KNEE HYPEREXTENSION IN STANCE

This common gait deficit occurs when the quadriceps fail to perform their customary role during LOADING RESPONSE and the first part of midstance. The quadriceps may not act appropriately in the event of:

• QUADRICEPS WEAKNESS
• PAIN WITH QUADRICEPS ACTIVATION
• PROPRIOCEPTIVE DEFICIT

When the knee extensors fail to control the ground reaction force's knee flexor moment, THE PERSON MUST COMPENSATE TO PRESERVE KNEE STABILITY.

THESE COMPENSATIONS WILL LIKELY HYPEREXTEND THE KNEE DURING STANCE. THE COMPENSATIONS MIGHT INCLUDE ONE OR MORE OF THE FOLLOWING:

1. SUBSTITUTION OF ANOTHER MUSCLE IN A CLOSED CHAIN FOR EXAMPLE,
   • INCREASED HIP EXTENSOR FORCE
   • INCREASED ANKLE PLANTAR FLEXOR FORCE

2. MOTIONS THAT RELOCATE THE GRF VECTOR, CHANGING THE MOMENT THE GRF PRODUCES AT A JOINT. FOR EXAMPLE,
   • FORWARD TRUNK LEAN DURING LOADING RESPONSE AND MIDSTANCE
   • FLAT FOOTED INITIAL CONTACT

3. MOTIONS THAT RELOCATE THE JOINT AXIS, CHANGING THE MOMENT THE GRF PRODUCES AT A JOINT FOR EXAMPLE,
   • DECREASED FORWARD PELVIC ROTATION

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Last updated 5-15-98 ©Dave Thompson PT
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