session 15 | muscles of the trunk and posture

Session 15 | Muscles of the Trunk andPosture

© Australian Institute of Fitness 1 / 37

SETTING THE SCENEWe continue our great study of the muscles by learning the attachments and actions of the majormuscles of the trunk. This includes muscles of the abdominal wall affectionately known as the‘abs’ and muscles of the vertebral column. Think of the muscles of the trunk as the ‘commandcentre’ as these muscles are actively involved in the movement patterns we use every day and inexercise such as walking, bending, pushing, pulling, turning, reaching and so on. In other words,there are not many movements that don’t involve the trunk.

As the muscles of the trunk influence the position of the spine, we add the next layer of posture inthis session by introducing common postural abnormalities relating to the vertebral column. Aswe progress through the muscles, we will discuss strengthening exercises to address some ofthese abnormalities.

Last but not least, we make sure we understand the function of these muscles by analysingcommonly performed trunk exercises then we put this awesome anatomy into practice with a coreconditioning practical.


eLog Book Check

You are now several months into your Fitness Instructor course and nearly past the steepestlearning curve of the course which is studying anatomy - well done!

But we also want to ensure we are preparing you physically as well as mentally. It is time tocomplete the 'PT Fitness Challenge' as part of the Master Trainer eLog Book. Then over thecoming weeks, plan to complete your 'Personal Workouts' in the eLog Book.


ABOUT THE TRUNKThe abdominal wall is comprised of skin, fascia and four pairs of flat sheet-like muscles thatcomprise the abdominal muscle group – from deep to superficial, they are transverse abdominis,internal oblique, external obliques and rectus abdominis.

The muscles that attach onto and move the vertebral column are very complex due to theirmultiple origins and insertions and the considerable overlapping amongst them. It is important tounderstand the function of these muscles and in particular, the major muscle group, the erectorspinae.

In summary, we will study the following five muscles in detail and discuss the role of many othermuscles in relation to movement of the neck, the lower back and the trunk as a whole, as well asthe stabilisation responsibilities.

Transverse abdominisInternal obliquesExternal obliquesRectus abdominis Erector spinae


Snapshot - Anterior View

Muscle Origin Insertion Joint Action

TransverseAbdominus (TAor TVA)

6th-12th ribs,lumbar vertebraeand iliac crest viathelumbothoracicfascia from thetransverseprocesses of L1-5

Linea albaXiphoid process(at bottom ofsternum) andpubis

Vertebral/trunk AbdomenCompression(TA is a majorspinal stabiliserand does notmove the trunk)

Internal oblique Iliac crest and thethoracolumbarfascia

Ribs & LineaAlba

Vertebral/trunk Lateral FlexionRotation

External oblique Ribs 4th-12thpair of ribs

Iliac crest to lineaalba

Vertebral/trunk Lateral Flexion,Rotation

RectusAbdominus

Pubis Pubicsymphisis

Ribs 5th-7th ribcartilages

Vertebral/trunk Trunk Flexion


Snapshot - Posterior View

Muscle Origin Insertion Joint Action

Erector SpinaeIliocostalisLongissimusSpinalis

VertebralColumnIliac crest andribsTransverseprocessesCervical tolumbar spinousprocesses

VertebralColumnRibs andvertebraeTransverseprocessesSpinousprocesses

Vertebral/trunk Extendsvertebral columnMaintains erectpostureAssists in headrotation


Thoracolumbar Fascia

As we have previously learnt, fascia is like a bigcobweb of dense connective tissue that runsthroughout your entire body and as such, everythingis connected. The thoracolumbar fascia, so called dueto its attachment onto the thoracic and lumbarvertebra, is particularly relevant to the muscles of thetrunk.

It covers the deep muscles of the posterior trunk andprovides attachment for some of the abdominalmuscles. It is made up of three layers and there arespaces formed between the layers where variousmuscles are located. For example, the erector spinaemuscle is enclosed between the middle and posteriorlayers.


What About the Neck?

The ability to stabilise the neck in a neutral alignment is essential in the performance of anyexercise. Unless the neck is supposed to move as part of the exercise such as a small amount ofneck flexion in an abdominal curl, it should be in a neutral position – in line with the spine!

