Anatomy (Locomotor) (Subject) / Elbow and Knee (Lesson)

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• Elbow Joint (Bones + Joint + Stability) 1. Bones - synovial hinge joint (flexion/Extension) between the surfaces of the trochlea and capitulum (humerus) and trochlear notch (ulna) and head of radius --> humeroulnar and humeroradial joints  - In Flexion: coronoid fossa (humerus) receives coronoid process (ulna), radial fossa receives head (radius) - In Extension: posterior olecranon fossa (humerus) receives olecranon process (ulna)  2. Joint - articulating surface of humerus covered with hyaline cartilage  - fibrous capsule enclosing joint and prox. radioulnar joint --> attaches laterally to annular ligament  - Medial collateral ligament - med. epicondyle of humerus to ulna - Lateral collateral ligament -  lat. epicondyle of humerus to annular ligament/rad. notch
• Muscles producing Flexion/Extension at elbow + Innervation 1. Flexors (anterior compartment) - Innervation: Musculocutaneous muscle a) Brachialis (ant. surface humerus - coronoid process ulna)  b) Biceps brachii (short head coracoid process scapula/long head tendon glenoid fossa - rad. tuberosity and bicipital apaneurosis to deep fascia forearm) c) Brachioradialis (coracoid process scapula - med. humeral shaft) d) Some forearm flexors  2. Extensors (posterior compartment) - Innervation: Radial nerve a) Triceps brachii (three heads attaching to humerus and beneath glenoid fossa - olecranon process) b) some of the forearm extensors 
• (Prox.)Radioulnar joint (Bones + Joint + Muscles) 1. Bones - pivot joint between the head of the radius and the radial notch of the ulna  2. Joint - head rotates within the fibro-osseous ring (rad. notch ulna + annular ligament) - shares same synovial capsule and fibrous capsule with elbow joint  3. Muscles a) Pronation (crossing over of radius)  - Pronator teres (med. epicondyle humerus/coronoid process ulna - lat. surface radius) - Pronator quadratus (lat. surface ulna - ant. surface radius) b) Supination (parallel)  - biceps brachii - flexed elbow  - supinator - extended elbow (lat. epicondyle humerus - surface radius)
• Knee joint (bones + joint + stability) 1. Bones - synovial hinge joint between condyles of the femur and tibial plateau  2. Joint - articular surfaces of patella, femur and tibia lined with hyaline cartilage  - joint capsule (cylindrical sleeve) --> anterior deficiency for patella  - synovial membrane lines fibrous capsule  - 2 fibrocartilagineous menisci: medial meniscus (anchored to the med. collateral ligament), lat. meniscus (lat. unattached) 3. Stability - fused tendons of quadriceps femoris muscle (anterior) - iliotibial tract blending the capsule (lateral) - tendon of sartorius, semitendinosus and gracilis (medial) - Medial collateral ligament (med. epicondyle femur - shaft tibia) - Lateral collateral ligament (lat. epicondyle femur - head of fibula) - Cruciate ligaments anterior and posterior --> anteroposterior stability - Arcuate popliteal ligament (posterior) 4. Bursae - Suprapatellar bursa (between femur and quadriceps tendon) - Gastrocnemius bursa (beneath med. and lat. heads of gastrocnemius) - Subcutaneous prepatellar and infrapatellar bursae (between patella and overlying tissue) - Deep infrapatellar bursa (between patella ligament and tibia)
• Patellofemoral joint - articulation between the patella (sesamoid bone) and the patellar surface of the femur - articulating surface of patella covered with hyaline cartilage  - the quadriceps femoris tendon ("Patellar ligament") covers the patella 
• Muscles of the thigh + Innervation 1. Extensors - Anterior compartment  - Innervation: Femoral nerve a) Quadriceps femoris - Rectus femoris (iliac spine - tibial tuberosity) --> also flexor (hip joint) - Vastus lateralis (surface femur/lat. linea aspera - tibial tuberosity) - Vastus medialis (linea aspera - tibial tuberosity) - Vastus intermedius (surface femur - tibial tuberosity) b) Sartorius (Iliac spine - med. side tibia) --> also flexor (knee joint), Flexion/abduction (hip joint) c) Iliopsoas muscle - Psoas major (lumbar vertebrae - iliopsoas tendon to lesser trochanter of femur) --> Flexor (hip joint) - Iliacus (iliac spine -iliopsoas tendon to lesser trochanter of femur) --> Flexor (hip) d) Pectineus (sup. ramus pubis - lesser trochanter femur) --> also Flexion (hip) 2. Flexors - posterior