LE Orthotics

January 15, 2025

This review covers the subtle differences between AFOs including solid AFOs, articulating AFOs, spring AFOs, ground reaction AFOS, as well as covers foot orthotics and KAFOs. HKAFOs are not covered in this review...I just remember HKAFOs as controlling everything with reciprocating gait orthoses being a type that mimics natural gait. However, due to energy insufficiencies this ends up being used more for pediatric patients.

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Super important to remember normal gait to understand where a device may help a patient, so here are some gait reminders:

Torques:

  • Induced Torque: External force that is INDUCED on our joints. Torque on a joint. Ex: gravity, ground reaction force (GRF)
  • Reactionary Torque: How our body REACTS to the induced torque. Torque by a joint via our muscles.

Gait Takeaways:

  1. IC: Glute max ECC control leg from flinging forward, this phase is very short.
  2. LR: Quads ECC control the induced flexion torque created from the plantarflexors. Require ECC pretibial control to prevent foot slap. This is also where there is the highest induced hip flexion torque ( = Glute max ECC reactionary). Heel rocker happens here.
  3. MSt: ADD induced torque peaks ( = Glute med active control). Gastrocs are super important here to keep the knee from buckling (not the quad, not the glute max) since the plantarflexors ECC control the knee. Tib Post is important here to prevent excess pronation. Ankle rocker happens here.
  4. TSt: Closed chain DF most important here for windlass mechanism and forefoot rocker to occur. Gastroc still controlling knee tibial advancement but becomes more quiet during this phase.
  5. PSw: Rapid PF ROM most important here along with 60deg MTP extension for a good push off via supinated midtarsal joints. Gastroc activity carries over from last phase to drive a passive knee flexion (hence an induced knee flexion torque) passively to 40deg knee flexion.
  6. ISw: Knee Flexion ROM most important here coming to 60deg flexion via the hamstrings concentric slightly (although more momentum from PSw passive knee flexion). MTPs to neutral via ECC extensor control. Quads CON to get to 15deg flexion.
  7. MSw: Hip flexion ROM most important here coming to 25deg. Hamstrings ECC control knee flexion from 60 to 30deg. Tib Ant stabilizes medial arch. Phase also requires adequate DF to neu to clear the foot concentrically.
  8. TSw: Glute max and hamstrings ECC control extension into IC to restart the cycle over again. Very little quad action. Max pelvis rotation to keep the leg from swinging forward.