Many people have weak necks and as such, a poor ability to stabilise and control the neck duringexercise. Encouraging a neutral neck alignment with a slight chin tuck will enhance both postureand stabilisation for these people.

Let's use the example of the squat. Next time you are at the gym, watchpeople performing squats; look for poor alignment such as the neck archingwith the person trying to look forwards in the down position; to correct this, theeyes should look along the floor on the down phase and straight ahead onstanding. Also look for unsteady heads where the head moves forwards andbackwards; again this is incorrect and a conscious effort to hold a slight chintuck to help keep the head still is required. Check your own head positionduring squats – is your neck aligned correctly and your head still?

The movements at the neck are flexion, lateral flexion, extension and rotation. Let’s take a quicklook at the major muscles influencing neck movement and neck stabilisation.

Sternocleidomastoid (SCM)

This superficial muscle originates from the sternum andclavicle and attaches to the mastoid process of the skull andis involved in neck flexion, lateral flexion and rotation. Instabilising the neck which involves a slight chin tuck, thepreference is to activate the deep cervical flexors rather thanrelying on SCM.

Upper Trapezius and Levator Scapula

These muscles were discussed in an earlier session. Inrelation to the neck, the upper trapezius is a superficialmuscle attaching to the base of the skull and the cervicalvertebra. The upper fibres of trapezius are involved in neckextension, lateral flexion and rotation. Levator scapula isdeep to the trapezius and is also involved in neck extension,lateral flexion and rotation.


Potentially Dangerous Exercises (PDEs)

The head is surprisingly heavy and the cervical vertebrae smallconsidering the weight they have to support. Hence, care must be takenwith neck movements. In fact, extreme movements of the head/neck andentire spine are not recommended.

Avoid exercises that involve:

Hyperextension – excessive arching of the back Circumduction – circling the spineExtreme flexion – excessive forwards bending Extreme lateral flexion – bending the back sidewaysUncontrolled and /or extreme rotation – twisting the back beyond normal range and/ortwisting on a fixed base

The exercise shown is called a windmill where the hands alternate in touching the opposite foot,usually with speed. The windmill used to be a popular warm-up exercise but is now consideredcontraindicated as it involves flexion with rotation and has little function in preparing the body forexercise.


MUSCLES THAT MOVE THE TRUNKWe are now going to study the muscles acting on the trunk in detail.

This includes the four abdominal muscles which form a musculargirdle that wraps from the thoracolumbar fascia, superiorly to themiddle ribs and inferiorly to the pubis. The immense span of thesemuscles, with their unique overlapping arrangement and varyingfibre direction, helps stabilise the entire abdominal region.

The transverse abdominis, the deepest muscle of the group, plays amajor role in stabilisation. The thin internal oblique fibres are deepand perpendicular to the fibres of the more superficial externaloblique. The two strips of muscle running up the middle of the bellyare the superficial rectus abdominus.

Posteriorly, we have the erector spinae group which consists of three muscles; spinalis,longissimus and iliocostalis. Their names describe their position to some degree with spinalisbeing the smallest and closest to the spine hence deep, longissimus being more superficialrunning up the length of the spine and the more lateral iliocostalis running from the ilium (ilio) tothe ribs (costal).

As a group, you can feel the erectors from the lumbar region all the way to the neck but theindividual muscles are more challenging to palpate. In the lumbar region, the erectors lie deep tothe thoracolumbar fascia then deep to rhomboids and trapezius in the thoracic and cervicalregions.


Trunk Actions

Before you study each muscle in detail, let's review the joint actions of the trunk. Stand up and trythe following. Firstly, let's isolate the movements to the trunk only; to do this, imagine that youhave wrapped bandages around your pelvis and thighs like a 'mummy' so that you can't movethese body parts. Then perform the following and note that the movements are quite limited:

Trunk flexion – flex the trunk while standing then try this in a supine position (laying on yourback) Trunk extension – from a flexed position in standing, extend (stand up) then see if you canextend or hyperextend in a prone position (laying on your front) Trunk lateral flexion – laterally flex the trunk while standing then try this in a supine position Trunk rotation – rotate the trunk while standing (hint - move ribs towards opposite hip) then trythis in a supine position

