Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Week 8 - Biomechanics of Human Lower Extremity
Document related concepts
Transcript
ENT 214 Biomechanics Biomechanics of Human Lower Extremity Picture retrieved from http://upload.wikimedia.org/wikipedia/commons/ d/d6/CT_3D_human_Foot_Skin_and_Bone.jpeg Picture retrieved from http://upload.wikimedia.org/wikipedia/en/f/f0/Tablum.jpg Structure of the Hip What is the hip joint? a ball and socket joint where the head of the femur articulates with the concave acetabulum a more stable joint than the shoulder because of bone structure and the number and strength of the muscles and ligaments crossing the joint Structure of the Hip Iliofemoral (Y) ligament Iliofemoral ligament Pubofemoral ligament Ischium Ischiofemoral ligament Femur Posterior view Ischium Femur Anterior view The integrity of the hip is enhanced by the strong ligaments crossing the joint. Structure of the Hip Sacrum Ilium Acetabulum Femoral head Pubis Ischium Femur The pelvic girdle includes the two ilia and the sacrum. It can be rotated forward, backward, and laterally to optimize positioning of the hip. Movements at the Hip What movements of the femur are facilitated by pelvic tilt? Pelvic tilt direction Femoral movement posterior flexion anterior extension lateral (to opposite abduction side) Movements at the Hip What muscles contribute to flexion at the hip? iliacus psoas major assisted by: pectineus rectus femoris sartorius tensor fascia latae Picture retrieved from http://en.wikipedia.org/wiki/Image:Sartorius.png Picture retrieved from http://upload.wikimedia.org/wikipedia/commons/e/e2/Anterior_Hip_Muscles_2.PNG Movements at the Hip What muscles contribute to extension at the glenohumeral joint? gluteus maximus hamstrings biceps femoris semimembranosus semitendinosus Picture retrieved from http://en.wikipedia.org/wiki/Gluteus_maximus Picture retrieved from http://upload.wikimedia.org/wikipedia/commons/c/c6/Gluteus_maximus_muscle.PNG Movements at the Hip What muscles contribute to abduction at the glenohumeral joint? • gluteus medius • assisted by: • gluteus minimus Movements at the Hip What muscles contribute to adduction at the glenohumeral joint? adductor magnus adductor longus adductor brevis assisted by: gracilis Picture retrieved from http://en.wikipedia.org/wiki/Image:Anterior_Hip_Muscles_2.PNG Structure of the Knee What is the tibiofemoral joint? dual condyloid articulations between the medial and lateral condyles of the tibia and the femur; composing the main hinge joint of the knee considered to be the knee joint Structure of the Knee Femur Patella Tibia Fibula Bony structure of the tibiofemoral joint. Structure of the Knee What is the patellofemoral joint? articulation between the patella and the femur the patella improves the mechanical advantage of the knee extensors by as much as 50% Structure of the Knee What are the menisci? cartilaginous discs located between the tibial and femoral condyles structures that distribute the load at the knee over a large surface area and also help absorb shock Structure of the Knee Lateral meniscus Transverse ligament Medial meniscus Posterior cruciate ligament Anterior cruciate ligament Superior view The menisci of the knee. Structure of the Knee What major ligaments cross the knee? collateral ligaments - cross the medial and lateral aspects of the knee cruciate ligaments - cross each other in connecting the anterior and posterior aspects of the knee Picture retrieved from http://en.wikipedia.org/wiki/Image:Gray348.png Movements at the Knee What muscles contribute to flexion at the knee? popliteus - “unlocks” the fully extended knee by laterally rotating the femur with respect to the tibia to allow flexion to proceed Picture retrieved from http://upload.wikimedia.org/wikipedia/commons/c/c1/Gray439.png Movements at the Knee What muscles contribute to flexion at the knee? hamstrings assisted by: gracilis sartorius popliteus gastrocnemius Picture retrieved from http://upload.wikimedia.org/wikipedia/commons/d/dc/Gray1239.png Movements at the Hip What muscles contribute to extension at the hip? quadriceps: rectus femoris vastus lateralis vastus medialis vastus intermedius Picture retrieved from http://en.wikipedia.org/wiki/Image:Illu_lower_extremity_muscles.jpg Structure of the Ankle Fibula Tibia Talus Calcaneus Posterior view The bony structure of the ankle. Structure of the Ankle What is the tibiotalar joint? hinge joint where the convex surface of the superior talus articulates with the concave surface of the distal tibia considered to be the ankle joint Structure of the Ankle What is the distal tibiofibular joint? a syndesmosis where dense, fibrous tissue binds the distal tibia and fibula together Picture retrieved from http://en.wikipedia.org/wiki/Image:Ankle_en.svg Movements at the Ankle What muscles contribute to dorsiflexion at the ankle? tibialis anterior extensor digitorum longus peroneus tertius assisted by: extensor hallucis longus Picture retrieved from http://upload.wikimedia.org/wikipedia/commons/4/46/Peroneus_tertius.png Movements at the Ankle What muscles contribute to plantar flexion at the ankle? gastrocnemius soleus assisted by: tibialis posterior, plantaris, peroneus longus, flexor hallucis longus, peroneus brevis, flexor digitorum longus Structure of the Foot What is the subtalar joint? the anterior and posterior facets of the talus articulate with the sustencalculum tali on the superior calcaneus) Picture retrieved from http://en.wikipedia.org/wiki/Image:Foot.png Structure of the Foot Picture retrieved from http://en.wikipedia.org/wiki/Image:Gray268.png Structure of the Foot What are the tarsometatarsal and intermetatarsal joints? nonaxial joints that permit only gliding movements enable the foot to function as a semirigid unit and to adapt flexibly to uneven surfaces during weight bearing Picture retrieved from http://en.wikipedia.org/wiki/Image:Gray358.png Structure of the Foot What are the metatarsophalangeal and interphalangeal joints? condyloid and hinge joints, respectively the toes function to smooth the weight shift to the opposite foot during walking and help maintain stability during weight bearing by pressing against the ground when necessary Structure of the Foot What are the plantar arches? the medial and lateral longitudinal arches stretch form the calcaneus to the metatarsals and tarsals the transverse arch is formed by the bases of the metatarsal bones Plantar Plantar Arch Fascia Picture retrieved from http://en.wikipedia.org/wiki/Plantar_arch Picture retrieved from http://en.wikipedia.org/wiki/Plantar_fascia Structure of the Foot What are the plantar fascia? thick bands of fascia that cover the plantar aspects of the foot During weight bearing, mechanical energy is stored in the stretched ligaments,tendons, and plantar fascia of the foot. This energy is released to assist with push-off of the foot from the surface. Structure of the Foot Lateral view Plantar fascia Plantar view The plantar fascia. Movements of the Foot What muscles are responsible for toe flexion and extension? flexion - flexor digitorum longus, flexor digitorum brevis, quadratus plantae, lumbricals, interossei extension - extensor hallucis longus, extensor digitorum longus, extensor digitorum brevis Picture retrieved from http://en.wikipedia.org/wiki/Image:Gray442.png Movements of the Foot What muscles are responsible for inversion and eversion? inversion - tibialis posterior, tibialis anterior eversion - peroneus longus, peroneus brevis, assisted by peroneus tertius
