Anatomy of Lower Limb - Dr. Joy Fall 2024 PDF

Anatomy of lower limb ANT.7: Understand the structural organization of the lower limb and the functional and clinical correlations. Dr. Teresa Joy Assistant Professor of Anatomy...

Anatomy of lower limb ANT.7: Understand the structural organization of the lower limb and the functional and clinical correlations. Dr. Teresa Joy Assistant Professor of Anatomy Office- Block C GC 22 Email: [email protected]  Learning Objectives ANT.7: Understand the structural organization of the lower limb and the functional and clinical correlations. Given a clinical scenario, image, or description, students should be able to: ANT.7.1. Identify key anatomical landmarks of the bones of the lower limb. ANT.7.2. Describe how weight is transmitted from the foot to the axial skeleton. ANT.7.3. Recognize the muscles of the hip and gluteal region, their innervation, and actions. ANT.7.4 Recognize the fascial compartments of the thigh and leg, delineating the muscles, their innervation, and actions. ANT.7.5 Recognize the joints of the lower limb, movements at these joints, and the main muscles acting on them. ANT.7.1. Identify key anatomical landmarks of the bones of the lower limb. Overview of lower limb Six major regions Gluteal region (buttocks) Femoral region (thigh) Knee region Leg region Ankle region Foot region Anatomical landmarks Iliac crest PSIS ASIS Iliac crest Pubic symphysis Anterior / posterior superior iliac spine Greater trochanter Pubic symphysis Greater trochanter of femur Patella Condyles of femur Lateral epicondyle Medial epicondyle Patella Head of fibula Tibial tuberosity Medial surface and anterior border of tibia Medial and lateral malleolus Head - fibula Tibial tuberosity Calcaneal tuberosity Medial surface Anterior border of tibia #Quick links The hip bone | Acland's Video Atlas of Human Anatomy (aclandanatomy.com) Lateral malleolus Medial malleolus The femur | Acland's Video Atlas of Human Anatomy Calcaneal tuberosity (aclandanatomy.com) ANT.7.2. Describe how weight is transmitted from the foot to the axial skeleton.  Weight transmission Sacroiliac joint Weight transmitted centrally through the vertebral column (1) Directed laterally by bony arch formed by the dense bony column sacrum and ilia (2) Hip joint Ilia to femur (3) Pubic rami (4) forms the ‘struts’ or braces to maintain the arch Head of femur to shaft through neck Neck - narrowest and weakest part of the bone and it lies at a marked angle to the line of weight bearing. Neck shaft angle (120° to 140°)- diagonal disposition of femur recentres support directly inferior to trunk to make bipedal standing Condyles of femur – condyles of tibia – ankle joint – foot (curved impression of foot) Applied anatomy: femur neck fractures are very common. ANT.7.4 Recognize the fascial compartments of the thigh and leg, delineating the muscles, their innervation, and actions. Fascial compartments of thigh Skin and superficial fascia Deep fascia of thigh – Fascia lata invests the muscles and neurovascular structure Lateral, medial and posterior intermuscular Iliotibial tract septa Iliotibial tract (lateral thickening) 3 compartments and its components Anterior compartment of thigh – flexors of hip & extensors of knee – femoral nerve Medial compartment of thigh – adducts of hip – obturator nerve Posterior compartment of thigh – extensors of hip & flexors of knee- sciatic nerve (common peroneal and tibial nerve)  Anterior Lumbosacral plexus (L2, L3, L4, L5, S1, S2, S3) Posterior – ventral rami Lumbar plexus (L2, L3, L4) - ventral rami – anterior division –obturator nerve; posterior division – femoral nerve Sciatic nerve – thickest nerve in body- 2 components - common peroneal and tibial (L4, Lumbosacral trunk L5,S1,S2,S3) Innervates all the muscles lower limb. Superior gluteal nerve Obturator