Now, imagine that you have taken the bandages off and your pelvis and hip joint are free tomove. Most everyday actions that move the trunk also move the pelvis and hip joint. Try thefollowing movements and be aware of how much each body part contributes to the overall rangeof motion:

Perform a sit-up (in supine with the knees bent) – on the up phase, did you notice your trunkflexing and your pelvis tilting posteriorly to flatten the lower back at the start of the movement,then the largest movement is hip flexion to sit up (hence a full sit-up engages the hip flexorswhile an abdominal curl is more isolated to focus on rectus abdominus) Perform a back extension (in prone, lift the chest up while keeping the thighs and feet on thefloor) – on the up phase, the trunk can extend quite a lot (pending mobility), the pelvis tiltsanteriorly (together these create a lower back arch) and the hips extend minimally henceactivating gluteus maximus

The pelvis joins the sacrum of the vertebral column at a joint called the sacroiliac joint (seebelow) and as such, the pelvis has a very intimate relationship with the vertebral column;meaning that if the spine moves, so too does the pelvis.

On the diagram above, can you identify the 'need to know' bones and bony landmarks discussed


in Session 6? These include the iliac crest, ischium, pubis and anterior superior iliac spine(ASIS).


Transverse Abdominis

Derivation transverse – running transversely

abdominis – refers to the abdomen

Frequently abbreviated to TVA and TA

Attachments

In simple terms:

Iliac crest, lumbar vertebrae via thethoracolumbar fascia and ribs

to the Pubic crest and linea alba

Specifically:

Inguinal ligament, iliac crest,thoracolumbar fascia (from lumbarvertebrae) and the lower costalcartilages

to the Pubic crest and linea alba

Actions/Functions

Abdominal compressionForced expirationDeep stabiliser of the lumbar spine

Stabilisation exercises to activate TA are covered in the core conditioning practical at the end ofthis session.

The video uses the analogy of a paint can to describe what's going on in the core. A summary ofthis follows:

The body of the can is the transverse abdominis


The seal or join on the side of the can is the multifidus (see image) –these small, deep muscles of the transversospinalis muscle group, livebetween the spinous processes of the vertebral column and are highlyinvolved in spinal stabilityThe lid of the can is the diaphragmThe bottom of the can is the pelvic floor

All these muscles work together to provide trunk stability i.e., keeping thetrunk still through isometric contractions. Transverse abdominis andmultifidus play key roles in 'local stabilisation' which refers to deepstablisation at the spinal level.


Internal Oblique

Derivation internal – inside

abdominal – refers to the abdomen

oblique – diagonal

Attachments

In simple terms:

Iliac crest to the Ribs

Specifically:

Inguinal ligament, iliac crest andthoracolumbar fascia

to the Lower ribs (8-10) and theabdominal aponeurosis

Actions

Both sides: trunk flexion (assists rectus abdominis)Right side: trunk lateral flexion and rotation to the rightLeft side: trunk lateral flexion and rotation to the leftAbdominal compression


External Oblique

Derivation external – outside

abdominal – refers to the abdomen

oblique – diagonal

Attachments

In simple terms:

Ribs to the Iliac crest

Specifically:

Inferior border of the lower 8 ribs(ribs 5-12)

to the Anterior iliac crest, pubis and lineaalba

Actions

Both sides: trunk flexion (assists rectus abdominis)Right side: trunk lateral flexion and rotation to the leftLeft side: trunk lateral flexion and rotation to the right


Rectus Abdominus

Derivation rectus – straight

abdominis – refers to the abdomen

Attachments

In simple terms:

Pubis to the Ribs

Specifically:

Pubic crest and pubic symphysis to the Xiphoid process and the cartilageof ribs 5-7

Actions

Trunk flexionTrunk lateral flexion (assists obliques)

The revered ‘six pack’ or ‘washboard’ is formed by the multiple, superficial bellies of the rectusabdominus.


Erector Spinae Muscle Group

The erector spinae group runs from the sacrum to the skull along the posterior aspect of thevertebral column. Its musculature has a dense, layered arrangement that can be difficult tovisualise. It might simplify matters if you imagine the erector spinae muscles as a tall poplartree with three main branches – the spinalis, longissimus and iliocostalis, which furtherdivide into numerous smaller branches.

