Speaker: Jeff Houck, PT, PhD George Fox Uiversity Lab Preseters: Je Davis, DPT Christopher G. Neville, PT, PhD Likig Video-Based Motio Aalysis with Cliical Cases of Ijured Ruers Ruig is beautiful, but Novice: Higher risk Ijury Novice - 17.8 ijuries/1k hours Recreatioal - 7.7 ijuries/1k hours [Sports Med (2015) 45:1017 1026] Shoes ad exteral supports Traiig Icrease <10 %/wk High (40?) miles/wk High frequecy/wk Other Ruer Sprit ruers (~60%) Cross coutry (3.2%) [Sports Med (2015) 45:1143-1161) Persoal Characteristics Prior Ijury Techique/Style Over Stridig Boudig Kee IR Pelvic drop Foot ladig Other? 1
Where do ijuries occur? Kee Hip FAI, GTB Specific Ijuries [Sports Med 2012; 42 (10)] Akle/Foot PFS,ITB, PT Medial Tibial Stress Achilles Tedo Patellofemoral Sydrome Platar Fasciitis Achilles, Platar fasciitis Traiig Maarte et al, JOSPT, 2016 Shoes/orthotics No proximal ifluece Almoroeder et al, JOSPT, 2016 Miimalist cotrol load rate Rice et al, Med Sci & Sports Ex, 2016 Shoes ad exteral supports Traiig Icrease <10 %/wk High (40?) miles/wk High frequecy/wk Techique (Hiederschiet, JOSPT, 2012) Barefoot ruig- o chage ijury rates but lower vertical load rate Altma AR, et al. Br J Sports Med 201 & Davis et al, British J of Sports Med, 2015 May variables alter joit load. Lehart, JOSPT, 2014, Hiederscheit, JOSPT 2016, Teg, JOSPT 2014 Persoal Characteristics Hip abductio weakess Plastaras et al, Am J Sports Med, 2016 Achilles?? stiffess Persoal Characteristics Prior Ijury Muscle imbalaces Techique/Style Over Stridig Boudig Kee IR Pelvic drop Foot ladig Other? Speed Costat Icreasig/ decreasig cadece Breakig Bigger strides Shorter strides Heiderscheidt et al, Med & Sci Sports & Ex 2011 Propulsio 2
Potetial of the effect of chage i techique 3D Motio Aalysis Altered foot strike patter Red is Heel strike IC White Forefoot strike IC What determied joit load? Magitude of Momet of Coectig Kiematics/Kietics Recorded Still Truk Motio Capture i the Cliic Sagittal 1. Treadmill 2. Work light 3. HS camera Casio EX-FH25 4. Maxtrac Software (Optioal) 300 FPS Frotal Reliable ad Predictive of Kee Load Validity Willie et al, JOSPT, 2014 Reliable Pipki et al, JOSPT, 2016 3
Affect of Over Stride Recorded Still Over stride Icreased Truk heal distace Icreased Icliatio agle Effect Icreased Hip, kee, akle DF load Truk Willie et al, JOSPT, 2014, Pipki et al, JOSPT, 2016 Peak Kee flexio/akle Df Peak Kee Flexio (~40 degrees) Decrease Icrease (~40 degrees = appropriate) Akle Dorsiflexio Agle Decrease Icrease Mass Sprig Model Hip Flex Kee Flex Akle Df Affect of Boudig Boudig Theoretically Iflueces magitude of, icreasig loadig ( Vertical Distace) Vertical Oscillatio (VO) 10.3 (1.3) cm High Cadece 8.4(1.5) cm Use techology (video - NOT reliable) VO ~ watch/chest strap Adams et al, JOSPT, 2016 4
Applyig Visual Aalysis Video Based Markers of High Kee Load Greater vertical excursio (ext slide) foot icliatio agle Greater to heel strike distace Greater *Note that kee flexio @IC ad peak kee agle were less powerful at predictig kee loads tha the kiematic variables Icreasig or decreasig step rate also sigificatly iflueces kee loads Forward Truk Lea Aterior Truk Lea Truk Truk Joit Work Lower kee Higher hip No chage Akle Teg et al, Joural of Athletic Traiig 2016;51(7):519 524 doi: 10.4085/1062-6050-51.8.05 Foot Strike Patters LETTERS Vol 463 28 Jauary 2010 doi:10.1038/ature08723 Foot strike patters ad collisio forces i habitually barefoot versus shod ruers Daiel E. Lieberma1, Madhusudha Vekadesa1,2*, William A. Werbel3*, Adam I. Daoud1*, Susa D Adrea4, Iree S. Davis5, Robert Ojiambo Mag Ei6,7 & Yais Pitsiladis6,7 Humas have egaged i edurace ruig for millios of years1, but the moder ruig