Posture and Core stability Flashcards
skeletal, muscular and neural factors that can cause posture issues
poor exercise technique and/or exercise programming repetitive working patterns they way we stand leisure activities genetics injury age emotional issues environmental factors
optimum posture definition
the state of musculoskeletal balance whereby the body can carry its own weight and that of gravity with minimal muscular effort and limited joint compressions and shearing forces
static posture
refers to body’s alignment when standing, sitting or lying
normally assessed using the line of gravity to determine stress that gravity places on the body in such a posture and how balanced each body segment is relative to neighbouring segments
dynamic posture
body’s alignment whilst moving
formed by a series of actions and reactions
postural adjustments are made while moving which are based on feedback from sensory receptors and anticipation based on learning from similar tasks that have been previously completed
3 posture control mechanisms
passive, active, neutral
passive (posture mechanism)
passive musculoskeletal sub-system comprises of a variety of structures, including bones, ligaments, joint capsules, connective tissue, cartilage, spinal discs and the passive mechanical properties of the muscles and fascia.
this subsystem creates tension and stability through passive opposition to movement
the stretchy elements (muscle, fascia and tendons) can store and then return elastic energy
the bones can acts as levers to transfer force from place to place
all work done by this subsystem is on a ‘for free’ basis because it does not require any metabolic energy to be expended
active (posture mechanism)
active musculoskeletal subsystem consists of skeletal muscles
energetically expensive because muscles require energy to contract whether or not they are working to prevent or create movement
neural (posture mechanism)
consists of various sensory receptors
sensory receptors detect changes and the nerves send signals from the receptors to the motor units to fire as is required to recruit
birth defects contributing to postural deformities
achondroplasia - bone growth disorder that causes dwarfism. sufferers also often present with lordosis
congenital kyphosis - lump of spine which presents at birth which becomes worse with growth
spina bifida - when a baby’s spinal cord doesn’t develop correctly, causing a gap in the spine commonly associated with kyphosis
environmental/lifestyle factors contributing to postural deformities
poor postural awareness
poor diet - affecting bone mineral density
poor or unsuitable footwear
uneven carrying of load = overuse and underuse of muscles cause joints to become misaligned
pregnancy alters mother centre of gravity. hormonal changes create joint laxity
obesity alters centre of gravity. as the pelvis tilts anteriorly, the lumbar curvature increases = increased risk of developing lordosis
overuse and underuse of specific muscles
gravity and posture
in an upright and optimally aligned posture, the centre of gravity is deep in pelvic region, slightly anterior and between the first and second sacral vertebrae
line of gravity is a vertical line which passes through the centre of gravity
the neutral spine
‘optimum’ spinal position
will prevent joint and ligament damage within the vertebral column, increase biomechanical efficiency of body and enable the effective transmission of forces through the pelvis from activities that involve either impact or axial loading
lordosis
also referred to as 'hyper lordosis' also known as 'lower cross(ed) syndrome' exaggerated curve in lumbar spine in many cases also accompanied with some degree of kyphosis increased risk of lower back pain and hamstring injuries tight muscles in need of stretching: - hip flexors - erector spine - quadratus lumborum weak muscles in need of strengthening: - hamstrings - gluteals (ideally in isolation) - core stabilisers (esp transverse abs) - rectus abdominis
Kyphosis
/ ‘hyper-kyphosis’
excessive curvature of upper thoracic and lower cervical region
/ ‘hump’, ‘Dowagers Hump’, ‘upper cross(ed) syndrome’
common causes = neuromuscular disorders, poor postures
people with severe kyphosis, the vertebra often becomes wedge shaped which can be from a trauma related fracture or from infection or tumour
‘Schuermann’s Disease’ is a cause of kyphosis during development - anterior aspects of thorax do not develop at same speed as posterior segments
tight muscles in need of stretching:
- pectoralis major
- upper trapezius
weak muscles in need of strengthening:
- lower trapezius
Flat Back
not as common as lordosis or kyphosis
