Core Stabilization Training in Rehabilitation Assistant professor of Sports Medicine Department of Sports Medicine Tehran university of Medical Sciences
Introduction To develop a comprehensive functional rehabilitation program, The athletic trainer must fully understand the functional kinetic chain. Functional kinetic chain rehabilitation Is a comprehensive approach that strives to improve All components necessary to allow a patient to return to a high level of function. The kinetic chain operates as An integrated, interdependent, functional unit.
Functional kinetic chain rehabilitation must therefore address Each link in the kinetic chain and Strive to develop functional strength and neuromuscular efficiency. Functional strength Is the ability of the neuromuscular system to Reduce force, Produce force, and Dynamically stabilize the kinetic chain During functional movements, upon demand, in a smooth coordinated fashion. Neuromuscular efficiency Is the ability of the central nervous system (CNS) to Allow agonists, Antagonists, Synergists, Stabilizers, and Neutralizers To work efficiently and interdependently during dynamic kinetic chain activities. A dynamic core-stabilization training program should be a key component of all comprehensive functional closed-kinetic-chain rehabilitation programs.
WHAT IS THE CORE? The core is defined as the lumbo-pelvic-hip complex. The core is where our center of gravity is located and where all movement begins. There are 29 muscles that attach to the lumbo-pelvic-hip complex. An efficient core allows for Maintenance of the normal length-tension relationship of functional agonists and antagonists, which Promotes normal force-couple relationships in the lumbo-pelvichip complex. These allows optimal arthrokinematics in the lumbo-pelvic-hip complex during functional kinetic chain movements.
An efficient core provides optimal neuromuscular efficiency in the entire kinetic chain, allowing for optimal Acceleration, Deceleration, and Dynamic stabilization of the entire kinetic chain during functional movements. It also provides proximal stability for efficient lower extremity movements. The core operates as an integrated functional unit, whereby The entire kinetic chain works synergistically to produce force, reduce force, and dynamically stabilize against abnormal force.
CORE STABILIZATION TRAINING CONCEPTS If the extremity muscles are strong and the core is weak, There will not be enough force created to produce efficient movements. A weak core is a fundamental cause of inefficient movements that lead to injury. The core musculature is an integral component of the protective mechanism That relieves the spine of deleterious forces that are inherent during functional activities.
A core stabilization training program is designed to help an individual gain Strength, Neuromuscular control, Power, and Muscle endurance Of the lumbo-pelvic hip complex. This approach facilitates a balanced muscular functioning of the entire kinetic chain. Greater neuromuscular control and stabilization strength will offer a more biomechanically efficient position for the entire kinetic chain, therefore Allowing optimal neuromuscular efficiency throughout the kinetic chain.
Neuromuscular efficiency is established by The appropriate combination of Postural alignment (static/dynamic) and Stability strength, Which allows the body to Decelerate gravity, ground reaction forces, and momentum At the right joint, in the right plane, and at the right time. As the efficiency of the neuromuscular system decreases, The ability of the kinetic chain to maintain appropriate forces and dynamic stabilization decreases significantly. This decreased neuromuscular efficiency leads to Compensation and substitution patterns, as well as poor posture during functional activities.
REVIEW OF FUNCTIONAL ANATOMY The key lumbar spine muscles include the Transversospinalis group, the rotatores, Interspinales, intertransversarii, semispinalis, and multifidus. Erector spinae, Iliocostalis Longissimus Spinalis Quadratus lumborum, and Latissimus dorsi.
Semispinalis muscles (semispinalis thoracis muscle) Origin: Transverse processes of the 6 th to 10 th thoracic vertebrae Insertion: Spinous processes of the first four thoracic and last two cervical vertebrae Bilaterally extend the cervical & thoracic regions of the vertebral column and the head. Unilaterally rotate toward the opposite side.
Multifidus muscles Origin: Dorsal surface of the sacrum, transverse processes of all lumbar, thoracic and lower cervical vertebrae Insertion: Spinous procsses of lumbar, thoracic and cervical vertebrae Unilaterally flex the trunk laterally and rotate it to the opposite side. Bilaterally extend the trunk and stabilize the vertebral column.
