Gluteal Muscles: Anatomy and Function

• Muscles of the gluteal region can be recognized from images.

Gluteus Maximus

• Originates at ilium and fascia covering the gluteus medius.
• Inserts at gluteal tuberosity of femur.
• Innervated by the inferior gluteal nerve.
• Responsible for lateral rotation of hip and thigh extension.

Gluteus Medius

• Originates at the ilium.
• Inserts at greater trochanter of femur.
• Innervated by the superior gluteal nerve.
• Causes hip abduction and medial rotation.

Gluteus Minimus

• Originates at the ilium.
• Inserts at greater trochanter of femur.
• Innervated by the superior gluteal nerve.
• Causes hip abduction and medial rotation.

Tensor Fascia Latae

• Originates at the ilium.
• Inserts at fascia lata and IT band.
• Innervated by superior gluteal nerve.
• Tenses the IT band and causes weak medial rotation of hip.

Piriformis

• Originates at anterior surface of sacrum.
• Inserts at greater trochanter of femur.
• Innervated by lumbosacral nerves.
• Causes lateral rotation of hip.

Obturator Internus

• Originates at internal surface of obturator membrane.
• Inserts at greater trochanter of femur.
• Innervated by lumbosacral nerves.
• Causes lateral rotation of hip.

Superior/Inferior Gemellus

• Originates at ischial spine and inserts at greater trochanter of femur.
• Innervated by lumbosacral nerves.
• Causes lateral rotation of hip.

Quadratus Femoris

• Originates at ischium and inserts at intertrochanteric crest.
• Innervated by lumbosacral nerves.
• Causes lateral rotation of hip.

Ligaments of the Hip

• Pubofemoral prevents hyperabduction.
• Iliofemoral prevents hyperextension.
• Ischiofemoral prevents hyperextension.
• Round ligament of femur stabilizes the hip joint and maintains lubrication.

Femur Identification

• The bottom crevice faces right, it is the left femur.
• If the bottom crevice faces left it is a right femur.

Thigh Compartments

• Anterior, medial, and posterior compartments exist.

Pes Anserinus

• Sartorius (anterior), gracilis (medial), and semitendinosus (posterior) insert into the proximal, medial tibia.

Femoral Triangle Boundaries

• Superiorly by the inguinal ligament.
• Laterally by the medial border of the sartorius muscle.
• Medially by the medial border of the adductor longus muscle.
• Contents from lateral to medial: femoral nerve, femoral artery, and femoral vein ("NAVEL").

Psoas Major

• Originates at lumbar vertebrae.
• Inserts at the lesser trochanter of the femur.
• Innervated by ventral rami L1-L3.
• Causes hip flexion.

Iliacus

• Originates at iliac fossa.
• Inserts at the lesser trochanter of the femur.
• Innervated by femoral nerve.
• Causes hip flexion.

Rectus Femoris

• Originates at the anterior inferior iliac spine.
• Inserts at the quadriceps femoris tendon.
• Innervated by femoral nerve.
• Causes both hip flexion and knee extension.

Vastus Lateralis

• Originates at the lateral proximal femur.
• Inserts at the quadriceps femoris tendon.
• Innervated by femoral nerve.
• Causes knee extension.

Vastus Intermedius

• Originates at the femoral shaft.
• Inserts at the quadriceps femoris tendon.
• Innervated by femoral nerve.
• Causes knee extension.

Vastus Medialis

• Originates at the medial proximal femur.
• Inserts at the quadriceps femoris tendon.
• Innervated by femoral nerve.
• Causes knee extension.

Sartorius

• Originates at the anterior superior iliac spine, and inserts at the medial surface proximal tibia.
• Innervated by the femoral nerve.
• Causes hip flexion, abduction, and lateral rotation; knee flexion.

Pectineus

• Originates at proximal femur.
• Inserts at proximal femur.
• Innervated by both femoral and obturator nerves.
• Causes hip flexion and adduction.

Obturator Externus

• Originates at external surface of obturator membrane.
• Inserts at posterior aspect of proximal femur.
• Innervated by obturator nerve.
• Causes lateral rotation of the hip.

Adductor Brevis

• Originates at pubis and pubic ramus and inserts at linea aspera of femur.
• Innervated by obturator nerve.
• Causes hip adduction.