most frequent in ectomorph body type
simple to identify a sufferers will appear to lean forward when standing and walking + usually have little shape in gluteal area
largely created by forward inclination of leg as hip shifts anteriorly, causing lumbar to flatten. head position often forward with cervical spine slightly extended
tight muscles in need of stretching:
- hamstrings
- rectus abdominis
weak muscles in need of strengthening:
- erector spinae in lumbar region - develop through a full range of motion
- hip flexors (if posterior tilt is present)
good idea to perform posture training with such clients using a plumb line type posture
Sway Back
commonly confused with lordosis because will appear to have abnormal curvature of lumbar spine
anterior hip displacement and posterior displacement of the thorax places strain on the spinal ligament usually results in spinal laxity
women suffer more than men, especially when high heels worn frequently - elevated heel causes the pelvic girdle to move anteriorly = posterior lean to maintain balance
tight muscles in need of stretching:
- hamstrings
- internal obliques
weak muscles in need of strengthening:
- external obliques
- hip flexors
plumb line type posture training
Scoliosis
concerned with lateral and transverse plane deviations whilst others are sagittal plane concerns
spine cannot laterally flex without rotating, therefore involves rotation
may be caused by hereditary conditions, birth defects or develop from medical issue
mild scoliosis may also be acquired from factors like lifestyle, occupation, or sport.
more common in females - esp in puberty = spine grows asymmetrically into a lateral curve that may be accompanied by some degree of rotation - ‘idiopathic’
should be emphasis on unilateral training approaches = both sides are strengthened equally
medical conditions and postural disorders
there are a variety of medical conditions and spinal disorders associated with chronic and untreated postural deviations including:
- a loss of functional range of movement
- herniated disc
- facet joint pain/dysfunction
- scoliosis
- spinal stenosis (narrowing of spinal canal)
- osteoarthritis in load-bearing joints
- ankylosing spondylitis (spinal arthritis)
- spondylisthesis (anterior slipping of the vertebra)
the core
comprises of all the muscles involved in providing stability to axial skeleton.
there is some debate as to which muscles specifically form the core, those which are universally accepted include:
- external obliques
- internal obliques
- rectus abdominis
- transverse abdominis
- erector spinae
- multifidus
- quadratus lumborum
collectively speaking, the core performs a variety of essential roles, including:
- contain and protect the visceral organs
- to provide essential mobility for the spine so that spinal tissues to be nourished
- to stabilise the upper portion of the body over the lower portion
- to control the pelvic-lumbar relationship
core stability
describes the ability to move the limbs whilst maintaining an optimal alignment of the spine, pelvis and shoulder girdle.
local and global muscles
a key stabilisation consideration is the relationship between ‘local’ muscles (deep stabilising muscles) and ‘global’ muscles (larger, more superficial muscles that produce movement).
muscles closer to the spine have a limited range of movement = mechanical disadvantage for movement production.
when muscular imbalances exist between global and local muscles of a joint, passive structures like spine and ligaments are placed under tension. other muscles are recruited to compensate which continues the muscular imbalances. = synergistic dominance
eg glutes and hamstrings (gluteal amnesia)
local primary core stability muscles
transverse abdominis multifidus quadratus lumborum internal obliques pelvic floor diaphragm
global primary core stability muscles
erector spinae
rectus abdominis
external oblique
intra abdominal pressure
the pressure of all gases in the abdominal cavity.
particularly important for the stabilisation of lumbar and lower thoracic vertebrae.
key function of core muscles is to elevate IAP = increases stability.
most of core muscles are interconnected via a sheet of connective tissue called an aponeurosis
abdominal balloon mechanism
mechanism by which the core muscles elevate intra-abdominal pressure
core stability is at its greatest when the pressure exerted on the abdomen and its contents by the core muscles is synchronised, sustained and equal
when the pelvic floor, diaphragm, local back muscles and various layers of abdominal tissue contract, intra-abdominal pressure increases and so does stability in this region. this is the abdominal balloon mechanism.