Rotator muscles (Rotator (Rotator thoracis & lumborum) Origin: Transverse processes of vertebrae Insertion: Roots of the spinous processes of the adjacent vertebra above
The Transversospinalis group These muscles are small and have a poor mechanical advantage For contributing to motion. They contain primarily type I muscle fibers and are therefore designed primarily for stabilization. The transversospinalis muscle group contains two to six times the number of muscles spindles found in larger muscles. Therefore, it has been established that this group is primarily responsible for providing the CNS with proprioceptive information.
This group is also responsible for Inter/intrasegmental stabilization and Segmental eccentric deceleration of flexion and rotation Of the spinal unit during functional movements. The multifidus is the most important of the transversospinalis muscles. It has the ability to provide intrasegmental stabilization to the lumbar spine in all positions.
The erector spinae muscle group Iliocostalis muscle column) muscle (lateral Origin: The three columns have a common origin. A broad tendon which is attached to the posterior part of the iliac crest, the sacrum, the sacroilliac ligament and the sacral and inferior lumbar spinous processes. Insertion: the angles of ribs
Longissimus muscle (intermediate column) Origin: a broad tendon which is attached to the posterior part of the iliac crest, the sacrum, the sacroilliac ligament and the sacral and inferior lumbar spinous processes. Insertion: the transverse processes of the thoracic and cervical and the mastoid process.
Spinalis muscle column) muscle (medial Origin: spinous processes of the last two thoracic and first two lumbar vertebrae Insertion: spinous processes of 3 rd to 9 th thoracic vertebrae These muscles are the chief extensors of the spinal column.
Quadratus lumborum Origin: iliac crest (posterior inner lip) Insertion: transverse processes of upper 4 lumbar vertebrae & lower border 12 th rib Lateral flexion Rotation Stabilizes pelvis and lumbar spine
Latissimus dorsi Origin: ilium & sacrum & lumbar and thoracic vertebrae & ribs Insertion: inter-tubercular tubercular groove humerus (medial side) Shoulder adduction, extension, internal rotation and transverse extension.
The erector spinae muscle group functions to provide Dynamic intersegmental stabilization and Eccentric deceleration of trunk flexion and rotation During kinetic chain activities. The quadratus lumborum muscle functions primarily as a Frontal plane stabilizer that works synergistically with the gluteus medius and tensor fascia lata. The latissimus dorsi has the largest moment arm of all back muscles and therefore has the greatest effect on the lumbo-pelvic-hip complex. The latissimus dorsi is the bridge between the upper extremity and the lumbo-pelvic-hip complex. Any functional upper-extremity kinetic chain rehabilitation has to pay particular attention to the latissimus dorsi and its function on the lumbo-pelvic-hip complex.
The key abdominal muscles include The rectus abdominis, External abdominal oblique, Internal abdominal oblique, and Transversus abdominis.
When working efficiently, the abdominals offer Sagittal, Frontal, and Transverse plane stabilization By controlling forces that reach the lumbo-pelvic-hip complex. The rectus abdominis eccentrically Decelerates trunk extension and lateral flexion, and provides dynamic stabilization During functional movements.
The external obliques work Concentrically to produce contralateral rotation and ipsilateral lateral flexion, and Eccentrically to decelerate trunk extension, rotation, and lateral flexion During functional movements. The internal oblique works Concentrically to produce ipsilateral rotation and lateral flexion, and Eccentrically to decelerate extension, rotation, and lateral flexion. The transversus abdominis is probably the most important of the abdominal muscles. The transversus abdominis functions to Increase intra-abdominal pressure, Provide dynamic stabilization against rotational and translational stress in the lumbar spine, and Provide optimal neuromuscular efficiency to the entire lumbo-pelvic-hip complex.
The transversus abdominis works by a feedforward mechanism. Contraction of the transversus abdominis precedes The initiation of limb movement and Contraction of all other abdominal muscles, Regardless of the direction of reactive forces. Like the multifidus, the transversus abdominis is active during all trunk movements, Suggesting that this muscle has an important role in dynamic stabilization.
The key hip musculature includes The psoas, Gluteus medius, Gluteus maximus, and Hamstrings.
The psoas produces Hip flexion and external rotation in the open-chain position. Hip flexion, lumbar extension, lateral flexion, and rotation in the closed-chain position. The psoas Eccentrically decelerates hip extension and internal rotation, as well as trunk extension, lateral flexion, and rotation. The psoas works synergistically with the superficial erector spinae and creates an anterior shear force at L4- L5. The deep erector spinae, multifidus, and deep abdominal wall (transverse, internal oblique, and external oblique) counteract this force.
