Functional Anatomy and Lower Extremity Biomechanics

Transcription

1 Functional Anatomy and Lower Extremity Biomechanics Eric Folmar, MPT, OCS Functional Lower Extremity Biomechanics The science of foot, ankle, knee and hip biomechanics and their relationships and interactions during closed kinetic chain function. 1

2 Bony Anatomy Foot (28 bones) Calcaneus Talus Navicular Cuboid Cuneiforms Metatarsals Sesmoids Phalanges Metatarsals 1 st MT Shortest and widest; meant for stress 2 nd longest most stable; not meant for stress 3 rd and 4 th similar to each other; not much doing here 5 th narrow and mobile; not meant for loading stress 2

3 Sesamoids and Phalanges Phalanges tell story of what is occurring mechanically behind them Hammer toes, claw toes, bunions Medial sesamoid is weight bearing Biomechanics 3

4 Triplane Motion Triplanar subtalar joint motion is referred to as PRONATION and SUPINATION Nature of STJ motion is dependent on whether foot is in open kinetic chain or closed kinetic chain environment. PRONATION Eversion ABDuction Dorsiflexion SUPINATION Inversion ADDuction Plantarflexion All or none rule of Triplane Motion If one of the 3 component motions of Pronation or Supination is initiated then the other 2 motion will occur at the same time If one of the component motions is stopped then the others will also stop immediately 4

5 Pronation of the STJ Open Chain: calcaneus free to move around talus which is fixed in ankle mortise; calcaneal ABD; DF and EVE Closed Chain: calcaneus fixed to ground by body weight; calcaneus everts; talus PF and ADD; foot ABD and DF; tibia IR Supination of the STJ Open Chain: calcaneal ADD; INV and PF Closed Chain: calcaneus inverts; talus DF and ABD; foot ADD and INV; tibia ER 5

6 What is a normal foot??? Criteria of Normalcy (Cailliet) Absence of pain Normal muscle balance Central heel Straight and mobile toes Functional Divisions of the Foot Rearfoot Consists of: Calcaneus and Talus Purpose: converts the torque of the lower limb (into sagittal, frontal, and horizontal plane movements); influences the function and movement of the midfoot and forefoot 6

7 Functional Divisions of the Foot Midfoot Consists of : Navicular and Cuboid Purpose: transmits movement from the rearfoot to the forefoot and promotes stability Functional Divisions of the Foot Forefoot Consists of: cuneiforms, metatarsals, and phalanges Purpose: adapts to the terrain 7

8 Rays of the Foot Arches of the foot Medial/lateral/and transverse arches Stability maintained by bony structure, ligamentous integrity, and muscle tension Very important concept when comes to CKC therex Restoring arches is important to consider with orthotic therapy 8

9 Sagittal Plane Cardinal Body Planes Motion occurs in sagittal plane (plantarflexion and dorsiflexion) Axis lies in coronal and transverse planes Cardinal Body Planes Frontal/Coronal Plane Motion occurs in coronal plane (inversion and eversion) Axis lies in sagittal and horizontal planes planes 9

10 Cardinal Body Planes Transverse / Horizontal Plane Motion occurs in horizontal plane (ABDuction and ADDuction) Axis lies in coronal and sagittal planes Joint Axes Terminology Pitch (of the Joint Axis) slope of the line (in relation to a body plane) The more perpendicular the line is to the body plane the greater the joint motion will be in that plane. 10

11 Terminology Axis - a straight line about which a body or a geometric figure rotates or may be supposed to rotate Motion of a joint is perpendicular to the axis Not necessarily the joint line Significant in allowing us to understand normal joint motion, perform joint motions, and improve rehab techniques Joint Axes Not important to know specific pitch IT IS important to have basic understanding Allows for better understanding of motion about the joint and muscular influences on the joint Also allows for better understanding of normal vs. abnormal movement patterns 11

12 Ankle Joint (Mortise Joint, Talocrural Joint) Distal tibia, fibula, and talus Joint axis ~8-10 to the transverse plane and ~23 to the frontal plane DF/PF and ABD/ADD are the clinically significant motions 12

13 Subtalar Joint Articulation of the talus and calcaneus - Joint axis lies ~42 to the transverse plane ~23 to the sagittal plane - EVE/INV and ABD/ADD are the clinically significant motions 13

14 Midtarsal Joint Medially talonavicular joint Laterally calaneocuboid joint Lyne of Cyma division b/w FF and RF 14

15 MTJ Joint Axes Longitudinal Axis (Talonavicular Joint) Joint lies ~15º to the transverse plane and ~ 9º to the sagittal plane INV and EVE are the clinically significant motions MTJ Joint Axes Oblique Midtarsal Joint (Calcaneocuboid Joint) Joint ~52º to the transverse plane and ~57º to the sagittal plane DF/ABD and PF/ADD are the clinically significant motions 15

16 First Ray Joint Axis Crosses all 3 body planes and has triplane motion but is not a pronatory supinatory axis not subject to all or none rule Axis is 45º to both frontal and sagittal planes Motion occurs primarily in PF/eversion and DF/inversion directions *** 5 th Ray is a mirror image of the first Plantar Fascia Plantar Fascia Attachments Medial calcaneal tubercle Proximal phalanges Function Major stability Windlass mechanism toe extension tightens the fascia 16

