- 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.