It is extremely common for athletes to develop tightness in their psoas. A tight psoas increases the anterior shear force and compressive force at the L4-L5 junction. A tight psoas also causes reciprocal inhibition of the Gluteus maximus, Multifidus, Deep erector spinae, Internal oblique, and Transversus abdominis. This leads to extensor mechanism dysfunction during functional movement patterns.
Lack of lumbo-pelvic-hip complex stabilization prevents appropriate movement sequencing and leads to Synergistic dominance by the hamstrings and superficial erector spinae During hip extension. This complex movement dysfunction also Decreases the ability of the gluteus maximus to decelerate femoral internal rotation during heel strike, predisposes an individual with a knee ligament injury to abnormal forces and repetitive microtrauma.
The gluteus medius functions as the primary frontal-plane stabilizer during functional movements. The gluteus medius Decelerates femoral adduction and internal rotation during closedchain movements. A weak gluteus medius increases frontal- and transverse-plane stress at the patellofemoral joint and the tibiofemoral joint. A weak gluteus medius leads to synergistic dominance of the tensor fascia latae and the quadratus lumborum. This leads to tightness in the iliotibial band and the lumbar spine. This will affect the normal biomechanics of the lumbo-pelvic-hip complex and the tibiofemoral joint as well as the patellofemoral joint.
The gluteus maximus functions Concentrically in the open chain to accelerate hip extension and external rotation. Eccentrically decelerate hip flexion and femoral internal rotation. It also functions through the iliotibial band (ITB) to decelerate tibial internal rotation. The gluteus maximus is a major dynamic stabilizer of the sacroiliac joint. It has the greatest capacity to provide increased compressive forces at the SI joint secondary to its anatomical attachment at the sacrotuberous ligament. Lack of proper gluteus maximus activity during functional activities leads to Pelvic instability and decreased neuromuscular control. The EMG activity of the gluteus Medius and the gluteus maximus is decreased following an ankle sprain.
The hamstrings work Concentrically to flex the knee, extend the hip, and rotate the tibia. Eccentrically decelerate knee extension, hip flexion, and tibial rotation. The hamstrings work synergistically with the ACL. These muscles have been reviewed to emphasize to the athletic trainer that Muscles not only produce force (concentric contractions) in one plane of motion, but also reduce force (eccentric contractions) and Provide dynamic stabilization in all planes of movement during functional activities. It is the synergistic, interdependent functioning of the entire lumbo-pelvic-hip complex that enhances the stability and neuromuscular control throughout the entire kinetic chain.
POSTURAL CONSIDERATIONS The core functions to maintain Postural alignment and Dynamic postural equilibrium During functional activities. Optimal alignment of each body part is a cornerstone to a functional training and rehabilitation program. Optimal posture and alignment will allow for maximal neuromuscular efficiency, because The normal length-tension relationship, Force-couple relationship, and Arthrokinematics Will be maintained during functional movement patterns.
If one segment in the kinetic chain is out of alignment, It will create predictable patterns of dysfunction throughout the entire kinetic chain. These predictable patterns of dysfunction are referred to as serial distortion patterns. This leads to abnormal distorting forces being placed on the segments in the kinetic chain that are above and below the dysfunctional segment. A comprehensive core stabilization program will prevent The development of serial distortion patterns and Provide optimal dynamic postural control During functional movements.
ASSESSMENT OF THE CORE The athlete must undergo a comprehensive assessment to determine Muscle imbalances, Arthrokinematic deficits, Core strength, Core neuromuscular control, Core muscle endurance, Core power, and Overall function of the lower-extremity kinetic chain.
Core strength can be assessed by utilizing the straight leg lowering test.
The athlete is placed supine. A blood pressure cuff is placed under the lumbar spine at approximately L4-L5. The cuff pressure is raised to 40 mmhg. The athlete's legs are maintained in full extension while the athlete flexes the hips to 90 degrees. The athlete is instructed to perform a drawing-in maneuver (pull bellybutton to spine) and then flatten their back maximally into the table and pressure cuff. The athlete is instructed to lower their legs toward the table while maintaining their back flat. The test is over when the pressure in the cuff decreases. The hip angle is then measured with a goniometer to determine the angle.
