posture

What is posture?

Relative arrangement of body parts that balances musculoskeletal structures, protects tissues/organs, and promotes efficient function

What are the characteristics of good posture?

Protects supporting structures, minimizes strain, optimizes muscle efficiency, supports organs, reduces energy expenditure

What is poor posture?

Faulty alignment causing increased tissue stress, decreased efficiency, and potential dysfunction

Why do PTs assess posture?

Gather information, identify impairments, guide examination, correlate findings with symptoms, improve movement efficiency, and direct treatment

Does abnormal posture automatically mean pain is present?

No; posture must be correlated with symptoms and clinical findings

What is static posture?

Posture in standing, sitting, lying, or other stationary positions

What is dynamic posture?

Posture during movement such as walking, squatting, reaching, or running

Why should both static and dynamic posture be assessed?

Patients may appear normal statically but demonstrate dysfunction during movement

What is regional interdependence?

Dysfunction in one body region influences other regions throughout the kinetic chain

How can pelvic position affect posture?

Pelvic alignment influences lumbar, thoracic, cervical, and lower extremity mechanics

What is ergonomics?

Analysis of body position and movement during work, recreation, and daily activities

Why is ergonomics important in PT?

Treating symptoms without correcting movement habits often leads to recurrence

What is postural control?

Ability to maintain stability when external forces disturb equilibrium

Which systems contribute to postural control?

CNS, visual system, vestibular system, musculoskeletal system, and joint receptors

How does the visual system affect posture?

Eyes seek eye level, causing cervical and thoracic compensations when posture changes

How can vestibular dysfunction alter posture?

Patients may adopt abnormal head positions to reduce dizziness, causing secondary musculoskeletal issues

How can diabetic neuropathy affect posture?

Reduced proprioception impairs postural control and balance

What are tonic muscles?

Postural muscles responsible for stability and maintaining position

What are phasic muscles?

Prime mover muscles responsible for force production and movement

A patient with chronic neck pain demonstrates overactive upper traps and weak deep neck flexors. Which muscle type is likely inhibited?

Tonic stabilizing muscles (deep neck flexors)

What should a PT observe before formal examination begins?

Walking, transfers, sitting posture, standing posture, and spontaneous movement patterns

What is the approximate location of the body’s center of mass during standing?

Just below the umbilicus

What is normal postural sway in the sagittal plane?

Approximately 12°

What is normal postural sway in the frontal plane?

Approximately 16°

Should normal postural sway be interpreted as a postural impairment?

No, it is a normal physiological finding

What is ground reaction force (GRF)?

Force exerted by the ground on the body

What are the three components of GRF?

Vertical, anterior/posterior, and medial/lateral

What equals body weight during quiet standing?

Vertical ground reaction force

How does GRF change during running and jumping?

Significantly increases

What is the line of gravity (LOG)?

Vertical line representing the body’s gravitational force

What occurs when the LOG passes directly through a joint axis?

No torque is produced and minimal muscle activity is required

What occurs when the LOG falls outside a joint axis?

A moment arm and torque are created, requiring restraint

What are external moments?

Forces outside the body that create motion tendencies

What are internal moments?

Muscular, ligamentous, and connective tissue forces that resist external moments

What structure resists a plantarflexion moment when the LOG is posterior to the ankle?

Tibialis anterior

A patient with foot drop demonstrates excessive hip flexion during gait. Which muscle is likely weak?

Tibialis anterior

What external moment occurs when the LOG is posterior to the ankle?

Plantarflexion

What external moment occurs when the LOG is posterior to the knee?

Knee flexion

What structure resists knee flexion when the LOG is posterior to the knee?

Quadriceps

What external moment occurs when the LOG is anterior to the hip?

Hip flexion/trunk flexion

What structures resist hip flexion caused by an anterior LOG?

Gluteals, hamstrings, and paraspinals

Why is the LOG slightly anterior to the lateral femoral condyle in standard posture?

Creates a small extension moment allowing passive support and energy conservation

What is the preferred posture term used clinically?

Standard posture

Why are the terms normal, ideal, and optimal posture avoided?

Posture varies among individuals and changes throughout life

What tools can be used for postural assessment?

Plumb line, posture grid, tape measure, photography, smartphone apps, and 3D systems

What descriptors should be used for postural deviations?

Slight, moderate, and marked

What is the reference point for the lateral plumb line?

Just anterior to the lateral malleolus

Where should the plumb line pass in standard posture from lateral view?

EAM, acromion, trunk, posterior to greater trochanter, anterior to lateral femoral condyle, anterior to lateral malleolus

What is the first step after identifying a postural deviation?