nerve Inferior gluteal nerve Femoral nerve Sciatic Sciatic nerve - Tibial nerve & common peroneal Femoral nerve Obturator nerve Anterior compartment of thigh Sartorius Iliopsoas Quadriceps femoris Iliopsoas Rectus femoris Vastus medialis Vastus intermedius Vastus lateralis Quadriceps femoris tendon Sartorius inserted to Tibial Rectus femoris Vastus lateralis tuberosity through Vastus medialis Ligamentum patellae ❖Applied anatomy – avulsion Rectus femoris tendon fractures of tibial tuberosity Patella – young athletes- unable to straighten(extend) leg. Patellar ligament Nerve of the anterior compartment of Tibial tuberosity thigh – Femoral nerve Knee jerk – patellar tendon reflex – testing the femoral nerve When the patellar ligament is tapped, sudden contraction of quadriceps femoris. Iliopsoas – iliacus +psoas major Acting on hip joint - flexion Postural muscles  Anterior compartment of thigh- innervation and action Muscle Innervation Actions Sartorius Flexes, abducts and laterally rotates hip joint Flexes leg at knee joint Femoral nerve (L2, L3,L4) Iliopsoas Flexing thigh at hip joint Iliacus Stabilizes hip joint Psoas major Anterior rami of L1,L2,L3 Quadriceps femoris – inserts to tibial tuberosity through ligamentum patellae Rectus femoris Extend leg at knee joint- striking a football Vastus medialis Femoral never (L2, L3, L4) Rectus femoris also steadies the hip joint and helps Vastus intermedius iliopsoas flex hip joint Vastus lateralis Primary action of the anterior compartment of thigh muscles – extensors of knee and flexors of hip  Hip flexion Hip flexion Abduction Knee flexion Knee extension Medial/adductor compartment of thigh Pectineus Adductor longus Adductor brevis Adductor longus Adductor magnus Gracilis Gracilis Obturator externus Adductor brevis (cut) Pectineus Obturator externus Adductor magnus Nerve of the medial compartment of thigh – Obturator nerve  Medial/adductor muscle innervation and action Muscle Innervation Action Adductor longus Adduction Adducts the hip joint Adductor brevis Adducts the hip joint Medially rotates hip joint Obturator nerve (L2, L3, L4) Gracilis Adducts the hip joint Flexes knee joint Obturator externus Laterally rotates hip joint Pectineus (hybrid) Femoral nerve (L2, L3, L4) Adducts and flexes hip joint Additionally, obturator nerve Assist with medial rotation of hip joint Adductor magnus Adductor part : obturator nerve (L2, Adducts the hip joint L3, L4) Hamstring part : tibial part of sciatic Adductor part flexes the hip joint nerve (L4) and hamstring part extends it. Primary action of the medial compartment of thigh muscles – adduction of hip  Back of thigh (Posterior compartment ) Hamstring muscles Semitendinous Semimembranous Biceps femoris: long head Adductor magnus: ischial head (hamstring part) Short head of biceps femoris is not a Semitendinosus hamstring muscle. Biceps femoris Semimembranosus Characteristics: Origin from Ischial tuberosity Insertion into one of the bones of the leg Nerve Supply: Tibial part of Sciatic nerve Flexors of the knee & Extensors of the Hip  Hamstrings strains (pulled and/or torn hamstrings) are common in people who run and/or kick hard (e.g., quick-start sports such as sprinting, baseball, and soccer) Nerve of the posterior compartment of thigh – Sciatic nerve Hamstrings muscles– Tibial part (division/component) of Sciatic nerve Short head of biceps femoris – Common peroneal part (division/component) of Sciatic nerve  Posterior compartment of thigh Muscle Innervation Action Knee flexion Semitendinous Flexion of knee joint Extension of hip joint Tibial division of sciatic Semimembranosus nerve (L5, S1, S2) When hip and knee joints are flexed, these muscles can extend trunk at hip joint. Biceps femoris-long Long head: tibial division Flexes knee joint and short heads of sciatic nerve (L5, S1, laterally rotates it when S2) flexed; Short head: common long head extends hip joint peroneal division of (e.g., accelerating mass sciatic nerve (L5, S1, S2) during first step of gait). ANT.7.3. Recognize the muscles of the hip and gluteal region, their innervation, and actions. Gluteal region muscles Superficial layer Gluteus maximus Gluteus medius Gluteus minimus Gluteus medius Tensor fascia latae Gluteus minimus Deep layer Piriformis Piriformis Obturator internus Gluteus maximus Superior & inferior gemelli Quadratus femoris Tensor fascia lata Quadratus femoris Gluteus maximus – innervated by inferior gluteal nerve Action – Extension of hip (rising from a sitting position & climbing the stairs) Lateral rotation of hip Gluteus medius and minimus – innervated Gluteus medius by Superior gluteal nerve Action – Abduct and medial rotation of hip Gluteus minimus SuMMi(e)T Gluteus medius Superior gluteal nerve Inferior gluteal nerve Gluteus minimus Tensor fascia lata Sciatic nerve Abduction Muscle Innervation Actions Gluteus maximus Inferior gluteal nerve (L5, S1, S2) Extends hip joint between flexed and standing positions and assists in its lateral rotation; fixes hip joint and assists in rising from sitting position Gluteus medius Abduct and medially rotate hip jointb; keep pelvis level when opposite limb is Gluteus minimus Superior gluteal nerve (L4, L5, S1) elevated. Tensor fasciae latae (tensor of Flexes hip joint; acts with gluteus maximus fascia lata) to stabilize the extended knee joint Piriformis (passes through greater Branches of anterior rami of S1, S2 sciatic foramen) Obturator internus (passes Nerve to obturator internus (L5, S1) through lesser sciatic foramen) Laterally rotate extended hip joint; Abduct flexed hip joint; stabilize hip joint Gemelli, superior and inferior Superior: same as obturator internus Inferior: same as quadratus femoris Quadratus femoris Nerve to quadratus femoris (L5, S1) Laterally rotates hip joint; stabilizes hip joint Movements and muscles of hip region ANT.7.4 Recognize the fascial compartments of the thigh and leg, delineating the muscles, their innervation, and actions.  Compartments of leg Tibia and fibula Interosseous membrane 3 compartments – anterior and lateral intermuscular septa Anterior compartment of leg – dorsiflexors of ankle - deep fibular/ deep peroneal nerve Lateral compartment of leg – evertors of foot - superficial fibular/superficial peroneal nerve Posterior compartment of leg – plantar flexors - tibial nerve Anterior compartment of leg Tibialis anterior Extensor hallucis longus Extensor digitorum longus Tibia (subcutaneous Peroneus/Fibularis tertius surface) Tibialis anterior Nerve of the compartment – Deep peroneal (fibular) nerve Action – Dorsiflexion at the ankle Extensor hallucis longus Medial surface of tibia is cutaneous Tall Husbands Are Never Dear People Hallux = great toe Extensor digitorum longus Digitorum = toes Peroneus tertius  Common peroneal Common peroneal nerve nerve winds around the Superficial peroneal neck of fibula nerve Deep peroneal nerve Tibialis anterior Superficial and deep Extensor digitorum longus branches Tibia Extensor hallucis longus  Muscles of anterior compartment of leg Muscle Innervation Action Tibialis anterior (TA) Dorsiflexes ankle joint; inverts subtalar joint; supports medial longitudinal arch of foot Extensor hallucis longus (EHL) Deep peroneal (fibularis) nerve Extends great toe; dorsiflexes ankle joint Extensor digitorum longus (EDL) Extends lateral four digits; dorsiflexes ankle joint Peroneus tertius Dorsiflexes ankle joint Lateral/peroneal compartment of leg Peroneus = Fibularis Peroneus longus Peroneus brevis Nerve of the compartment – superficial peroneal nerve Common peroneal nerve Action- evertor of foot Fibula Peroneus longus Superficial peroneal nerve Peroneus