11
Posture
and Body
Mechanics
Importance
of Correct Posture
and Body Mechanics
In daily activities
In sport activities
In the activities that sport
rehabilitation specialists undertake in
treatment sessions
posture: the relative alignment of the
various body segments with one
another
good posture: The body’s alignment
is balanced so that stress applied to
the body segments is minimal.
poor posture: The body’s alignment is
out of balance, causing unusual
stresses to various body segments,
which can lead to abnormal
anatomical adaptations, alterations in
performance, and less efficiency.
Correct Standing
Alignment: Anterior View
Plumb line bisects nose, mouth,
sternum, umbilicus, pubic bones.
Earlobes are level, as are the
shoulders, fingertip ends, nipples,
iliac crests, patellae, and medial
malleoli.
Patellae point straight ahead with feet
straight or turned slightly outward.
Knees and ankles in line.
Correct Standing
Alignment: Posterior View
Plumb line bisects head and follows
spinous processes.
Earlobes, shoulders, scapulae, hips,
PSIS, gluteal fold, posterior knee
creases, medial malleoli are level.
(continued)
Correct Standing
Alignment: Posterior View
Scapulae lie against rib cage between
T2 and T7, 5 cm from spinous
processes.
Calcanei are straight; calcaneal
tendon is perpendicular to floor.
Weight is distributed equally.
Correct Standing
Alignment: Lateral View
Plumb line passes through external
auditory meatus, earlobe, bodies of
cervical vertebrae, center of shoulder
joint, greater trochanter; midway
between back and chest; slightly
anterior to center of knee just behind
patella; slightly anterior to lateral
malleolus.
(continued)
Correct Standing
Alignment: Lateral View
Horizontal line should connect ASIS
and PSIS
Weight balanced between heel and
forefoot
Knees straight, not locked
Chin slightly tucked, chest slightly up
and forward, mild inward curve in
neck and low back regions
Correct Sitting Alignment
Feet rest comfortably on floor with
hips and knees at 90°.
Chair seat does not run into posterior
knee; chair back comes to lower
scapula border.
Chair arms are at a level that provides
shoulder relaxation and permits
forearms to rest comfortably with
elbows at 90°.
lordosis: an excessive forward curve
in the lumbar or cervical area
kyphosis: an excessive posterior
curve, often in the thoracic area
scoliosis: a lateral curve of the
normally straight spine, classified as
either a C-curve or an S-curve
Pathological Alignment:
Pelvis and Lumbar Area
Lordosis
Flat lumbar spine
Scoliosis
Pathological Alignment:
Thoracic Area
Thoracic kyphosis
Flattening of upper back
Scoliosis
Lateral shift
Pathological Alignment:
Head and Cervical Area
Forward head
Cervical lordosis
Pathological Alignment:
Lower Extremities
Hips: coxa valga, coxa varus;
anteversion, retroversion
Knees: genu valgus, genu varus;
squinting patellae, “frog’s eye”
patellae; genu recurvatum
Femoral Neck-Shaft Angles
a
b
c
Pathological Alignment:
Lower Extremities
Lower leg; tibial torsion
Ankle and foot: pes cavus, pes
planus; pronation, supination; hallux
valgus; claw toes, hammertoes
Arch Positions
Adapted from Richardson and Iglarsh 1994.
Toe Deformities
Parts b and c reprinted from Richardson and Iglarsh 1994.
Pathological Alignment:
Upper Extremities
Rounded shoulders
Forward and downward scapulae
Internally rotated shoulders
Causes of Muscle
Imbalances Read pp 337-338
Sustained shortening of one muscle
and compensatory lengthening of
opposite muscle
Overuse: weakness of one group
overpowered by strength of opposing
group
Postural deviations with aging
Joint abnormalities
Injuries, muscle strains
Treatment of Muscle
Imbalances Read pp 337-338
Lengthen shortened muscle groups
Strengthen weak muscle groups.
Educate patient on proper posture
for conscious correction.
Encourage bilateral activities.
Conditioning programs include a
balanced program.
body mechanics: the way the body is
positioned and used during activity
Body Mechanics
Principles
Straight or neutral spine
Stability maintained by a low center
of gravity, a broad base of support,
and a stance in the direction of force
application
Strong abdominals
Body Mechanics
During Daily Activities
Lifting objects
Pushing or pulling objects
Carrying objects
Rising from a chair
Getting on the floor
Body Mechanics in Sport
Straight back
Abdominal strength
Pelvic neutral
Examples of specific sports
Body Mechanics for Sport
Rehabilitation Specialist
Equal distribution of weight over the
two feet
Feet in correct alignment and in
direction of forces
Force applied from legs
Back straight
Move from right to left foot and back
again
Keep upper extremities relaxed, in
proper alignment