er Q angle in females w as t he m ain gender differences t o occur in t he kinet ics and kinem at ics of t he fencing lunge occurred for t he front leg, w it h no differences occurring for the back leg [8].Apart from in-depth t heoret ical underst anding of every movement biomechanics, t he movement assessment and exercise dem onst rat ion skills of t he exercise professionals are alw ays a paramount requisit e because even a slight fluct uat ion in t he exercise form can expose an individual to injurious forces.
A 2° increase in ext ension from a neut ral spine posit ion increased compressive stress w ithin the p o st er io r an n u lu s by an av er age o f 16% com pared w it h m aint aining a neut r al spine
posit ion during lunges [9]. For Physiot herapist s
t o get involved in devising appropriat e exercise-based rehabilit at ion program and advanced researches, t he musculoskeletal biom echanics of ever y j oint and it s m ovem ent s m ust be t horoughly learned in order t o relat e various relevant scient ific lit erat ures and predict t he out com es of st rengt h deficit and m ovem ent disorders. To learn t he biomechanics of every movement as deep as possible, at least very basic components of mathematics and geomet ry m ust be ut i lized. To kindle t he int erest s of b ur geon i n g Ph ysi o t h er ap i st s f or d et ai led learning of biomechanics, t his art icle discusses about underst anding t he lunge using geomet ric met hods w it h near normal low er limb lengt h dimensions and rat ionale approaches.
Lungeometry:
Photograph-1: This is t he st art ing posit ion of Lungeomet ry for full dept h vert ical lunge. The knee of t he lead ext remit y coincides w it h t he metatarsophalangeal joint (M TPJ) region of t he lead foot . The knee of t he rear ext remit y is in cont act w it h t he ground and t he rear foot is perpendicular t o t he ground w it h it s M TPJ fully ext ended. The t high of t he rear leg is kept in line w it h t he t runk t o elim inat e t he st r et ch effect s on Iliopsoas muscles. The individual has t o overcome t he resist ance of t he upper body (Head, Arm & Trunk - HAT) and vert ically uplift t he st able HAT, exhi bit ing t he st rengt h and neuromuscular cont rol of low er limbs.
Photograph-2: (a) Finishing posit ion of vert ical lunge (b) Finishing posit ion of for w ard propulsion lunge (c) Finishing posit ion of backw ard propulsion lunge. For convenience, only vert ical lunge has been select ed in t his analysis. All t hese m echanism s are exam ples of CKC m ot ions ut ilizing leg-split st ance.
Table-1: Show ing t he ant hropom et ric dim ensions used in t his sagit t al view analysis.
Height 172 cm
Weight 70 Kg
Thigh lengt h 45 cm (Hip joint to Knee joint)
Leg length
48 cm - Knee joint to t he ground that includes the height contribut ion from t alus and calcaneus bones as well which
coincides with beginning point of arch of foot (BPA) - Photograph-3
Feet lengt h
25 cm - Divided into three regions; Post erior heel t o beginning of arch of foot = 5 cm, Beginning point of arch of
foot to M et at arsophalangeal joints (M TPJ) = 15 cm, M TP joints to t ip of forefoot preferably tip of great t oe = 5 cm. Photograph-3: The lengt h of t he leg is the sum of lengt hs cont ribut ed by t ibio-fibular unit , t alus and calcaneus. This can be m easured from knee joint (KJ) t o t he ground coinciding w it h t he beginning point of arch (BPA) of foot . This relat ionship show n in 3a and 3b can also be figured out b y exam in ing r adi ological im ages and skel et on illust rat ions in anat om y t ext books.
Lungeomet ry is divided int o t w o phases (Phase 1 & Phase 2). To ease t he geomet ric draw ings, ever y 5 cm of all t hese segm ent al lengt hs (Table 1) can be considered as 1 cm.
PHASE 1 (Blue colored lines in t he Figure - 1 & 2): To understand t he alignment of lead and rear extremit ies w hen t he knee of t he rear ext remit y is in cont act w it h t he ground)
St ep 1: Draw a 25 cm long dashed horizont al line (HL1) t hat represent s t he ground.