Adductor Longus

• Originates at pubis and inserts at linea aspera of femur.
• Innervated by obturator nerve.
• Causes hip adduction.

Adductor Magnus

• Originates at ischiopubic ramus and inserts at linea aspera of femur.
• Innervated by both obturator and tibial nerves.
• Causes hip adduction and extension.

Biceps Femoris (Long Head)

• Originates at ischial tuberosity.
• Inserts at head of fibula.
• Innervated by tibial nerve.
• Causing hip extension and knee flexion.

Biceps Femoris (Short Head)

• Originates at linea aspera of femur.
• Inserts at head of fibula.
• Innervated by common fibular nerve.
• Flexes knee.

Semimembranosus

• Originates at ischial tuberosity.
• Inserts at medial surface of proximal tibia.
• Innervated by tibial nerve.
• Causes hip extension and knee flexion.

Semitendinosus

• Originates at ischial tuberosity.
• Inserts at medial surface of proximal tibia.
• Innervated by tibial nerve.
• Causes hip extension and knee flexion.

Medial Collateral Ligament (MCL)

• Located on medial aspects of the knee joint.
• Taut when the knee is extended and lax when flexed.
• MCL contributes to stability of the knee joint.

Lateral Collateral Ligament (LCL)

• Located on the lateral aspects of the knee joint.
• Taut when knee is extended and lax when flexed.
• LCL contributes to overall stability of the knee joint.

Anterior Cruciate Ligament (ACL)

• Runs from the anterior aspect of tibia to the posterior/medial aspect of lateral femoral condyle.
• ACL prevents hyperextension.

Posterior Cruciate Ligament (PCL)

• Runs from the posterior aspect of tibia to the anterior/lateral aspect of the medial femoral condyle.
• The PCL prevents hyperflexion.

"Unhappy Triad"

• The ACL, MCL, and medial meniscus are typically all torn
• Usually occurs for example in an accident involving lateral impact to the knee.

Tibialis Anterior

• Location: anterior compartment of the leg.
• Innervation: deep fibular nerve.
• Attachments: medial cuneiform, base of metatarsal I.
• Actions: dorsiflexes ankle, inverts foot.

Extensor Digitorum Longus

• Location: anterior compartment of the leg.
• Innervation: deep fibular nerve.
• Attachments: distal phalanges of digits II-V.
• Actions: dorsiflexes ankle, extends digits 2-5 (MTP, PIP, DIP).

Extensor Hallucis Longus

• Location: anterior compartment of the leg.
• Innervation: deep fibular nerve.
• Attachments: distal phalanx of the hallux.
• Actions: dorsiflexes ankle, extends hallux (MTP, IP).

Fibularis Tertius

• Location: anterior compartment of the leg.
• Innervation: deep fibular nerve.
• Attachments: base of metatarsal V.
• Actions: dorsiflexes ankle, everts foot.

Fibularis Longus

• Location: lateral compartment of the leg.
• Innervation: superficial fibular nerve.
• Attachments: plantar surface of the base of metatarsal I.
• Actions: plantarflexes and everts foot.

Fibularis Brevis

• Location: lateral compartment of the leg.
• Innervation: superficial fibular nerve.
• Attachments: base of metatarsal V.
• Actions: plantarflexes and everts foot.

Gastrocnemius

• Location: posterior (superficial) compartment of the leg.
• Innervation: tibial nerve.
• Attachments: calcaneal tendon.
• Actions: knee flexion, plantarflexion of foot.

Plantaris

• Location: posterior (superficial) compartment of the leg.
• Innervation: tibial nerve.
• Attachments: calcaneal tendon.
• Actions: weak knee flexion, plantarflexion of foot.

Soleus

• Location: posterior compartment of the leg.
• Innervation: tibial nerve.
• Attachments: calcaneal tendon.
• Actions: plantarflexion of foot.

Tibialis Posterior

• Location: Posterior compartment of the leg.
• Innervation: Tibial nerve.
• Attachments: Navicular and medial cuneiform bones.
• Actions: Plantarflexes and inverts foot.

