Execution
- 1Position the patient relaxed with the tested limb supported.
- 2Tap the patellar tendon to assess primarily L3-L4.
- 3Tap the Achilles tendon to assess primarily S1.
- 4Test the medial hamstring reflex when L5-S1 involvement is suspected and the response can be elicited reliably.
- 5Compare amplitude and symmetry bilaterally and integrates the result with strength and sensation.
Positive outcome
Reduced or absent reflex compared with the opposite side is positive for possible lower motor neuron or nerve-root involvement. Hyperreflexia, clonus, or pathological reflexes suggest upper motor neuron involvement and require a different clinical pathway. Reflex asymmetry is more meaningful than an isolated low response in a generally hyporeflexic patient.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Tawa et al. (2017) — systematic review | NA | 14-67 | 60-93 | NA | NA |
| Suri et al. (2011) | NA | NA | NA | NA | NA |
CommentDeep tendon reflex testing is often more specific than sensitive for radiculopathy, especially when the reflex level matches motor and sensory findings. Reflexes can be absent for reasons unrelated to radiculopathy, including age, peripheral neuropathy, or systemic disease. Use the lower-limb reflex screen as a pattern-confirming component rather than a stand-alone test.
Low Clinical Value