In the lumbar region, the erector spinae lie deep to the thoracolumbar fascia but can bepalpated. In the thoracic and cervical areas, they are deep to the trapezius and therhomboids.

Derivation erector – to erect (L.)

spinae – thorn (refers to spine) (L.)

Attachments

In simple terms:

Pelvis to the Vertebrae, ribs and skull

Specifically:

Iliocostalis: Sacrum, iliaccrest and ribs 3-12

to the Ribs 1-12 and the TP ofC4-7

Longissimus: sacrum,iliac crest and TP of L1-5and T1-5 and the articularprocesses of C5-7

to the

Ribs 4-12, TP of T1-12and C2-6 and themastoid process of thetemporal bone

Spinalis: SP of T11-L2and C7 and ligamentumnuchae

to the SP of T5-12 and C2

Actions

Neck and trunk extensionNeck and trunk lateral flexionNeck and trunk rotationAnterior tilt of the pelvis


Trunk Exercises

Refer to this extract from the Exerpedia for some common and popular trunk exercises. Theseexercises are to be referred to in the core conditioning practical at the end of this session somake sure you are aware of the classifications, precautions and steps for good technique.

In addition to these exercises, you would have heard some other exercises mentioned in thevideos. Let's take a look at these now.

Oblique crunch – this is similar to the abdominal crunch except that the movement is performedobliquely or in other words, diagonally, to encourage trunk rotation and hence, activate theobliques.

Horizontal woodchop – this exercise is usually performed on a cable machine with a lightweight; the arms are fixed and the rotation is initiated from the trunk and shoulders with the hipsand feet following through. While this is a total body exercise, the aim is to target the obliques ina functional manner.


https://repository.fitness.edu.au/ausfitness/assets/files/exerpedia16_17.pdf

YOUR TURN | MUSCLES THAT MOVE THETRUNKIt's time to test your memory and cement the anatomy of the mid-section.

Visit your Your Turn Diary to complete a series of tables to identify attachment, joint crossed, jointactions and target exercises.


MOVEMENT ANALYSISBy now, you should be a pro at movement analysis. Before you complete the Quick Quiz, let'sanalyse a stabilisation exercise, the hover, where the body is held in position for up to a minutepending experience.

JAM Description Hover

Joint Refers to the joints moving No joints moving – goal is tomaintain neutral spine

Action Refers to the actions at those joints None

Muscle Refers to the muscles creating thoseactions, or in this case, the musclescontributing to the maintenance ofneutral spinal alignment

Trunk stabilisers (transverseabdominis, internal obliques,multifidus) and Erector Spinae

Even though no joints are moving, we can still use JAM to identify the target muscles.


Quick Quiz

Complete the JAM tables for the trunk exercises below; the good news is that both are isolatedso there is only one body part moving. To check your answers, hover the cursor over 'Answer'.

Exercise 1 – Abdominal Curl (is concentric up or down?) Answer

Joint Action Muscle/s Role/s

Answer Answer Answer Answer

Exercise 2 – Back Extension (is concentric up or down?) Answer

Joint Action Muscle/s Role/sAnswer Answer Answer Answer


BENEFITS, RISK, ALTERNATIVES (BRA)Earlier in this session, we highlighted the types of movement that can be potentially dangerousfor the spine. Together with all that awesome anatomy and understanding of movement analysis,we are now in a position where we can apply BRA and choose only the safest and most effective‘ab’ and back exercises.

Benefit – Why do the exercise? What is its purpose? Does it achieve the intended purpose?Risk – Is there a risk of injury involved? Is the movement extreme, sustained (held) or involveexcessive loading on joints? Is the exercise unstable? Does it compromise any joints? Doesthe exercise significantly alter blood pressure?Alternatives – for every exercise, weigh up the benefits vs the risks. If the risks outweigh thebenefits, we need to look for an exercise alternative for that exercise.

Here is a detailed BRA for the 'double leg throw down' introduced in the video.

BenefitIf you ask people who perform this exercise, why they do so, the answer is likely to be 'work theabs'. So let's imagine that the intended purpose of this exercise is either to strengthen the 'abs'(rectus abdominis) or the 'core' (trunk stablisers) but does it achieve this? To answer thisquestion, let's apply JAM.

