3. Objectives
At the end of this lecture you should able to;
1. Define posture
2. Recognize Postural Alignment
3. Investigate Types of posture
4. Recognize the factors affecting Postural Stability in
the Spine
5. Recognize the factors affecting posture
6. Differentiate between Muscles of the Spine
7. Investigate the Etiology of Pain
8. Investigate assessment of common faulty posture
4. Definitions of Posture
O Posture is a “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.”
O It is alignment of the body parts whether upright,
sitting. It is described by the positions of the joints
and body segments and also in terms of the
balance between the muscles crossing the joints.
5. Impairments in the joints, muscles, or connective tissues
may lead to faulty postures.
Many musculoskeletal complaints can be attributed to
stresses that occur from repetitive or sustained activities
(habitually faulty postural alignment).
6. Curves of the Spine
O The adult spine is divided into four curves:
O Two primary , or posterior, curves, so named
because they are present in the infant and the
convexity is posterior.
O Two compensatory, or anterior, curves, so named
because they develop as the infant learns to lift the
head and eventually stand, and the convexity is
anterior.
7.
8. Postural Alignment
O Gravity places stress on the structures responsible for
maintaining the body upright and therefore provides a
continual challenge to stability and efficient
movement.
O For a weight-bearing joint to be stable, or in
equilibrium, the gravity line of the mass must fall
exactly through the axis of rotation, or there must be
a force to counteract the moment caused by gravity.
O In the body, the counterforce is provided by either
muscle or inert structures. In addition, the standing
posture usually involves a slight anterior/posterior
swaying of the body of about 4 centimeters (cm), so
muscles are necessary to control the sway and
maintain equilibrium.
9. A plumb line is typically used for reference
and represents the relationship of the
body parts with the line of gravity. Surface
landmarks are:
• slightly anterior to the lateral
malleolus,
• slightly anterior to the axis of the knee
joint,
• through the greater trochanter (slightly
posterior to the axis of the hip joint),
• through the bodies of the lumbar and
cervical vertebrae,
• through the shoulder joint
• through the lobe of the ear.
Lateral view of standard postural alignment
10.
11. Types of posture:
O 1-Static Posture:
• body segments aligned and maintained in
certain positions (standing, lying, and sitting).
• No mechanical work is performed.
• Muscle tension equal external load (isometric
contraction).
O 2.Dynamic posture:
• body segments are moving (walking, jumping,
throwing, and lifting).
• The bones, joints, and ligaments provide major
torque needed to counteract gravity.
12. Postural Stability in the
Spine
O Spinal stability is described in terms of three
subsystems:
1. Passive (inert structures/bones and
ligaments),
2. active (muscles)
3. neural control
13. O The three subsystems are interrelated
and can be thought of as a three-legged
stool; if any one of the legs is not providing
support, it affects the stability of the whole.
O
O Instability of a spinal segment is often a
combination of tissue damage, insufficient
muscular strength or endurance, and poor
neuromuscular control.
14. O A spinal segment
consists of the following:
• Two vertebrae
• An intervertebral disc
between the two
vertebrae
• Two nerve roots that
leave the spinal cord, one
on each side
15. Inert Structures: Influence on Stability
O ROM of any one segment is divided into
an elastic zone neutral zone.
O When spinal segments are in the neutral zone
(midrange/neutral range)
the inert joint capsules and ligaments provide minimal
passive resistance to motion and therefore minimal
stability.
16. As a segment moves into the elastic zone,
the inert structures provide restraint as passive resistance
to the motion occurs. When a structure limits movement in a
specific direction, it provides stability in that direction.
O In addition to the inert tissues, the sensory receptors in
the joint capsules and ligaments sense position and
changes in position. Stimulation of these receptors
provides feedback to the CNS, thus influencing the
neural control system.
17. Muscles: Influence on Stability
Role of Global and Core Muscle Activity
O The muscles of the neck and trunk act as
O
• Both superficial and deep muscles function to maintain the upright
posture. The global muscles, being multisegmental, are the large
guy wires that respond to external loads imposed on the trunk that
shift the center of mass.
