Spine Motor Control & Learning PDF

Spine 1.​ Motor control and motor learning MOTOR CONTROL The ability to regulate or direct the mechanisms essential for movement: -​ How does the central Nervous System (CNS) organize the many individual muscles and joints into coordinated functional movement? -​ H...

Spine 1.​ Motor control and motor learning MOTOR CONTROL The ability to regulate or direct the mechanisms essential for movement: -​ How does the central Nervous System (CNS) organize the many individual muscles and joints into coordinated functional movement? -​ How is sensory information from the environment and the body used to select and control movement? -​ How do our perceptions of ourselves, the tasks we perform, and the environment in which we are moving influence our movement behaviour? MOTOR LEARNING Motor learning refers to the acquisition and reacquisition of movement and coordination that leads to a permanent change in movement performance. The heart of balance training is practicing progressively challenging tasks and activities that facilitate the development of postural behaviours needed for the (re)acquisition of skilled functional movement. Movement emerges from interactions between the individual, the task, and the environment. Factors within the individual, the task, and the environment affect the organization of movement. Motor control research that focuses only on processes within the individual without taking into account the environment in which that individual moves or the task that he or she is performing will produce an incomplete picture Motor learning: principles The key effective motor learning lies in identification of the nature of the deficits in performance and utilization of optimal strategies to induce change in performance that are tailored to the individual patient’s needs. The goal of interventions aimed at the strategy level is to facilitate the development of sensory, motor, and cognitive strategies that are effective in meeting postural control demands associated with a variety of functional tasks that require steady-state, anticipatory, and reactive aspects of balance control. Key features of 4 distinct motor learning mechanisms: FITTS AND POSNER (1967): theory of motor learning related to the stages involved in learning a new skill. Motor learning: stages Fitts and Posner’s Model of Motor Learning: -​ Cognitive Stage: learners expend cognitive energy to understand how they are supposed to move -​ Associative Stage: learners have to mastered the basic forms of movement and begin to refine their skills with practice -​ Autonomous Stage: learners perform movements automatically without cognitive energy, and can focus on strategy COGNITIVE STATE: -​ The learner is concerned with understanding the nature of the task, developing strategies that could be used to carry out the task, and determining how the task, and determining how the task should be evaluated -​ Most improvement -​ More variability -​ These efforts require a high degree of cognitive activity such as attention -​ Instructions, feedback and demonstrations. ASSOCIATIVE STATE: -​ Best strategy determined so able to refine the skill -​ There is less variability -​ Improvement occurs more slowly -​ It is proposed that verbal/cognitive aspects of learning are not as important at this stage because the person focuses more on refining a particular pattern -​ This stage may last from days to weeks or months, depending on the performer and the intensity of the practice. AUTONOMOUS STAGE: -​ Automaticity of the skill and the low degree of attention required for its performance -​ Less interference from simultaneously-performed tasks (dual tasks). Motor learning: influencing factors Factor Description Verbal instruction It is essential to preserve attention and direct observation during instructions, as they directly influence learning Practice characteristics Distributed practice, which includes extended rest periods between work sessions, and variability enhances learning transfer. It prevents fatigue that could lead to errors due to physical and mental exhaustion Active participation The total time dedicated to practice directly influences learning outcomes. Participant and motivation motivation is crucial to maintaining a high level of engagement in practice Possibility of making It is important to analyze each task or activity to determine which movement components errors should be emphasized during learning, helping to minimize errors and improve accuracy. Postural control Involves the ability to control the body’s position in space to maintain balance and orientation, which is fundamental for effective motor learning  Memory Memory is a key component in motor learning, allowing for the retention and reproduction of learned movements Feedback Provides motivation, reinforces the development of an activity, and offers information on progress. It should be administered carefully to avoid creating dependency and should only be provided when truly necessary. Extrinsic Feedback: -​ Provides information about individual progress in learning the activity, which enhances motivation -​ Provides information on the parts that make up the action, allowing the individual to create a mental representation of the activity and assess their potential to achieve the goals -​ Provides positive reinforcement by informing the subject about the correct execution of tasks, which has an immediate effect on motivation, attention, and concentration on the task. -​ Repeated feedback on error correction can create dependency and prevent the subject from experiencing and evaluating their actions independently. To avoid dependency, feedback should only be given when necessary, depending on task complexity and the individual’s experience. Reinforcement should be intermittent, avoiding feedback on every execution 2.