brevis  Muscles of lateral compartment of leg Muscle Innervation Action Peroneus longus (FL) Superficial fibular nerve (L5, S1, Eversion of foot Peroneus brevis (FB) S2) weakly plantarflex ankle joint. Posterior compartment of leg Largest of three compartment in leg Superficial group of muscles Gastrocnemius (lateral and medial heads) Soleus Plantaris Deep group of muscles Popliteus Flexor hallucis longus Flexor digitorum longus Tibialis posterior  Triceps surae – 2 heads of gastrocnemius + soleus – Archilles tendon/tendo calcaneus/calcaneal tendon Popliteus Flexor digitorum longus Gastrocnemius Tibial nerve Flexor hallucis longus Tibialis posterior Soleus Plantaris Archilles tendon Nerve of the posterior compartment of leg Main action – Plantar flexion – Tibial nerve  Muscles of posterior compartment of leg Muscles Innervation Action Gastrocnemius: Plantarflexes ankle joint when knee joint is extended, Lateral head raises heel during walking, and flexes knee joint Medial head Soleus Plantarflexes ankle joint; stabilizes ankle joint Plantaris Weakly assists gastrocnemius in plantarflexing ankle joint; function is probably mainly proprioceptive. Popliteus Weakly flexes knee joint and unlocks it by laterally Tibial nerve (S1, S2) rotating femur on fixed tibia; may also medially rotate tibia of unplanted limb Flexor hallucis longus Flexes great toe at all joints; weakly plantarflexes ankle joint Flexor digitorum longus Flexes lateral four digits; plantarflexes ankle joint Tibialis posterior Plantarflexes ankle joint; inverts foot ANT.7.5 Recognize the joints of the lower limb, movements at these joints, and the main muscles acting on them. Joints of lower limb Hip joint Knee joint Ankle joint Subtalar joint  Hip joint Type: Synovial joint Sub-type: ball & socket (multiaxial ) Articular surfaces head of femur acetabulum of hip bone Ligaments: Iliofemoral ligament Pubofemoral ligament Ischiofemoral ligament Muscles and movements of hip joint  Knee joint Type: Synovial joint Sub-type - modified hinge Articular surface – 3 components Medial and lateral condyles of femur Medial and lateral condyles of tibia Femero-patellar Mechanically weak – incongruence of articular surfaces Supported anteriorly by quadriceps muscles and posteriorly by hamstring muscles Ligaments – medial and lateral collateral Fibula is not involved in articulation of knee joint.  Knee joint -Movements and muscles Action Muscle responsible Flexion (unlocking of knee) Hamstrings, Gracilis, Sartorius, Gastrocnemius Extension (locking of knee) Quadriceps femoris Medial rotation Semitendinosus, Semimembranosus Lateral rotation Biceps femoris Initiation of unlocking: Popliteus muscle  Ankle joint Type: Synovial joint Sub-type: hinge joint Articular surfaces : Distal end of tibia and fibula Superior surface of talus  Ankle joint – movements and muscles Action Muscle responsible Dorsiflexion Tibialis anterior Extensor hallucis longus Extensor digitorum longus Peroneus tertius Plantarflexion Tendo-calcaneus, Tibialis posterior Flexor digitorum longus Flexor hallucis longus  Subtalar joint / talocalcaneal joint Type: plane synovial joint Articulations: Inferior surface of body of talus upper surface of calcaneus Movements : inversion and eversion of foot  Movements and muscles Action Muscle responsible Inversion Tibialis anterior Tibialis posterior Eversion Peroneus longus, brevis and tertius Quick video links https://aclandanatomycom.auamed.idm.oclc.org/MultimediaPlay er.aspx?multimediaId=10528131 https://aclandanatomycom.auamed.idm.oclc.org/MultimediaPlay er.aspx?multimediaId=10528133 https://aclandanatomycom.auamed.idm.oclc.org/MultimediaPlay er.aspx?multimediaId=10528135  Flash cards to review https://www.bookwidgets.com/play/yshY XCZ1-iQAFYSQzugAAA/FFBJKF8/anatomy- of-lowe?teacher_id=5602236642623488 [email protected]