Step 2: Find t he midpoint of t his HL1 and draw a 20 cm long dashed vert ical line (VL) upwardly. This midpoint can be named as KJ (Knee joint ) of t he rear ext remit y.
plane as normally demanded by a proper lunge. St ep 4: From HJ, draw a 9 cm horizont al line t o represent t he t high part of t he lead ext remit y and it s end can be named as KJ (Knee joint ) of t he lead ext remit y.
St ep 5: Plot a point on t he HL1 exact ly st raight below KJ of t he lead ext remit y and t his point w ill represent M etatarsophalangeal joint (M TPJ) of t he lead ext remit y.
Step 6: From M TPJ of t he lead ext remit y, draw a 1 cm line forw ardly on t he HL1 t o represent t he great t oe lengt h t o get t he t oe region (TR) and dr aw a 4 cm line backw ar dly on t he HL1 t o represent t he lengt h of t he rest of t he foot t ill t he post erior heel region (HR). On t he same line from M TPJ t o heel region, plot a point 3 cm away from M TPJ t o represent t he beginning point of arch (BPA) of lead foot .
Step 7: Join KJ and BPA t o get t he leg lengt h (knee level t o t he ground t hat includes t he height cont ribut ion from t alus and calcaneus bones) and on t he basis of draw ing, t his leg lengt h w ill be 9.6 cm.
Step 8: W it h prot ract or, measure t he angles at hip, knee and ankle of t he lead ext remit y. (Hip joint angle in relat ion t o t he t runk = 90° flexion, Knee joint angle = 72° flexion, Ankle joint angle = 72° at dorsiflexion.
St ep 9: From a point 3 cm above t he KJ of t he rear ext remity, draw a 12.5 cm dashed horizontal line (HL2) t ow ards t he rear ext remit y side.
St ep 10: M easure 9.6 cm w it h t he compass, fix it s needle at point KJ of t he rear ext remit y and draw an arc t o int ersect t he dashed HL2 (t his arc is not show n in t he Figure 1 & 2). This point of intersect ion w ill represent t he BPA of t he rear foot . Connect point KJ of t he rear ext remit y and BPA of t he rear foot and t his line w ill represent t he leg lengt h of t he rear ext remit y.
Step 11: From BPA of t he rear foot , draw a 3 cm vertical line downwardly t o meet the HL1 at M TPJ (t o represent t he port ion from BPA t o M TPJ of rear foot ). Also draw a 1 cm horizont al line from M TPJ of t he rear fo ot for w ard ly on HL1 t o represent t he t oe region (TR) of rear foot and draw a 1 cm vert ical line from BPA t o represent t he heel region (HR) of rear foot .
Step 12: W it h prot ract or, measure t he angles at hip, knee, ankle and M TP j oint of t he r ear ext remit y. (Hip joint angle in relat ion t o t he trunk = 0° (Neut ral), Knee joint angle = 72° flexion, Ankle joint angle = 72° at dorsiflexion, M TP joint angle = 90° ext ension)
This is t he arrangement of low er ext remit ies at rest during lunge for t he given ant hropomet ric dimensions w it h t he knee of t he rear ext remit y in cont act w ith ground. The geometric procedure should ent er int o t he next phase t o underst and t he interact ion of low er ext remit ies as t he HAT is lift ed vert ically upw ard t ill t he leg of t he lead ext r em it y at t ains a ver t ical posit ion (f r om dorsiflexion st at e t o plant arflexion of ankle).
PHASE 2 (All red colored lines in t he Figure 1 & 2 ): To understand t he alignment of lead and rear ext rem it ies af t er t he HAT is ver t ically uplift ed t ill t he leg of t he lead ext remit y at t ains a ver t ical p o sit i o n an d m ai nt ai ns a 90° relat ionship w it h t he lead foot )
Step 13: Draw a 9.6 cm vert ical line from BPA of t he lead ext remit y and it s end w ill be KJ of t he l ead ext r em i t y d i sp l aced up w ar d l y an d backwardly.
St ep 14: M easure 9 cm w it h t he compass, fix it s needle at t he displaced point KJ of t he lead ext remit y and draw an arc (Arc 1) t o int ersect t he dashed VL. This point of int ersect ion w ill represent t he vert ically displaced HJ of t he lead and t he rear ext remit y considering t he pelvic alignment as horizont al in t he coronal plane. Draw a line from t his HJ t o KJ t o get t he t high part of t he lead ext remit y.
