Lumbosacral Radiculopathy: Neurologic Features
| Lumbosacral Nerve Roots | Examination Findings | Pain Distribution | ||
|---|---|---|---|---|
| Reflex | Sensory | Motor | ||
| L2a | — | Upper anterior thigh | Psoas (hip flexors) | Anterior thigh |
| L3a | — | Lower anterior thigh | Psoas (hip flexors) | Anterior thigh, knee |
| Anterior knee | Quadriceps (knee extensors) | |||
| Thigh adductors | ||||
| L4a | Quadriceps (knee) | Medial calf | Quadriceps (knee extensors)b | Knee, medial calf |
| Thigh adductors | Anterolateral thigh | |||
| L5c | — | Dorsal surface—foot | Peronei (foot evertors)b | Lateral calf, dorsal foot, posterolateral thigh, buttocks |
| Lateral calf | Tibialis anterior (foot dorsiflexors) | |||
| Gluteus medius (hip abductors) | ||||
| Toe dorsiflexors | ||||
| S1c | Gastrocnemius/soleus (ankle) | Plantar surface—foot | Gastrocnemius/soleus (foot plantar flexors)b | Bottom foot, posterior calf, posterior thigh, buttocks |
| Lateral aspect—foot | Abductor hallucis (toe flexors)b | |||
| Gluteus maximus (hip extensors) | ||||
aReverse straight leg-raising sign present—see “Examination of the Back.”
bThese muscles receive the majority of innervation from this root.
cStraight leg-raising sign present—see “Examination of the Back” in Engstrom JW, Deyo RA: Back and Neck Pain, Chap. 22. Status Epilepticus, p. 111, in HPIM-19.