How we move..
What do muscles do for us? Provide movement Maintain posture/stability Generate heat (skeletal muscle accounts for 40% body mass)
So looking at skeletal muscles.. What do skeletal muscles do? Provide movement at joints How do they do that? By contracting How is a muscle attached to a bone Via a tendon
Basic muscle structure
So what is a ligament? A ligament attaches bone to bone... Think of ligaments like cellotape!
Tendon v. ligament
Why are tendons so problematic? Because they have a poor blood supply, so take a long time to heal...
Ligament structure
Let s look at some major muscles
Erector spinae Gluteus maximus Rectus abdominis Biceps Triceps Quads Hamstrings Gastrocnemius
Are these muscles superficial or deep? They are superficial, can be seen on muscle charts and easily identifiable... Anyone know what group these muscles fall into?
These muscles fall broadly into the group of mobiliser muscles... ie. action muscles
What about these? Subscapularis Serratus anterior Transversus abdominis Gluteus medius Soleus Multifidus These are mostly deeper and hidden away...
These muscles fall into the stabiliser group ie. the muscles that hold us in place so that we can move...
But remember, muscles are much cleverer than that, they rarely do only one thing...
Muscle actions Which muscles flex the trunk? Show their action in supine (on your back) Which muscles extend the trunk? Show their action in prone (on your front) Demonstrate hip extension in standing. Which muscles do this? Demonstrate knee extension in sitting. Which muscles?
What kind of muscle contractions are these? What is happening to the muscle length? It s shortening to create movement at a joint Do you know what this is called? CONCENTRIC
Concentric contraction of biceps ie. muscle shortens Also called Isotonic Here Biceps is working against a load = weight and against resistance = gravity
Concentric contraction of abdominals ie. isotonic Here, abdominals are working against gravity to flex the front of the body.
Concentric activity of triceps (bent to straight arm)
Concentric (isotonic) contraction against a load Which trunk muscles are working here? Answer: the obliques
Biceps curl Turn to the person next to you. Describe the muscle actions involved in bending and straightening the elbow.
Eccentric contraction Biceps concentrically contracts to bend the elbow. Then biceps eccentrically contracts to straighten the elbow to starting position.
Let s look at triceps again: As she straightens her arms, triceps works concentrically ie. shortens And how does she control bending the elbow again? Triceps works eccentrically.
So as she straightens her arm using concentric triceps, what does biceps do? It lengthens and relaxes. What does it do when she bends her elbow? It stays relaxed. NB If resistance is strong, biceps may help control the movement.
Why does she stand in this position? To position triceps so that it works against gravity. Another position?
Triceps activity. As she pushes up, what kind of triceps muscle activity is it? As she lowers, what is triceps doing? What is the load that she is working against?
Biceps and triceps anatomy at elbow A classic example of agonist and antagonist. Can you think of others?
Agonist and antagonist (1) Muscles act around joints to create movement. The agonist is the muscle that creates the movement, often called the prime mover. The antagonist is its opposite and either stretches and relaxes or helps control the movement of the agonist by providing resistance eg. to slow or stop a movement.
Agonist and antagonist (2) It is not necessary to know the names of all the muscles, but it is important to know muscle groups by their function Eg. trunk flexors and extensors Eg. hip abductors and hip adductors Eg. shoulder external and internal rotators Eg. ankle dorsiflexors and plantarflexors Eg. right and left trunk rotators
Plank to chaturanga dandasana (Look at triceps activity) Static triceps (and biceps). Eccentric triceps into position Concentric triceps back to plank
To lower the trunk back to the bench, how is this movement controlled?
Isometric contraction Also called Static Which shoulder muscles are working here?
Summary Eccentric lengthening Static Concentric - shortening
Let s look at our own muscles in action! Stand up and let s feel these things happening...