Step 15: W it h prot ract or, measure t he angles at hip, knee and ankle of t he lead ext remit y. (Hip joint angle in relat ion t o t he t runk = 42° flexion, Knee joint angle = 138° flexion, Ankle joint angle = 90° an d t he p ost er i o r t il t of t h e l eg o r m agn i t ud e of ank l e p l ant ar f l exio n f r o m dorsiflexion = 20° approximat ely).
Step 16: It looks like t here is necessit y for t he rear foot (BPA t o M TPJ port ion) t o t ilt backwardly using it s M TP joint axis. The magnit ude of t his t ilt can be around 50% more t han t he post erior t ilt of t he leg of t he lead ext remit y. So, draw a
3 cm line at 30° angle (20° + 10°) from t he M TPJ deviat ed backw ardly and it s end w ill be t he displaced BPA of t he rear foot and along w it h t hat , i t s h eel p o r t i o n (HR) also get s aut omat ically aligned in t he same angle.
St ep 17: M easure 9 cm w it h t he compass, fix it s needle on t he vert ically displaced HJ and draw an arc (Arc 2) t ow ards t he ground. M easure 9.6 cm w it h t he com pass and from t he point of backwardly displaced BPA of t he rear foot ; draw anot her arc (Arc 3) t o int ersect t he Arc 2 t o get KJ.
Step 18: W it h prot ract or, measure t he angles at hip, knee and ankle of t he rear ext remit y. (Hip j oi n t angl e i n r el at i on t o t h e t r un k = 15° ext ension, Knee joint angle = 136° flexion, Ankle joint angle = 90° and t he M TP joint angle = 120° ext ension (but 30° moves t ow ards flexion).
St ep 19: M easure t he dist ance bet w een HJ and t he di sp l aced HJ w hi ch w i l l equ al 7.3 cm indicat ing t he t ot al vert ical displacement of t he HAT.
St ep 20: Observe t he finished draw ing closely t o (i) relat e t he findings w ith goniomet ric studies (Ph o t ogr aph -4) o n h u m an sub j ect s (i i ) und er st and t h e int er -ext r em i t y an d int r a-ext remit y joint adjust ment s during ascent and descent phases of vert ical lunge (iii) calculat e t he w ork done (iv) underst and various scient ific l it er at u r es p er t ain i n g l u nge ki n et i cs an d kinemat ics.
Photograph-4: 4a & 4b show s sam ples of goniom et er ut ilit y in t he kinem at ic analysis of ver t ical lunge w hile doing Lungeometry.
The body w eight of t he individual used in t his analysis is 70 Kg. It is possible t hat t he HAT m ass can be, based on t he st udies of body segment paramet ers of de Leva and Plagenhoef et al, up t o 59.26 % and 73.12%, respect ively [10,11]. If w e t ake t he report of de Leva for considerat ion, t hen t he HAT mass of t his 70 Kg individual w ill be 41 Kg, so 410 New t on (F) approxim at ely. Wor k is defined as force (F) applied against a resist ance, mult iplied by t he di sp lacem en t (d ) of t h e r esi st ance of t he direct ion of t he force (W=Fd) [12]. As a result o f t h is sam p l e Lu ngeo m et r y, t he v er t i cal displacement of t he hip (on w hich t he HAT is placed) w as found t o be 7.3 cm, so in real it w ill be 36.5 cm because in t he geomet ric draw ing analysis every 5 cm of t he segment al length w as con si der ed t o b e 1 cm . Th is v er t i cal displacem ent (d) should be convert ed int o met ers for calculat ion of w ork done. Therefore, t he w ork done for uplift ing t he HAT mass used in t his scenario equals 150 joules approximat ely (410 N x 0.365m).
