Clean FRCS notes with inline figures
Crouch gait
•Midstance gait problem
•Excess ankle dorsiflexion, knee flexion, hip flexion
•GRF falls behind knee center
•Failed PF/KE coupling
•Leading to persistent quadriceps contraction and fail screw-home mechanism of knee
•Overall increase energy expenditure, short stride length
•Causes
•1. Weakness (triceps surae, quads)
•2. Spasticity (hamstring, iliopsoas)
•3. Joint contracture (knee joint flexion contracture)
•4. Lever arm dysfunction (increase femoral anteversion, increase tibial torsion, collapse tripod)
•Brief summary
•Weak gastrosoleus / excessive ankle dorsiflexion → unable to have KE/APF couple → GRF falls posterior to knee → knee flexion moment
Management
•Muscle weakness
•Gastroc: Avoid iatrogenic excessive gastrosoleus release/ recession. GRAFO
•Quads: hamstring transfer
•Spasticity
•Hamstring lengthening
•Sequelae: weak HE + ant pelvic tilt
Tech:
•SemiM + gracilis fractional lengthening +/- bicep femoris in severe cases
•Semi T to adductor tubercle transfer (biarticular to mono articular → prevent hip extension and decrease anterior pelvic tilt)
•Psoas
•Release at pelvic brim or LT
•Joint contracture
•Extension osteotomy
•Hip, tibia or Foot lever arm dysfunction → recon
•GRAFO (Posterior entry)
•Indication: For crouch gait with weak gastrocnemius and quadriceps with failure of knee extension-ankle plantar flexion couple
•Static, accommodative type of orthosis made of high temp thermoforming plastic, covered from level of mid patella to MT
•Utilizes Newton’s third law to alter the GRF by controlling the distal joints to alter the proximal joint
•Prevent excessive tibial anterior translation during ankle rocker with a rigid anterior tibial shell
•Prevent excessive DF of the ankle with a toe plate and riding ankle in neutral position
•Keep GRF anterior to knee joint by creating an extension moment at the knee
•Help to stabilize the knee and decreased quad workload to extend the knee
•Contraindicated in crouch gait due to high tone / knee FFC