shoe was ot iveted util the 1970s. For most of huma evolutioary history, ruers were either barefoot or wore miimal footwear such as sadals or moccasis with smaller heels ad little cushioig relative to moder ruig shoes. We wodered how ruers coped with the impact caused by the foot collidig with the groud before the ivetio of the moder shoe. Here we show that habitually barefoot edurace ruers ofte lad o the fore-foot (fore-foot strike) before brigig dow the heel, but they sometimes lad with a flat foot (mid-foot strike) or, less ofte, o the heel (rear-foot strike). I cotrast, habitually shod ruers mostly rear-foot strike, facilitated by the elevated ad cushioed heel of the moder ruig shoe. Kiematic ad kietic aalyses show that eve o hard surfaces, barefoot ruers who fore-foot strike geerate smaller collisio forces tha shod rear-foot strikers. This differece results primarily from a more platarflexed foot at ladig ad more akle compliace durig impact, decreasig the effective mass of the body that collides with the groud. Fore-foot- ad mid-foot-strike gaits were probably more commo whe humas ra barefoot or i miimal shoes, ad may protect the feet ad lower limbs from some of the impactrelated ijuries ow experieced by a high percetage of ruers. Ruig ca be most ijurious at the momet the foot collides with the groud. This collisio ca occur i three ways: a rear-foot strike (RFS), i which the heel lads first; a mid-foot strike (MFS), i which the heel ad ball of the foot lad simultaeously; ad a forefoot strike (FFS), i which the ball of the foot lads before the heel comes dow. Spriters ofte FFS, but 75 80% of cotemporary shod edurace ruers RFS2,3. RFS ruers must repeatedly cope with the impact trasiet of the vertical groud reactio force, a abrupt collisio force of approximately 1.5 3 times body weight, withi the first 50 ms of stace (Fig. 1a). The time itegral of this force, the impulse, is equal to the chage i the body s mometum durig this period as parts of the body s mass decelerate suddely while others decelerate gradually4. This patter of deceleratio is equivalet to some proportio of the body s mass (Meff, the effective mass) stoppig abruptly alog with the poit of impact o the foot5. The relatio betwee the impulse, the body s mometum ad Meff is expressed as ðt 0{ Fz (t)~mbody (Dvcom zgt )~Mef f ({vf oot zgt ) ð1þ 2 where Fz(t) is the time-varyig vertical groud reactio force, 0 is the istat of time before impact, T is the duratio of the impact trasiet, Mbody is the body mass, vcom is the vertical speed of the cetre of mass, vfoot is the vertical speed of the foot just before impact ad g is the acceleratio due to gravity at the Earth s surface. Impact trasiets associated with RFS ruig are sudde forces with high rates ad magitudes of loadig that travel rapidly up the body ad thus may cotribute to the high icidece of ruigrelated ijuries, especially tibial stress fractures ad platar fasciitis6 8. Moder ruig shoes are desiged to make RFS ruig comfortable ad less ijurious by usig elastic materials i a large heel to absorb some of the trasiet force ad spread the impulse over more time9 (Fig. 1b). The huma heel pad also cushios impact trasiets, but to a lesser extet5,10,11, raisig the questio of how ruers struck the groud before the ivetio of moder ruig shoes. Previous studies have foud that habitually shod ruers ted to adopt a flatter foot placemet whe barefoot tha whe shod, thus reducig stresses o the foot12 15, but there have bee o detailed studies of foot kiematics ad impact trasiets i log-term habitually barefoot ruers. We compared foot strike kiematics o tracks at preferred edurace ruig speeds (4 6 m s21) amog five groups cotrolled for age ad habitual