The m uscular role in lead and rear ext remit y during lunges can also be part ly underst ood observing at t he Lungeomet ric illust rat ions. In vert ical lunge, as t he rear foot is aligned vert ical w it h M TPJ in com plet e ext ension, t he rear ext remit y must apply force on t he ground. To accomplish t his rear foot force applicat ion, t he ent ire foot must remain highly st able w it hout medio-lateral and antero-post erior movement at t he ankle and t he foot . A variat ion of lunge is forw ard lunge and during t he performance of t he forw ard lunge, ankle mobilit y on bot h t he lead and t rail legs is crit ical t o ensure a balanced
biomechanically correct lunge pat t ern [13]. As show n in t he phot ograph-5, t he foot should be aligned st able w it hout medio-lat eral mot ions because t he rear leg can be t he key force supplier for t he vert ical lunge and also various ot her mult i-direct ional lunges commonly used in sport s, exercise t raining and act ivit ies of daily living. Upon analysis of t he lunge, it w as found t hat pow er pr od uct ion of t he low er lim bs occur r ed alm ost exclu sively f r om t h e t r ail leg [14].
Phot ograph-5: 5a show s pr oper f oot alignm ent f or effect ive propulsion during lunge. 5b & 5c show s m edial and lat eral deviat ions of heel, respect ively, t hat can aff ect t he propulsive biom echanics of lunge.
Fig. 3: 3a schem at ically show s t he Iliopsoas m uscle crossing t he hip joint . This hip flexor can severely aff ect t he lunge form if it is inflexible. Physiot herapist s m ay have t o pay closer att ent ion t o t his m uscle’s flexibilit y and if f ound t ight , t he lunge post ur e w it h increase in t he dist ance bet w een t he knee of rear ext rem it y and heel of the lead extrem ity (with rear hip extension) can be chosen t o st ret ch t he Iliopsoas as com m only seen in flexibilit y program s (3b).
In vert ical lunge, on t he ot her hand, t he lead ext remit y undergoes a different mechanism t o apply upward t hrust t o t he femur t o lift t he HAT w it h t he lead foot complet ely cont act ing t he ground but the tibio-fibular unit approaches ver-t ical posiver-t ion caused by CKC planver-tarflexion of ankle. While t he CKC ankle plantar flexion of t he lead extremit y appears in the biomechanical play of vert ical lunge, t here w ill be t endency for t he pelvis t o be rot at ed posteriorly in t he transverse plane in t he same side; hence t he ongoing in-t ra-exin-t remiin-t y adjusin-t menin-t of in-t he rear exin-t remiin-t y can count eract and ensure t he t ransverse plane pelvic st abilit y (Int er-ext remit y adjust ment s). Gluteus maximus and Vast i muscles can apply force couple mechanics (FCM ) on femur t o lift t he HAT mass during closed kinet ic chain act ivi-t ies of low er limbs [16]
.
The crit ical role of FCM
on femur of lead ext remit y in different lunges should be explored furt her but may be an int e-gral part of lunges w it h forw ard t runk propul-sions (Phot ograph-2b). All safe and product ive CKC mot ions, including vert ical lunge, occurs as a result of skilled applicat ion of forces on t he ground, using the requisit e st rengt h of t he lower limb muscles t o derive appropriat e ground react ion forces. Various individuals exhibit im -mense difficult y in applying appropriat e ground react ion forces w hile get t ing up from t he floor
(Phot ograph-6). Runners reach fast er t op speeds
not by reposit ioning t heir limbs more rapidly in t he air, but by applying greater support forces t o t he ground.17
Photograph-6: 6a show s t he very com m on st rat egy used t o get up fr om t he floor in w hich individuals apply force on t heir lead ext rem it y t hrough hands t o com pensat e for t he inabilit y t o lunge proper ly and independent ly. 6b show s anot her finding in w hich individuals lacking low er lim b st r engt h exhibit a jerky shoulder shr ugging in t he ascen t p h ase o f l u n ge . 6c sh o w s t h e st r at egy o f individuals w it h ver y w eak low er lim b st r engt h and neurom uscular cont rol as t hey cannot lunge and get up at all, alm ost resem bling Gow er ’s sign in M uscular dyst rophy. W hen asked t o get up from t he supine lying t o st anding posit ion as quick as possible w it h proper lunge incorporat ed, individuals w it h average and above-average fit ness levels take < 2 seconds only.
