Knee extension is carried out by L-2, 3 and 4 (Femoral nerve). Injury at the level of L- 5, doesn't affect knee extension. Knee flexion is carried out by the root value: L -5 and S-1 (Tibial nerve). Toe extension requires L-5 (deep peroneal nerve) Ref - BDC 6th e p140 lowerlimb