Determine the cause

What should be assessed after observing a postural deviation?

ROM, strength, muscle length, motor control, mobility, and contributing factors

What does a forward head posture indicate relative to standard posture?

A deviation from standard posture

Where should the plumb line pass relative to the head in standard posture?

Through the external auditory meatus

Why is forward head posture so common?

Modern visual demands and compensation to maintain eye level

What is the most important concept regarding the spine and posture?

The line of gravity should bisect the trunk

What spinal curves should be assessed during posture analysis?

Cervical lordosis, thoracic kyphosis, and lumbar lordosis

What is a hinge point in the spine?

Abrupt angulation at a spinal segment suggesting hypermobility or instability

A patient extends primarily through one lumbar segment during extension testing. What should be suspected?

Segmental hypermobility and a hinge point

What may a flattened spinal curve indicate?

Segmental hypermobility

How should scapulae appear in standard posture?

Flat against the thorax and approximately 4 inches from the spine

How should clavicles appear in standard posture?

Horizontal or slightly oblique

What shoulder position is commonly seen in throwing athletes and may be normal?

Increased scapular abduction and upward rotation

How should the upper extremities appear in standard posture?

Neutral rotation, palms facing thighs, arms equidistant from trunk

What elbow position is considered standard posture?

0–10° of flexion

How is a neutral pelvis defined in the sagittal plane?

ASIS and pubic symphysis in the same plane with ASIS slightly below or level with PSIS

How is a neutral pelvis defined in the frontal plane?

ASIS and PSIS are level

Which muscles commonly influence pelvic posture?

Abdominals, hip flexors, rectus femoris, gluteals, paraspinals, TFL, and sartorius

A patient presents with excessive anterior pelvic tilt. Which muscles are commonly tight?

Hip flexors and rectus femoris

A patient presents with excessive anterior pelvic tilt and weak abdominal control. Which interventions may be indicated?

Abdominal strengthening and hip flexor stretching

Why is the pelvis considered highly influential in posture?

It affects alignment throughout the entire kinetic chain

How should knees appear in standard posture?

Neutral to slight valgus and extended to 0°

How should the patellae face in standard posture?

Forward

What lower leg alignment is considered standard?

Slight varus with neutral rotation

What conditions should be assessed at the knee during posture evaluation?

Genu valgum, genu varum, genu recurvatum, and flexion contracture

How should body weight be distributed through the feet?

Evenly between both feet

How should the calcaneus align in standard posture?

Perpendicular to the Achilles tendon and tibia

What is observed when assessing foot posture?

Weight distribution, arch height, calcaneal position, toe position, and subtalar alignment

How does a pronated foot differ from a supinated foot?

Pronated foot has a lower arch and greater flexibility; supinated foot has a higher arch and greater rigidity

Why are toes important for posture and balance?

They contribute to balance, propulsion, and gait mechanics

A patient develops plantar fasciitis after altering gait due to great toe pain. What concept does this demonstrate?

Regional interdependence and the importance of toe mechanics

What factors affect posture?

Gravity, tissue adaptability, occupation, recreation, sleep position, genetics, ADLs, emotions, handedness, aging, and pregnancy

How can sleep position contribute to pain?

Sustained poor alignment can place repetitive stress on tissues

How does handedness commonly influence posture?

Dominant shoulder may be lower and ipsilateral pelvis slightly higher

How can emotions affect posture?

Protective, guarded, or slumped postures may occur

What postural changes commonly occur with aging?

Increased thoracic kyphosis and forward head posture

Why should an elderly patient with structural kyphosis be treated differently from a younger patient with flexible kyphosis?

Structural deformities are less reversible and require different intervention strategies

What postural changes commonly occur during pregnancy?

Forward head posture, thoracic kyphosis, lumbar lordosis, anterior pelvic tilt, knee hyperextension, and foot pronation

Why does pregnancy alter posture?

Anterior shift of center of mass and hormonal influences

A pregnant patient continues to demonstrate excessive lordosis months postpartum. What should the PT consider?

Persistent postural adaptations may require intervention and retraining

A child with cerebral palsy demonstrates toe walking, knee flexion, and anterior pelvic tilt. What should be assessed?

Hip flexor length, hamstring length, gastroc length, dorsiflexion ROM, strength, and neurological involvement

When a postural deviation is observed, what is the most important clinical question?

Why is the deviation occurring?

What is the ultimate purpose of posture assessment?

To guide examination, identify impairments, determine relevance, and direct treatment decisions.