Question | Answer |
C4 | Disc: C3-4 / Muscles: Trapezius, scalene / Weakness: Shoulder shrugging / Reflexes: None |
C5 | Disc: C4-5 / Muscles: Deltoid, biceps, brachioradialis / Weakness: Shoulder abduction, external rotation of the arm, elbow flexion / Reflexes: Biceps, brachioradialis |
C6 | Disc: C5-6 / Muscles: Brachioradialis, biceps, pronator teres, extensor carpi radialis / Weakness: Elbow flexion, arm pronation, finger and wrist extension. Radial nerve injuries produce similar findings except brachioradialis function is normal. / Reflex |
C7 | Disc: C6-7 / Muscles: Triceps, pronator teres, extensor digitorum / Weakness: Elbow extension, finger and wrist extension / Reflexes: Triceps |
C8 | Disc: C7-T1 / Muscles: Flexor digitorum, flexor, abductor pollicis, interossei. / Weakness: Long flexors of fingers, intrinsics of hand (finger abduction, palmar abduction of thumb) / Reflexes: Finger flexor |
T10 | Disc: T9-10 / Muscles: --- / Weakness: Beevor's sign (sit-up -> umbilicus pulled upward) / Reflexes: --- |
L2 | Disc: L1-2 / Muscles: Iliopsoas / Weakness: Hip flexion / Reflexes: Cremaster |
L3 | Disc: L2-3 / Muscles: Iliopsoas, adductors / Weakness: Hip flexion, thigh adduction / Reflexes: Knee jerk |
L4 | Disc: L3-4 / Muscles: Quadriceps, sartorius, tibialis anterior / Weakness: Knee extension, ankle dorsiflexion and inversion / Reflexes: Knee jerk |
L5 | Disc: L4-5 / Muscles: Glutei, hamstrings, tibialis, extensior hallus/digiti, peronei / Weakness: Thigh adduction and internal rotation, knee flexion, plantar and dorsiflexion of ankle and toes / Reflexes: None |
S1 | Disc: L5-S1 / Muscles: Gluteus maximus, hamstrings, soleus, gastrocnemius, extensor digitorum, flexor digitorum / Weakness: Hip extension, knee flexion, plantar flexion of ankle and toes / Reflexes: Ankle jerk |
S2 | Disc: S1-2 / Muscles: Interossei / Weakness: Cupping and fanning of toes / Reflexes: --- |
Ulnar nerve lesions | Similar to C8 but also weaken thumb adductor |
Deep peroneal nerve lesions | Weakness limited to ankle and toe extensors |
Posterior tibial nerve lesions | Weakeness of foot inversion |
Femoral nerve injury | Weakness limited to knee extension; associated hip flexion and adduction weakness localizes to plexus; similar to L4 |
Radial nerve injury | Produce findings similar findings to C6 except brachioradialis function is normal |