Position:  0-5 degrees

Moment:  Brief Flexor/extension

MA: Hamstrings and quads (Co-contraction to stabilize and protect the knee), upper g-max

FS:control knee extension moment and prevent excessive extension.  Prepare for loading response

Position:  15 degrees flexion

Moment:  Extensor/flexion

MA:  Quadriceps (PEAK), Hamstrings are active but functioning primarily at hip

FS:  Continued control of knee flexion moment

Position:  0-5 degrees of flexion (extension)

Moment:  Flexor/extension,  Abductor/adduction

MA:  Quads (Fade away) and plantarflexors, G-max (via ITB attachment)

FS: Quads extend the knee initially, plantarflexors stabilize knee by controlling the tibia, Adduction(varus) moment is opposed at knee

Position: 0-5 degrees flexion

Moment: Extension/flexor early then Flexion/extensor

MA:  Gastroc, Popliteus, Biceps Femoris short head

FS:  Prevent hyperextension of the knee (early), Promote knee flexion (late)

Position:  40 degress flexion

Moment:  Extensor/flexion

MA:  Gastroc, Gracilis, Popliteus, Sartorius, Rectus Femoris

FS:  Flexors aide momentum and GRF to flex the knee. The rectus if active, prevents excessive knee flexion

Position: 60 degrees flexion

Moment:  extensor/flexion

MA:  Iliacus, Rectus Femoris, Bicep Femoris short head, Sartorius, Gracilis

FS:  Assist momentum to gat sufficient knee flexion (biceps directly, iliacus and rectus indirectly).  Rectus also prevents excessive knee flexion

Position:  25 degrees flexion

Moment:  Extensor/flexion initially then flexor/extension later

MA:  Hamstrings

FS:  Knee extension needed for step length begins here and is created by momentum created by the advancing tibia.  Flexors prevent too much extension.

Position:  0-5 degrees extension

Moment: Flexor/extension

MA:  Hamstrings and Quads

FS:  Hamstrings decelerate the thigh and prevent hyperextension.  Quads achieve knee extension.  Hamstrings and quads co-contract prior to heel strike