radiology 2

Anterior arm muscles

Long and short head of biceps, Corachobrachialis, Brachialis

Weakness with elbow flexion most strongly localizes injury to which compartment?

Anterior arm compartment

Injury to the musculocutaneous nerve affects which muscle compartment?

Anterior arm compartment

Weakness with forearm supination AND elbow flexion together localizes injury to which compartment?

Anterior arm compartment

Sensory loss over the lateral forearm with impaired elbow flexion points to injury of which compartment?

Anterior arm compartment

Posterior arm muscles

Triceps

Weakness with elbow extension localizes injury to which compartment?

Posterior arm compartment

Injury to the radial nerve at the level of the arm affects which compartment?

Posterior arm compartment

Loss of the triceps reflex indicates dysfunction of which compartment?

Posterior arm compartment

Which arm compartment is affected when elbow extension is impaired but elbow flexion is preserved?

Posterior arm compartment

Which compartment contains muscles responsible for extending the elbow joint?

Posterior arm compartment

Compression injury to the radial nerve in the arm (eg, “Saturday night palsy”) affects which compartment?

Posterior arm compartment

Dorsal/Extensor forearm- Superficial muscles

Extensor carpi ulnaris, Extensor digiti minimi, Extensor digitorum, Extensor carpi radialis brevis and longus, Brachioradialis

Weakness with wrist extension localizes injury to which compartment?

Dorsal (extensor) superficial forearm compartment

Inability to extend the fingers at the MCP joints points to dysfunction of which compartment?

Dorsal (extensor) superficial forearm compartment

Radial nerve injury at the forearm level with preserved elbow extension affects which compartment?

Dorsal (extensor) superficial forearm compartment

Which compartment is affected when a patient cannot open the hand but can still flex the fingers?

Dorsal (extensor) superficial forearm compartment

Wrist extension weakness with intact elbow extension localizes injury to which compartment?

Dorsal (extensor) superficial forearm compartment

Loss of finger extension without loss of finger flexion indicates injury to which compartment?

Dorsal (extensor) superficial forearm compartment

Dorsal/Extensor forearm - Deep muscles

Abductor pollicis longus, Extensor pollicis brevis and longus, Extensor indicis, Supinator

Difficulty extending or abducting the thumb localizes injury to which compartment?

Dorsal (extensor) deep forearm compartment

Loss of isolated index finger extension indicates dysfunction of which compartment?

Dorsal (extensor) deep forearm compartment

Supination weakness with preserved elbow flexion localizes injury to which compartment?

Dorsal (extensor) deep forearm compartment

Injury to the posterior interosseous nerve affects which compartment?

Dorsal (extensor) deep forearm compartment

Which compartment contains muscles responsible for thumb-specific extension and abduction?

Dorsal (extensor) deep forearm compartment

A patient can extend the wrist and fingers but cannot extend the thumb — which compartment is affected?

Dorsal (extensor) deep forearm compartment

Volar/Flexor forearm- Superficial muscles

Pronator teres, Flexor carpi radialis, Palmaris longus, Flexor digitorum superficialis, Flexor carpi ulnaris

Weakness with wrist flexion localizes injury to which compartment?

Volar (flexor) superficial forearm compartment

Difficulty pronating the forearm indicates dysfunction of which compartment?

Volar (flexor) superficial forearm compartment

Loss of finger flexion at the PIP joints with preserved DIP flexion localizes injury to which compartment?

Volar (flexor) superficial forearm compartment

Which forearm compartment is primarily responsible for wrist flexion and pronation?

Volar (flexor) superficial forearm compartment

A patient can flex the distal phalanges but has weak proximal finger flexion — which compartment is affected?

Volar (flexor) superficial forearm compartment

Weak grip due to inability to stabilize the wrist in flexion points to injury of which compartment?

Volar (flexor) superficial forearm compartment

Volar/Flexor forearm- Deep muscles

Flexor digitorum profundus, Flexor pollicis longus, Pronator quadratus

Inability to flex the distal interphalangeal (DIP) joints localizes injury to which compartment?

Volar (flexor) deep forearm compartment

Loss of thumb flexion at the interphalangeal joint indicates dysfunction of which compartment?

Volar (flexor) deep forearm compartment

Weakness with precision or pinch grip localizes injury to which compartment?

Volar (flexor) deep forearm compartment

Isolated pronation weakness with preserved elbow flexion points to injury of which compartment?

Volar (flexor) deep forearm compartment

Injury to the anterior interosseous nerve affects which forearm compartment?

Volar (flexor) deep forearm compartment

A patient can flex the PIP joints but cannot flex the DIP joints — which compartment is affected?

Volar (flexor) deep forearm compartment

Anterior thigh muscles

Vastus Lateralis, Vastus Intermedius, Vastus Medialis, Rectus Femoris, Sartorius, Pectineus

Weakness with knee extension localizes injury to which compartment?

Anterior thigh compartment

Loss of the patellar reflex indicates dysfunction of which thigh compartment?

