Lower Limb Nerve Injuries Sammy Case and matt vreugde Feel free to send questions to s.case@warwick.ac.uk and m.vreugde@warwick.ac.uk

Starting from the top and working our way down… Superior gluteal artery & nerve (L4-S1) Inferior gluteal artery & nerve (L5-S2) Sciatic nerve (L4 – S3)

Superior Gluteal Nerve L4-S1 - What muscles does it innervate? Gluteus Medius and Gluteus Minimus - What do these muscles do in a normal person? Abduction of the hip. Prevent the pelvis from tipping towards the unsupported side when walking - What is the consequence of a superior gluteal nerve injury? Pelvis tips towards side unsupported by limb during gait - How does the patient correct for this? Compensated Trendelenburg gait – the patient will lean the trunk when walking to help prevent the tilt towards the unsupported side. https://www.youtube.com/watch?v=HE0lk5MVFEg

Inferior Gluteal Nerve L5-S2 - What muscle does it innervate? Gluteus Maximus - What does this muscle do in a normal person? Extend a flexed hip and bring it inline with the trunk - What is the consequence of an inferior gluteal nerve injury? Weakness of hip extension Difficulty getting out of a chair and going up stairs - How does the patient correct for this? Gluteus Maximus Lurch - Gait in which trunk lurches back on heel strike to prevent it from toppling forward https://www.youtube.com/watch?v=bTQ5ID7Tpa4

Thigh Compartments

Femoral Nerve L2-L4 - What actions does the femoral nerve bring about? Hip flexion and knee extension - What will be the result of damage to this nerve? No knee extension. Weakened hip flexion (partly done by medial compartment which is innervated by the obturator nerve). - How is it commonly injured? Compression on iliacus during childbirth In the femoral triangle (femoral stab damage)

Obturator Nerve L2-L4 - What actions does the obturator nerve bring about? Hip adduction - What will be the result of damage to this nerve? Wide based gait with instability, Centre of gravity shifts laterally - How is it commonly injured? Compression on the pelvic brim during childbirth Surgery to the pelvic cavity

Sciatic Nerve L4-S3 - What actions does the sciatic nerve bring about? Hip extension and knee flexion/rotation - What will be the result of damage to this nerve? Impaired hip extension Very weak knee flexion Absent ankle and digit plantarflexion or dorsiflexion - How is it commonly injured? Posterior hip dislocation (car accident) Stab injury to the gluteal region

Leg Compartments

Common Fibular Nerve L4-S1 Divides to form the deep and superficial fibular nerves that supply the anterior and lateral leg compartments - What actions does the common fibular nerve bring about? Foot inversion, eversion and dorsiflexion - What is the result of damage to this nerve? Absent dorsiflexion of the foot = foot drop Absent ankle eversion meaning the patient is more likely to sprain or fracture their foot following an inversion injury - How is it commonly injured? Posterior hip dislocation (car accident) Stab injury to the gluteal region Car accident damaging the lateral aspect of the fibula head

Tibial Nerve L4-S2 - What actions does the tibial nerve bring about? Foot and digit plantarflexion and inversion - What is the result of damage to this nerve? Weak plantarflexion - How is it commonly injured? Posterior hip dislocation (car accident) Stab injury to the gluteal region Damage posterior to the medial malleolus in the tarsal tunnel

MCQ practice! What functional problem would be caused by damage to the inferior gluteal nerve? A. Inability to flex the hip B. Pelvic tilt toward the unsupported side during walking C. Wasting of the posterior compartment of the thigh D. Weak hip extension E. Weak lateral hip rotation A 36 year old male is hit by a slow moving car on the lateral side of his knee. Which nerve would be responsible for the foot drop experienced as a consequence? Obturator nerve Tibial nerve Common fibular nerve Femoral nerve Superior gluteal nerve

MCQ practice! A Dr is injecting a patient’s bum. To ensure that the needle is placed in a safe area they draw a vertical line through highest point of the iliac crest and another line from PSIS to the greater trochanter and inject into the upper outer quadrant of the patient's gluteal region. What nerve is the Dr trying to avoid by employing this method? Pudendal nerve Sciatic nerve Superior gluteal nerve Inferior gluteal nerve A 75 year old female is enjoying her weekly yoga class when she suddenly experiences severe back pain. She tries to stand and realises that she’s unable to pick her foot up properly to walk. She is also experiencing numbness and pain on the sole of her foot. Which IV disc has prolapsed to cause these symptoms? L2/L3 L3/L4 L4/L5 L5/S1