Lecture 2 Flashcards
What are the different types of gait?
Inverted pendulum walk
Impulsive run
Pendular run - running with straight legs, hybrid
What is Henneman’s size principle?
Smallest motor units are most excitable, innervated first (ST)
What is electromyography?
Technique that records activity of a muscle.
Electrodes are compared to determine whether a muscle is activated or not.
Tells you exactly when a muscle is activated.
What is the gait cycle of a cat?
Swing phase - flexors Stance phase - extensors E1: point of contact with the ground E2: taking weight of the body E3: pushing back on weight to propel forward
What happens to locomotion after a spinal transaction of a cat?
Cat can still generate patterned locomotor output due to sensory sensations through lumbar/sacral region.
Can even increase treadmill speed.
How does a cat adjust speed after a spinal transection?
Hip flexor is extended, interrupting the gait cycle.
Extension is cut short and flexion is brought forward causing the gait to speed up.
Muscles detect they are taking too long to get to the next phase in the gait cycle.
Brain is not involved (intrinsic).
What is the function of fetal locomotor activity?
Important in developing joints and muscles.
Refine neural networks.
Newborns have everything set up and ready to go.
What is a Golgi tendon?
Force detector
Signal load during walking (extensors taking weight)
What is a muscle spindle?
Stretch/length receptor
Negative feedback of muscle length
What is the difference between human and quadrapedal/bipedal chimpanzees?
Humans:
More force at ankle joint
Little activity at the knee and hip
Keep point of gravity directly about point of contact with the ground
Chimps:
More force required at the hip joint
Don’t keep point of gravity directly above point of contact with the ground