• Their reaction is direction-specific to control spinal orientation.
they are important stabilizers of the
spine. Without the dynamic
stabilizing activity from the trunk
muscles, the spine would collapse in
the upright position.
prime movers or as
antagonists to movement
caused by gravity during
dynamic activity,
18. Muscles of the Spine
Lumbar spine
O Rectus abdominis (RA) Internal obliques (IO) and
external obliques (EO)
Trunk flexion (sit-up and curl-up exercises). Bilateral
contraction causes trunk flexion;
EO on one side with IO on contralateral side together
cause diagonal trunk rotation with flexion;
EO and IO on same side cause side bending of trunk
O Transversus abdominis (TrA)
O Contributes to rotation
19.
20.
21. O Quadratus lumborum (QL
Pelvic hiking and side bending of the spine
O Multifidus Intersegmental rotators and
intertransversarii
Spinal extension and contralateral rotation
O Superficial erector spinae (ES) muscles (iliocostalis,
longissimus, spinalis)
Primary trunk extensors; extend thorax on pelvis causing
spinal backward bending;
O Iliopsoas (iliacus and psoas major)
Primary hip flexors and indirectly lumbar extensors; Iliopsoas
creates an anterior shear on the lumbar vertebrae
22. Cervical spine
O Sternocleidomastoid and scalene group
O Bilateral contraction causes cervical flexion;
O unilateral contraction causes side bending with contralateral rotation and
flexion
O .When the neck is stabilized, the scalenes elevate the upper ribs during
inspiration,
O and the sternocleidomastoids (SCM) elevate the clavicles and sternum,
which assists in inspiration
O Upper trapezius and cervical erector spinae
O Bilateral contraction causes cervical extension;
O unilateral contraction causes side bending
O Levator scapulae
The levator scapulae works with the upper trapezius to elevate the scapulae
O Longus colli; rectus capitis anterior and lateralis
Craniocervical flexors; longus colli is the prime mover for cervical retraction
(axial extension)
23.
24.
25.
26. Factors affecting Posture
1-Age
Children: At birth, the whole spine is concave forward or
flexed, as the child crawls and looks up, a cervical
lordosis develops. When the child assumes an erect
posture, a lumbar lordosis also develops. Children have
similar postural alignment to an adult by 10 or 11 years
Elderly :have more flexed posture, and wider base of
support.
29. 4- Occupational changes: evaluate each person
individually, look for "overuse injuries" (dancers,
lifter), repetitive work situations for changes in
postural alignment
5- Handedness: low shoulder on the dominant
hand side.
6-Weak muscles
7-Tight muscles; decreased flexibility
33. Postural Habits
O Good postural habits in the adult are necessary to
avoid postural pain syndromes and postural
dysfunction.
O Also, careful follow-up in terms of flexibility and
posture training exercises is important after trauma or
surgery to prevent impairments from contractures and
adhesions.
O In the child, good postural habits are important to
avoid abnormal stresses on growing bones and
adaptive changes in muscle and soft tissue.
34.
35.
36.
37. Posture assessment
Posture analysis methods
A wide range of methods has been used to objectively
assess spinal posture. These can be broadly divided into five
categories:
1 -roentgenography, (X ray)
2 -three-dimensional motion analysis, (3D motion)
3 -raster stereography, (Frometric)
4- photographic analysis
5-manual measurement. consists of several different methods,
such as manual goniometer, electro goniometry , the use of a
flexible ruler or ‘‘flex curve’’, and the measurement of
horizontal displacement of spinal landmarks from a vertical
plumb line.
38. O 1- Roentgenography
Because it allows clear visualization of bony
landmarks, is the gold standard method and has
been shown to be reliable. However, radiation
hazards preclude its widespread use in research
studies.
39. 2- -Motion analysis systems
The motion analysis systems offer high resolution,
accurate motion capture systems to acquire, analyze
and display 3D motion data on patients while walking.