Lower abdominal neuromuscular control The athlete is supine with the knees and hips flexed to 90 degrees. The pressure cuff is placed under the lumbar spine at L4-L5 and inflated to 40 mmhg. The athlete is instructed to perform a drawing-in maneuver to stabilize the lumbar spine, and then to slowly lower the legs until the pressure in the cuff decreases. This indicates the ability of the lower abdominal wall to preferentially stabilize the lumbo-pelvic-hip complex.
It has been demonstrated that approximately 80 to 85 percent of the general population suffers from low back pain. It has also been demonstrated that individuals with low back pain have decreased muscle endurance in the erector spinae muscle group. Erector spinae performance can be assessed by having the athlete lie prone on a treatment table, hands crossed behind the head. The axilla is used as a reference for the axis of a goniometer. The adjustable arm is aligned with the lateral side of the body and chin while the stationary arm is parallel to the table. The athlete is instructed to extend at the lumbar spine to 30 degrees and hold the position for as long as they can while the athletic trainer times the test.
Power of the core musculature needs to be assessed as well. Power production of the core musculature can be assessed by performing an overhead medicine ball throw. The athlete is instructed to hold a 4-kg medicine ball between their legs as they squat down. They are instructed to jump as high as possible while simultaneously throwing the medicine ball backward over their head. The distance is measured from a starting line to the point where the medicine ball stops. This is an assessment of total body power production with an emphasis on the core.
A lower-extremity functional profile should also be carried out on all athletes with kinetic chain deficits. These tests should include Isokinetic tests, Balance tests, Jump tests, Power tests, and Sport-specific functional tests.
GUIDELINES FOR CORE STABILIZATION TRAINING All muscle imbalances and arthrokinematic deficits need to be corrected prior to initiating an aggressive coretraining program. A comprehensive core stabilization training program should be systematic, progressive, and functional. The rehabilitation program should emphasize the entire muscle contraction spectrum, focusing on force production (concentric contractions), force reduction (eccentric contractions), and dynamic stabilization (isometric contractions).
A progressive continuum of function should be followed to systematically progress the athlete. The program should be manipulated regularly by changing any of the following variables: Plane of motion, Range of motion, Loading parameters (Physioball, medicine ball, bodyblade, power sports trainer, weight vest, dumbbell, tubing, etc.), Body position, Amount of control, Speed of execution, Amount of feedback, Duration (sets, reps, tempo, time under tension), and Frequency.
Specific Core Stabilization Guidelines TABLE 1: Guidelines for Core Stabilization Training Program 1. The program should be based on science. 2. The program should be systematic, progressive, and functional. 3. The program should begin in the most challenging environment the athlete can control. 4. The program should be performed in a proprioceptively enriched environment.
TABLE 2: Program Variation 1. Plane of motion 2. Range of motion 3. Loading parameter 4. Body position 5. Speed of movement 6. Amount of control 7. Duration 8. Frequency
TABLE 3: Exercise Selection 1. Safe 2. Challenging 3. Stress multiple planes 4. Incorporate a multi-sensory environment 5. Proprioceptively enriched 6. Derived from fundamental movement skills 7. Activity-specific
TABLE 4: Exercise Progression 1. Slow to fast 2. Simple to complex 3. Stable to unstable 4. known to unknown 5. Low force to high force 6. eyes open to eyes closed 7. static to dynamic 8. General to specific 9. Correct execution to increased intensity
Goal of program develop optimal levels of functional strength & stabilization Focus on neural adaptations instead of absolute strength gains Increase proprioceptive demands by utilizing A multisensory, multimodal (Tubing, bodyblade, Physioball, medicine ball, etc.) environment. Quality not quantity Poor technique and neuromuscular control results in poor motor patterns & stabilization Focus on function
To determine whether a program is functional, answer the questions: 1. Is it dynamic? 2. Is it multiplanar? 3. Is it multidimensional? 4. Is it proprioceptively enriched? 5. Is it systematic? 6. Is it progressive? 7. Is it activity-specific? 8. Is it based on functional anatomy and science?
CORE STABILIZATION TRAINING PROGRAM There are four levels to the core stabilization training program: level 1 (stabilization)
level 2 (stabilization and strength)
level 3 (integrated stabilization strength)
level 4 (explosive stabilization)