see also: [[Trauma - C-spine exam]], [[Weakness]] OSCE examples: [2024 - EH station 1](x-devonthink-item://9EE514EB-0C4F-42A3-978C-AB30671318D1), [2021 RMH Feb station 6](x-devonthink-item://CC843F8C-5839-42A1-A522-22B9B28B6C9D) - General inspection - gait - Tone - Power - Reflexes - coordination - special tests ## myotomes of lower limb | Movement | muscle | nerve | nerve root | | --------------- | -------------------------------------------------------------------------- | ------------------------- | ---------- | | hip flexion | psoas, iliacus | | L2/L3 | | hip extension | gluteus maximus | | L5, S1, S2 | | hip ABduction | gluteus medius<br>gluteus minimus<br>tensor fasciae latae | | L4, L5, S1 | | hip ADDuction | adductors longus, brevis, magnus | | L2 - L4 | | knee flexion | biceps femoris<br>semimebranosus<br>semitendinosus | sciatic | L5-S1 | | knee extension | quadriceps femoris | femoral | L3-L4 | | plantar flexion | soleus, gastrocnemius, plantaris | | S1 - S2 | | dorsiflexion | tibialis anterior<br>extensor digitorum longus<br>extensor hallucus longus | sciatic → common peroneal | L4-L5 | | ankle eversion | peroneus longus / brevis<br>extensor digitorum longus | | L5/S1 | | ankle inversion | tibialis posterior<br>gastrocnemius<br>hallucus longus | | L5/S1 | > Quick test for lower limb power: > - stand on toes (s1) > - stand on heels (L4/L5) > - squat and stand again (L3/L4) ![[Pasted image 20250316174909.png]] ## Reflexes knee jerk - L3/L4 ankle jerk - S1/S2 Plantar reflex - L5, S1, S2 - "positive babinski" indicates UMN lesion, but poor reliability; can also have bilat upgoing toes after generalised seizure, in in a pt in a coma cremasteric reflex - L1-L2 saddle sensation and reflex: - buttocks or around anus (s3-s5) may be only sensory loss of cauda equina - anal reflex S2-S4 (contraction of external sphincter in response to perianal prick) ## Dermatomes of lower limb See also: [[Dermatomes]] T12 - inguinal ligament at midpoint L1 - half distance between T12 and L2 L2 - mid-upper anterior thigh L3 - anterior knee L4 - medial malleolus and medial leg L5 - lateral aspect of leg and medial side of dorsum of foot at third MTP joint S1 - lateral heel and most of the sole S2 - popliteal fossa in midline, posterior aspect of the thigh S3 - ischial tuberosity S4-5 - peri-anal region ![[Pasted image 20250102234655.png]] ![[Pasted image 20250103161207.png]] ## Gait - antalgic, high stepping, or dragging in foot drop - waddling gait in proximal myopathy - ataxic or spastic gait ## coordination - dysmetria - heel-shin testing - dysdiadochokinesia - toe tapping ## Causes of foot drop see: [Cabrini 2024 OSCE station 2 - foot drop](x-devonthink-item://67D0651D-1E46-4065-9D3A-E9900EDC70A5) clinical features: weakness of ankle dorsiflexion, weakness of eversion/inversion depending on pathology. variable sensation loss can affect lateral lower leg, dorsum of foot, and 1st web space - common peroneal nerve palsy - sciatic nerve palsy - lumbosacral plexus lesion - L4/L5 root lesion - peripheral motor neuropathy - distal myopathy - motor neurone disease - stroke -- ACA or lacunar syndrome | cause | findings | history | | --------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | L5 nerve root lesion | - weakness of ankle dorsiflexion and inversion<br>- loss of sensation to medial aspect of foot and 1st web space<br>- neuropathic pain down posterior leg | - often history of sciatica radiating from back<br>- weakness in hip extension<br>- straight leg test positive<br>- "L F**I**V**E** → **I**nversion and **E**version are lost" | | sciatic nerve palsy | - sensory loss of whole foot<br>- weakness of ankle dorsiflexion and eversion, toe extension<br>- sensory loss to lateral lower leg and dorsum of foot | | | common peroneal nerve palsy | - weakness of ankle dorsiflexion and eversion, toe extension<br>- sensory loss to lateral lower leg and dorsum of foot<br>- reflexes intact | - usually history of direct trauma to lateral knee or sustained pressure <br>- forcefully inverting ankle puts pressure on peroneal nerve, which may reproduce symptoms<br>- "common peroneal only **E** so only **E**version is lost" |