Joints moving = hipJoint action = hip flexion in the concentric phaseMuscles creating this action = hip flexors (iliacus, psoas major and rectus femoris)

So the prime movers/target muscles are the hip flexors, not rectus abdominis as there is no trunkflexion. The superficial abdominal muscles act as global stablisers in the attempt to stabilise thetrunk; the movement is too loaded and fast to activate the deep spinal stablisers such astransverse abdominis.

RiskUsing our awesome knowledge of anatomy, we know that the attachment of hip flexor, psoasmajor, is the vertebral bodies of T12 to L5. In this exercise, the legs are both a long lever andheavy load. The job of lifting and controlling the heavy weight of the legs against gravity, couldstrain the lumbar vertabrae where the muscles attach and/or cause back hyperextension, whichis an extreme movement. In addition, this exercise is performed at speed leading to uncontrolledmovement where momentun, rather than muscle, could add to the strain at the lower back.

So now we have to weigh up benefit and risk – if the goal is to train rectus abdominis or activatethe deep spinal stablisers, then this exercise is not effective in achieving this. The risks outweighthe benefits and as such this exercise would not be recommended at any level.

AlternativesIn this day and age, we have a wide range of core stablisation exercises to choose from. Thisexercise could be modified to resemble the 'deadant' (refer to the core conditioning practical) orsubstituted with exercises such as the hover, plank or prone arm/leg extension. Once theseexercises have been mastered, an unstable base such as a fitball can be used which will bediscussed in your Personal Trainer course.

Other exercises to avoid include:


Abdominal curl with the feet held – holding the feet changes the fulcrum and the hip flexorsare able to do the majority of the work rather than the abdominals Back extension lifting feet and the shoulders – this creates more load and hyperextension atthe lumbar region particularly with the legs acting as a long lever and heavy load; the generalrule of thumb is to either lift the shoulders or the legs (and the lever can be reduced bybending the knees), not both at the same time.


POSTURAL ABNORMALITIESIn a previous session, we discussed what good posture was, using the plumb line. We now knowthe importance of neutral spine. Let's now further our knowledge on posture by discussing thedeviations from good or normal posture.

Postural abnormalities are when the normal curves of the vertebral column may becomeexaggerated or diminished, or the column may develop a lateral bend. Some causes that maylead to postural abnormalities include congenital (at birth) defects, excessive weight as can occurduring pregnancy, leg length differences, muscle imbalances and poor posture throughoccupations, bad habits or sporting pursuits.

Postural abnormalities place excessive, unequal stresses through the associated joints, musclesand ligaments and can lead to joint pain, degeneration and lack of function. As a fitnessprofessional, it is important to be aware of postural abnormalities and the importance of strengthand flexibility training to improve and maintain good posture.

Let’s take a look at some abnormalities now

ForwardHead Excessive forward protraction of the neck also known as poke chin

Kyphosis Excessive curvature of the thoracic region which results in the developmentof a ‘hunch-back’ posture and protraction of the scapula

RoundedShoulders

This is a term used to describe protraction of the scapulae and may also belinked with a mild form of kyphosis

Lordosis Exaggerated curvature in the lumbar spine

Flat back Lack of curvature in the lumbar spine

Scoliosis Abnormal lateral (sideways) curvature of the vertebral column

Before you view the video, stand up and practice these movements of the head, trunk and pelvis– protraction of the neck (forward head), slight trunk flexion, lateral flexion, anterior pelvic tilt(APT) and posterior pelvic tilt (PPT). Can you identify which movements are associated withcertain postural abnormalities, for example, trunk flexion and a PPT are associated with a flatback whereas an APT is linked with lordosis.

A good way of remembering APT and PPT is to imagine that your pelvis is a bucket full ofwater and if you tilt the 'bucket' forwards, the water would spill anteriorly – that movement isthe APT; if you tilt the 'bucket' backwards, the water would spill posteriorly – that movement isthe PPT.