17 Musculature Musculature Anterior Compartment Tibialis Anterior Extensor Hallucis Longus Extensor Digitorum Longus Peroneus Tertius 17

18 Musculature Lateral Compartment Peroneus Longus Peroneus Brevis Musculature Posterior Compartment Superficial Gastrocnemius Soleus Plantaris Deep Popliteus Tibialis Posterior Flexor Digitorum Longus Flexor Hallucis Longus 18

19 Soft Tissue Structures of the Foot Intrinsic Muscles of the Foot 1 st Layer -Abductor Hallucis -Flexor Digitorum Brevis -Abductor Digiti Minimi 2 nd Layer -Quadratus Plantae -Tendons of the FHL & FDL Lumbricals 3 rd Layer - Flexor Hallucis Brevis - Adductor Hallucis - Flexor Digiti Minimi Brevis 4 th Layer - 3 plantar interossei - 4 dorsal interossei 19

20 The Biomechanical Exam Assessment of the lower extremity with regard to osseous and soft tissue mobility in relation to all three cardinal planes Gather pieces of information Establish treatment direction Exam is really ongoing throughout treatment Detailed History Includes??? Medical/Surgical/Orthopedic History Work/Recreational Activities Workout Routine/Training Regimen Workout/Training Patterns including how far, how often, surface, route, etc Shoeware What type? How often? Last changed? Mileage? Where purchased? Etc. Previous Orthoses When? Who? Wear patterns 20

21 Biomechanical Exam Hip to toe exam Static Dynamic Functional Hip ROM Looking for symmetry on both sides of joint ~90 degree arc of motion Differentiate between bony and soft tissue limitations 21

22 Hip Muscle Flexibility Testing Hip flexors Quadriceps Hamstring ITB Hip Ryder s or Craig s Test Assessment of hip version Normal degrees in adults Significant influence throughout the kinetic chain 22

23 Hip Anteversion - Palpate greater trochanter Find its most lateral position Measurement of line bisecting femoral condyles in relation to the horizontal (table) Hip Anteversion Can measure with inclinometer or goniometer 23

24 Malleolar Position With femoral condyles in the frontal plane, assessing the amount of tibial torsion in the transverse plane Normal = degrees Knee Sagittal Plane Influence Frontal Plane Influence Q angle Normal degrees * Should zero out in sitting 24

25 Supine Foot Evaluation Get to know the foot!!! General joint mobility/tightness/laxity General appearance Scars, etc Supine Foot Evaluation Midtarsal Joint Lock-up assessing the stability of the MTJ and relating that to CKC function Arch Height First Ray Mobility / position Toe Positions (claw, hammer, etc) Hallux Position / ROM 65 necessary for level walking 80 necessary for stairs 25

26 Mid-tarsal Joint Lock-up Maximum supination foot should be stable (this stability is representative of how the foot functions at push-off) Maximum pronation foot should be mobile represents how the foot functions during early weight bearing phase Supine Foot Evaluation Forefoot equinus Plantar flexion deformity of the MTJ in the sagittal plane Significant functional influence 26

27 Forefoot Equinus -Forefoot comes to ground earlier in gait cycle - Rigid vs. flexible foot Prone Evaluation Subtalar Joint Neutral Congruency method Evaluate position of calcaneus in frontal plane Evaluate position of forefoot relative to rearfoot 27

28 Subtalar Joint Neutral -Palpate talar head evenly b/w thumb and forefinger - gently load 4 th and 5 th MT Heads to hold position - assess relationship of RF to Lower Leg and Forefoot to Rear foot Prone Evaluation Subtalar joint mobility - ~30 total ROM RF frontal plane movement: 20º inversion; 10º eversion 28

29 Prone Evaluation Plantar Lesions Callus patterns and their ability to clue us in to foot interaction with surface Prone Evaluation Talocrural Joint ROM (DF 20º and PF 50º) Knee flexed and extended 10 of DF with knee extended is necessary for normal gait Important in determining success or orthotic treatment *** Important to take ROM norms in context of patients activity 29

30 Standing Evaluation - Standing Leg length - Neutral Tibial Stance attitude of lower 1/3 tibia as it comes to floor - Neutral vs. Relaxed Calcaneal Stance - Looking for total excursion *** - Iliac Crest Heights relaxed vs. STN - Forefoot Position (transverse plane) - Hallux DF -- Arch Height - Navicular Drop Test Leg Length Clinical assessment of leg length not accurate but informative Rule out SI joint influence Assess supine and correlate with standing exam Often see with onesided biomechanical issues 30

31 Dynamic/Functional Exam Assessing ability to control functional movements in each cardinal plane Single leg squat Step down Balance Jump Testing Gait analysis Running Analysis Dynamic/Functional Exam Assessing ability to control functional movements in each cardinal plane Single leg squat Step up/down Balance Jump Testing Gait analysis Running Analysis 31

32 Dynamic/Functional Exam Assessing ability to control functional movements in each cardinal plane Single leg squat Step up/down Balance Jump Testing Gait analysis Running Analysis Dynamic/Functional Exam Assessing ability to control functional movements in each cardinal plane Single leg squat Step down Balance Jump Testing Gait analysis Running Analysis 32

33 Dynamic/Functional Exam Assessing ability to control functional movements in each cardinal plane Single leg squat Step down Balance Jump Testing Gait analysis Running Analysis Thank you! 33