footwear usage (Methods ad Supplemetary Data 2). Adults were sampled from three groups of idividuals who ru a miimum of 20 km per week: (1) habitually shod athletes from the USA; (2) athletes from the Rift Valley Provice of Keya (famed for edurace ruig16), most of whom grew up barefoot but ow wear cushioed shoes whe ruig; ad (3) US ruers who grew up shod but ow habitually ru barefoot or i miimal footwear. We also compared adolescets from two schools i the Rift Valley Provice: oe group (4) who have ever wor shoes; ad aother group (5) who have bee habitually shod most of their lives. Speed, age ad distace ru per week were ot correlated sigificatly with strike type or foot ad akle agles withi or amog groups. However, because the preferred speed was approximately 1 m s21 slower i idoor trials tha i outdoor trials, we made statistical comparisos of kiematic ad kietic data oly betwee groups 1 ad 3 (Table 1). Strike patters vary withi subjects ad groups, but these trials (Table 1 ad Supplemetary Data 6) cofirm reports2,3,9 that habitually shod ruers who grew up wearig shoes (groups 1 ad 5) mostly RFS whe shod; these ruers also predomiatly RFS whe barefoot o the same hard surfaces, but adopt flatter foot placemets by dorsiflexig approximately 7 10u less (aalysis of variace, P, 0.05). I cotrast, ruers who grew up barefoot or switched to barefoot ruig (groups 2 ad 4) most ofte used FFS ladigs followed by heel cotact (toe heel toe ruig) i both barefoot ad shod coditios. MFS ladigs were sometimes used i barefoot coditios (group 4) 1 Departmet of Huma Evolutioary Biology, 11 Diviity Aveue, 2School of Egieerig ad Applied Scieces, Harvard Uiversity, Cambridge, Massachusetts 02138, USA. 3Uiversity of Michiga Medical School, A Arbor, Michiga 48109, USA. 4Ceter for Restorative ad Regeerative Medicie, Providece Veteras Affairs Medical Ceter, Providece, Rhode Islad 02906, USA. 5Departmet of Physical Therapy, Uiversity of Delaware, Newark, Delaware 19716, USA. 6Departmet of Medical Physiology, Moi Uiversity Medical School, PO Box 4606, 30100 Eldoret, Keya. 7Faculty of Biomedical & Life Scieces, Uiversity of Glasgow, Glasgow G12 8QQ, UK. *These authors cotributed equally to this work. Effect o Mechaics 75% of ruers rear foot strikers Lower i forefoot strikers Vertical impact peak Average vertical loadig rate Istataeous loadig rate Kee extesor momet JOSPT 2011(41:914-919) Hypothesis: lower ijuries because: Lower loadig rates Lower kee loads 531 2010 Macmilla Publishers Limited. All rights reserved Vol 463 28 Jauary 2010 doi:10.1038/ature08723 LETTERS Foot strike patters ad collisio forces i habitually barefoot versus shod ruers Daiel E. Lieberma1, Madhusudha Vekadesa1,2*, William A. Werbel3*, Adam I. Daoud1*, Susa D Adrea4, Iree S. Davis5, Robert Ojiambo Mag Ei6,7 & Yais Pitsiladis6,7 Humas have egaged i edurace ruig for millios of years1, but the moder ruig shoe was ot iveted util the 1970s. For most of huma evolutioary history, ruers were either barefoot or wore miimal footwear such as sadals or moccasis with smaller heels ad little cushioig relative to moder ruig shoes. We wodered how ruers coped with the impact caused by the foot collidig with the groud before the ivetio of the moder shoe. Here we show that habitually barefoot edurace ruers trasiet, Mbody is the body mass, vcom is the vertical speed of the cetre of mass, vfoot is the vertical speed of the foot just before impact ad g is the acceleratio due to gravity at the Earth s surface. Impact trasiets associated with RFS ruig are sudde forces with high rates ad magitudes of loadig that travel rapidly up the body ad thus may cotribute to the high icidece of ruigrelated ijuries, especially tibial stress fractures ad platar fasciitis6 8. Moder ruig shoes are desiged to make RFS ruig 5
