Emergence of Walking Flashcards
What did Taub and Berman do/prove?
They forced the use of a sensory deprived animal by constraining the other limb. They concluded that rehabilitation can occur by engaging the limb in activities.
What did Forssberg do/prove?
He worked with cats that had a transected spinal cord and found that they have the same muscle activity that normal cats have. He concluded that lower limb activity can be activated under certain situations.
Describe what happens in prenatal to postnatal stepping.
- infants kick or step in utero
- at birth children elicit stepping patterns
- stepping patterns disappear at 2 months and reappear at the start of walking
What did Sherrington do/prove?
They found that severed spinal cords and hind limbs continued alternating movements and concluded that they do not need the influence of higher brain centers to walk. In monkey’s it was found that eliminating sensory information results in rhythmic walking patterns, concluding that removing sensory input on both sides resulted in pattern remains.
Describe the progression from stability to mobility
- standing with assistance
- standing alone
- mobility with two hands
- independent mobility
Is there an average timeframe for the emergence of gait?
- on average infants begin to walk from 9-15 months (motor delay in gait at 18 months)
- myelination occurs from caudal to distal- at 9 months it reaches the lower limbs (critical factor in gait emergence)
What are the componendets of gait that are developed from birth to 12 months?
- locomotion pattern (CPG); innate
- postural control in standing
- motivation and navigation towards a distant object
- standing on one leg: stance phase stability (cruising)
- high guard posture
What are the necessary components for gait emergence?
- motor production (stabilization, for or power)
- CPG’s
- myelination
- intact sensory system (vision, vestibular, somatosensory)
- balance or postural control
- dissociation of limbs
What are some sensory contributions to gait?
- Vision: balance, steering, and avoiding obstacles, visual optic flow, stabilizing head; vision vertical
- Vestibular system: stabilization of head, postural control
- Somatosensory/Proprioception: feedback of body awareness, tactile feedback from ground
Describe the characteristics of a child’s first steps?
- high step pattern
- wide BOS
- no push off
- knees flexed at stance
- no arm swing
- high guard position
- short steps
- synchronized patterns in legs
- waddling pattern
What is synchronization and dissociation?
In the gradual emergence of normal gait the joints demonstrate an increasing complexity. Synchronization means moving simultaneously and dissociation means moving joints individually.
Children go from synchronization to dissociation.
What is controlled fall?
Infants lean forward when walking
What type of posture do children have when first learning to wlak?
they have a forward center of mass
How would a child demonstrate the ability to control equilibrium responses and postural control?
- they would fall forward with hands extended or backwards on their bottom
When does the ability to control single leg stance occur?
usually occurs at one year
When are they able to change directions?
at 15-18 months
When do children obtain a heel strike?
at two years
When does a child’s gait pattern start to mature?
- age of 3 with small improvements until 7-10 years of age
- repetition is important for the maturation of gait
When does the center of mass stabilize?
stabilizes at 7 years of age
What are other skills associated with walking?
- avoid obstacles (stepping over, around, with downward gaze)
- protective responses (parachute and protective extension)
- distance (knowing how far one travels)
- navigation (moving from one place to place using memory and landmarks)
- cognitive processing (dual task emerging)
What are some sensory contributions to gait?
- stretching of hip flexors
- step length, appropriate frequency
- contributions of loading the limbs (pressure sensors, practice standing for long periods)
What happens to the muscular system after we age?
- loss of muscle mass after the age of 60
- especially type 2 fibers (train endurance)
- may lead to sarcopenia or the loss of muscle mass in elderly
What is atrophy in simple dissuse?
- voluntary inactivity induced: decrease is PA local unloading, and short term illness
- reduced mechanical loading fasting and fed anabolic resistance
- Protein breakdown : side to side
- Protein synthesis: down
What is atrophy in sarcopenia?
- age induced: anabolic resistance decreased PA, low grade chronic inflammation, longer term inactivity
- aging disuse and inflammation
- Protein breakdown: up
- Protein synthesis: down
Explain what the use it or lose it philosophy means
If an individual exercises and stays active the loss of muscle can be minimized. Note that muscle changes to fat when there is disuse.
What happens to the skeletal system in older adults?
- loss of vertebral body height
- increased risk of fracture
Under which circumstances do individuals lose the tactle or cutaneous receptors?
- Diseases ( Type 2 diabetes, peripheral nerve damage, stroke)
- Aging (loss of fine touch & temperature sensation, loss of pain perception)
What is loss of visual acuity?
- Reading: accommodation or the lens doesn’t bend to accommodate light
- distance
What disease processes can lead an individual to start experiencing a loss of vison?
- type 2 diabetes (retinal damage)
- macular degeneration
- glaucoma
T/F Vestibular system is a use it or lose it system
True
What is the purpose of the vestibular system?
Acceleration (forwards/up/down)
Head rotation: speed and movement
What losses in the vestibular system do the elderly show?
- loss of quick acceleration in movement (constant speed: no variation)
- loss in cervical rotation
- elderly maintain a forward head posture and forward trunk posture
What do protective responses reduce?
- reduced ankle and hip strategy
- reduced speed of protective arm extension (parachute in infants)
What percent of falls lead to injuries of the head?
20-30%
How is cognitive decline related to gait speed?
cognitive decline leads to reduced gait speed
