Spinal Segment | Motor Function | Sensory Function | Remarks |
C2 | None | Greater occipital nerve — occiput sensation | ㅤ |
C4 | Diaphragm | Clavicle | "C3–C5 keep the diaphragm alive" |
C5 | Deltoid (arm abduction) | Lateral arm | Biceps tendon reflex, radioperiosteal reflex |
C6 | Biceps and brachioradialis (forearm flexion) | Thumb | ㅤ |
C7 | Triceps (forearm extension) | Fingers 2 and 3 | Triceps tendon reflex |
C8 | Finger flexors (grip strength) | Fingers 4 and 5 | ㅤ |
T1 | Hand intrinsics (finger abduction) | Inside arm and forearm | ㅤ |
T4 | Intercostals | Nipples | ㅤ |
T10 | Upper abdominal muscles | Umbilicus | Abdominal cutaneous reflex |
T12 | Lower abdominal muscles | Belt line | Abdominal cutaneous reflex |
L1 | Adductors | Groin | ㅤ |
L2 | Iliopsoas, adductors | Inner thigh | Cremasteric reflex |
L3 | Adductors, quadriceps | Anterior thigh | ㅤ |
L4 | Quadriceps | Anterior thigh and shin | Patellar tendon reflex |
L5 | Foot extensors | Lateral thigh & calf to big toe | Caution: a. L5 radiculopathy: affects multiple muscle groups (foot extension, inversion, hip rotation) b. Peroneal nerve palsy: only foot extensor weakness |
S1 | Gastrocnemius | Posterolateral calf to little toe | Achilles tendon reflex |
S2 | Toe flexors | Posterior thigh | ㅤ |
S3–S4 | Bowel and bladder control | Perianal region | Bulbocavernosus reflex |
Spine
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Status
Done