The Impact of Obesity and Weight Loss on Gait in Adults - The Mechanobiology of Obesity and Related Diseases - page 123

Step

Stride

Left step length

Right step length

Step
width

Stride length

Fig. 1 Gait cycle (stride) phases. Stance and swing phases divided into seven periods
corresponding to seven events: IC initial contact, OT opposite toe off, HR heel rise, OI opposite
initial contact, TO toe off, FA feet adjacent, TV tibia vertical. Below illustration of step length and
width

The ground contact usually begins with heel contact (initial contact), pro-
ceeding to foot-flat during single limb support and forefoot contact [ 28 , 43 , 61 ].
The double support phase ends up with a toe-off (Fig. 1 ). The stance and swing
phases can be further divided into seven functional phases (Fig. 1 ). The middle
and terminal stance take place in the single support phase. The final phase of the
stance is pre-swing, in which forward movement of the limb starts.
The forward movement continues through the three swing phases (Fig. 1 )[ 28 ,
43 , 61 ]. During the initial swing, the leg is accelerated forward by knee and hip
flexion; the ankle joint is dorsiflexed. At the beginning of the middle swing, the
swinging leg is aligned with the stance limb, which is in the middle stance. The
foot is prepared for smooth ground contact in the terminal swing with the help of
eccentric (i.e. decelerating) activity of the hamstrings [ 42 ].