From the Research
The dermatome that supplies pain reception to the calf area is primarily L5 (fifth lumbar) with some contribution from S1 (first sacral), as supported by the most recent study 1. The calf region, located at the posterior aspect of the lower leg between the knee and ankle, receives its sensory innervation through these spinal nerve roots.
- L5 generally covers the lateral and anterior aspects of the calf,
- while S1 supplies the posterior and medial portions. This dermatome distribution is important clinically when evaluating patients with lower limb pain, numbness, or tingling, as it helps localize potential nerve root compression or irritation. For example, patients with L5 radiculopathy (nerve root compression) often experience pain radiating down the lateral aspect of the calf, while S1 compression may cause pain along the posterior calf. Understanding this dermatome pattern aids in diagnosing conditions like herniated discs, spinal stenosis, or other pathologies affecting these nerve roots, as noted in studies 2, 3, 4, 5. However, it's essential to consider that pain patterns may not always follow a specific dermatome, as highlighted in studies 4 and 5, which found that pain distribution did not correspond well with dermatomal patterns in patients with L5 and S1 nerve root compressions. Despite this, the most recent and highest-quality study 1 suggests that the L5 and S1 dermatomes are involved in the sensation of the calf area. Therefore, when evaluating patients with calf pain, it's crucial to consider the potential involvement of both L5 and S1 nerve roots.