thoraco lumbar fascia
/ lumbodorsal fascia
broad flat sheet or connective ligamentous tissue which spans the posterior surface of the lumbar and lower thoracic spine
primary function is to stabilise the lumbar and thoracic region of the spine and assist with sacroiliac stabilisation
posterior surface of TLF also plays a role in transmitting forces and load between spine, pelvis and legs
also an attachment site for many of the muscles in this region ~ including gluteus maximus
abdominal wall muscles are attached via an aponeurosis. when tension is applied to the TLF by these muscles, it stiffens spine to increase stability + cocontraction of the core stabilising musculature = ‘thoraco lumbar fascia gain’
the pelvic floor
/ pelvic diaphragm
2 groups of muscles = levator ani and coccygeus
the functions of the pelvic floor
maintaining intra-abdominal pressure inferiorly
supporting abdominal and pelvic organs
providing stability inferiorly for the pelvic girdle
controlling continence (urine and faeces)
supporting weight of foetus during pregnancy
reflex activity to counteract pressure changes ( e.g. coughing, sneezing, blowing nose, vomiting etc)
pelvic floor exercises (slow twitch)
best to learn the basics of these exercises from a seated position with feet flat on ground
1) close and draw up muscles around back passage, as if you are trying to stop passing wind. make sure you do not contract buttock muscles
2) now close and draw up the muscles around the front as though trying to stop flow of urine
3) hold for 5 seconds but try not to hold ur breath
4) slowly relax then let go
5) repeat 5 times in total
pelvic floor exercises (fast twitch)
1) pull up the pelvic floor muscles but focus on engaging them as fast as possible
2) hold for one second then relax
3) repeat 5-10 times or until your muscles feel tired
pelvic stabilisation
because pelvis is attached to sacrum, and sacrum is fixed to lumbar spine, any instability at pelvis is transferred to spine.
instability and stress also transferred inferiorly - both the knee and ankle need stable platform to operate
pelvic stabilisation is an essential link in the kinetic chain and is the gateway between upper and lower body
scapula stabilisation
when a laxity and weakness at the scapulae presents, unwanted and compensatory movement occurs = increases mechanical strain on surrounding structures, esp glenohumeral joint the scapulae are able to anchor themselves to the axial skeleton in order to generate stability they need. this anchor is essentially created by the collective action of following muscles: inferior trapezius intermediate trapezius rhomboid major and minor serratus anterior levator scapulae pectoralis minor
abdominal adipositry
‘adipositry’ describes how body stores fat tissue
excessive levels of fatty tissue in lower ab area will cause centre of gravity to shift anteriorly and inferiorly which may lead to reduced stability
will also result in greater ‘shear forces’ imposed on lumbar region = greater strain on spinal extensors, ligaments and intervertebral discs
men store fatty tissue/adipose tissue centrally around abdomen = android body type
females = store in hips and lower waist = gynoid
lower back belts
most are designed to fit around the lumbar region of the spine
are typically wider posteriorly and narrower anteriorly
research conducted by academic authorities in spinal rehabilitation and preservation have concluded that the use of back belts in a healthy population has no positive advantages can actually be detrimental to long term stability and health of spine.
the belt is applied tightly around the abdomen which compresses the abdominal viscera, increasing pressure and stability = but will not reduce compressive loads on intervertebral discs = as many manufacturers will claim.
predisposes the spine to injury when loaded without a belt
should not be considered permanent and should only be used in those with acute bouts of lower back pain.