Flexor Digitorum Longus

• Location: Posterior compartment of the leg.
• Innervation: Tibial nerve.
• Attachments: Distal phalanges digits 2-5.
• Actions: Flexes digits 2-5, plantarflexes foot.

Flexor Hallucis Longus

• Location: Posterior compartment of the leg.
• Innervation: Tibial nerve.
• Attachments: Distal phalanx of hallux.
• Actions: Flexes hallux, plantarflexes foot.

Popliteus

• Location: Posterior compartment of the leg.
• Innervation: Tibial nerve.
• Attachments: Posterior proximal tibia.
• Actions: Unlocks knee from extended position.

Medial Collateral Ligament (Ankle)

• Has 4 parts, including tibionavicular, tibiocalcaneal, anterior tibiotalar, and posterior tibiotalar liagments.
• Prevents hypereversion of the subtalar joint.

Lateral Collateral Ligament (Ankle)

• Has 3 parts, including anterior talofibular, posterior talofibular, and calcaneofibular ligaments.
• Prevents hyperinversion of the subtalar joint.

Fibular Retinacula

• These are fibrous retaining bands.
• They secure the tendons of the fibularis longus and brevis muscles.
• These muscles run along the side of the ankle.

Extensor Retinacula

• This structure is a broad ligament.
• It holds the tendons of the foot in place.
• It includes the superior and inferior extensor retinaculum.

Extensor Digitorum Brevis

• Location: foot.
• Innervation: deep fibular nerve.
• Attachments: extensor expansion of digits II-IV.
• Actions: extends digits II-IV at the MTP, DIP, and PIP joints.

Extensor Hallucis Brevis

• Location: foot.
• Innervation: deep fibular nerve.
• Attachments: base of proximal phalanx of hallux.
• Action: extends hallux at the MTP joint.

Abductor Hallucis

• Location: foot.
• Innervation: medial plantar nerve.
• Attachments: proximal phalanx of hallux.
• Actions: abducts and flexes the hallux.

Abductor Digiti Minimi

• Location: foot.
• Innervation: lateral plantar nerve.
• Attachments: proximal phalanx of digit V.
• Actions: abducts and flexes digit V.

Flexor Digitorum Brevis

• Location: foot.
• Innervation: medial plantar nerve.
• Attachments: intermediate phalanges of digits II-V.
• Actions: flexes digits II-V.

Quadratus Plantae

• Location: foot.
• Innervation: lateral plantar nerve.
• Attachments: flexor digitorum longus tendon.
• Actions: flexes digits II-V.

Lumbricals

• Location: foot.
• Innervation: medial and lateral plantar nerves.
• Attachments: extensor expansions of digits II-V.
• Actions: flexes MTP and extends PIP and DIP.

Flexor Hallucis

• Location: foot.
• Innervation: medial plantar nerve.
• Attachments: proximal phalanx of hallux.
• Action: flexes hallux.

Adductor Hallucis

Location: foot Innervation: lateral plantar nerve Attachments: Proximal phalanx digit 1 Actions: Adduct hallux

Flexor Digiti Minimi Brevis

Location: foot Innervation: lateral plantar nerve Attachments: Proximal phalanx V Actions: Flex digit V

Dorsal Interossei

Location: foot Innervation: Lateral plantar nerve. Attachments: Proximal phalanges II-IV Actions: Abduct digits II-IV

Plantar Interossei

Location: foot Innervation: Lateral plantar nerve. Attachments: Proximal phalanges III-V Actions: Adduct digits III-V

Glenohumeral Joint

• The head of the humerus articulates with the glenoid cavity of the scapula.
• Glenoid labrum increases the depth of the glenoid cavity.
• Movements include extension, flexion, abduction, adduction, lateral and medial rotation.

Scapulothoracic Joint

• It is not a true joint; bones do not articulate directly through the scapula.
• It functions like a joint in that the scapula moves over the posterior rib cage.
• Movements include elevation, depression, protraction, retraction, upward and downward rotation.

Sternoclavicular Joint

• Located between the medial clavicle and the manubrium.

Acromioclavicular Joint

• Located between the lateral clavicle and the acromion process.
• Allows for limited rotation of the acromion around the clavicle.

