wk 11- biomechanics of running gait Flashcards
what is the key difference between walking and running
float phase in running instead of double support which includes loading response (which is now weight acceptance) and pre swing phases (absent in running)
phases of running now
stance phase: (reduced to 35% from 60%)
loading response, mid stance and terminal stance (no pre swing)
swing phase:
early float, middle swing, late float
when does float phases become longer
during faster speeds
stance phase becomes longer during
slower speeds
sagittal kinematics of hip and knee (stance)
hip- at IC approx 25 degrees flexion (it’s less for walking because less shock to absorb)
reaches approx 25 deg extension around TO
knee- at IC approx 10-20 deg flexed and continues to flex up to approx 40 degrees
during midstance, begins to extend until 5-10 deg flexed around TO
sagittal kinematics of ankle (stance)
At IC, slightly dorsiflexed
* Rapid small plantarflexion ‘arc’
(if heel strike pattern)
* After forefoot contact,
dorsiflexion up to approx 20°
* This is only true for HEEL
strikers
sagitall kinematics (stance)
At middle of midstance:
peak ankle DF (20°),
knee flexion (40°), and
hip flexion (25°) are
reached
* Ankle plantarflexion,
knee & hip extension
then occur
simultaneously to
generate power for
propulsion
frontal plane kinematics - foot
At IC, rearfoot is inverted approx 5-10
deg
– Rearfoot eversion then occurs rapidly
(up to 8-12 deg)
– This motion helps attenuate impact
forces
– Important to note this is NORMAL,
not pathological
transverse plane kinematics - knee
At IC, the knee is slightly internally
rotated, continues to internally rotate
approx 8 deg until mid support, then
begins to externally rotate through
propulsion
– Remember the link between foot
pronation and internal shank (tibial)
rotation?
swing phase is aout what % in walking?
60
swing phase kinematics for hip, knee and ankle
HIP: rapid flexion during midswing (attaining
a position 30-45° flexed ready for IC)
- KNEE: moves through flexion (up to approx
100°) then extension (10° flexed ready for
IC) - ANKLE: from a position of peak PF (30°),
DF now occurs during early float (to 5° DF
foot strike patterns for distance runners and sprints
distane:
-80% strike with rearfoot
-20% with midfoot and forefoot
sprinters
-forefoot strike (eccentric loading of achilles to absorb)
muscle control during stance, what muscles are active for stance running
controlled fall by the posterior muscles
– Gastroc/soleus
– Tibialis posterior: supports MLA and
controls pronation
– Peroneus brevis: supports the lateral
ankle
– Tibialis anterior: constantly active, but
more active during swing
* Quadriceps:
– Very important during loading response
– Eccentrically control knee flexion
– Absorb impact forces
* Hip extensors are active during weight acceptance
* Add magnus/TFL important for medial/lateral stability of pelvis
muscle control during swing, whats active
- Early float and midswing:
– Tib anterior (ankle DF)
– Hamstrings (knee flexion)- more active in running than walking
– Iliacus and rectus femoris (hip flexion) - Late float:
– Quads (knee extension) - Throughout swing, coordinated eccentric and concentric contractions accelerate
and decelerate the limb
what is biarticular muscles, hamstrings as an example
hamstrings cross knee and hip
flexor moment at knee
extensor at hip
hammies grab energy from the eccentric movement from the tibia flying through and sends it to the hip during the concentric movement caused up there (eccentric generates energy, concentric uses energy(