benefits of stabilisation exercise on posture
reduced risk of injury in both weight-bearing and non weight-bearing tissues improved application of power by limbs in an unsupported environment improved aesthetics improved motor skills improved proprioception and balance reduced incidence of lower back pain improved posture/alignment more efficient patterns of breathing
exclusion from core stability training
due to increased risks associated with core stability training, you must ensure your client is fit and healthy enough to participate
with scoliosis - need to establish id it is result of muscular imbalances or genetic curvatures. exercise will not be effective for correcting genetic scoliosis but it may help prevent the condition from worsening
core stability exclusion criteria
answered yes to any PAR-Q questions
any concerns regarding readiness to exercise raised by client and/or instructor
hypertension
resting heart rate greater than 100 bpm
elements of passive mechanism
bones ligaments joint capsules connective tissue spinal discs cartilage fascia
elements of active mechanism
skeletal muscles (local and global)
elements of neural mechanism
nerves sensory receptors (eg propriceptors, mechanoreceptors)
corrective exercise and poor posture
in general, tight muscles need to be lengthened, long muscles need to be shortened, weak muscles need to be strengthened
corrective exercise should be conducted by an exercise professional with the sufficient qualifications
clients with poor posture may also get out of breath faster because of tight and shortened muscles exerting additional strain on the thoracic cavity which restricts its expansion
points to consider when designing programmes for kyphosis and lordosis
can experience irritation to coccyx during seated activities, so better to adopt kneeling, lying or standing variations
kyphosis sufferers should avoid flexion exercises like sit ups
lower back pain and posture
as the nation becomes more sedentary, the lack of neural stimulation to the deep stabilising muscles of the spine diminishes.
this loss in neural activation results in weakness and atrophy, causing instability and pain in spinal column.
imbibition
the process through which spinal disks need movement for nourishment as they are avascular and have no blood supply
force couple
while muscles may appear to create completely different patterns of movement, relationships exist between seemingly unrelated muscles.
eg the erector spinae is primarily a spinal extensor, however it can also tilt the pelvis anteriorly.
by exerting forces in different directions, muscles are able to create force couples that result in the same movement. therefore it is imperative that all 29 muscles are trained equally to prevent muscle imbalances.
the lid (IAP)
the diaphragm forms the superior surface of the cylinder
the corset (IAP)
the entire abdominal, lower back and oblique musculature form the anterior, posterior and lateral portions of the cylinder
the base (IAP)
pelvic floor muscles create the inferior surface of the cylinder
aponeuroses (single aponeurosis)
sheets of glistening white connective tissue
furnish large surface areas of the body to provide attachment sites for muscles, connect tissues to each other and join muscles to the body parts they act upon.
they have a limited blood supply
posture and core stability DON’TS
squeeze ur bum together
bring ur knees together
hold your breath
lift your shoulders/eyebrows or toes upwards
abdominal draw-in (stabilisation) exercise
progression = perform kneeling, on unstable surface or from quadruped position regression = perform lying on ground equipment = can use stability disc, BOSU or stability ball to reduce stability
superman (stabilisation) exercise
progression = perform on unstable surface, from quadruped position or use resistance to perturb the core even more regression = perform with no resistance, move arms and legs in isolation, perform alternative left and right leg for balance equipment = can use BOSU or stability disc to reduce the stability of exercise. both dbs and rbs can be used
bridge (stabilisation) exercise
progression = perform on unstable surface, use only one leg for support, slow down pace and use resistance regression = perform with no resistance, use both legs for support, slightly speed up exercise equipment = BOSU ball to reduce stability, dbs, rbs and medicine balls can be used
plank (stabilisation) exercise
progression = perform on unstable surface, progress from 3/4 to full plank, use only one leg for support and focus on shoulder stability regression = increase contact with ground and stability, perform from knees and widen the elbows and knees equipment = BOSU, stability ball and stability discs to reduce stability
side plank (stabilisation) exercise
progression = lift the feet onto a box or bench to increase ROM regression = bend the knees and perform with their lower leg on the ground equipment = BOSU, stability ball and stability discs can be used to reduce stability
