NASM Chapter 9 – Core Training Concepts

Chapter 9 Core Training Concepts:

• Know all definitions throughout the chapter
• Local Stabilization System
• Global Stabilization System
• Table 9.1 Muscles of the Core
• It is your responsibility to learn how to categorize, progress, and regress body position while performing certain types of exercises.
• The OPT model is divided into three different blocks of training and each building block contains specific phases of training that systematically advances the student in a safe and progressive manner. Exercises can be categorized by adaptation and by type of exercise:
• OPT Level (adaptation): Stabilization, Strength, or Power (be familiar with all exercises listed, as well as how to regress and progress the exercises listed)
• Type of Exercise: Core
• Table 9.3 Core training program design

Core Musculature

• Core – Structures that make up lumbo-pelvic-hip complex(LPHC) including lumbar spine, pelvic girdle, abdomen, and hip joint.
  
• Core is where body’s center of gravity is located and where all movement originates. Strong and efficient core is necessary for maintaining proper muscle balance throughout the entire human movement system(kinetic chain).
• Optimal length-tension relationships, recruitment patterns, and joint motions in muscle of LPHC establish neuromuscular efficiency throughout entire human movement system. Allow for efficient acceleration, deceleration, and stabilization during dynamic movements, as well as prevention of possible injuries.

Local Stabilization System

• Local stabilizers are muscles that attach directly to vertebrae. Consist primarily of slow twitch type I fibers with high density of muscle spindles. Work to limit excessive compressive, shear, and rotational forces between spinal segments. 
• Primary muscles that make up local stabilization system include transverse abdominis, internal obliques, multifidus, pelvic floor musculature, and diaphram. INcrease intra-abdominal pressure(pressure within abdominal cavity) and generating tension in thoracolumbar fascia(connective tissue of low back), increasing spinal stiffness for improved intersegmental neuromuscular control.

Global Stabilization System

• Muscles of global stabilization system attach from pelvis to the spine. These transfer loads between upper extremity and lower extremity, provide stability between pelvis and spine, and provide stabilization and eccentric control of the core during functional movements.
• Primary muscles that make up global stabilization system include quadratus lumborum, psoas major, external obliques, portions of the internal oblique, rectus abdominis, gluteus medius, and adductor complex.

Movement System

• Movement system includes muscles that attach the spine and/or pelvis to the extremities. These muscles are primarily responsible for concentric force production and eccentric deceleration during dynamic activities. Primary muscles that make up movement system include latissimus dorsi, hip flexors, hamstring complex, and quadriceps.
• Collectively all muscles within each system provide dynamic stabilization and neuromuscular control of entire core (LPHC). These produce force(concentric), reduce force(eccentric), and provide dynamic stabilization in all planes of movement during functional activities. In isolation, these muscles do not effectively achieve stabilization of LPHC; rather it is through their synergistic interdependent functioning that they enhance stability and neuromuscular control.
• Training movement system muscles before training muscles of global and local stabilization systems would not make sense from structural and biomechanical standpoint. Doing so would be analogous to building a house with no foundaiton.

Importance of Properly Training the Stabilization Systems

• Some active individuals have developed strength, power, and muscular endurance in the movement system, which enables them to perform functional activites. Few people have developed the local stabilization muscles required for intervertebral stabilization. The body’s core stabilization system has to be operating with maximal eficiency to effectively use the strength, power, and endurance that has been developed in prime movers. If movement system musculature of the core is strong and local stabilization system is weak, the kinetic chain senses imbalance and forces are not transferred or used properly. This leads to compensation, synergistic dominance, and inefficient movements.
• Weak core can lead to inefficient movement and predictable patterns of injury. Resulting in lower back pain and injury.

Scientific Rationale for Core Stabilization Training

• Individuals with chronic LBP have decreased activation of certain muscles or muscle groups, including transverse abdominis, internal obliques, pelvic floor muscles, multifius, diaphram, and deep erector spinae. Also waeaker back extensor muscles and decreased muscular endurance. 
• Studies support role of core training in prevention and rehabilitation of lower back pain. Core stabilization exercises restore size, activation, and endurance of multifidus(deep spine muscle) in individuals with lower back pain. Programs that include specific core stabilization training tend to be more effective than manual therapy alone.
• Drawing-in Maneuver – Used to recruit the local core stabilizers by drawing the navel in toward the spine.
• Bracing – Occurs when you have contracted both the abdominal, lower back, and buttock muscles at the same time.
• Traditional low-back hyperextension exercises without proper lumbo-pelvic-hip stabilization have been shown to increase pressure on discs to dangerous levels.

