Posture stability and Balance

Posture Principles Definition of “good” posture Examples of poor posture

Posture Posture is the relative alignment of the various body segments with one another Good posture – body alignment is balanced so that stress applied to the body segments is minimal Poor posture – body alignment out of balance – causing exaggerated stress to various body segments Overtime continued stress cause anatomical adaptations These changes alter the individuals ability to perform

Correct Standing Alignment Three planes - sagittal, frontal , transverse Plumb line – point of reference Anterior ( frontal) Bisects body – left and right Standing facing forwards, feet relaxed , arms handing by side Plumb line bisects nose , mouth , sternum, umbilicus and pubic bones Following should be level , earlobes, shoulders , finger tips, nipples, iliac crest, patella and medial malleoli Patella should point forward , feet straight ahead or slight outward rotation Body weight equally distributed

Correct Standing Alignment Posterior Similar to anterior view to anterior Plumb line should bisect the head, follow the spinous process So posteriorly the iliac crests , gluteal fold , posterior knee creases should appear level Scapulae should lie about 2” from spinous process, Calacneous should be straight Shoulders relaxed , symmetrical trunk musculature Body weight equally distributed

Correct Standing Alignment Lateral Plumb line anterior to lateral malleolus Plumb line passes through the external auditory meatus, the earlobe , bodies of cervical vertebrae , centre of the shoulder , greater trochanter, midway between the back and the chest, posterior to the hip and slightly ant to the knee. Knees are straight but not locked , body weight equally distributed between heel and forefoot Chin slightly tucked Mild curve inward in low back and neck regions

Pathological Alignment Bad posture usually develops as we age Toddlers have good posture , start to develop bad habit by the time we enter primary school Good posture allows the individual to use body effectively and efficiently Bad posture causes shortening and lengthening of structures , which may cause impairment , pain and injury Posture recorded in terms of relativity Mild Moderate severe

Pelvis and Lumbar Area Excessive lumbar lordosis ( anterior pelvic tilt) Excessive – sway back Tight hip flexors , low back extensors Weak abdominals and gluteals Overtime causes narrowing of disc space , facial tightness , approximation of vertebral facets , increase stress on ant longitudinal ligament Flat lumbar spine ( posterior pelvic tilt) Abnormal hip extensor and Rectus abdominis tightness Weak hip flexors and lumbar extensors This posture reduces bodies ability to absorb impact forces and increase stress on post longitudinal ligament

Thoracic Area This area can be excessively rounded or excessively flat Mild kyphosis is normal , but excessive rounding in response to a lumbar curve or cervical lordosis is pathological Chest muscles tight , weak thoracic ES , rhomboids, traps Often associated with rounded shoulders Scapulae is more than normal 2” from spine Flat back- reduction of thoracic curve – not as common Depressed scapulae and flat neck Tight ES , rhomboids and weak anterior thoracic muscles

Thoracic Area Scoliosis- lateral curve of spine Either S shaped or C shaped Usually includes rotation of the vertebrae Can be congenital Often caused by leg length differences , long term unilateral activities

Head and Cervical area Cervical lordosis- weakness in lower cervical and upper thoracic erector spinae and anterior neck muscles is over powered by tightness in upper cervical muscles including Lev Scap , Sternocleidomastoid, scales and upper traps Increases cervical disc pressure , irritates cervical facets , nerve pressure and increased stress on ligaments

Lower extremities Hip Knee Patella Coxa valga- abnormally larger angle between femoral neck and femoral shaft More likely hood of hip arthritis Coxa vara – smaller than normal angle between femoral neck and femoral shaft More likely hood of femoral fractures Knee Genu valgum- knock kneed Genu varum – bow legged Patella Squinting – face towards each other Frogs eye angle away from each other Genu recurvatum – hyperextension

Lower extremities Foot Medial longitudinal arch , draw a line from the distal aspect of med mal to the weight bearing surface of the 1st MT , in both non and weight bearing the navicular should be on the line Pes cavus – high arch – hypomobile – more rigid reduced ability to absorb stress , more prone to stress fractures Pes planus- low arch – hypermobile – difficult to create a solid platform – PF , Achilles issues Hallux valgus –positioning laterally of the great toe

Muscle balance Good mechanics require that joint ROM be adequate, but not excessive The more flexibility, the less stability The more stability, the less flexibility Why do only some people get pain? Posture may be faulty, but individual has mobility so position can change readily Posture may appear good, but mobility lacking so position cannot change readily

Mechanical Imbalance Results from abnormal relationships between forces that act on area An alteration of structure and function which is reflected in combinations of muscle tightness and weakness, ligamentous laxity and/or poor alignment of body segments Faulty alignment results in undue stress on bones, ligaments and muscle Adaptive shortening can develop in muscles that remain in a shortened condition Stretch weakness can occur in muscles that remain in elongated conditions

General population Swayback: Approximately 30% of men and 20% of women. Kyphosis-Lordosis: Approximately 20% of women and 15% of men. Flatback: Approximately 10% of men and women. Only 5% of persons may have the optimal posture depicted to the left, with a further 15% coming reasonably close

Summary Postures that deviate from ideal can produce adaptive shortening, strengthening, elongating and weakening that can affect structures quite distal to the poor posture culprit Use a postural assessment to guide your specific assessment and treatment plans, especially for chronic, non-traumatic problems

Treatment Important to correct postural deviations and not only address current injury Could be a source or a contributing factor Must identify the tight structure and the over stretched structure We must lengthen and strengthen Example – swimmers rounder shoulder Provide reminders – visual clues Physical reminders – tape Habit & relationship between tight and weak muscles