Lesson 1Path of the Radial Nerve in the Armpit and Upper Arm: Relations to Armpit Blood Vessels, Upper Arm Bone Head, and Latissimus Dorsi MuscleIn this part, we trace the radial nerve through the armpit and upper arm, explaining its position near the armpit artery, upper arm bone head, latissimus dorsi muscle, and nearby tissues, highlighting spots where it can get squeezed, risks from injuries, and ways to access it during surgery.
Relations to axillary artery and veinCourse around humeral head and neckRelations to latissimus dorsi and teres majorFascial tunnels and potential compression sitesSurgical approaches in the proximal armLesson 2Important Landmarks for Locating at Bedside and Surgical Access: Outer Elbow Bump, Radial Bone Head, Spiral Groove, Supinator TunnelThis part points out dependable surface and deeper markers to find the radial nerve and its branches, helping with checks at the patient's bedside, ultrasound scans, and surgical access near the outer elbow bump, radial bone head, spiral groove, and supinator tunnel.
Palpation of lateral epicondyle and radial headLocating the spiral groove on the humerusIdentifying the supinator tunnel regionUltrasound landmarks for radial branchesSafe windows for surgical approachesLesson 3Key Tiny Anatomy: Outer Nerve Covering, Middle Nerve Covering, Inner Nerve Covering, Nerve Blood Supply and Effects on Injury and HealingWe describe the tiny structure of the radial nerve, covering the outer sheath, middle sheath, inner sheath, and blood vessels, showing how they react to pulling, squeezing, and cutting, and how this affects healing, lump formation, and repair methods.
Epineurial structure and surgical handlingPerineurium and fascicular organizationEndoneurial tubes and axonal supportVasa nervorum and ischemic vulnerabilityMicroanatomy and regeneration patternsLesson 4Brachial Plexus Roots and Contribution to Radial Nerve (C5–T1): Formation of Back Cord and Body VariationsThis part looks at how roots from C5 to T1 make the back cord and radial nerve, noting positions in the neck and armpit, common body differences, and how these affect weakness, feeling loss, and electrical tests.
C5–T1 root contributions to radial nerveTopography of trunks, divisions, and cordsPosterior cord formation and branching patternCommon root and cord anatomical variantsClinical impact of high or low root lesionsLesson 5Back Interosseous Nerve (PIN): Entry Through Supinator Muscle (Frohse Arch), Motor Branches to Forearm Straightening Muscles, Usual Branching PatternHere we examine the back interosseous nerve, from passing through the supinator muscle and Frohse arch to its branches for forearm straightening muscles, describing usual and different branching and their role in specific weaknesses and surgery plans.
Entry beneath ECRB to supinatorArcade of Frohse anatomy and variantsIntramuscular course within supinatorMotor branches to wrist and finger extensorsPatterns in selective PIN palsiesLesson 6Spiral (Radial) Groove Structure: Position Relative to Upper Arm Bone, Branches to Triceps and Anconeus, Blood Vessel RelationsThis part studies the spiral groove area, describing its place on the back of the upper arm bone, links to triceps and anconeus branches, nearby blood vessels, and why this area is at risk in breaks, squeezes, and operations.
Surface and radiographic localizationRelations to triceps and anconeus branchesContact with posterior humeral cortexRadial collateral and profunda brachii vesselsRisk zones in humeral shaft fracturesLesson 7Ending Motor and Feeling Areas: Straightening Compartment Muscles, Triceps, Brachioradialis, Anconeus, Finger Straighteners, and Back Hand Feeling MapThis part maps the ending motor and feeling areas, connecting each radial nerve branch to specific straightening muscles, triceps, brachioradialis, anconeus, and back hand skin areas, to aid accurate bedside location and electrical test reading.
Motor map of triceps and anconeusInnervation of wrist and finger extensorsBrachioradialis and ECRL innervation zonesDorsal hand and thumb sensory territoriesPatterns of overlap with median and ulnarLesson 8Common Body Variations Affecting Patient Presentation: High Split, Extra Branches, Changing Supply to Brachioradialis and ECUWe look at common radial nerve body variations, like high split, extra branches, and changing supply to brachioradialis and ECU, stressing how these change signs, nerve tests, and surgery hopes.
High radial bifurcation patternsAccessory branches to triceps or brachialisVariable innervation of brachioradialisECU and ECRB innervation variantsImpact on EMG and nerve conduction testsLesson 9Split at Outer Elbow Bump/Elbow: Surface Feeling Branch and Deep Branch (Back Interosseous Nerve) Body DetailsWe study the radial nerve split near the outer elbow bump, comparing the surface feeling branch and deep motor branch (PIN), their bundle setup, links to the radial bone head, and effects on squeezes, injections, and surgery release.
Anatomy at the lateral epicondyleBranching into superficial and deep branchesRelations to radial head and joint capsuleFascicular topography at the bifurcationEntrapment and iatrogenic injury risksLesson 10Forearm Path of Surface Branch: Under-Skin Route, Branches to Back of Hand and Thumb Side BoxThis part traces the surface radial nerve along the forearm, detailing its under-skin path, tissue layers, branches to the back of the hand and thumb side box, and how this guides feeling tests, blocks, and surgery cuts.
Course deep to brachioradialisTransition to subcutaneous positionBranches to dorsum of hand and fingersAnatomic snuffbox relations and branchesSites of Wartenberg syndrome compression