In addition to quantify 3D posture parameters
adopted by persons during specific tasks or at static.
Methods of measurement include static, video and
opto-electronic systems. To ensure accurate and
reliable results,
technical concerns such as calibrated alignment of
the camera image contrast, standardized postures for
repeated measures and distortion effects must be
addressed.
40.
41. 3)- Raster stereography (Formetric)
is a special development for fast, contactless, and radiation-free
static measurement of the back surface and spine. It offers a 3D
analysis of the back surface, spinal form and functions
paraparameter, and visualizes a unique 3D-reconstruction of the
surface and spine.
analyses the back surface form in a sophisticated, automatic way,
with no need for manual fixation of markers. Formetric System is a
method based on photogrammetric principles that make three-
dimensional surface analysis possible
42. It uses a system of horizontal parallel white light lines
projected onto the back surface of the patient. Observing
this light raster from a direction that is different from the
projection reveals shape information from the distortion
of the white lines.
The synchronous projection and registration of all light
lines in one instant reduces the measurement time of all
the surfaces to typically 0.25 sec.,.
raster stereography allows the automatic localization of
anatomical landmarks on the back surface, like for
example, the spinous processes of C7 vertebra (vertebra
prominence) or the right and left dimple points in the
pelvic region (spinae iliacae posterior superior).
On the basis of these landmarks the sagittal back profile
is established automatically and a set of shape
parameters characterizing the back profile is provided.
43.
44. 4-photographic analysis
Static photographic analysis with reflective
markers placed on specified anatomical
landmarks may be more suited to large-scale
studies.
This is because it is relatively cheap, requiring
only a camera, markers and adhesive tape; is
highly portable; and permits the measurement of
several posture angles simultaneously. It is thus
frequently used in field and clinical studies.
45.
46. 5- manual measurement
Some manual measurement techniques such as
the pelvic goniometer and flexicurve have also
been shown to be valid, and some have good
reliability in adults. However, though such manual
techniques may be useful for single angular
measures, they may be time-consuming if several
angles need to be measured.
47.
48.
49. Plumb line analysis
The most common method. The plumbline provides
the clinician a visual frame of reference to evaluate
various body landmarks and the alignment in relation
to the verticality of the plumbline. The evaluation of
the patient is done from the anterior, posterior and
lateral stances.
Standing posture is assessed in comparison to a
standard reference line. The subject is positioned with
a plumb-line passing just in front of the lateral
malleolus. In an ideal posture this line should pass
just anterior to the midline of the knee, and then
through the greater trochanter, bodies of the lumbar
vertebrae, shoulder joint, bodies of the cervical
vertebrae, and the lobe of the ear.
50.
51. When viewed from the front, with the feet three inches apart, the
line should bisect the body into two equal halves.
The anterior superior iliac spines (ASIS) should be in the same
horizontal plane, and the pubis and ASIS should be in the same
vertical plane. Anatomical landmarks are compared for horizontal
level on the right and left sides of the body, and include the knee
creases, buttock creases, pelvic rim, inferior angle of the scapulae,
acromion processes, ears, and the external occipital protuberances.
In addition the alignment of the spinous processes and rib angles
is observed, with minor scoliosis becoming more evident. The
distance between the arms and the trunk, skin creases, and unequal
muscle bulk are indicators of asymmetry requiring closer
examination. Foot and ankle alignment are also assessed.
The subject stands barefooted in a relaxed posture wearing shorts
or swimming trunks. They need to stand a sufficient distance away
to allow the person doing the rating to adequately view the
posture. The different components of the postural assessment are
viewed anteriorly, posteriorly and from the side
52. The following postural assessment was done:
a)Shoulder symmetry: Are the shoulders level when viewed from
the front or the back?
b) Roundedness of shoulders: Observed from the front and side.
