Reference Data
Category: Lumbosacral Radiculopathy
| Nerve root | Reflex affected | Sensory loss* | Weakness |
|---|---|---|---|
| L2-L4** | Patellar | Anteromedial thigh Medial shin | Hip flexion (iliopsoas) Hip adduction Knee extension (quadriceps) |
| L5 | None | Lateral shin Dorsum of the foot | Foot dorsiflexion & inversion (tibialis anterior) Foot eversion (fibularis) Toe extension (extensor hallucis & digitorum) |
| S1 | Achilles | Posterior calf Sole & lateral foot | Hip extension (gluteus maximus) Knee flexion (hamstrings) Foot plantarflexion (gastrocnemius) |
| S2-S4** | Anocutaneous | Perineum | Urinary or fecal incontinence Sexual dysfunction |
*Radicular pain typically has a similar distribution to sensory loss.
**Difficult to distinguish between individual nerve roots clinically.
Category: Upper Extremity Radiculopathy
| Nerve root | Reflex affected | Sensory loss | Weakness |
|---|---|---|---|
| C5 | Biceps | Lateral arm (Deltoid area) | Shoulder abduction (Deltoid) External rotation (Infraspinatus) |
| C6 | Brachioradialis | Lateral forearm, Thumb, Index finger | Elbow flexion (Biceps/Brachioradialis) Wrist extension (Extensor carpi radialis) |
| C7 | Triceps | Middle finger, Posterior forearm | Elbow extension (Triceps) Wrist flexion Finger extension |
| C8 | None (common) | Ring/Little finger, Medial forearm | Finger flexion (Grip strength) Thumb adduction |
| T1 | None | Medial arm (Axilla area) | Finger abduction/adduction (Interossei) |
Quick Mnemonics & Study Tips
- L2, L3, L4 kick the door (Patellar).
- S1, S2 buckle my shoe (Achilles).
- S2, S3, S4 keep the poop off the floor (Anocutaneous/Anal wink).
- L5 allows you to walk on your heels (Dorsiflexion).
- S1 allows you to walk on your toes (Plantarflexion).
- C5, C6 pick up sticks (Biceps and Brachioradialis).
- C7, C8 lay them straight (Triceps).
- C6 is the "Six-shooter": Think of a hitchhiker's thumb (C6) and pulling the trigger (wrist extension).
- C7 is for "Point Seven": The middle finger points to C7.
- T4 is at the Teat (nipple line).
- T10 is at the Belly But-ten (umbilicus).