CONCLUSION
REFERENCES
Conflicts of interest: None
[ 1] . Ch ek P. M o vem en t That M at t er s. San Di ego, CA: C.H.E.K Inst it ut e, 2000. pp. 54.
[2]. Flanagan SP, Wang M Y, Greendale GA, Azen SP, Salem GJ, Biom echanical at t ribut es of lunging act ivit ies f o r o l d er ad u l t s, J St r en gt h Co n d Res. 20 04 Aug;18(3):599-605.
[3] . Schellenberg F, Ram seier M , Lorenzett i S., M uscle Fo r ces o f Qu ad r i cep s an d Ham st r i n gs d ur i n g Lunges, Jahr est agung der SGS 2013 in Basel. [4] . St one, M . H., St one, M ., Sands, W. Principles and
Pract ice of Resistance Training: Hum an Kinet ics, 2007.
[5]. Wilmore, J. H., Cost ill, D. L., Kenney, W. L., Physiology of Sport and Exercise, 4t h edit ion: Hum an Kinet ics, 2008.
[6] . Priscilla Dw elly, Gretchen Oliver, Heat her Adam s-Blair, David Keeley, Hiedi Hoffm an, Im proved m uscle act ivat i on in per f or m ing a bod y w eight lun ge com pared t o t he t radit ional back squat - Ret rieved f rom ht t ps:/ / ojs.ub.uni-konst anz.de/ cpa/ art icle/ view /3341/3141, 27 Int er nat ional Conference on Biom echanics in Sport s (2009), pdf.
[7]. M yer, G.D., Chu, D.A., Brent , J.L., Hew ett , T.E., Trunk an d h i p co n t r o l n eu r o m u scu l ar t r ai n i n g f o r prevention of knee injury. Clinics in Sport s M edicine 2008;27:425-448.
[ 8] . 8. Jonat han Sinclair, Lindsay Bott om s, Gender dif f er ences in t he kinet ics and low er ext rem it y kinem at ics of t he fencing lunge - Int er nat ional Jo u r n al o f Pe r f o r m an ce An al y si s i n Sp o r t , 2013;13:440-451.
[9]. Hollm an JH, Kolbeck KE, Hichcock JL, Koverm an JW, Krause DA, Correlat ions bet w een hip st rengt h and st at ic f o ot and knee po st u r e. J Spor t Rehabi l, 2006;15:12–23.
[10]. de Leva P, Adjust m ent s t o Zat siorsky-Seluyanov’s Segm e n t I n e r t i a Par am e t e r s, Jo u r n al o f Biom echanics, 1996;29(9):1223-1230.
[11]. Plagenhoef, S., Evans, F.G., Abdelnour, T., Anat om ical d at a f o r an al yzi n g h u m an m o t i o n . Resear ch Quart erly for Exercise and Sport , 1983;54:169-178. [ 12] . Susan J Hall, Basic Bio m echan ics, Chapt er -12, Linear kinet ics of Hum an m ovement, Brow n & Bench m ar k, 1991.
[13]. Bennell K, Talbot R, Wajsw elner H,Techovanich W, Kelly D, Int ra-rat er and int er-rat er reliabilit y of a w eight-bearing lunge measure of ankle dorsiflexion. Aust J Physiot her, 1998;44:175–180.
[14]. Nat han M orris, M ark Farnswort h, D.G.E. Robert son, Kinet ic analyses of t w o fencing at t acks – lunge and f lech e, Por t uguese Jou r nal of Spo r t Sciences, 2011;11(Suppl. 2).
[15]. Claiborne TL, Ar m st rong CW, Gandhi V, Pincivero DM , Relat ionship bet w een hip and knee st rengt h and knee valgus during a single leg squat , J Appl Biom ech, 2006;22:41–50.
[16] . R.Vinod h Rajkum ar, Force couple m echanics on femur during closed kinet ic chain act ivit ies of low er lim bs. Int J Physiot her Res 2014;2(6):766-771. [17]. P G Weyand, D B St ernlight , M J Bellizzi ,S Wright ,
Faster t op running speeds are achieved w it h greater gr ound f or ces not m or e r apid leg m ovem ent s, Journal of Applied Physiology 12/2000; 89(5):1991-9.
