FUNCTION TRANSVERSUS ABDOMINUS SUPPORT OF ABDOMINAL CONTENTS VIA CIRCUMFERENTIAL ARRANGEMENT BILATERAL CONTRACTION CAUSES DRAWING IN OF ABDOMINAL WALL CAN WORK WITH MULTIFIDUS VIA TENSION OF THORACOLUMBAR FASCIA CONTRIBUTES TO BOTH SUPPORTING AND TORQUE ROLES

MULTIFIDUS ORIGINATES ON DORSAL SURFACE OF SACRUM SACROTUBEROUS & POSTERIOR SACROILIAC LIGAMENT PSIS & ERECTOR SPINAE APONEUROSIS INSERTS ON SPINOUS PROCESSES OF SACRAL & LUMBAR VERTEBRAE FILLS CHANNELS BETWEEN SACRUM & ILIUM & BETWEEN LUMBAR SPINOUS & TRANSVERSE PROCESSES

Multifidus

FUNCTION (MULTIFIDUS) Provides control of shearing forces of intervertebral motion segments Unique segmental arrangement of multifidus suggests capacity for fine control of movement Control anterior rotation translation in trunk flexion Continuously active in upright posture compared with recumbency Provides anti gravity support Active in both ipsilateral and controlateral trunk rotation Stabiliser rather than prime mover

Gluteal Stabilizers

Hip Musculature Psoas Closed chain vs. open chain functioning Works with erector spinae, multifidus & deep abdominal wall Works to balance anterior shear forces of lumbar spine Can reciprocally inhibit gluteus maximus, multifidus, deep erector spinae, internal oblique & transverse abdominus when tight Extensor mechanism dysfunction Synergistic dominance during hip extension Hamstrings & superficial erector spinae May alter gluteus maximus function, altering hip rotation, gait cycle

Gluteus medius: provides frontal plane stabilization, decelerate femoral adduction , assist in deceleration femoral internal rotation (during closed chain activity)

Gluteus Medius Provides frontal plane stabilisation in walking cycle Prevents downward rotation of the pelvis (Trendelenburg) Allows unsupported leg to swing clear of the ground Decelerates femoral adduction and internal rotation Anterior fibres assist the iliotibial tract to flex hip and stabilise the extended knee

Hip Musculature Gluteus medius Gluteus maximus Frontal plane stabilizer Weakness increases frontal & transverse plane stresses (patellofemoral stress) Controls femoral adduction & internal rotation Weakness results in synergistic dominance of TFL & quadratus lumborum Gluteus maximus Hip extension & external rotation during OKC, concentrically Eccentrically hip flexion & internal rotation Decelerates tibial internal rotation with TFL Stabilizes SI joint Faulty firing results in decreased pelvic stability & neuromuscular control

All muscles produce & control forces in multiple planes Hamstrings Concentrically flex the knee, extend the hip & rotate the tibia Eccentrically decelerate knee extension, hip flexion & tibial rotation Work synergistically with the ACL to stabilize tibial translation All muscles produce & control forces in multiple planes

Neuromuscular efficiency Ability of CNS to allow agonists, antagonists, synergists, stabilizers & neutralizers to work efficiently & interdependently Established by combination of postural alignment & stability strength Optimizes body’s ability to generate & adapt to forces Dynamic stabilization is critical for optimal neuromuscular efficiency Rehab generally focuses on isolated single plane strength gains in single muscles Functional activities are multi-planar requiring acceleration & stabilization Inefficiency results in body’s inability to respond to demands Can result in repetitive microtrauma, faulty biomechanics & injury Compensatory actions result

The CORE Functions & operates as an integrated unit Entire kinetic chain operates synergistically to produce force, reduce force & dynamically stabilize against abnormal force In an efficient state, the CORE enables each of the structural components to operate optimally through: Distribution of weight Absorption of force Transfer of ground reaction forces Requires training for optimal functioning! Train entire kinetic chain on all levels in all planes

Core Stabilization Concepts A specific core strengthening program can: IMPROVE dynamic postural control Ensure appropriate muscular balance & joint arthrokinematics in the lumbo-pelvic-hip complex Allow for expression of dynamic functional performance throughout the entire kinetic chain Increase neuromuscular efficiency throughout the entire body Spinal stabilization Must effectively utilize strength, power, neuromuscular control & endurance of the “prime movers” Weak core = decreased force production & efficiency Protective mechanism for the spine Facilitates balanced muscular functioning of the entire kinetic chain Enhances neuromuscular control to provide a more efficient body positioning

Postural Considerations Core functions to maintain postural alignment & dynamic postural equilibrium Optimal alignment = optimal functional training and rehabilitation Segmental deficit results in predictable dysfunction Serial distortion patterns Structural integrity of body is compromised due to malalignment Abnormal forces are distributed above and below misaligned segment

Neuromuscular Considerations Enhance dynamic postural control with strong stable core Kinetic chain imbalances = deficient neuromuscular control Impact of low back pain on neuromuscular control Joint/ligament injury  neuromuscular deficits Arthrokinetic reflex Reflexes mediated by joint receptor activity Altered arthrokinetic reflex can result in arthrogenic muscle inhibition Disrupted muscle function due to altered joint functioning

Optimum Dynamic Function Integrated proprioceptively enriched multi-directional movement controlled by an efficient neuromuscular system Optimum human dynamic function involves …… From walking to more challenging sporting movment patterns. All exercise is subject to forces saggital, frontal and transverse and therefore the system is also able to provide control against these forces, reduce the forces and stabilise the body.

