Gait Analysis

Hip Drive - Observed in the Plantargrade Foot

Gravity Drive - Observed in Rothbarts Foot orThe Preclinical Clubfoot Deformity

Gravity Drive Mechanics (Abnormal Pronation)

Gravity Drive - Left Foot (Rothbarts Foot)

Left foot is pronating at Midstance due to the pull of gravity on the structurally unstable foot.

Inventor and Designer of Postural Control Insoles

Hip Drive Mechanics (Normal Pronation)

Hip Drive - Right Foot

Right foot is supinating at Midstance due to the clockwise rotation of the hip.

Normal Foot Motion - More Correctly referred to as Hip Drive.   This motion is observed in the Plantargrade Foot.

  • Internal hip rotation (more correctly referred to as pelvic rotation) pronates the ipsilateral foot  
  • External hip rotation (more correctly referred to as pelvic rotation) supinates the ipsilateral foot

Discussion Above Animation

  • From Heel Strike to Flat Foot, the foot (subtalar joint) is pronating (due to internal hip rotation).  This unlocks the forefoot and allows it to adapt to uneven ground surfaces.
  • From Flat Foot to Heel Off, the foot (subtalar joint) is supinating (due to external hip rotation).  This locks the forefoot and allows it to function as a rigid lever at Toe (Push) Off (Zitzlesperger, 1960).



References

    Zitzlesperger S 1960.The mechanics of the foot based on the concept of the skeleton as a statically indetermined space framework. Clinical Orthopedics, 16:47-63
    Rothbart BA 1973. Part I. Biomechanical analysis of a normal gait pattern.  Journal Canadian Podiatry Association, (3):3-7.
    Rothbart BA 1973. Part II. Biomechanical analysis of a normal gait pattern.  Journal Canadian Podiatry Association, (4):1-12.

Abnormal Foot Motion - More Correctly referred to as Gravity Drive. This motion is observed in the Rothbarts Foot and PreClinical Clubfoot Deformity

  • Internal hip rotation no longer controls the motion of the ipsilateral
  • External hip rotation no longer controls the motion of the ipsilateral foot
  • The Pull of Gravity drives the pronation pattern of the foot

Discussion

  • At Heel Contact to Mid-stance the foot is pronating
  • From Foot Flat to Mid-stance, the foot continues to pronate (due to the pull of gravity on Rothbarts Foot).  The forefoot remains unlocked. 
  • From Mid-stance to Heel Lift the foot is pronating (due to the pull of gravity on Rothbarts Foot).  The forefoot remains unlocked.
  • At Heel Lift the foot is unstable (loose bag of bones syndrome).