compartment  - Innervation: Sciatic nerve a) Hamstring muscles  - Biceps femoris (ischial tuberosity - head of fibula) - Semimembranosus (ischial tuberosity - med. condyle/med. shaft tibia) - Semitendinosus (ischial tuberosity - med. condyle/med. shaft tibia) --> also extensors (hip joint) 3. Adductors - medial compartment  Innervation: Obturator nerve a) Adductor longus (pubis - linea aspera) b) Adductor brevis (pubis - upper linea aspera) c) Adductor magnus  - Hamstring part (ischial tuberosity - med. condyle femur) --> Innervation: sciatic nerve  - Adductor part (ischial tuberosity - linea aspera) d) Gracilis (Pubis - med. tibia) e) Obturator externus (ant. obturator foramen - greater trochanter femur)
• Popliteal fossa (borders + contents) - diamond-shaped intermuscular space at the back of the knee  1. Borders  a) Lateral - biceps femoris(above); lat. head of gastrocnemius and plantaris (below) b) Medial - semimembranosus and semitendinosus (above); med. head of gastrocnemius (below) c) Floor (anterior wall) - popliteal surface femur, capsule knee joint, post. ligament knee joint d) Roof - skin, siperficial fascia, fascia lata/deep fascia 2. Contents a) Artery - popliteal artery (medially) b) Vein - popliteal vein (laterally) c) Nerves - tibial and common peroneal nerves (laterally) d) Lymph nodes 
• Cubital fossa (Borders + contents) - triangular space anterior to the elbow 1. Borders a) Base - imaginary line between the med. and lat. epicondyles of humerus b) Lat. border - brachoradialis muscle c) Med. border - pronator teres muscle d) Floor - Medial - brachialis muscle  - Lateral - supinator muscles  e) Roof - skin, deep fascia of the forearm, bicipital apaneurosis  2. Contents a) Nerves - Median nerve (medially), Radial nerve (laterally)  b) Artery - brachial artery (laterally to median nerve) --> bifurcation into ulnar and radial arteries c) Tendon - biceps brachii tendon (lateral to brachial artery) d) Vein - Cephalic vein (lateral) and basilic vein (medial) united by median cubital vein 
• Innervation upper limb - Brachial plexus 1. Axillary nerve  - roots C5/6 - Location: posterior and lateral aspect arm/shoulder   - Innervation: deltoid, teres minor muscles, shoulder joint, overlying skin  - vulnerable to damage (e.g. dislocation of the shoulder joint) 2. Radial nerve  - roots C5-T1  - Location: posterior and lateral arm/forearm and wrist --> bifurcation into deep (posterior osseous nerve) and superficial branch  - Innervation: Posterior muscles arm (triceps brachii), posterior osseous nerve (extensor muscles forearm), superficial branch (skin and dorsum hand) - Vulnerable to fracture of the humerus  3. Musculocutaneous nerve  - roots: C5-7 - Location: Lateral/anterior arm --> termination as lateral cutaneous nerve of the forearm  - Innervation: Anterior muscles arm (Coracobrachialis, biceps brachii, brachialis), skin and lateral foreamt (lat. cutaneous branch)
• Innervation of the lower limb - lumbar and sacral plexus 1. Lateral cutaneous nerve of the thigh (Lumbar plexus) - roots: L2/3 - Location: lat. border iliopsoas muscle, lateral thigh - Innervation: skin overlying the lateral thigh 2. Obturator nerve (lumbar plexus) - roots: L2/3/4 - Location: md. border iliopsoas muscle -> obturator foramen - Innervation: Adductor muscles of thigh (except pectineus), skin overlying med. aspect thigh 3. Femoral nerve (lumbar plexus) - Roots: L2/3/4 - Location: lat. aspect iliopsoas muscle -> lat. to femoral blood vessels -> divides below inguinal ligament into anterior and posterior division -> ppst. division gives rise to the saphenous nerve in the leg - Innervation: Anterior thigh muscles (iliacus, pectineus, sartorius, rectus femoris, vastus medialis/lateralisintermedius), skin overlying ant. thigh, skin overlying med. leg/foot 4. Gluteal nerves (Sacral plexus) - roots: L4/5-S1) - Location: superior and inferior gluteal nerves exit the pelvis via greater sciatic notch - Innervation: gluteal muscles  5. Sciatic nerve (Sacral plexus) - roots: L4/5-S3 - Location: greater sciatic foramen -> midway between greater trochanter and ischial tuberosity --> division into tibial and common peroneal nerve (mid-thigh level) - Innervation: all leg and foor muscles + skin + joint via the tibial nerve (muscles post. muscle department thigh) and common peroneal/fibular nerve

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