Winged Scapula

• The shoulder blade protrudes visibly from the back.
• It signifies weakness or paralysis of muscles holding it to the rib cage.
• Most commonly is caused by damage to the long thoracic nerve via the serratus anterior muscle.
• Other causes: damage to trapezius or rhomboid muscles, resulting in lateral winging.

Pectoralis Major

• Innervated by lateral and medial pectoral nerves.
• Attaches to the medial aspect of proximal humerus and the lateral and medial pectoral nn.
• Responsible for adduction, flexion, and medial rotation of humerus.

Pectoralis Minor

• Innervated by medial pectoral nerve.
• Attaches to the coracoid process of scapula and superior ribs (3-5).
• Supports the protraction and depression of scapula.

Serratus Anterior

• Innervated by long thoracic nerve.
• Attaches to ribs 1-8 and medial border of scapula.
• Supports protraction and upward rotation of scapula.

Subclavius

• Innervated by nerve to subclavius.
• Attaches to rib 1 and clavicle.
• Depresses clavicle.

Teres Major

• Innervated by the lower subscapular nerve.
• Attaches to the inferior angle of scapula
• Supports medial rotation and adduction of GHJ.

Teres Minor

• Innervated by axillary nerve.
• Attaches to: The lower lateral border of the scapula; Greater tubercle of the humerus.
• Laterally rotates and stablizes the glenohumeral joint.

Supraspinatus

• Innervated by suprascapular nerve.
• Attaches to: The supraspinous facia; Greater tubercle of the Humerus.
• Allows for abduction and stabilization of the glenohumeral joint.

Infraspinatus

• Innervated by suprascapular nerve.
• Attaches to: The infraspinous facia; Greater tubercle of the Humerus.
• Laterally rotates and stabilizes the Glenohumeral Joint.

Subscapularis

Innervated by: the super and lower subscapular nerves.

• Attaches to: The Subscapular facia; Lesser tubercle of the humerus.
• Allows for Medial rotation, adduction, and stabilization of GHJ.

Axillary Artery

• The right subclavian a. comes off of the brachiocephalic trunk
• The left subclavian a. comes directly off of the arch of the aorta.

Thyrocervical trunk

• Transverse cervical a. is the superficial branch of the Artery and supplies the Trapezius muscle.
• the deep branch becomes the Dorsal Scapular A and supplies the rhomboids and levator scapulae.
• The Suprascapular A. supplies the supraspinatus and infraspinatus, maintain relationship with the ligament.

Brachial Plexus

• The Brachial Plexis is created by the C5-T1 Vernal Rami.
• It is organized from Vernal Rami, Trunks, Divisions, Cords, and finally the terminal nerves.

Biceps Brachii

• Compartment: anterior
• Motor Innervation: Musculocutaneous n
• Attachments: Long head supraglenoid tubercle, Short head - coracoid processs, Radial tuberosity
• Primary Functions: Forearm flexion at elbow; arm flexion at GHJ

Coracobrachialis

• Compartment: anterior
• Motor Innervation: Musculocutaneous n
• Attachments: Humeral shraft, Coracoid Process
• Primary Functions: arm flexion at GHJ

Brachialis

• Compartment: anterior
• Motor Innervation: Musculocutaneous n
• Attachments: Humeral shaft, Tuberosity of ulna
• Primary Functions: Forearm flexion at elbow

Triceps Brachii

• Compartment: Posterior
• Motor Innervation: Radial N
• Attachments: Long head – infraglenoid tubercle of scapula, Medial head - humeral shaft (deep), Lateral head – humeral shaft & Olecranon process of ulna
• Primary functions: Arm extension at GHJ; forearm extension at elbow

Flexor Carpi Radialis

• Location: anterior forearm.
• Innervation: median nerve.
• Attachments: medial epicondyle of humerus, base of metacarpal II.
• Action: wrist palmarflexion and radial deviation.

Palmaris Longus

• Location: anterior forearm.
• Innervation: median nerve.
• Attachments: medial epicondyle of humerus, flexor retinaculum.
• Action: wrist palmarflexion.

Pronator Teres

• Location: anterior forearm.
• Innervation: median nerve.
• Attachments: medial epicondyle of humerus, radial shaft.
• Action: pronates forearm.

