Stance
How much of gait is made up of stance?
60%
What is happening at the knee in initial swing?
Fully passive knee flexion to achieve toe clearance.
How many rockers are there?
Four- heel, ankle, forefoot, and toe
Name an essential accomplishment of loading response.
Hip stability, controlled weight transfer, shock absorption, promote progression, and having a stable base for weight acceptance.
What movements need to be closest to end range for gait?
What maintains pelvis stability in mid-stance phase?
Eccentric activity from hip abductors.
What muscle is most active in all of the swing phases?
Tibialis anterior
What stage is the heel rocker found in and what is its function?
Initial contact
Eccentrically controlled PF that brings the tibia forward as the knee flexes and ankle dorsiflexes - fulcrum for loading response.
Name an essential accomplishment of pre-swing.
Passive hip and knee flexion in preparation for swing phase, weight is unloaded and transferred to CL limb, initiates limb progression, unweighting results in toe only contact.
What is vector summation?
Composite of multiple lines of pull which makes a singular effort.
What is the only muscle activity that happens in terminal stance?
DF eccentrically controlled by plantarflexors.
Is pre-swing part of the swing phase or the standing phase?
Technically swing, but not part of "traditional swing phase" because it has double limb support.
What stage is the ankle rocker in and what is it's function?
Mid-stance
Tibia moves forward about the talocrural joint, dorsiflexion eccentrically controlled by gastroc and soleus.
Name an essential accomplishment of initial contact.
Initiate heel rocker, heel contact to advance center of mass, deceleration.
Examples of external forces.
Gravity, friction, ground reaction forces.
In initial contact, what muscle actions happen (internal moments) against the ground reaction forces (external moments)?
Eccentric hip extension, isometric quad activation, and eccentric dorsiflexion
Successful initial swing requires concentric activity of which muscles?
Hip flexors, primarily iliopsoas.
Also tib anterior
What stage is the forefoot rocker found in and what is it's function?
Terminal stance, controls progression of the center of mass anterior to the foot.
Name an essential accomplishment of initial swing.
Thigh advances forward, knee flexion achieves tow clearance, hip flexion to 15 degrees and knee flexion to 60 degrees.
Why do we have ground reaction forces?
For every action there is an equal and opposite reaction! If you strike the ground, it strikes back!
If loading response is done poorly, what can happen?
Instability and falls, or inefficiency that requires increased energy expenditure for normal ambulation.
What muscles are active in terminal swing?
Hamstrings (eccentric), quadriceps (eccentric), dorsiflexors (concentric to prevent toe drag)
What stage is the toe rocker found in and what is it's function?
Final pivot point for the body's continued forward movement and transition into swing phase.
Elastic recoil of achilles tendon causes 15 degrees of plantarflexion here!
Name an essential accomplishment of terminal swing.
Knee extends to prepare for heel contact, full limb clearance, weight shift.
Name the causes of external moments in initial swing.
Gravity, air flow, and friction
*no GRF since limb is in air!!