Key concepts First, ask yourself, Is the movement going against gravity or with gravity? If the muscle is moving against gravity, it will shorten and so control will be concentric. If the muscle is moving with gravity, it will lengthen and so the control will be eccentric. Then identify which muscle/group is going to activate the movement
Squatting... On the left, is the movement going with or against gravity? On the right, is the movement going with or against gravity?
Looking at Quads activity On the left, what do the quads do to lower her bum towards the floor? On the right, what have the quads done to straighten her knees?
What about glut max activity? Is this action with or against gravtiy? To lower her bottom towards the floor, do the gluts lengthen or shorten? LENGTHENING IS A MAJOR CLUE TO THE ACTIVITY!
Gluts How does she straighten up? With gravity or against gravity? Do the gluts shorten or lengthen?
From flexion to standing With gravity or against gravity? So is it a lengthening or a shortening? Which muscle group controls the movement?
From standing to flexion With or against gravity? Is it a lengthening or shortening action? Which muscle group controls the movement?
From crouched to standing... Which muscle group produces the movement? What type of muscle activity?
How do we back bend? Ask yourself: is the movement going with gravity or against gravity? Compare the next slide that we saw before...
To lower the trunk back to the bench, the abdominals have to lengthen to control the response to gravity ie eccentric control
Which muscles group moves us... from hollow to arch? And from arch to hollow?
Explore what is happening here...
How do we reduce our muscular effort in asana? What are your ideas?
Bones v muscles Compare hands and knees with the shoulders directly over the hands, to placing the hands wider than shoulder width.
Bones v muscles Compare doing the plank with the hands under the shoulders (ie. vertical arms) and then with the hands further under the body (towards the feet)
If we are aligned... We will be more efficient Muscles will do less. Our paired muscles will gently cocontract to maintain our position eg hams and quads at the knee in standing; biceps and triceps in arm balances
What about the core muscles Our core muscles will work to stabilise us in our balance positions. If our core muscles are efficient, we simply allow them to work. Our balance will be at its best when we don t interfere... When we stop thinking about what should be working, we will allow our body s intelligence to take over.
Should we pull in our abs when we balance on one foot? Let s do an experiment Stand with your right foot crossed over your left shin. Rotate your trunk to the left, keeping your pelvis facing forwards. Notice your range of movement. Now repeat but draw your abdomen in and tighten your pelvic floor. What has happened to your range of movement?
Why has ROM decreased? Think of the anatomy. Where are the abdominals attached? Pelvis to the ribs and they also connect to the thoracolumbar fascia.
The end result? By tightening these muscles, we have stiffened the body and so REDUCED our movement, REDUCED our choices.
And the effect on our breathing? Pulling in our abdominal muscles and pelvic floor will adversely affect our breathing. The diaphragm will not be able to descend and so chest breathing will be inevitable.
Let s look at some yoga postures
Key concepts a reminder! First, ask yourself, Is the movement going against gravity or with gravity? If the muscle is moving against gravity, it will shorten and so control will be concentric. If the muscle is moving with gravity, it will lengthen and so the control will be eccentric. Then identify which muscle/group is going to activate/control the movement
Side flexion Which side controls the trunk movement? Is it lengthening or shortening? So what kind of activity is it?
Warrior 1 What type of muscle activity in the left gluteus maximus? What type of muscle activity in the right glut max? What type of muscle activity in the right quads? What type of muscle activity in the front of the left hip? A perfect example of agonist/antagonist activity at the hip!
Where does the muscle activity come from to raise the pelvis from the floor? What kind of activity?
From supine lying to trunk rotation How is the trunk movement controlled? Into the rotation? Out of the rotation?
Bridging Is the movement with gravity or against? Which muscle group? (Interesting question) What kind of activity? What s happening to the antagonists? Does pelvic tilt position matter?
Wheel Is the movement with or against gravity? Which muscles? Mainly hip and back extensors.
Spinal extension With or against gravity? Which muscles? Concentric or eccentric?
The Plough From supine to the plough, with or against gravity?... Careful! Which muscle group(s)? Concentric or eccentric?