PG

126問 • 1年前

問題一覧

Alignment and orientation of body segments to maintain equilibrium and stability

posture

It encompasses static and dynamic postures, which interact with both internal and external forces

posture

Understanding posture is essential for addressing altered postural control and funcitonal challenges, particularly in clinical settings

true

Position or attitude of the body, the relative arrangement of body parts for a specific activity or a characteristic manner of bearing one’s body

posture

Relative disposition of the body at any movement, is a composite of the posituon of the different joints of the body at that time

posture

Positions of joints and body segments and also in terms of the balance between the muscles crossing the joints

posture

Area bounded posteriorly by the tips of the heels and anteriorly by a line joining the tips of the toes is considerably smaller than the quadrupedal base

bos

Places stress on the structures responsible for maintaining the body upright in posture

gravity

For WB joint to be stable or in equilibrium,

gravity line of mass must fall exactly through axis of rotation, there must be a force to counteract the force of gravity

Im the body, the counterforce is either

muscle, inert structures

Upright posture usually involves a slight A-P swaying of the body of about _____, so the muscles are necessary to control the sway and maintain equilibrium

4 cm

Inert structures that support the body

ligaments, fascia, bones, joints

Dynamic structures that maintain the body in a posture or move it from one posture to another

muscles, tendinous attachments

Defining human trait, offering both advantages and challenges

erect bipedal stance

Where is COM located

Center of mass in children is lower

false

Relies on passive structures like ligaments, reducing the need for constant muscle activity

stability

Depends on the integration of sensory inputs, CNS and musculoskeletal components

postural stability

Provides environmental and head position feedback

visual

Detects head movement and spatial orientation via the inner ear

vestibular

Offers feedback from joints, muscles and skin about body position and movement

proprioceptive

CNS processes sensory inputs to generate appropriate postural adjustments

central integration

Disruptions impair balance and coordination

central integration

Visual system, vestibular system and proprioceptive system

sensory inputs

Supplies the structural framework and strength for maintaining stability

musculoskeletal system

Weakness, stiffness or deformities compromise postural control

musculoskeletal system

Forces or movements that disrupt equilibrium, requiring corrective actions

perturbation

BOS remains unchanged

fixed support strategies

Ankle and hip strategies

fixed support strategies

BOS changes

change in support strategies

Stepping or grasping responses maintain COM over the BOS

change in support strategies

Used for small perturbations

ankle strat

Muscles activate distally to proximally

ankle strat

Used for larger perturbations

hip strat

Muscles activate proximally to distally

hip strat

Fewer, larger corrective steps

young individuals

Multiple smaller, cautious steps

older individuals

Anterior hip strat response

abdominals, quads, ta

Posterior hip strat response

paraspinals, hamstrings, gastroc

Anterior ankle strat response

ta, quads, abdominals

Posterior ankle strat response

gastroc, hamstrings, paraspinals

Absent or altered inputs

proprioceptive loss, visual deficits, vestibular dysfunction

Altered outputs

muscle weakness, delayed reactions

Reduced feedback impairs balance

proprioceptive loss

Hinder environmental awareness and head positioning

visual deficits

Causes dizziness and disorientation

vestibular dysfunction

Atrophy reduces stabilizing responses

muscle weakness

Common in aging and neurological disorders, increasing fall risk

delayed reactions

Predictive actions based on expected changes

anticipatory

Compensatory actions in response to unexpected disturbances

reactive

Breathing and neurological disorders

clinical relevance

Causes minor COM shifts, countered by subtle muscular adjustments

breathing

Impair anticipatory and reactive adjustments, increasing fall risk

neurological disorders

Maintain head stability during dynamic activities like walking or transitioning from sitting to standing

head stabilizing strategies

Crucial for visual focus, orientation and balance

head stabilizing strategies

HSS

head stabilization in space

HST

head stabilization on trunk

Head adjusts independently of trunk motion to maintain stability

hss

Anticipates body movements caused by shifts in the center of gravity

hss

Head and trunk move as a single unit

hst

Ensures coordination between head and trunk during movements like sudden directional changes

hst

External forces

inertia, gravity, grf

Resists changes in motion

inertia

More significant in dynamic tasks than static posture

inertia

Constant downward force acting on the body

gravity

Point of reaction of grf

cop

Rotates joint of LE; opposed by muscles, if not = gait deviations

grf

Generated by muscles, ligaments, and other connective tissues to balance external forces

internal forces

Stabilize jts and maintain posture

internal forces

Natural oscillation in static standing

postural sway

Reflects the body’s ability to adjust and maintain COG over the BOS

postural sway

Sagittal plane

~12 deg, front to back sway

Frontal plane

~16 deg, side to side sway

Represents the total force appled by the ground on the body

GRFV

Vertical line representing the direction of gravitational force

line of gravity

In_____ posture, the LoG aligns with GRFV

static

Supports BW

vertical

Stabilizes side to side motion

medial lateral

Stabilizes forward backward motion

anteroposterior

Y axis

vertical

X axis

medial lateral

Z axis

anteroposterior

Reflects the GRFV’s point of application, which shifts with posture and movement

center of pressure

Alignment of body segments to minimize stress on jts, muscles and ligaments while efficiently countering gravitational forces

optimal posture

LOG passes near jt axes, minimizing torque and energy expenditure

optimal posture

Maintained by low level muscle activity and passive tension in ligaments and other connective tissue

stability

Habitual poor posture leads to

muscle imbalances, chronic strain and structural adaptations

Small deviations are normal but large ones increase strain on structures and energy demands

true

Static posture

Involves holding a fixed position, such as standing, sitting or lying down, relies on the balance of muscular and passive structures, standing in line, sitting at a desk

Dynamic posture

involves movements where body segments continuously adjust, coordination between sensory, nervous and musculoskeletal systems ensure stability

LOG should pass through or near key landmarks

lateral view

LOG divides the body into symmetrical halves

AP view

LOG and COP shift with movement

dynamic posture

Focuses on maintaining balance and recovering from perturbations during movement

dynamic analysis

Result from LOG deviations from jt axes, creating torques

external moments

Generated by muscle activity to counteract external moments and maintain stability

internal moments

Ideal posture reduces snergy expenditure by minimizing gravitational moments

energy efficiency

Faulty postures increase muscular effort leading to fatigue and potential injury

energy efficiency

Atlanto-occipital jt

anterior, flexion

100

Cervical

posterior, extension

ROM

Kyla Rafols · 71問 · 2年前

ROM