4 challenges to maintaining normal gait
- maintaining upright posture
- Maintaining equilibrium
- Control of foot trajectory and ground clearance
- Control of multiple body segments
Gravity tends to produce ____
flexion
What do you need to overcome the pull of gravity and maintain upright posture
- Muscles work required to counteract the effects of gravity
- Joint stability
What are the requirements to maintain equilibrium
- Coordinated and sufficient neuromuscular responses
- Adaptability
What are the requirements for control of foot trajectory and ground clearance
Proprioception
Intact tactile sensation
Dorsiflexion
Compensation
Minimum toe clearance
1.5cm
what two things reduce toe clearance
aging
dual tasking
What are the requirements for control of multiple body segments
- Proprioception/kinesthesia
- Adequate neuromuscular coordination
what are the 4 phases of gait
- Initial contact
- Stance phase
- Toe off
- Swing phase
What is initial contact
The instant at which any part of the foot first touches the ground
What is the stance phase
the period in which the foot is in contact with the ground 60%
What is toe off
the instant in which the entire foot is no longer in contact with the ground
What is swing phase
the period in which the foot is not in contact with the ground 40%
What is a gait cycle
contact to subsequent contact of the same limb
What is stride
the initial contact to subsequent initial contact of same limb - the distance covered in one gait cycle
What is step
Initial contact of one limb to initial contact of the contralateral limb
What occurs to step length and stride length if you have a unilateral impairemtn
decrease in step length of the effected side (they want to weight bear on it the least) so they quickly get back on good limb
Stride length stays the same because it is sum of the two - evens out
what are the 3 main tasks during gait
- weight acceptance
- maintenance of stability during single leg support
- Limb advancement
Which tasks of gait are in stance phase? which are in swing phase?
Stance - Weight acceptance and single limb support
Swing - Limb advancement
What are the objectives of weight acceptance
- Shock absorption
- Stability
- Preservation of forward progress
What is the most important aspect of pathological gait
Single limb support
What are the objectives of single limb support
- Progression over stationary foot
- Limb and trunk stability
What are the objectives of limb advancement phase
- Foot clearance over the floor
- Advancement of limb from trailing position
- Preparation for stance
What are the 7 periods of gait
- weight acceptance
- mid stance
- terminal stance
- pre swing
- initial swing
- mid swing
- terminal swing
What is average stride length? step length?
- 4 m
0. 7 m
What is average cadence? velocity?
110 steps/min
1.3 m/s
What is cadence
total number of steps in a given time
What is the equation for velocity
V = d/t = cadence
3 reasons why cadence is lower in older population
- stiffer - less ROM
- balance
- muscle weakness
Elderlly have a reduced ____ phase
swing phase
want both feet to be on the ground for longer
What is the typical vertical oscillation during gait? medial lateral movement?
4 cm
2-3 cm
what is the main movement of the ankle
Strong plantarflexion at toe-off
What is the role of the strong plantar flexion seen at toe-off
to provide momentum necessary to produce limb clearance
Dorsiflexion during stance is ____
passive
What has the largest ROM of any lower limb joint during gait
knee
What are the 2 main periods of flexion in gait
- weight acceptance
- foot clearance and preparation for heelstrike
Hip remains ____ for the majority of gait
flexed
What are the 2 major movements at the hip during gait
- stance phase extension
2. Swing phase flexion
The efficiency of gait is dependent on…
timely coordination response of muscles, joints, segments, nerves, systems