Muscle lines/trains/relationships
Recruitment of glutes with core to correct anterior tilt w/ tight hip flexors
any internal biomechanical abnormalities
along this chain = injury-prone
The body works like pulleys and levers.
Tabulate the following:
Hamstrings – quads (antagonist-agonist/reciprocal inhibition)
Calves
Quads
Glute max – hamstrings (muscle of the same function/synergistic dominance)
Quad dominance, and in general, muscles dominating over each other (e.g. part of glute
weakness).
With respect to posture, and around a joint, whilst one muscle is tight (best example is
overactive neck being tight), another in the area is correspondingly lengthened and weak.
Intrinsic and extrinsic (having its origin some distance from the part which it moves)
TFL (lateral front) <--> glutes (posterior chain)
Lower Crossed Syndrome
June 29, 2009, filed under Chiropractic 101
Tight vs weak muscles in lower crossed syndrome
Just like in upper crossed syndrome, lower crossed syndrome is a muscular abnormalities of
the body brought on by one’s posture. Common patterns of lower crossed syndrome include
tight lower back muscles, potentially with lower back pain. The individual might also have
sore knees due to tight leg adductor muscles (muscles that move your legs towards the
center of your body.
Lower crossed syndrome can develop from someone who sits for long periods of time,
leaning in a slightly flexed position. This causes the lower back muscles or erector spinae to
continually contract to hold the body’s weight upright while the constantly flexed position
shortens the muscle length of the iliopsoas and rectus femoris muscles. Through continued
concentric contraction or in a shortened position, the muscles adapt and shorten in length
leading to muscle tightness.
However, since the body acts like a series of pulleys and levers, when one muscle gets
shortened, it usually means that another muscle gets lengthened. This phenomenon is
known as reciprocal inhibition. How it works is that when a muscle is contracting, the
muscle opposite of its function, or antagonist muscle, is turned off so that they aren’t both
contracting at once. Your brain can of course override this, but the purpose of reciprocal
inhibition is to make the body more efficient and to avoid injury. While inhibited though, the
antagonist muscle is not only prevented from contracting, but in many cases is actually
stretched or lengthened. If you think of your quads (front thigh muscles) versus your
hamstrings (back thigh muscles), if you flex one, you’ll usually feel the other stretch when you
maximally stretch (I really feel this if I’m sitting down). In the end, the shortened tight
muscles cause the stretching and lengthening of their antagonist muscles. This
ultimately leads to the weakening of those muscles.
Due to the tightened and lengthened muscles, one with lower crossed syndrome will typically
present with anterior pelvic tilt. This could look like someone is hunching over forward since
their feet are more than likely planted on the ground. They might also have an increased
lumbar lordotic curve, or increased lower back arch, which contributes to the anterior pelvic
tilt. Both of these conditions help to further enforce the lower crossed syndrome, resulting in
one of the many reasons for lower back pain.
Muscles commonly tight or shortened in lower crossed syndrome include:
 Iliopsoas
 Rectus femoris
 Erector spinae
 Piriformis
 Tensor fascia latae (TFL)
 Leg adductors
The weakened or lengthened muscles include:
 Abdominal group
 Gluteal group
More: How to treat lower crossed syndrome
Upper Crossed Syndrome
June 29, 2009, filed under Chiropractic 101
Tight vs weak muscles in upper crossed syndrome
Ventral crosses
Notice the anterior head carriage: the ear is supposed to be directly above the shoulder.
Upper crossed syndrome, also known as “student syndrome” or “corporate syndrome”, is a
pattern of tight and weak muscles the body develops based off of one’s postural tendencies
just like lower crossed syndrome. The most common trait for someone with upper crossed
syndrome is tight upper traps (a muscle in between the edge of your shoulder and your neck)
and sometimes right at the back posterior base of your skull. This is a very common
occurrence in today’s population. In fact, there is a good chance that even YOU have it!
The people this affects the most are those that sit all day, usually in front of a computer or at
a desk. This is why it’s called student or corporate syndrome! Due to poor ergonomics, most
people in these situations either find themselves leaning over a desk to read, or hunched at a
computer typing all day. If you don’t believe me, stroll down your work aisle or school library
and take a look. In order to maintain this unnatural position, the body has to
continually contract certain muscles. If you think about a muscle’s length when it is
(concentrically) contracting, it gets shorter. If you hold that contracted position for
long enough, the muscle will actually remain shorter, resulting in tight muscles.
This isn’t all though…think about the other muscles that you are NOT using in holding these
positions. The musculature of the human body is an amazing example of balance. When
one muscle is working, the opposite muscle is generally not. This is called reciprocal
inhibition. In many cases, the opposite muscle is actually stretching. Think about your biceps
for example. If you are lifting something really heavy such as a dumb bell for example, your
biceps has to contract to lift it. Your triceps, the antagonist or opposite muscle, does not work
when lifting the dumb bell and you may actually feel it getting stretched at the very end of
your biceps curl. With the continual stretching and overall lack of use, the muscles
opposite to the ones doing all of the work will eventually stretch out and get weak.
This can lead to a whole new swing of body aches and make it harder to attain proper
posture.
This is why people with upper crossed syndrome have tight shoulders and base skull
muscles. Given the tightness of these muscles, these people will also tend to have anterior
head carriage, also known as forward head carriage, a position where the center of their head
is far more in front of their body then the center of their body. The muscles most likely to be
tight on a person with upper crossed syndrome include:
 Upper trapezius
 Sub occipital
 Deep neck extensors
 Pectoralis major
 Levator scapuli
The muscles that tend to be weak or lengthened include:
 Rhomboids
 Middle and lower trapezius
 Deep neck flexors
More: How to treat upper crossed syndrome
These imbalances in tightness and weakness are not just isolated to upper and lower crossed
syndrome; muscle imbalances occur at every joint.
Biomechanical and Neurological Paradigms of Muscle Imbalance
Be aware that there are two paradigms to muscle imbalance.
There are two schools of thought on muscle imbalance: one that believes in a biomechanical
cause of muscle imbalance resulting from repetitive movements and posture, and one that
believes in a neurological predisposition to muscle imbalance. Both biomechanical and
neurological muscle imbalance are seen clinically, so clinicians must understand both in order
to make a more accurate diagnosis and treatment. Patients may also exhibit hybrid muscle
imbalance syndromes consisting of factors from each paradigm, further challenging clinicians
as they work to prescribe the appropriate treatment.
Janda, widely considered the father of the neurological paradigm of muscle imbalance, did
recognise that muscle imbalances may also result from biomechanical mechanisms (Janda
1978). The neurological approach to muscle imbalance recognizes that muscles are
predisposed to become imbalanced because of their role in human motor function (as
opposed to biomechanical imbalance due to repetitive movements and prolonged postures).
Janda considered muscle imbalance to be an impaired relationship between muscles prone
to tightness or shortness, and muscles prone to inhibition. He more specifically noted that
predominantly static or postural muscles have a tendency to tighten whilst muscles that are
predominantly dynamic and phasic in function, have a tendency to grow weak (Janda 1978).
Detailed comparison of the biomechanical paradigm imbalance and Janda’s neurological
paradigm of muscle imbalance
Site:
http://books.google.com.au/books?id=TkMyMb_z6HkC&pg=PA7&lpg=PA7&dq=muscle+imbalance+paradigms&sour
ce=bl&ots=HSzlUGmt2G&sig=k1FbygkRe7bDMOXQTm5hpOnGLTM&hl=en&sa=X&ei=BmYLUMTkF8TYigeT2y2DQ&ved=0CFYQ6AEwAw#v=onepage&q=schools%20of%20thought&f=false