Everyone’s posture will be slightly different. Start developing the skill of assessing posture and ifyou are aware of any postural non-alignments, see if they are similar to the posturalabnormalities above. Keep in mind that they could be structural (very hard to change) orfunctional, resulting from lifestyle habits such as slouching, footwear, seating or carrying. Someof these causes can be changed and will help your clients to look and feel better! We will alsolook at trunk movements to address some common postural abnormalities.


Postural Implications

There are two key strategies used to help improve posture – strengthen what’s weak and stretchwhat’s tight. Let’s take a look at the muscles likely to be weak for each of the more commonpostural abnormalities discussed earlier.

As we go though each abnormality, assume the position then go through the motions of therecommended exercises to understand how this exercise would improve posture. You will berequired to prescribe exercise for postural correction in your Personal Trainer course so this is agreat place to start. We have covered many of the upper body strength exercises mentioned andthe trunk exercises are explained in the following core conditioning practical.

Postural Abnormality Strengthen these muscles/areas

Forward head or pokehead

Deep neck/cervical flexorse.g., cervical retraction in prone or supine (see images below)

Kyphosis Thoracic erector spinae, mid/lower trapezius, rhomboidse.g., seated row, prone back extension

Rounded shoulders(protracted scapula)

Mid/lower trapezius, rhomboidse.g., seated row with a neutral or underhand grip (notoverhand)

Lordosis Rectus abdominise.g., abdominal crunches/curls

Flat back Back extensors/erector spinaee.g, prone back extension, 4 point opposing arm/leg extension

Prone cervical retraction (start) Prone cervical retraction (finish)

From the start position, slowly retract the neck by pulling the chin back toward the spine toactivate the deep cervical flexors. For exercise above and below, hold for 2-3 seconds thenrelease; perform 5-10 quality repetitions.

Supine cervical retraction


CORE CONDITIONING PRACTICALCore conditioning refers to the development of a strong, stable and functionaltorso and is crucial for maintaining good posture, preventing back pain andhelping individuals reach their peak physical performance. In addition, itimproves the ‘aesthetics’ of the torso.

The development of a strong and stable core provides the ‘foundation’ for allother movements and should be established early in a person’s exerciseprogram. This will assist with the maintenance of a neutral spine during otheractivities such as weight training, and hence reduce the risk for injury.

The fitness professional can design a core conditioning program for a client or add core and trunkexercises to complement other types of programs. Either way, balance is important and stabilityshould be achieved before mobility.

There tends to be an obsession with abdominal training in the fitness industry. Be sure that as afitness professional you avoid the over prescription of trunk exercises.

Many muscles of the trunk are postural muscles; ones that are ‘working’ the entire time even if weare motionless. The trunk muscles are primarily responsible for keeping the body in the uprightposition in both static and dynamic posture, and act to stabilise our mid section during dynamicmovements of the limbs. As such, they require less targeted work than our other muscles, asthey are active during all other movements and exercises. Before we can progress to teachingthese exercises to clients we must first develop a good understanding of these exercises anddevelop great proficiency in their execution!

Let’s take a look at three categories of exercises that contribute to a strong and stable torso –trunk stabilisation exercises, abdominal exercises and back extension exercises.

Refer to the trunk exercises in the Exerpedia as you work through this practical activity.


https://repository.fitness.edu.au/ausfitness/assets/files/exerpedia16_17.pdf

Trunk Stabilisation Exercises

These exercises aim to recruit various muscles to stabilise the trunk (keep it still) and are whatmost people refer to as ‘core’ exercises. Stabilisation refers to controlling trunk movement and‘holding’ the spine in neutral alignment which is required in day-to-day life and crucial in manyforms of exercise. Many muscles play a role in both local and global stabilisation.

Local stabilisation occurs at a spinal level and is achieved through the isometric co-contractionof transverse abdominis and deep spinal muscles such as multifidus – it is often referred to as‘bracing the abdominals’ or ‘narrowing the waist’.

Global stabilisation recruits all of the abdominals, the erector spinae muscle group and othermuscles as required to ‘keep the body still’ in a particular position – again, this is achievedthrough an isometric co-contraction of these muscles.

