By Jon Trister MD
Posture is the result of the dynamic interaction of two groups of forces-environmental force of gravity on one hand and the strength of the individual on the other.
Strength of the individual is determined by quality of the connective tissues:ability to interact with forces of gravity-accumulate,store and release of elastic energy to support multiple functions of musculoskeletal, visceral organs and neurological structures.Without gravity normal function of the connective tissue is impossible.Consequences of life without gravity is well known.Any attempt to alter the forces of gravity ( “comfortable” mattresses, chairs,footwear etc) will lead to allostatic compensatory responses with unpredictable consequences.
Therefore, posture is a the formal expression of the balance of power existing at any time between these two groups of forces.
Gravity is constant.Quality of the connective tissue is changing throughout the live and affected by multiple factors:
Macrotrauma and microtrauma
Connective tissue disorders: Ehlers-Danlos syndrome
Certain predictable changes can be seen in the function of musculoligamentous structures, nervous system and visceral organs as a consequence of gravitational stress-induced pathophysiology.
The “ideal” postural alignment , in which gravitational force is transferred along structures adapted to weightbearing, requires a minimum energy expenditure by postural muscles and minimal strain on postural ligaments.
Here I would like to summarize some clinical observation of the postural changes:
Shape of Gluteus Maximus muscles:
Observe symmetry. Look at the level of gluteal folds- asymmetry indicates inhibition or weakness of the ipsilateral side, which will be lower.
Slight asymmetry indicate inhibition or weakness-look at the upper external quadrant.In this case it will be flat on palpation as the result of decreased of the muscle tone.
Asymmetry of the pelvis will cause changes to lower back extensors and hamstrings.
Weakness of Gluteus Maximus will lead to lowering of gluteal fold on the same side.
Than look to the lumbar and thoracolumbar area.Look for scoliosis, rotation or kyphosis which may influence the shape of the muscles.
Check length of arms when they flexed to 90 degrees:difference will point to rotoscoliosis.
Than compare muscles at the lower lumbar region to the muscles at the thoracolumbar junction. Atrophy at the lower segment of the lumbar muscles will require stabilization and lead to the hypertrophy of the muscles at the thoracolumbar segment.
Normally, lumbar segment is symmetrical and flatter than thoracolumbar segment which is slightly more prominent but still symmetrical.
Than proceed to the upper part of the body:
Shoulder blades can be protracted, retracted, shifted upward or abducted.
Look at the stabilizers: lower stabilizer (lower trapezius) interplays with upper stabilizers (upper trapezius,m. levator scapulae)
This area will be flat in the case of muscular inhibition. Weakness or inhibition of the serratus anterior will lead to winging of the scapulae.
If you see atrophy of the lower stabilizers (lower trapezius) than observe upper stabilizers (upper trapezius and m. levator scapulae) which will be compensatory hypertrophic, which will lead to abduction and weaning of the scapula.
To look closely to the quality of the upper trapezius and levator scapulae focus on the reference line from the occiput/lateral neck and the Acromion . This line normally should have “S” shape.When levator scapulae and trapezius are overactive this line became straight.This called “Gothic shoulders”.
Another example of insufficient scapular stabilization will be protracted scapulae due to inhibition of the medium and lower trapezius, rhomboids and overactive serratus anterior.
Upper trapezius in this cases usually overactive which lead to superior shift of the scapulae.
Observation of the anterior shoulder provide information about humeral control:
flattening of the deltoid abductors indicate deltoid atrophy, altered pattern of the shoulder’s muscles and impaired proprioception from the shoulder joint.
In the assessment of the lower extremity first view the subject general posture.
External Rotation of the feet may indicates problem with the muscles or the joint of the hip.
Look at the knee joints: varus , valgus or hyperextension
Correlate limb alignment with calcaneal bone and the position of the forefoot.
Varus leg deformity associated with pronation of the foot and flattening of the foot.
Than estimate the shape of each individual muscle groups.
First, look at the Hamstrings: note if the size of the hamstrings is symmetrical
Usually if gluteal muscle is weaker ipsilateral hamstring compensatory stronger.
