12 - Lower Extremity

12 - Lower Extremity - Foundations of Occupation:...

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Unformatted text preview: Foundations of Occupation: Foundations Kinesiology The Lower Extremity Hip, Knee, Ankle/Foot Lecture 12 Summer 2010 Overview Overview The Hip Complex: Bones & Joints Pelvic Motions Muscles of the Hip The Knee Complex: Bones, Joints and Supporting Structures Mobility of the Knee Muscles of the Knee The Ankle/Foot Complex: Bones & Joints Arches of the Foot Motions of the Ankle/Foot Muscles of the Ankle/Foot Hip Complex Hip Relationship between hip joint and pelvis Hip Complex Hip L1 L2 L3 L4 L5 Movement of the pelvis depends upon – lumbar joints – lumbosacral joint (between L5 – S1) – hip joints Hip Complex Hip Primary function of hip joint – support the weight of Head, Arms, and Trunk HAT GRF – Ground Reaction Force Anatomical Review: Hip Complex Anatomical Pelvis Femur Anatomical Review: Pelvis Pelvis Formed by 2 pelvic bones, sacrum and coccyx – Pelvic bones = union of ilium, ischium, and pubis – Acetabulum ­ cuplike, concave socket – Acetabular fossa ­ nonarticular, contains fibroelastic fat covered with synovial membrane – Acetabular labrum ­ ring of wedge­shaped fibrocartilage Ilium Pelvic Bones Sacrum Coccyx Acetabulum Ischium Pubic Symphysis Pubis Bones of the Pelvis and Hip Pelvis Sacroiliac Joint: Anatomical Review: Pelvis and its articulations Pelvis – Composed of the articulation between the first 3 sacral vertebrae and the ilium Lumbosacral Joint (L5­ S1): – Two articular facets of first sacral vertebrae that face posteriorly and articulate with the inferior facets of 5th lumbar vertebrae Hip Joint Dorsal Ventral Dorsal Ligaments of Pelvis Pelvis Anatomical Review: Femur Femur Head covered with hyaline cartilage. The Hip Joint is formed by the union of the acetabulum of the pelvis and the head of the femur. Femoral neck and shaft Greater and lesser trochanters – sites of muscular and ligamentous attachments Angulation of Femur Angulation The angle of inclination occurs in the frontal plane between the axis of the femoral neck and the axis of femoral shaft. Function is to place the center of the knee under the center of motion of the hip. Mechanical axis ­ line connecting the center of the femoral head with the center of the knee joint Angle of Inclination Mechanical Axis Stability of the Hip Complex Stability Capsule – Lined with synovial membrane on the inside – Covers the femoral neck like a sleeve to attach to base of neck; has three reinforcing ligaments: – “Y” ligament, anterior, strongest hip ligament – All fibers become taut during hip hyperextension – Also prevents excessive internal and external rotation – Anterior, becomes taut in hip Abduction and extension – Posterior, spiral fibers tighten in extension and unwind in flexion – Provides check on hyperextension and limits internal rotation and Adduction when hip is flexed Iliofemoral Ligament Pubofemoral Ligament Ischiofemoral Ligament Ligaments Ligaments of the Hip Joint Pelvic Motions Pelvic Forward or anterior pelvic tilt – – rotation of pelvis in sagittal plane about x axis pubis turns downward and posterior sacrum turns upward Backward or posterior tilt – rotation of pelvis in sagittal plane around x axis. – pubis moves upward and posterior sacrum moves downward Lateral Tilt – – – rotation of pelvis in frontal plane about z axis one iliac crest is depressed, the other elevated often clinically referred to as “hip hike” & “hip drop” Rotation – occurs in horizontal (transverse) plane around y axis Lateral Pelvic Tilt Lateral Relationship of Pelvis to Trunk and Lower Extremities During Movement Movement Pelvis on stationary femur (closed chain hip motions) Pelvis on (relatively) stationary trunk Pelvis and trunk together Pelvis and femur together (“going along for the ride”) – Lumbar­pelvic rhythm… (later) Pelvic Motions Pelvic Video Video Video: Relationship Between Hip, Lumbar Spi Video: Relationship Between Hip, Lumbar Sp Elevation of the right pelvis = Depression of the left pelvis = Left Lateral Pelvic Tilt Left Depression of the right pelvis = Depression Hip Motions Hip Flexion ­ forward movement of femur in sagittal plane Extension – backward movement of femur in sagittal plane Hyperextension – Extension beyond “normal” range ABduction ­ sideward movement of femur in frontal plane, thigh moves away from midline ADduction – return from ABduction Internal rotation ­ rotation around longitudinal axis so that the knee is turned inward External rotation ­ knee turned outward Circumduction ­ combination of flexion, abduction, extension, and adduction performed sequentially in either direction Flexion Flexion Extension ABduction ABduction ADduction Internal Rotation Internal External Rotation Lumbar-Pelvic Rhythm… Lumbar-Pelvic The coordinated activity of lumbar spine, pelvis, and femur that results in production of greater range of motion than is available to one segment alone. Coupled Actions: oupled Pelvis and Femur Pelvis Coupled Actions: Pelvis & Femur Femur More detail: Given the limitation of the ROM of the thigh at the hip joint, movement of the pelvis will often move in conjunction with the thigh to increase the ability of the foot to rise in the air. Let’s look at the soccer player… And the ballet dancer Muscles of Lower Extremities Muscles Hip Flexors (Anterior muscles) – Iliopsoas ­ prime mover for hip flexion when pelvis is stabilized (open – chain) – Pectineus ­ prime mover for hip flexion; assists with ADduction – Rectus Femoris ­ only portion of quadriceps that crosses hip and knee; prime mover for hip flexion and knee extension Pectineus Muscles of Lower Extremities (cont’d) Muscles Hip Extensors (Posterior muscles) – Hamstrings ­ biceps femoris, semimembranosus, semitendinosus; very strong hip extensors and knee flexors – Gluteus Maximus ­ most superficial fibers insert into iliotibial band; prime mover for hip extension and external rotation of hip Muscles of Lower Extremities (cont’d) Muscles Hip ADductors (Medial muscles) – Group of muscles that includes pectineus, adductor minimus, brevis, longus, magnus, and gracilis. – All, except pectineus, are prime movers for hip ADduction and assist for hip flexion. – ADductors may also function as internal rotators Hip ABductors (Lateral Muscles) – Gluteus Medius ­ anterior, middle, and posterior portion; all prime movers for ABduction. – Gluteus Minimus ­ prime mover for Abduction; stabilizes pelvis against gravity. Hip External Rotators Rotators The Knee Complex The Anatomical Review Review Anatomical Review Anatomical Bones of the Knee Complex Femur – Medial femoral condyle and lateral femoral condyle – Patellar surface separates the condyles anteriorly and is a shallow, saddle shaped groove. – Lateral and medial condyles. Medial condyel provides 50% more articulating surface with femur than lateral tibial plateau. – Largest sesamoid bone in the body. Fits anteriorly against the femur where it is anchored by ligaments and the tendon of the quadriceps. Tibia Patella Anatomical Review Anatomical Joints of the Knee Complex Tibiofemoral joint ­ articulation of the distal femur and the proximal tibia. Patellofemoral joint ­ articulation of the patella and the femur. Superior tibiofibular joint ­ proximal articulation of the tibia and fibula. The knee joint is a modified hinge joint, allowing flexion and extension in a sagittal plane around a “X” axis. It also allows a slight amount of rotation. Stability of the Knee Complex: Stability Menisci Menisci – – accessory structures of each condyle. Two asymmetric, wedge­shaped fibrocartilaginous joint discs located on the tibial plateaus. – Medial meniscus joint capsule. more prone to injury because it is firmly attached to the tibia and – Lateral meniscus moves more freely, more flexible, and so less prone to injury. Stability of the Knee Complex: Ligaments Ligaments Cruciate Ligaments Anterior cruciate ligament (ACL) – arises from anterior surface of tibia, runs superiorly and posteriorly to attach on inner aspect of lateral femoral condyle. ACL Posterior cruciate ligament (PCL) – arises from the posterior aspect of the tibia and runs superiorly and anteriorly to attach to anterior portion of the inner aspect of medial femoral condyle. PCL Collateral Ligaments Collateral Reinforce medial and lateral aspects of the knee. Medial Collateral (MCL) resists valgus stresses, runs from tibia to femur. Lateral Collateral (LCL) resists varus stresses, runs from fibula to femur. Patellar Ligament AKA Patellar Tendon AKA Patellar Tendon