GASTROC M Flashcards
what period is the gastroc m active?
late contact/early propulsion
what is the origin and insertion of the gastroc m?
*what is significant about the insertion?
origin on the femur
insertion on the calcaneus
*inserts medially on the calcaneus so it can invert the heel
what is the relationship between the gastroc m and the knee?
maintains flexion tension on knee while knee extends
the knee is antagonistic to what kind of extension forces?
knee extension forces placed on the knee by other calf muscles
what is the end result of the gastroc effect on knee?
to prevent hyperextension of the knee
when do flexor forces of the knee begin?
late contact period and continue until early propulsion and so this contributes to smooth knee extension to prepare for heel lift
what muscles does knee assist? purpose
assists posterior tibial and soles muscles in decelerating internal rotation of lower extremity near end of contact
also gastroc stops internal rotation of the femur while post tib and soleus stop internal rotation of tibia
what other function of gastroc is performed?
external rotation of the femur to prevent torque at knee while post tib, soleus, and long flexors accelerate lower leg in external rotation
assists the PT, soleus and long flexors in supinating the STJ during midstance and early propulsion
how is the heel related to the gastroc?
flexes the knee and lift heel to initiate the propulsive period causing an upward and forward acceleration of the trunk
for pathology, what happens if the muscle action or functional length of tendon is lengthened?
leads to heel lift at end of midstance/start of propulsion is impossible
clawing of toes and plantarflexion of first ray
what are the articulations of the gastroc?
pull of achilles tendon allowing gastroc to have greater affect on ankle joint
pull of gastroc to the STJ is 45 degrees in which supination is likely from calcaneal inversion
