Gait Flashcards
Gait cycle
60% stance, 40% swing
- initial and terminal 10% double stance
- middle 40% single limb stance
Functional elements of gait cycle
- Progression
- Standing stability
- Energy conservation
Progression
Forces
- Forward fall of the body weight (begins in single limb stance as ankle DF and accelerates with heel rise)
- Generated by the conralateral swinging limb (starts with onset of single limb stance). This is important before body is aligned for an effective forward fall
Standing stability
- balance challenged by weight displacement (top-heavy) and walking continually alters segment alignment
- two functional units (passenger and locomotor)
- ever-changing alignment of body weight is stabilized by selective muscular control
- timing and intensity of each mm’s activity are dictated by the relationship of body weight to the center of the joint that mm controls
- selective neural control and proprioception as well as adequate mm response
Passenger unit
Head, arms, and trunk
- there are carried rather than contributing to the act of walking
- arm swing is passive reaction to monetum
Locomotor unit
Two limbs joined by intervening pelvis
- pelvis is both locomotor and passenger with two highly mobile junction points (L/S and hip joints)
Energy conservation
- Optimum use of momentum occurs during the person’s natural gait velocity. This pattern requires the lease energy expenditure per meter travelled
- faster or slower pace = increased energy cost - Minimization of body displacement from the line of progression
- accomplished by coordinating pelvic, knee, and ankle motion to keep limb length fairly constant throughout stance
Ankle ROM for gait
- 20 degrees PF (terminal stance to toe-off)
- 10 degrees DF (mid to terminal stance)
Knee ROM for gait
- 60 degrees of flexion (swing)
- 0 degrees of ext (heel strike and midstance)
Hip ROM for gait
- 30 degrees of flex (swing phase)
- 10 degrees of ext (terminal stance)
Initial contact
Heel strike (double limb support)
- begins when heel contacts ground
- ends at beginning of loading response
- torques: ankle PF, knee ext, and hip flex
Initial contact joint motion
- hip: 30 degree flex
- knee: 0 degree
- ankle: neutral
- pelvic rotation: forward on step side
Initial contact peak torque mm
- glute max: eccentric (hip position determines angle between foot and floor)
- quads: eccentric
- Pretibial mm: tib anterior, long extensors of the great and common toes, peroneus tertius
Loading response
Foot flat (double limb support)
- begins when weight shifted on to the limb and entire foot makes contact w/ ground
- ends within opposite foot leaves the ground
- heel rocker!
- goal is acceptance of body weight to ensure limb stability and still permit progression
Heel rocker
- strong action by pretibial mm slows the terminal arc of ankle PF, so forefoot contact is gradual
- first 6-8% of gait cycle
- initiates knee flex
Loading response joint motion
- hip: 30 degrees flex moving into ext
- knee: 15-20 degrees flex
- ankle: 15 degrees PF
- pelvic rotation: forward
Loading response peak torque mm
- tibialis anterior: eccentric
- quads - biceps femoris - glute max and adductor magnus (restrain hip flex)
Midstance
Single limb support
- begins when opposite foot leaves the ground
- ends when body is directly over WB limb
- goal is advancement of the body and limb over a stationary foot
- requires total contact of foot (heel, 1st and 5 metatarsal heads)
- ankle rocker!
Ankle rocker
Allows progression to continue
- occurs due to residual momentum and contralateral swinging limb
Midstance joint motion
- hip: ext toward neutral
- knee: 0 degrees
- ankle: 10 degrees dorsiflexion
- pelvic rotation: neutral
Midstance peak torque mm
- quads (early phase)
- glute med: concentric
- gastro/soleus: eccentric
- peroneals / post tibialis stabilize ankle
Midstance ankle
5 degrees of PF to 5 degrees of DF, with 10 degrees of DF being attained just as the heel rises to initiate terminal stance
- tibia is allowed to advance beyond the neutral position
- soleus responds by restraining tibia’s progression w/ assistance from gastroc
- available range and timely tibial restraint are the critical events for midstance