Here are the different phases of the gait cycle and the mechanics of the body in each of these phases:

Heel contact to mid stance (1-2 in image)

• The ankle starts to flex and pronates (In positive way) to absorb shock (This is the most important phase for shock absorption)
• Tibialis Anterior (TA) contracts to bring the shin forwards over the foot, while the calf eccentrically controls the shin
• The adductors (groin), quads and hamstrings are activated eccentrically to stabilise the movement

Mid stance to heel off (2-3 in image)

• The body’s centre of mass moves forwards over the foot
• The ankle reaches maximum pronation
• Eccentric contraction of the hamstrings and quads to stabilise the knee

Heel off to toe off (3-4 in image)

• The ankle goes into supination (Opposite of pronation) and windlass mechanism is activated to create a rigid foot to push-off the ground (Toe-off)
• The calf contracts to help with push-off and running economy. On top of that, the hamstrings, quads, glutes and TA transition from a stabilising function to a concentric function to help with push-off.

Initial Swing (5 in image)

• The quads and hip flexors contract concentrically to swing the leg forwards
• The glutes work to stabilise the pelvis
• TA helps to keep the foot up, and prevents catching on the ground

Terminal Swing (6 in image)

• Almost all the muscles of the lower limb activate in this phase to straighten the hip, knee and ankle for the next initial contact. The adductors and hamstring work to stabilise and decelerate the forward moving leg. 
  

• The ankle starts to flex and pronates (In positive way) to absorb shock (This is the most important phase for shock absorption)