Attaches the patella to tibia inferiorly. Patella is attached to the femur superiorly by the quadriceps tendon. Encloses Joint Capsule tibiofemoral and patellofemoral joints Large and lax with many communicating bursa. Joint Capsul e Bursae Bursae Mobility of the Knee Complex Mobility Flexion and extension result from rolling, spinning, and sliding of femoral condyles on tibial plateau. – During flexion (closed­ chain) femur needs to slide anteriorly & roll posteriorly – During extension (closed­ chain) femur needs to slide posteriorly & roll anteriorly Mobility of the Knee Complex (cont’d) Mobility Locking / Unlocking Mechanism of Knee – – An involuntary, passive rotation that occurs when moving in and out of final stages of full extension – Brings femur and tibia into closed­pack situation – Closed chain Posterior gliding, anterior rolling Medial rotation of femur on tibia (these two positions “screw the knee” Return: must “unscrew the knee” – Lateral rotation of femur on tibia – Anterior gliding, posterior rolling – Open chain Lateral rotation of the tibia on femur Return: medial rotation of tibia on femur Rotation ­ – Full extension = closed­pack – Full flexion = maximum loose­packed Rotation at the Knee Rotation Muscles of the Knee Complex Muscles Knee Flexors – Hamstrings Biceps Femoris Semimembranosus Semitendinosus Knee Extensors – Quadriceps Group Vastus Lateralis Vastus Intermedius Vastus Medialis Rectus Femoris Knee Flexors Biceps Femoris (Long Head) Lateral View (Short Head) Dorsal View Semitendinosis Semimembranosis Semitendinosis Knee Extensors Extensors Patella as an Anatomical Pulley Patella The patella increases the mechanical efficiency of the quadriceps – increases the distance of the quadriceps tendon and the patellar tendon from the axis of the knee joint Greatest torque from the quadriceps is produced at 45 to 60 degrees of flexion The Ankle/Foot Complex The Complexity of the Ankle / Foot Complex Complexity Stability Demands – providing a stable base of support without undue muscular activity – act as a rigid lever for effective push off during gait Mobility Demands – reducing impact of rotation of proximal joints – flexible enough to absorb shock of body weight as foot hits ground – allows the foot to conform to a variety of terrain & activities! Anatomical Review Anatomical Talus Navicular Calcaneous Cuboid Talus Navicular Cuneiforms Bones of the Ankle and Foot Ankle Articulations of the Ankle Articulations Talocrural joint – articulation between the talus and distal tibia (tibiotalar surface) – articulation between the talus and fibula (talofibular surface) Tibia Talus Fibula Articulations of the Ankle Mortise – formed by structures of distal tibia and malleoli Plantar Arches Plantar The bony and ligamentous structure of the transverse tarsal joint and the transverse metatarsal joints combine to produce a structural vault. – Functions as a shock absorber and to conform to surfaces Arches of the Foot Foot Dorsiflexion Plantarflexion Motions of the Ankle/Foot (Talocrural Joint) (Talocrural Motions of the Ankle/Foot (Subtalar Joint) (Subtalar Muscles of the Ankle / Foot Muscles Plantarflexors Dorsiflexors – Gastrocnemius, Soleus – Tibialis Anterior, Extensor Hallucis Longus, Extensor Digitorum Longus, Peroneus Tertius – Extensor Digitorum Longus, Peroneus Longus, Peroneus Brevis, Peroneus Tertius – Anterior Tibialis, Posterior Tibialis Pronators Supinators Plantar Flexors Plantar Gastrocnemeus Soleus Dorsiflexors Dorsiflexors Tibialis Anterior Extensor Hallucis Longus Extensor Digitorum Longus Peroneus Tertius Pronators Pronators Extensor Digitorum Longus Peroneus Longus Peroneus Brevis Peroneus Tertius Supinators Supinators Tibialis Anterior Tibialis Posterior Summary: LE Motions and Muscles** Summary: Motions Hip Flexion Hip Extension Hip ABduction Hip ADDuction Hip Internal Rotation Hip External Rotation Knee Flexion Knee Extension Ankle Plantar Flexion Ankle Dorsiflexion Ankle Pronation Ankle Supination Muscles Quadriceps Hamstrings and Gluteus Maximus Hip ABductors Hip ADDuctors Hip ADDuctors and Gluteus Minimus Hip External Rotators and Gluteus Maximus Hamstrings Quadriceps Plantar Flexors Dorsiflexors Pronators Supinators **that you need to know! ...
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