​ Core DEFINITION: Any exercise that stimulates neuromuscular recruitment patterns to ensure a stable spine while also allowing for efficient and powerful movement The spine stability system consists of the following interacting elements: -​ Neuromuscular control (neural elements) -​ Passive subsystem (osseous and ligamentous elements) -​ Active subsystem (muscular elements) A model showing the relationship between the three models proposed by Punjaby (1992), COmerford and Mottram’s (2001) an Bergmak (1989), which influence “spinal stability” ANATOMICAL CORE: PASSIVE TISSUES -​ Bones -​ Cartilage -​ Ligaments We considered solely, the passive tissues have limited ability to stabilize the spine. ANATOMICAL CORE: ACTIVE TISSUES -​ Muscles: The muscles provide the torque necessary to cause movement (concentric muscle actions), to control movement (eccentric muscle actions) or to prevent movement (isometric). Muscular box: -​ Abdominals in the front -​ Paraspinals and glutes in the back -​ Diaphragm as the roof -​ Pelvic floor and hip girdle musculature as the bottom Although considerable effort has been placed on identification of the muscles that contribute the “most” to stability, this is the wrong question. With consideration of the complexity of stability, it can be seen that no single muscle could provide the greatest contribution to all elements of stability.  The thoracolumbar fascia is like a “belt-like” structure with a complex network of fascial and aponeurotic layers, which separates the muscles of the spine from the abdominal wall muscles, quadratus lumborum, and iliopsoas. Classification of Bergmark (1989) Bergmark (1989) further classified the active system into the local and global stabilising system. (a). Local muscles Deep muscles and portions of some muscles that have their origin on the lumbar vertebrae. They have a primary role in the maintenance of spinal segment stability and stiffness. (b). Global muscles Large and superficial muscles of the truck that don’t have direct attachment to the vertebrae and cross multiple segments. Their primary function is to generate force to control movement. They act like guy ropes to control spinal orientation, balance the external loads applied to the trunk and transfer load from the thorax to the pelvis. Muscles of the lumbopelvic region: Classification of the Mottram and Comeford (1998): -​ LOCAL STABILIZER: -​ Deepest layers -​ Monoarticular -​ Minimal change in length -​ Prevent translation between vertebrae or joints -​ Maintain rigidity and control the movements of the spine in all directions -​ No antagonist muscles -​ Anticipate by activating before the movements of the joints -​ Tonic -​ Contract at low intensity -​ Example: lumbar multifidus muscles, the transversus abdominis or the oblique fibres of the vastus medialis quadriceps -​ GLOBAL STABILIZER: -​ More superficial -​ Monoarticular or polyarticular -​ Strong, their contraction does produce movement -​ Main function is eccentric control -​ Work in one direction only and therefore have antagonist muscles in the opposite direction -​ They can work tonically or phasically -​ Example: the abdominal obliques or the hamstrings of the legs  -​ GLOBAL MOVILIZER: -​ The largest and most superficial -​ Always polyarticular, they join several joints -​ Strong, intended for explosive contraction, to move large loads with the limbs unidirectional and with antagonist muscles -​ They are phasic, they work again great resistance, at high contraction intensity -​ Example: pectoralis major or rectus femoris Slow twitch and fast-twitch muscles fibres: -​ Slow-twitch fibres make up primarily stabilising muscle systems (the deep muscle layer). Shorter muscles in length, suited for controlling intersegmental motion required in postural and extrinsic loading responses -​ Fast-twitch fibres comprise the global muscle system (the superficial muscle layer). These muscles are long, have large lever arms, produce large amounts of torque and gross movements. Feature Slow-twitch muscle fibres (ST) Fast-twitch muscles fibres (FTS i FTB) Function Tonic (postural) Phase (motion) Fatigability Slow Fast Excitability Slow Fast Colour Red White (FTA) or pink (FTB) Number of Significant Moderate muscle spindles ANATOMICAL CORE: NEUTRAL ZONE With the lumbar spine in neutral, the muscles are able to most effectively provide the majority of stabilizing support and prevent excessive stress on the passive tissues. Conversely, when the lumbar spine is in flexed posture, the spinal extensor muscles are neurologically inhibited from developing tension; thus, the passive tissues provide the majority or stabilising support, which greatly increases the risk of injury to these structures (McGill 2007). ANATOMICAL CORE; CONTRIBUTING FACTORS TO POSTURAL DYSFUNCTION -​ Lack of education or awareness of correct -​ Decreased fitness posture -​ Muscle weakness -​ Sedentary lifestyle -​ Muscle tightness -​ Occupational demands -​ Poor core stability -​ Joint stiffness -​ Poor ergonomic workstations -​ Body composition. ANATOMICAL CORE: STABILITY FUNCTIONS -​ Anticipatory postural adjustments: pre-programmed muscle activation which heals the body to anticipate the subsequent force -​ To create interactive moments that help to control the exposure to force and the load applied to a joint -​ Help control force at different points of the body ANATOMICAL CORE: STAGES FOR EXERCISE MANAGEMENT -​ Section 1: entails segmental control and active recruitment over global mobilisers - specifically transversus abdominus, pelvic floor, and diaphragm -​ Section 2: whilst maintaining segmental control and activation, introducing closed chain exercises, with low velocity and low load -​ Section 3: whilst maintaining segmental control, introducing open-chain exercises with high velocity and load. Movement of adjacent body segments can be used to stress the core structures