Forefoot Lad Effects Higher Speed FF Lad(Miimalist Shoe) Lower Vertical impact peak Average vertical loadig rate Istataeous loadig rate Kee extesor momet JOSPT 2011(41:914919) Truk Higher Akle load (Work) Hip Load (Work)?? Ifluece o Kee Load Fore foot Strike Lower i forefoot strikers Vertical impact peak Average vertical loadig rate Istataeous loadig rate Kee extesor momet JOSPT 2011(41:914-919) JOSPT 2015(45:738-755) Shorter Stride (high cadece) Lower with High Cadece Foot icliatio agle IC Tibia icliatio agle vertical Heel to Truk Kee flexio @ IC Med & Sci Sports & Ex, 2011 Frotal Plae Proximal Cotrol Right Left Truk Side Flexio Excessive ipsilateral Truk Side Flexio Excessive ipsilateral Mild ipsilateral Mild ipsilateral Lateral Pelvic Drop Mild cotralateral Lateral Pelvic Drop Mild cotralateral Excessive Cotralateral Excessive Kee Gap Kee Gap Gap No Gap Gap No Gap Correlates with Side bedig Hip Abductio weakess 6
Frotal plae variables Rear foot eversio (@ Mid Stace) Cross Over (@ IC) Crossover Wide Excessive proatio Excessive Supiatio Frotal Plae Akle/Foot Forefoot IC (miimalist shoe) Iversio Eversio to foot flat (Shock absorptio) Neutral @ heel off (Stability) Iversio @ Push Off (Propulsio) Icreased load o the PF & Iverters Effect of Foot Arch Type o Ruig HA feet High stiffess Less akle/subtalar ROM LA Feet Low Stiffess More akle/subtalar ROM Cosider ifluece of LA/HA o 1) Ifluece o tibial icliatio 2) kee gap 3) kee flexio agle 4) hip extesio at toe off 5) vertical displacemet of Powell et al, Huma Movemet Sciece 50 (2016) 47 53 7
Stregtheig/Augmeted Feedback Video Sigle Leg Squat Augmeted Feedback Davis et al, Phys Med Rehabil Cli N Am 27(2016) 339-355 Itervetio 4/4 Auditory or visual Mirror (Hip/Pelvic Frotal) Visual feedback (Moitor) Auditory step couter Wearable techology? Iflueces techique AGRESTA et al, JOSPT, 2015 Obtaiig Cliical Effects @ Kee Problem: PFP Correct hip (Icreased hip IR, decreased hip stregth, differeces i muscle recruitmet. Souza et al, JOSPT 2009) Lower PF Joit Stress (Teg et al, Actios: Icreased Cadece Decreases kee load/alter hip load (Heiderscheidt et al, Med & Sci Sports & Ex 2011, Lehart et al, JOSPT, 2014) [icreases HS/Gmax & decreases Gmed/piriformis] Forefoot lad Decreases kee load & Alters hip loads (icrease akle loads~ equal shift) (Williams et al, The Iteratioal Joural of Sports Physical Therapy, 2012) Truk forward lea Decreases kee load & Alters hip loads (140% icrease i hip loads) [Med. Sci. Sports Exerc., Vol. 47, No. 3, pp. 625 630, 2015] Frotal (Trasverse) Plae - Augmeted Feedback Chage pelvic drop/hip IR Willy et al, JOSPT 2013 Pelvic Drop/Truk Side Bedig/Kee No Gap ITB/Lateral hip pai/pfp (Loadig problem) Decreased step width (appropriate Cross over) Decreased pelvic drop No lateral truk side bedig Kee Gap (appropriate some gap) Louw, J of Physical Therapy i Sport, 2014, Heidershiet, JOSPT, 2016 Souza, 2016 Pelvic Drop/Truk Side Bedig/Kee No Gap/Over Stride FAI (ROM problem) FAI more ROM focused tha load focused 8
Hads o Aalysis of Cases! Hip FAI High Performace Athlete Medial Tibial Stress Sydrome Objectives Motivatio for lookig at techique Takig a Biomechaical Approach Basics of Ruig Speed ad cadece Ruig Variables to Cotrol/Alter Cliically Makig adaptatios specific to ijury Forefoot Lad Effects Slower Speed FF Lad(Stadard Shoe) Higher Speed FF Lad(Miimalist Shoe) Truk Truk Lower Vertical impact peak Average vertical loadig rate Istataeous loadig rate Kee extesor momet JOSPT 2011(41:914919) Higher Akle load (Work) Hip Load (Work)?? 9
Checkig for Over Stride Icrease stride rate Chage foot strike Truk 10