Figure 4-17 Lumbar zygapophyseal joint pain referral patterns. Zygapophyseal pain patterns of the lumbar spine as described by Fukui and colleagues. Lumbar zygapophyseal joints L1/2, L2/3, and L4/5 always referred pain to the lumbar spine region. Primary referral to the gluteal region was from L5/S1 (68% of the time). Levels L2/3, L3/4, L4/5, and L5/S1 occasionally referred pain to the trochanteric region (10% to 16% of the time). Primary referral to lateral thigh, posterior thigh, and groin regions were most often from L3/4, L4/5, and L5/S1 (5% to 30% of the time).