Hamstrings best seen in the medium and upper thirds of the thigh.
The second important group of the thighs are ADDUCTORS
In general, there are two groups of adductors: Short (cover upper and middle thigh)and Long(cover entire thigh).
Normally, from posterior view adductors create very shallow letter “S”
If upper adductors are in spasm than upper portion of the “S” will be bulkier. As a compensation of this process lower portion of the “S” will be flat -hypotrophy,-hollow just above the knee.
Than look at the calfs: shape and symmetry. Estimate the tightness of hypotrophy of the m.soleus muscles in the relation to gastrocnemius muscles
If the solei are tight and short, the muscle belly is evident at the medial border just superior to the Achilles tendon. (The m.soleus is located just underneath the gastrocnemius, and together these two muscles form the Achilles tendon. Since these are the 2 biggest muscles in the calf, they provide the majority of the push off when walking, running, and jumping)
If m.Soleus is tight than Achilles tendon become slightly thicker and shorter.
observation of the heel.
No symmetrical person.No specific norms.
Variation of the muscle
ASIS and umbilicus
Rectus abdominis: Upper quadrants more active than lower quadrants. But left and right are symmetrical.
Observe the groove on the lateral edge of the rectus abdominis: it reflects quality of interplay between m.rectus abdominis and m.obliqus abdominis externus. The more prominent this groove -the stronger m.obliqus abdominis externus and m.Rectus abdominis is inhibited.
Next, look at the lateral edge of the waist, which is normally concave. If it become flat or convex shape- sign of weakness of m.transversus abdominis which stabilize abdominal wall and spine properly.
In the upper trunk look at the symmetry of the muscles and respiratory movement of the chest wall. Focus mainly on the pectoralis major.
Compare muscular folds on both sides.The pectoralis muscle is more prominent on the dominant side. Positions of the nipples. If pectoralis is tighten, nipple will be displaced superiorly and laterally. In female, asymmetry of breasts may indicate m.pectoralis tightness.
Observe neck: SCM muscle, which under normal circumstances will be almost invisible.
Usually we only see insertion in the sternoclavicular region. If the muscle belly is pronounced it indicates muscle hypertrophy.
Groove in the area medial to SCM (between SCM and Scalenus muscles )
The more prominent this groove the weaker (hypoactive)the Scalenus muscle
“Facial scoliosis”-asymmetry of face
These points must be symmetrical. Also observe lateral bending and rotation of the head.
Observe hip, knee and feet position.
First look at the tensor fascia latae. normally this muscle is invisible. If muscle is visible it indicate hypertonus of the MTFL.
Than look at the position of the patella: Symmetry, presence of the shift: if quadriceps is tight than patella shifted superiorly
if MTFL is tight patella will shift supero-lateraly and tilt
If vastus medialis is hypertrophied you will see muscle bulk medially to patella
It is usually sign of overstressed knee joint
When proprioception of the knee is altered patella will move in irregular manner from intermittent activity of the m.quadriceps to improve stability of the knee joint.
This vertical translation of the patella is an important sign of poor proprioception of the knee joint.
Look at the lower leg, primarily tibias anterior.
If M.tibialis anterior (anterolateral aspect of the lower leg, just below the knee) is weak than it’s fibers become flat or even they develop groove-early sign of L4-L5 irritation.
Look at the toes.
”Unquiet foot” irregular twitching movement of the tendons of the toes in the different directions-sign of impaired proprioception and the more demanding effort to maintain the balance.
Lateral view: Look at the presence of anterior or posterior tilts.
Look at the lumbar, thoracic and cervical curvatures:The interrelationships of which may depend on the balance between hips flexors and extensors or abdominal muscles and back extensors.
Look at the position of the head, particularly “push forward head position”
Observe line running from the jaw to the hyoid bone: if the supra-hyoid muscles is tight this line become more straight, indicating TMJ problems
Look at the position of the legs, particularly knees (genu recurvatum)
Look at the greater trochanter- MTFL: if groove is present-MTFL is tight