Flexor Carpi Ulnaris

• Location: anterior forearm.
• Innervation: ulnar nerve.
• Attachments: medial epicondyle of humerus, carpal bones, base of metacarpal V.
• Action: wrist palmarflexion and ulnar deviation.

Flexor Digitorum Profundus

• Location: anterior forearm.
• Innervation: median (lateral) and ulnar (medial) nerves.
• Attachments: ulna and interosseous membrane, distal phalanges of digits 2-5.
• Action: wrist palmarflexion, MCP/PIP/DIP flexion of digits 2-5.

Flexor Pollicis Longus

• Location: anterior forearm.
• Median n: Innervation
• Radial shaft, interosseous membrane: Radius shaft, interosseous membrane
• Flexes MCP joint of thumb: Action

Pronator Quadratus

• Location: anterior forearm.
• Median n: Innervation
• Distal ulna shaft: radius
• Pronation of forearm: Action

Anconeus

• Location: posterior forearm.
• Radial n: Innvervation
• Lateral epicondyle of humerus: Attachments
• The function is: Stabilizes elbow

Extensor Carpi Radialis Longus

• Location: Posterior Forarm
• Radial n: Nervers Humerous, the base of MC2: Attachment. Wrist Doorsiflexion & Radial Deviation: Action

Extensor Carpi Radialis Brevis

• Radial n: Location
• Humerous & 3rd metacarpal bone: Attachments.
• Wrist Dorsiflextion & Radial Deviation: Function

###. Extensor Carpi Ulnaris

• Radius: nerve.
• base of 5th Metacarpal: Attachment. -. Action: wrist Dorsiflexion & ulnar deviation

Extensor Digitorum

• radius: the Nerve.
• Attacgment: Expansion Digits.
• Function: Extends wrist and MCP, PIP & DIP

Abductor Digiti Minima

Action: The radius and nerve Attachment ( 1st Metacarpal) Function: (Extends PIP,DIP& MCP joints)

- Brachioradialis

Attachs= Distal humerus Nerve= Radius Function = Flexes Forearm

Supinator

Attachs = Humerrus - Radial epicondyle & proximal radius Nerve = Radius Function = Supination

Extensor indicies

• Nervers Expansion digits 2-5.
• (Extends PIP,DIP& MCP joints)
• Shafts ulna & interosseous membrane: Attacments

Contents of the Carpal Tunnel

• Formed by the flexor retinaculum.
• Flexor retinaculum maintains tendons of flexor digitorum superficialis, flexor digitorum profundus, and flexor pollicis longus.
• Median nerve also travels inside the Carpal Tunnel.

Carpal Tunnel Syndrome

• Median nerve becomes compressed in the carpal tunnel.
• Can cause weakness in theinar muscles and loss of sensation in the lateral palmar hand.
• Will cause pain and weakness in grip.

Flexor Pollicis Brevis

• thenar: Compartment
• recurrent median nerve: Nerves
• Flexor Retinaculum & Traperzium: Attachments
• Flex Thumb @ CMC & MCP Joint : action

Opponens Pollicis

• thenar -:Compartment
• Recurrent Median Nerve: Nerve
• Flexor Retinaculum & Traperzium : Atactchments
• thumb opposition at CMC Joint: action

Abductor Pollicis Brevis

• Thenar: Compartments
• Recurrent:Nerve
• Attachs to Flexor Retinaculum, Scaphoid and Trapezoid -: thumb abduction & CMC joints are the actions.

Addductor Pollicis

action: thumb adduction @CMC joint

Adductor Pollicis

• Adductor: compartment
• attacments:unlar nerve
• Adduction and Flexion

Lumbricals

• Compartment central Nerve: Lateral Median Tendons FDp: Actions

Flex Digiti Minima

• Hypothenar (Compartments.)
• ulna is the Nerve.

Abductor Digiti Minima

• Ulnar Nerves
• Attachment (Base)

Opponens digiti minimi

• ULNAR nerve
• Hypothenar
• Attachment ( 5th Bone)

Palmar Interossel

Proximal Ulnar Ulnar Nerves

Overview of the gluteal muscles including the gluteus maximus, medius, and minimus. Covers each muscle's origin, insertion, innervation, and function. Focuses on hip abduction, medial rotation, and thigh extension.