Drawing-in Maneuver

• Research has demonstrated electromyogram (EMG) activity is increased during pelvic stabilization and transverse abdominis activation when an abdominal drawing maneuver is initiated before activity.
• Transverse abdominis, when properly activated, creates tension in thoracolumbar fascia, contributing to spinal stiffness, and compresses sacroiliac joint, increasing stability.
• Pull region just below navel toward spine and maintain cervical spine in neutral position. Maintaining neutral spine during core training helps improve posture, muscle balance, and stabilization. If forward protruding head is noticed during drawing-in maneuver, sternocleidmastoid (large neck muscle) is preferentially recruited, which increases the compressive forces in the cervical spine and can lead to pelvic instability and muscle imbalances as a result of the pelvo-ocular reflex. Important to maintain the eyes level during movement.

Bracing

• Co-contraction of global muscles, such as rectus abdominis, external obliques, and quadratus lumborum. Muscular endurance of global and local musculature, when contracted together, create the most benefit for those with LBP compared with traditional LBP training methods. 
• Bracing focuses on global trunk stability, not on segmental vertebral stability, meaning that the global muscles, given the proper endurance training, will work to stabilize the spine.

Guidelines for Core Training

• Core training should be systematic, progressive, functional, and emphasize the entire muscle action spectrum focusing on force production, force reduction, and dynamic stabilization. Core training program should regularly manipulate plane of motion, range of motion, modalities(tubing, stability ball, medicine ball, Bosu ball, Airex pad, etc.) body position, amount of control, speed of execution, amount of feedback, and specific acute training variables(sets, reps, intensity, tempo, and frequency).
• When designing core training program, personal trainer should initially create a proprioceptively enriched(controlled yet unstable) selecting appropriate exercises to elicit maximal training response.
• Core exercises performed in unstable environment(such as with stability ball) have been demonstrated to increase activation of local and global stabilization systems when compared to traditional trunk exercises.
• Safe and challenging, stress multiple planes in a multisensory environment derived from fundamental movement skills specific to activity.

Designing a Core Training Program

• Goal of core training is to develop optimal levels of neuromuscular efficiency, stability(intervertebral and lumbopelvic stability-local and global stabilization systems) and functional strength(movement system). Neural adaptations become focus of program instead of absolute strength gains. 
• Increasing proprioceptive demand is more important than increasing external resistance.
• Quality of movement should be stressed over quantity.
• Client beings at highest level at which they are able to maintain stability and optimal neuromuscular control(coordinated movement). Progresses through program once mastery of exercise in previous level has been achieved while demonstrating intervertebral stability and lumbopelvic stability. Client has appropriate lumbopelvic stability when able to perform functional movement patterns(squats, lunges, step-ups, single-leg movements) without excessive spinal motion(flexion, extension, lateral flexion, rotation, singly or in combination). Critical that core training program is designed to achieve following functional outcomes:
• Intervertebral stability, lumbopelvic stability, movement efficiency

Levels of core training

• Three levels of training within OPT model, stabilization, strength, power, proper core training program follows same systematic progression.
• Core-Stabilization Training – Exercises involve little motion through the spine and pelvis. Designed to improve neuromuscular efficiency and intervertebral stability, focusing on drawing-in and then bracing during the exercises. Traditionally spend 4 weeks at this level of core training.
• Core Strength – Involve more dynamic eccentric and concentric movements of the spine throughout full range of motion while clients perform the activation techniques learned in core-stabilization training. Specificity, speed, and neural demands are progressed at this level. Traditionally spend 4 weeks at this level of core training.
• Core Power – Improve rate of force production of core musculature. Prepare an individual to dynamically stabilize and generate force at more functionally applicable speeds. Rotation chest pass, medicine ball pullover throw, front MB oblique throw, soccer throw.
• Core musculature helps protect spine from harmful forces that occur during functional activities. Core program designed to increase stabilization, strength, power, muscle endurance, and neuromuscular control in LPHC. Core training programs must be systematic, progressive, activity or goal-specific, integrated, and proprioceptively challenging. Proper core training follows same systematic approach as OPT model: stabilization, strength, and power.

Implementing a Core Training Program

• Requires that fitness professional follow progression of OPT model. Ex if client is in stabilization level(phase 1) select core stabilization exercises. For client in strength level, select core-strength exercises.