Anterior thigh compartment

Injury to the femoral nerve affects which thigh compartment?

Anterior thigh compartment

Which compartment is affected when knee extension is impaired but knee flexion and hip adduction are preserved?

Anterior thigh compartment

Difficulty standing from a seated position due to inability to extend the knee localizes injury to which compartment?

Anterior thigh compartment

Failure to stabilize the knee during gait indicates dysfunction of which thigh compartment?

Anterior thigh compartment

Medial thigh muscles

Adductor Magnus, Adductor Longus, Adductor Brevis, Obturator Externus, Gracilis

Weakness with hip adduction localizes injury to which compartment?

Medial thigh compartment

Injury to the obturator nerve affects which thigh compartment?

Medial thigh compartment

Which compartment is affected when hip adduction is impaired but knee extension is preserved?

Medial thigh compartment

Loss of thigh adduction with preserved knee flexion localizes injury to which compartment?

Medial thigh compartment

Difficulty bringing the legs together indicates dysfunction of which thigh compartment?

Medial thigh compartment

Medial thigh sensory loss with associated adduction weakness indicates injury to which compartment?

Medial thigh compartment

Posterior

Biceps Femoris, Semitendinosus, Semimembranosus

Weakness with knee flexion localizes injury to which compartment?

Posterior thigh compartment

Weakness with hip extension indicates dysfunction of which thigh compartment?

Posterior thigh compartment

Injury to the sciatic nerve affects which thigh compartment?

Posterior thigh compartment

Which compartment is affected when knee flexion is impaired but knee extension is preserved?

Posterior thigh compartment

Difficulty rising from a seated position due to loss of hip extension localizes injury to which compartment?

Posterior thigh compartment

Loss of knee flexion with preserved hip adduction indicates injury to which compartment?

Posterior thigh compartment

Anterior leg muscles

Tibialis anterior, Extensor hallucis longus, Extensor digitorum longus, Fibularis tertius

Weakness with foot dorsiflexion localizes injury to which compartment?

Anterior leg (shin) compartment

Inability to extend the toes indicates dysfunction of which leg compartment?

Anterior leg (shin) compartment

Injury to the deep fibular (peroneal) nerve affects which compartment?

Anterior leg (shin) compartment

Foot drop with preserved plantarflexion localizes injury to which compartment?

Anterior leg (shin) compartment

Which compartment is affected when dorsiflexion is impaired but foot eversion is preserved?

Anterior leg (shin) compartment

Difficulty clearing the toes during gait due to loss of toe extension points to injury of which compartment?

Anterior leg (shin) compartment

Lateral leg muscles

Fibularis Longus, Fibularis Brevis

Weakness with foot eversion localizes injury to which compartment?

Lateral leg (shin) compartment

Injury to the superficial fibular (peroneal) nerve affects which compartment?

Lateral leg (shin) compartment

Which compartment is affected when eversion is impaired but dorsiflexion is preserved?

Lateral leg (shin) compartment

Loss of foot eversion with intact plantarflexion indicates dysfunction of which compartment?

Lateral leg (shin) compartment

Recurrent ankle sprains due to inability to evert the foot point to injury of which compartment?

Lateral leg (shin) compartment

Lateral ankle instability without foot drop localizes injury to which compartment?

Lateral leg (shin) compartment

Superficial Posterior leg muscles

Gastrocnemius, Soleus, Plantaris

Weakness with plantarflexion of the foot localizes injury to which compartment?

Superficial posterior leg (shin) compartment

Inability to stand on the toes or perform a heel raise indicates dysfunction of which compartment?

Superficial posterior leg (shin) compartment

Injury to the tibial nerve with loss of plantarflexion affects which compartment?

Superficial posterior leg (shin) compartment

Plantarflexion weakness with preserved toe flexion localizes injury to which compartment?

Superficial posterior leg (shin) compartment

Reduced push-off during gait due to inability to plantarflex the foot points to injury of which compartment?

Superficial posterior leg (shin) compartment

Which compartment is primarily responsible for generating push-off during walking and running?

Superficial posterior leg (shin) compartment

Deep Posterior leg muscles

Popliteus, Flexor Digitorum Longus, Flexor Hallucis Longus, Tibialis Posterior

Inability to flex the toes localizes injury to which compartment?

Deep posterior leg (shin) compartment

Loss of great toe (hallux) flexion indicates dysfunction of which compartment?

Deep posterior leg (shin) compartment

Foot inversion weakness with preserved plantarflexion localizes injury to which compartment?

Deep posterior leg (shin) compartment

Collapse of the medial longitudinal arch due to muscle dysfunction points to injury of which compartment?

Deep posterior leg (shin) compartment

Tibial nerve injury with preserved plantarflexion but loss of toe flexion affects which compartment?

Deep posterior leg (shin) compartment

Difficulty initiating knee flexion from full extension (unlocking the knee) localizes injury to which compartment?

Deep posterior leg (shin) compartment