Are the shoulders held in internal rotation with anterior translation
of the humeral head?
c) Thoracic spine alignment: This is observed from the side. Does
the subject have an increased or decreased thoracic kyphosis?
d) Spinal curvature: This is observed from behind. Does the subject
have a spinal scoliosis?
e) Lumbar lordosis. This is observed from the side. Does the
subject have an increased lumbar lordosis or a flattened lumbar
spine?
f)Hip symmetry: Observed from the front or back. Are the hips
level?
g)Knee Hyperextension: This is observed from the side. Are the
knees held in hyperextension?
53. O COMMON FAULTY POSTURES:
O CHARACTERISTICS AND IMPAIRMENTS
O
O The head, neck, thorax, lumbar spine, and pelvis are all
interrelated; and deviations in one region affect the other
areas. In this section, the lumbopelvic and cervicothoracic
regions and typical muscle length–strength impairments for
each region are described separately for clarity of
presentation.
54. O Lateral view
O Head
O 1-Anterior tilt:
O Head tilted forward, C-Spine in Flexion.
O Causes: - stretched posterior cervical ligaments and extensor muscles.
- tight cervical flexor muscle
O 2-Posterior Tilt:
O Head tilted backward, C-Spine Hyper extended.
O Causes: - vertebral bodies and joints compressed posteriorly.
- Tightness of posterior ligaments and neck extensor muscles.
- Elongated levator scapulae muscles & anterior longitudinal
- ligament.
55. O Shoulders
O 1-Elevated shoulders: raised upward.
O Causes:
- Tightness in the upper trapezius and levator scapulae muscles
- Elongated and weak lower trapezius and pectoralis minor muscles.
- Scoliosis of the thoracic vertebrae.(unilateral shoulder elevation)
O 2-Depressed shoulders: lowered downward.
O Causes:
- Hand dominance (dominant shoulder is lower causing unilateral
shoulder elevation)
- Tightness of the rhomboid and latissimus dorsi muscles.
56. O 3-Forward shoulders:
O The acromion process lies anterior to the plumb line; the scapulae are abducted
O Causes:
- Tight pectoralis major and minor, serratus anterior, and intercostals muscles.
- Excessive thoracic kyphosis and forward head.
- Weakness of thoracic extensor, middle and lower trapezius, and rhomboid muscles.
O Cervical and Thoracic Region
O Round Back (Increased Kyphosis) with Forward Head
O The round back with forward head posture is characterized by: An
increased thoracic curve, protracted scapulae (round shoulders), and
forward (protracted) head.
o A forward head involves increased flexion of the lower cervical and
the upper thoracic regions, increased extension of the upper cervical
vertebra, and extension of the occiput on C1.
o There also may be temporomandibular joint dysfunction with
retrusion of the mandible.
57. O Flat Upper Back and Neck Posture
O The flat upper back and neck posture is characterized
by a decrease in the thoracic curve, depressed scapulae,
depressed clavicles, and decreased cervical lordosis with
increased flexion of the occiput on atlas. It is associated
with an exaggerated military posture but is not a common
postural deviation. There may be temporomandibular joint
dysfunction with protraction of the mandible.
58. Pelvic and Lumbar Region
1. Lordotic Posture
Lordotic posture is characterized by:
An increase in the lumbosacral angle (the angle that the
superiorborder of the first sacral vertebral body makes
with the horizontal, which optimally is 30o),
An increase in lumbar lordosis (Fig. 2 ), and an increase
in the anterior pelvic tilt and hip flexion. It is often seen
with increased thoracic kyphosis and forward head and is
called kypholordotic posture.
59. O 2.Relaxed or Slouched Posture
The relaxed or slouched posture is also called swayback.
The amount of pelvic tilting is variable, but usually there
is a shifting of the entire pelvic segment anteriorly,
resulting in hip extension, and shifting of the thoracic
segment posteriorly, resulting in flexion of the thorax on
the upper lumbar spine.
This results in increased lordosis in the lower lumbar
region, increased kyphosis in the thoracic region, and
usually a forward head.
