Stance Phase of Gait

- See:
    - Gait Menu:
    - Orthotics for the Foot

- Discussion:
    - stance phase represents about 60% of the gait cycle, swing 40%;
           - normal gait is symmetric & thus, relationship between swing and stance phases of each leg are consistent;
    - normal gait requires stability in stance phase, a means of progression, and energy conservation;
    - stability requires constant balancing of trunk over base of support;
    - during progression, potential energy is converted into kinetic energy;
    - much of kinetic energy for swinging limb is provided by inertia, which is augmented by the plantarflexors (85%) and hip flexors (15%);
    - energy is conserved by minimizing movements of center of gravity of body, by controlling momentum, and by transfer of energy between body segments;

- Five Parts of Stance Phase:
    - stance phase has five parts: contact, loading, midstance, terminal stance, and preswing;
    - throughout stance pelvis gradually rotates backward & hip extends (this resists the tendency for the hip to flex during early stance phase due to body wt and body inertia);
    - heel strike
           - at initial contact, the knee is extended and the ankle is neutral (or slightly plantarflexed);
           - during loading, knee flexes 15 deg while ankle plantarflexes 15 degrees, which is an energy-conserving mechanism;
           - throughout first phase of stance, hamstrings and ankle dorsiflexors remain active;
           - quadriceps and gluteal muscles act during loading and throughout early midstance to maintain hip and knee stability;
    - midstance:
           - by midstance the knee is extended & ankle is neutral again;
           - in midstance, triceps surae acts to control tibial advancement (preventing tendency for tendency for the ankle to dorsiflex due to body wt and inertia);
           - double support, when both feet are in contact with the ground, lasts about 10% of the whole gait cycle;
    - terminal stance
           - at preswing, knee flexes 35 degrees &ankle plantarflexes 20 degrees;
           - in these last phases of stance, the toes, which have been neutral, dorsiflex at the metatarsophalangeal joints

Dynamic Loading of the Plantar Aponeurosis in Walking.

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, May 24, 2012 12:56 pm