The goal of trunk stabilisation exercises is to consciously recruit the stabilisers while breathingnormally and stop the trunk from moving in a range of positions. Key points follow:

Neutral spine and pelvis – establish neutral alignment and maintain this alignmentthroughout the exerciseIsometric co-contraction – hold a subtle contraction of the abdominals while breathingnormally; start with 10 second contractions and gradually increase the duration to 60 secondsOverload – commence with 8-16 reps of low duration holds then increase the duration anddecrease the reps; reduce stability to make the exercises harder by:

Reducing the base of supportAdding arm/leg movementUsing equipment that challenges the stabilisers

NB: If participants experience discomfort and it does not ease as strength improves then refer forassessment.


Supine Examples - Stabilisation/Core Exercises

Remember that the spine is held still and in neutral hence emphasise no movement, no roundingand no arching or hyperextension of the back. The exercises are listed from easiest (supine) tohardest and each position shows progressions. Only progress to the harder variations ifalignment, posture, stabilisation and technique have been mastered. Work through the examplesbelow.

Supine – feet on floor (easiest as spine is supported on floor)

Set-Up

Lay on your back with knees at 90°, feet on the floor and hip width apartAssume neutral spinal position, brace the abdominals and breathe normally

Exercise Progression

1. Slowly lift one foot off the floor (small knee lift), keep pelvis and spine neutral,replace foot without relaxing to change to other foot

2. Progress to single leg extensions, extend one leg keeping knees at the samelevel

3. Perform the single leg extensions but at a lower level (the closer to the floor, the harder)4. Add arm movements overhead while extending one leg (watch arching of back and lifting of

ribs)

Supine – Dead Ant (harder to stabilise as feet are now off the floor)

Set-Up

Feet up, knees 90° and hips at 90° (dead ant position)Neutral spine with abdominals braced


1. Drop one heel down to the floor keeping knees bent at 90° (exhale on lowering)2. Start with a small range of motion and gradually increase range so that the lowering leg

extends but without touching the floor3. Move slowly and keep top knee over hip joint and still (the slower, the harder)4. Exhale on lowering5. Add arm movements overhead while extending one leg


Prone Examples - Stabilisation/Core Exercises

Prone positions are harder to stablise than supine as the pelvis is unsupported hence even moreimportant to keep the spine in neutral with no rounding and no arching of the back. As before, theexercises are listed from easiest (supine) to hardest and each position shows progressions. Onlyprogress to the harder variations if alignment, posture, stabilisation and technique have beenmastered.

These exercises are considered more functional than supine for the majority of people. Theyhave specific relevance to the performance of prone exercises such as push-ups and single armrows. Work through the examples below and refer to your Exerpedia.

Prone Arm/leg Extension – on hands and knees / 4 point (meaning hands and kneescreate 4 contact points with the grouund)

Set-Up

On hands and knees with hands under shoulders (elbows soft), knees under hips and kneesapartSet neutral alignment with neck in line with spine, hence look down and check that shouldersare down (away from ears)Brace the abdominals and breathe normally


1. Lift one arm upwards then bring back to start position, then lift the other arm making surehands return to start position and elbows stay soft (do not relax abdominals when returningto start position)

2. Extend one leg behind then return to the start position then extend the other leg makingsure the pelvis and spine stay still

3. Now lift one arm and extend the opposite leg (remember to look down and keep the spinestill)

Prone Hover – elbows and knees (harder as more load involved)

Set-Up

Lay on floor face-down then prop yourself up onto the elbowsBrace abdominals and slowly lift hips and chest until body ‘hovers’ above the floorCheck spine and neck in neutral and breathe normally

Prone Plank – elbows and toes (harder as more load involved and requires correct alignmentof entire body – this is a global stabilisation exercise)

Set-Up

From the hover, straighten the legs so that the body is supported by the elbows and toesCheck spine and neck are in neutral and breathe normally

NB: hover and plank can also be performed laterally (side-on)


Abdominal Exercises

Traditional abdominal exercises such as crunches/curls continue to be popular but should not bethe only form of trunk conditioning in a workout. Always aim to have some form of trunkstabilisation exercise either achieved through other training (e.g., resistance/weight training) orspecific core exercises. Also be aware that these exercises do not spot-reduce the fat off theabdominal area.

