Editing Running (section)

===Swing phase===
Initial swing is the response of both stretch reflexes and concentric movements to the propulsion movements of the body.  Hip flexion and knee flexion occur, beginning the return of the limb to the starting position and setting up for another foot strike.  The initial swing ends at midswing when the limb is again directly underneath the trunk, pelvis, and hip with the knee joint flexed and hip flexion continuing.  Terminal swing then begins as hip flexion continues to the point of activation of the stretch reflex of the hip extensors.  The knee begins to extend slightly as it swings to the anterior portion of the body.  The foot then makes contact with the ground with a foot strike, completing the running cycle of one side of the lower extremity.
Each limb of the lower extremity works opposite to the other.  When one side is in toe-off/propulsion, the other hand is in the swing/recovery phase preparing for footstrike.<ref name="Anderson 1996 76–89"/><ref name="Nicola 2012 187–201"/><ref name="Novacheck 1998 77–95"/><ref name="Schache 1999 30–47"/> Following toe-off and the beginning of the initial swing of one side, there is a flight phase where neither extremity is in contact with the ground due to the opposite side finishing terminal swing.  As the footstrike of the one hand occurs, the initial swing continues.  The opposing limbs meet with one in midstance and midswing, beginning the propulsion and terminal swing phases.