Posture Flashcards
static posture
- body and segments are aligned and maintained in certain positions
- standing, sitting, lying, kneeling
dynamic posture
- body/segments are moving
- walking, running, jumping, throwing, lifting
base of support (BoS)
area bounded posteriorly by the tips of the heels and anteriorly by a line jointing the tips of the toes
postural control
maintenance of center of mass (CoM) over BoS to control body’s orientation in space and stabilize head with respect to vertical to orient gaze
afferent inputs for postural control
- proprioceptive
- vestibular
- visual
efferent inputs for postural control
muscular contraction
primary goal of postural control
stabilize the head
reactive (compensatory) responses
responses occur as reactions to external forces that displace the body’s CoM
proactive (anticipatory) responses
responses occur in anticipation of internally generated destabilizing forces
altered or absent inputs
- posture may be altered
- stability may be compromised
- example: decreased sensation of LEs or post-injury
alterations in ____ can compromise posture
outputs
example of altered output
inability of muscles to respond appropriately to signals from CNS due to a neuromuscular disorder
maintenance of standing posture is the result of ____ controls
dynamic
sensory perturbation
may be caused by altering visual input
mechanical perturbation
displacement causing changes in the relationship of the body’s CoM to BoS
fixed support synergies/strategies
centrally organized patterns of muscle activity that occur in response to perturbations of standing postures
ankle synergy
discrete bursts of muscle activity that occur in a distal-to-proximal pattern
hip synergy
discrete bursts of muscle activity that occur in a proximal-to-distal pattern