Locomotion Flashcards
what is the gait cycle
rhythmic pattern of mvmts made when running/walking and consists of stance and swing phases
what are the phases of the gait cycle
stance = on the ground
swing = leg in air moving to the next position
what is bi pedal walking
refers to mode of locomotion in which the legs move in anti phase
- one moves forward while the other moves backwards
one foot of the other is always in contact with the ground and both feet are in contact with the ground briefly (double support)
what is bi pedal running
mode of locomotion when both legs move in antiphase
both feet are never on the ground at the saem time and there are periods where neither foot is on the ground (flight periods)
what is quadrapedal locomotion
has different and distinct patterns from bi pedal locomotion
depends on the type of animal
which types of animals run in antiphase vs in phase
kangaroo, deer, bunny = in phase
squirrels, cats, dogs = front and back limbs move in phase with each other
horses = all limbs in antiphase
humans = antiphase
what is the difference in gait kinematics between walking and running
different amounts of joint rotations
- larger flexion adn more dorsi/plantar flexion in running
difference amounts of muscle activations
- EMG greater for running (larger MUs involved)
what are central pattern generators (CPGs)
spinal circuits that are believed to be controlling the rhythmic mvmts of the legs during locomotion
what happens when the CPG is active
CPG circuit produces alternating rhythmic patterns of flexion and extension
- when one side is active, the other is inhibited (work in antiphase)
what is the pathway of the CPG
- tonic descending excitatory input
- shows constant tonic activity
- goes through rhythm generator
- turns into phasic bursting activity
- splits into flexor and extensor MNs
(each synapses onto its own MN and an inhibitory interneuron for the flexors and extensors to work in atniphase)
what is the use of multiple CPGs
multiple working together are needed to articulate multiple joints
what are the areas that give descending control to the CPGs
motor cortex - voluntary commands for visually guided corrections
visual cortex - processes visual info
cerebellum - fine tuning motor commands (smooth and fluid mvmts)
MLR and MRF - when MLR is stimulated, CPGs are activated and locomotion begins
what is the relationship between the intensity of stimulation and locomotion
higher intensities of stimulation leads to faster locomotion
- CPGs start to work together at higher stimulation (bounding of animal running)
how can sensory input control CPGs
can modulate spinal CPG circuits
applying a stretch during walking can cause an earlier activation of the knee flexor than normal
which type of vision detects obstacles while walking
peripheral vision is used
- dorsal stream is faster
- object mvmt is not processed in the foveal vision