PROPRIOCEPTION “Nerve impulses originating from the joints, muscles, tendons and associated deep tissues which are then processed in the central nervous system to provide information about joint position, motion, vibration and pressure”. (Bruckner & Khan 1999)

WHY IS PROPRIOCEPTION IMPORTANT? Sub-cortical systems are not under conscious control Stabilization response needs to be second nature. Sub-cortical systems act faster - rapid muscle reaction times. More rapid reaction times can be learnt which may lead to increased stability of the lumbar spine.

To improve the proprioceptive system in dynamic joint stability it must be challenged. Pain-free does not mean cured. If the proprioceptive deficit has not been addressed a complete rehabilitation has not been accomplished. Mechanically stable joints are not necessarily functionally stable ( eg. ACL reconstruction)

WHAT HAPPENS WHEN THE SYSTEM GOES WRONG? The Theories

“MUSCLE PAIN SYNDROMES ARE SELDOM CAUSED BY ISOLATED PRECITATING FACTORS AND EVENTS BUT ARE THE CONSEQUENCES OF HABITUAL IMBALANCES IN THE MOVEMENT SYSTEM” (Sahrmann 1993)

REPEATED MOVEMENTS SUSTAINED POSTURES ALTERS MUSCLE LENGTH ALTERS STRENGTH ALTERS STIFFNESS ALTERS FLEXIBILITY ALTERS CARTILAGE AND BONE STRUCTURE – BY OVERLOADING AT COMPENSATORY SITES OF MOVEMENT Flexibility of the the hips and pelvis will influence alignment and therefore stability in the trunk. Mulligan refutes this in that mobilisation of either lumbar or hip joints can immediately effect soft tissue length. Therefore, could be neural inhibition.

STRUCTURAL/SEGMENTAL DYSFUNCTION PAIN POSTURAL DYSFUNCTION MUSCULAR DYSFUNCTION STRUCTURAL/SEGMENTAL DYSFUNCTION “The body has the ability to adapt to minor stresses, but as you increase the number, the body has less room to adapt until you reach a point where the body cannot adapt any further” “Sarhmann muscle pain syndromes are seldom caused by located precipitating factors and events” “The body has the ability to adapt to minor stresses, but as you increase the number, the body has less room to adapt until you reach a point where the body cannot adapt any further” “Sarhmann muscle pain syndromes are seldom caused by located precipitating factors and events”

POSTURE AND PAIN Poor posture can lead to increased stress on the stabilising system of the joints (Chek P 1999) Multifidus dysfunction occurs after first episode acute unilateral LBP (Hides et al 1994) Multifidus dysfunction does not spontaneously restore following resolution of pain and disability (Hides et al 1996) Specific retraining does restore dysfunction (Hides et al 1996)

TrA contraction is delayed during normal movements in subjects with low back pain (Richardson et al 1999) Mulifidus function can be affected by spinal surgery Atrophy of multifidus has been shown to be more prevalent in post operative patients (Jull, et al 1999)

Sherington’s Law of Reciprocal Inhibition: Tight Muscles inhibit the functional antagonist. Leads to Positive Cross Syndromes of the lower or upper limb TIGHT MUSCLE WILL INHIBIT IT’S FUNCTIONAL ANTAGONIST. EXAMPLE: THIGH PSOAS (MOST ATHLETES) INHIBIT FUNCTIONAL ANTAGONISTS - DEEP ABDOMINAL WALL, TRANSVERSE ABDOMINIS, INTERNAL OBLIQUE, MULTIFIDI, DEEP TRANSVERSE SPINALIS MUSCLES AND GLUTEUS MAXIMUS. THUS THE STABILIZATION AND COUPLING PHASE WILL BE REDUCED INCREASING THE MOVEMENT PHASE & MUSCLE FORCES AND DECREASING EFFICIENCY.

Gluteus Maximus and minimus are inhibited in most athletes due to tight psoas (Summer, 1988). ATTEMPTING TO GET EXTENSION DURING JUMPING, COULDN’T EXTEND THROUGH HIP USING GLUTEUS MAXIMUS DUE TO PSOAS TIGHTNESS HYPEREXTEND AT THE KNEE AND DRIVE THE INFERIOR POLE OF THE PATELLA INTO THE FAT PAD CREATING THE INFLAMMATORY RESPONSE. (SUMMER, 1988).

Poor recruitment in the local stabilisers can lead to over- activity of the global stabilisers to compensate.