61. O 3.Flat Low-Back Posture
O Flat low-back posture is
characterized by
O A decreased lumbosacral angle,
decreased lumbar lordosis, hip
extension, and posterior tilting of
the pelvis.
62. O Knee
O 3- Genu Recurvatum: "Back Kneeing": The knee is Hyperextended
and the gravitational stresses lie far forward of the joint axis. Ankle joint is
plantarflexed.
O Causes
Tightness of quadriceps, gastrocnemius, and soleus muscles.
Stretched popliteus and hamstring muscles at the knee
Compression forces anteriorly.
O 4-Flexed Knee.. the plumb line falls posterior to the joint axis.
O Causes
Tightness of hamstring muscles at the knee. and tight gastrocnemius
muscles
Stretched quadriceps muscles.
Posterior compression forces.
Bony and soft tissue limitation.
63. O Foot
O a-Pes planus (flat foot): (Pronation) reduced or absent medial
longitudinal arch. In Flexible deformity, medial longitudinal arch
present in non weight bearing, while it reduced in normal weight bearing
position, (foot eversion)
O Causes:
Shortened peroneal muscles.
Elongated posterior tibial muscle.
O b- Pes cavus: (Supination) More stable foot. Weight bearing on lateral
borders of the foot. The medial longitudinal arch is high. (Foot
inversion)
O Causes:
Shortened posterior and anterior tibial muscles. Elongated peroneal
and lateral ligaments
64. Toes:
a- Hallux valgus: Lateral deviation of great toe at MTP joint.
Causes:- joint dislocation.
- Tight adductor hallucis muscle.
- Stretched abductor hallucis muscle.
b- Claw Toe: Hyperextension of the MTP with Flexion of PIP associated with pes
cavus.
Causes:- tightness of the long toe flexors.
- shortness of the toe extensors
c- Hammer Toe: Hyperextension of MTP and DIP joint
and flexion of the PIP. Callosities under heads of MTP
joint because of excessive weight bearing there.
Causes: - shortness of the toe extensors.
- lengthened lumbricals.
d- Mallet Toe: flexion deformity of DIP joint
&extension of PIP
66. O Anterior-posterior view
O Scapulae :
O 1-Winging: scapulae prominent the medial borders of the scapulae lift
off the ribs.
O Causes:
- Weakness of the serratus anterior muscle.
- Shortening of pectoralis &internal shoulder rotation.
O 2-Abducted: away from the spine
O Causes: - tightness of the serratus anterior muscle.
O - Lengthened rhomboid and middle trapezius muscles
O 3-Adducted: toward the spine.
O Causes: - shortened rhomboid muscles.
O - Stretched pectoralis major and minor muscles
67. O 3-Lateral pelvic tilt: one side of the pelvis is higher than the
other .
O Causes:
- Scoliosis with ipsilateral lumbar convexity.
- Leg-length discrepancies.
- Shortening of the contralateral quadratus lumborum.
- Tight ipsilateral hip abductor muscles on the same side and
tight contralateral hip adductor muscles.
- Weakness of the contralateral abductor muscles.
68. O Knee:
O 1-Genu Valgum:
O "Knock Knees": the mechanical axis for the lower limbs is displaced
laterally. Foot tends to be pronated with stress on medial longitudinal
arch, with weight bearing on the posterior-medial aspect of
calcaneus.(AP view.)
O Causes:
- Tightness of the iliotibial band and the lateral knee joint structures.
- Lengthened medial knee joint structures.
- Compression of lateral knee joint.
69. O 2-Genu Varus:
O "Bow Legs": the distal segment (leg) deviates toward the midline in
relation to the proximal segment (thigh);femurs medially rotate. The
knee joint lies lateral to the mechanical axis of the lower limb (AP view).
O Causes:
- Tightness of medial rotator muscles at the hip with hyperextended
knees, quadriceps, and foot evertor muscles.
- Compression of medial joint structures.
- Elongated lateral hip rotators muscles, popliteus, tibialis