what is postural control?
the controlling of the body’s position in space
three goals of postural control
to support the body against gravity, to maintain the centre of mass aligned and balanced your base, and to stabilize parts of the body while moving other parts
base of support
the area defined by the points of contact between the body and environment
what is a goal of a walking aid with respect to the BOS?
to increase BOS and allow hands to contribute to the BOS while increasing sensory input/proprioception through the hands which helps to retrain gait better
centre of mass of body
a point in space where there is equal amounts of body mass on all sides and the location of the COM changes with movement; it does not need to be located on the body
limits of stability
is how far the body’s COM can be moved over the BOS
postural sway
small movements of the body mass which occur when unsupported (standing, sitting) and this is normal
how can you measure postural sway?
through using trunk motion
benefit of postural sway
it is a strategy through our nervous system to gather proprioceptive information
what are the major muscles that control body sway during quiet standing?
triceps surae and tib ant
why does putting one finger out for support decrease postural sway?
it increases proprioceptive input therefore allows our body to take in more input from the environment
what variable does postural sway increase with?
age, therefore the risk of falls increase; this can differ a lot between individuals
how does narrowing the BOS affect postural sway?
the sway will increase in the mediolateral direction
what is a hypothesis of why older adults have increased postural sway?
to increase proprioceptive input
how is postural sway related to pathological brain conditions?
it increases in some conditions, therefore increases risk of fall
how does M-L sway change with cerebellar pathologies?
is decreases, thus weight shifting decreases
how does postural sway change in someone with MS?
with eyes open, it doesn’t change much but with eyes closed it is much larger compared to the control group; this is because of their reliance on vision for proprioceptive/afferent input that they rely on heavily
does direct feedback control or anticipatory reactions help with postural control more?
anticipatory reactions
feedback control
signals from sensors are compared with the desired position/movement; the difference or error signal is used to adjust the movement; however this is too slow of a system
feedforward control
predicts the disturbances and produces actions to maintain stability using prior experience to make a best guess action
anticipatory postural control
pre-setting sensory and motor systems in expectation of postural demands; anticipatory postural control is based on previous experience and learning
examples of anticipatory postural control
arm raise while standing, opening/pulling a door, rising on toe, or stepping over an obstacle
how do anticipatory postural muscles fire relative to the prime mover of the action occurring?
the stabilizing postural muscles fire before the muscle doing the desired action
how does anticipatory postural reaction change in stroke patients?
anticipatory reactions occur later than non-stroke patients
-
aerobic metabolosim52
-
pulmonary ventilation83
-
cardiovascular system59
-
detraining62
-
structure and function of muscle and neural control42
-
intro to development80
-
developmental milestones54
-
pediatric lower extremities development50
-
middle childhood24
-
adolescence42
-
motor learning39
-
biomechanics intro65
-
clinical biomechanics and gait70
-
normal gait lab13
-
normal gait lecture64
-
abnormal gait47
-
neural control of locomotion58
-
postural control48
-
mobility41
-
UE function36