The traditional approach of ‘quantity’ has now been replaced with ‘quality’ where all abdominalexercises are performed slowly with good form. Key points follow:

Starting position – set neutral spine and engage the abs; arms can be placed on the thighs,across the chest or with fingers at earsExercises – typically supine but a variety of actions is recommended, i.e., rib to hips (regularcurl/crunch), hips to ribs (reverse curl/crunch), opposing rib/hip (oblique curl/crunch orpreferably standing rotation).Overload – 8-16 reps, 1-3 sets then increase difficulty by:

Moving slowerIncreasing the range of movement Decreasing stability, e.g., fitballAdding resistance, e.g., medicine ball


Examples - Abdominal Exercises

Work through the examples below and where applicable, refer to your Exerpedia.

Crunches/curls

Start with knees at 90°, feet on the floor and hip width apartSelect appropriate arm position (thighs, chest, ears)Start in neutral and curl up (cue ribs to hips), exhale on up, then lower to return to neutralwhile inhalingEncourage a slight chin tuck and make sure eyes follow movementTrunk will flex about 30-40° depending on strength and mobility

Roll down/roll up

This is a highly functional exercise as it mimics the movement of getting out of bed and rollingdown and up from a bench – only clients with healthy backs should attempt thisStart in a seated position with knees at 90°, feet on the floor and hip width apartImagine that the vertebral column is a string of pearls, roll down to the floor ‘vertebra byvertebra’ then roll up

Reverse curl

Start with knees lifted above hip joints and arms on floorSlowly roll pelvis upwards (cue hips to ribs) and avoid kicking with the legsTrunk will flex about 30-40° depending on strength and mobility

Oblique crunch

The more effective way to train the obliques is by performing trunk rotation in a standing position.If a floor exercise is the only option then repeat instructions for the crunch/curl, except cue ribs tothe opposite hip.


Back Extension

The back extensors tend to be neglected in favour of training the abdominals so if you do trunkflexion exercises, make sure you ‘balance up’ with trunk/back extension exercises. This isessential for muscle balance, strength, maintenance of correct posture and to counteract lumbarand thoracic flexion.

There are many opportunities to work the erector spinae as they are involved as a globalstabiliser in many resistance exercises and stabilisation exercises such as those performed inprone 4 point position.

When doing back extension exercises it is important that they are performed slowly with goodform ensuring that the spine is not forced into hyperextension. Check that the neck does nothyperextend as well (look downwards).


Examples - Back Extension Exercises

Work through the examples below and where applicable, refer to your Exerpedia.

Prone back extension

Lay on floor face-down with arms down by your sidesKeep feet and hips in contact with the groundSlowly lift chest off floor, look downHands can also be placed at temples but check that feet stay in contact with the ground

Prone Supermans

Lay on floor face-down with arms stretched overheadStart with alternating arm lifts then do alternating leg liftsProgress to lifting opposite arm and leg in a slow and controlled manner


YOUR TURN | CORE CONDITIONINGEXERCISESBefore we can progress to teaching these exercises to clients we must first develop a goodunderstanding of these exercises and develop great proficiency in their execution! Now that youhave followed the core conditioning practical session; let's test your knowledge. You can do thisYour Turn at home.

Visit your Your Turn Diary for all the details.


ROUND UPWe have just clocked up 50 muscles over the last five sessions focusing on the major muscles ofthe body. By now you should have a belly full of exercises to take away and practise as you aresure to be tested on them.

In this session we covered:

Postural abnormalitiesMuscles that move the trunk

Thoracolumbar fasciaWhat about the neck?Potentially dangerous exercises (pdes)Abdominal muscle groupErector spinae muscle group

Movement analysisBenefits, risk, alternatives (bra) Core conditioning practical


REFERENCESThe following resources were used in the compilation of this session:

Biel, A. (2005). Trail Guide to the Body. Books of Discovery: Boulder

Thompson, C.W. and Floyd, R.T. (2004). Manual of Structural Kinesiology, 15th edition.WCB/McGraw Hill

http://www.fit-pro.com, Functionally Fit: Prone Neck Retractions, Brian Schiff

http://www.knowyourback.org/Pages/BackPainPrevention/Exercise/CervicalExercise.aspx


session 15 | muscles of the trunk and posture

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