Editing Running (section)

===Propulsion phase===
Research, especially in the footstrike debate, has primarily focused on identifying and preventing injuries during the absorption phases of running. The propulsion phase, which occurs from midstance to toe-off, is crucial for understanding how the body moves forward.<ref name="Nicola 2012 187–201" /><ref name="Novacheck 1998 77–95" /><ref name="Hammer 2010 2709–16">{{cite journal |last=Hammer |first=S.R. |year=2010 |title=Muscle contributions to propulsion and support during running |journal=Journal of Biomechanics |volume=43 |issue=14 |pages=2709–2716 |doi=10.1016/j.jbiomech.2010.06.025 |pmc=2973845 |pmid=20691972}}</ref> 

In a full stride length model, elements of both the terminal swing and footstrike contribute to propulsion.<ref name="Schache 1999 30–47" /><ref name="Ardigo 2008 17–22">{{cite journal |last=Ardigo |first=L.P. |year=2008 |title=Metabolic and mechanical aspects of foot landing type, forefoot, and rearfoot strike, in human running |journal=Acta Physiologica Scandinavica |volume=155 |issue=1 |pages=17–22 |doi=10.1111/j.1748-1716.1995.tb09943.x |pmid=8553873}}</ref> 
The setup for propulsion begins at the end of the terminal swing when the hip joint flexes, allowing the hip extensors to generate force as they accelerate through the maximal range of motion.

As the hip extensors transition from inhibitory to primary muscle movers, the lower extremity moves back towards the ground, aided by the [[stretch reflex]] and gravity.<ref name="Schache 1999 30–47" /> The footstrike and absorption phases follow, leading to two possible outcomes.

With a heel strike, this phase may be just a continuation of momentum from the stretch reflex, gravity, and light hip extension, offering little force absorption through the ankle joint.<ref name="Hammer 2010 2709–16" /><ref name="Bergmann 2000 817–827">{{cite journal |last=Bergmann |first=G. |year=2000 |title=Influence of shoes and heel strike on the loading of the hip joint |journal=Journal of Biomechanics |volume=28 |issue=7 |pages=817–827 |doi=10.1016/0021-9290(94)00129-r |pmid=7657680}}</ref><ref name="Lieberman 2010 531–535">{{cite journal |last=Lieberman |first=D. |year=2010 |title=Foot strike patterns and collision forces in habitually barefoot versus shod runners |journal=Nature |volume=463 |issue=7280 |pages=531–535 |bibcode=2010Natur.463..531L |doi=10.1038/nature08723 |pmid=20111000 |s2cid=216420}}</ref> On the other hand, a mid/forefoot strike helps in shock absorption, supporting plantar flexion from midstance to toe-off.<ref name="Lieberman 2010 531–535" /><ref name="Williams 2000 210–218">{{cite journal |last=Williams |first=D.S. |year=2000 |title=Lower Extremity Mechanics in Runners with a Converted Forefoot Strike Pattern |journal=Journal of Applied Biomechanics |volume=16 |issue=2 |pages=210–218 |doi=10.1123/jab.16.2.210}}</ref>

The actual propulsion begins when the lower extremity enters midstance.<ref name="Hammer 2010 2709–16" /> The hip extensors continue contracting, assisted by gravity and the stretch reflex from maximal hip flexion during the terminal swing. Hip extension pulls the ground underneath the body, propelling the runner forward.

During midstance, the knee should be slightly flexed due to elastic loading from the absorption and footstrike phases, preserving forward momentum.<ref name="Kubo 2000 181–187">{{cite journal |last=Kubo |first=K. |year=2000 |title=Elastic properties of muscle-tendon complex in long-distance runners |journal=European Journal of Applied Physiology |volume=81 |issue=3 |pages=181–187 |doi=10.1007/s004210050028 |pmid=10638375 |s2cid=10044650}}</ref><ref name="Magness">{{cite web |last=Magness |first=S. |date=4 August 2010 |title=How to Run: Running with proper biomechanics |url=http://www.scienceofrunning.com/2010/08/how-to-run-running-with-proper.html |access-date=3 October 2012}}</ref><ref name="Thys 1975 281–286">{{cite journal |last=Thys |first=H. |year=1975 |title=The role played by elasticity in an exercise involving movements of small amplitude |journal=European Journal of Physiology |volume=354 |issue=3 |pages=281–286 |doi=10.1007/bf00584651 |pmid=1167681 |s2cid=21309186}}</ref> The ankle joint is in [[dorsiflexion]] at this point, either elastically loaded from a mid/forefoot strike or preparing for stand-alone concentric plantar flexion.

The final propulsive movements during toe-off involve all three joints: ankle, knee, and hip.<ref name="Hammer 2010 2709–16" /><ref name="Bergmann 2000 817–827" /><ref name="Lieberman 2010 531–535" /><ref name="Williams 2000 210–218" /> The plantar flexors push off from the ground, returning from dorsiflexion in midstance. This can occur either by releasing the elastic load from an earlier mid/forefoot strike or through concentric contraction from a heel strike.

With a forefoot strike, the ankle and knee joints release their stored elastic energy from the footstrike/absorption phase.<ref name="Kubo 2000 181–187" /><ref name="Magness" /><ref name="Thys 1975 281–286" /> The quadriceps group/knee extensors fully extend the knee, pushing the body off the ground. Simultaneously, the knee flexors and stretch reflex pull the knee back into flexion, initiating the initial swing phase. The hip extensors extend to the maximum, contributing to forces pulling and pushing off the ground, as well as initiating knee flexion and the initial swing phase.