Postural ontogenesis entails maturation of body posture and related human locomotion. Postural muscle function ensures all possible positions in the joints determined by their anatomical shapes and has a strong formative influence on bone and joint morphology. Postural muscle activity is genetically predetermined and occurs automatically during CNS maturation. During newborn stage, bones and joints are morphologically immature. For example, the shape of the plantar arch is not well defined , the chest is shaped like a barrel, the posterior angles of the lower ribs are situated anteriorly relative to the spine, the ribs appear to be more horizontal than in adulthood, and the spine is maintained in kyphosis as the spinal lordotic curves have not yet developed. As the CNS matures, purposeful muscle function increasingly occurs. Muscles controlled by the CNS subsequently act on growth plates influencing the shape of bones and joints. Every joint position depends on stabilizing muscle function and coordination of local and distant muscles to ensure ?functional centration? of joints in all possible positions. The quality of this coordination is crucial for joint function and influences not only local but also regional and global anatomical and biomechanical parameters starting in the early postnatal stage.
Ontogenesis demonstrates a very close relationship between neurophysiological and biomechanical principles, which are important aspects in the diagnosis and treatment of locomotor system disorders. This relationship is very apparent in cases where there is a CNS lesion and muscle coordination is affected. The disturbed muscle coordination subsequently alters joint position, morphological development, and ultimately posture. Postural function and motor patterns are not only the indicators of the stage of maturation, but can point to the fact if the CNS development is physiological or pathological. Posture is a term very closely related to early individual development. The quality of verticalization during the first year of life strongly influences the quality of body posture for the rest of a persons life.
All afferent systems, including vision, hearing, vestibular, proprioceptive, and exteroceptive information, are integrated in these global patterns of stabilization and stepping forward/supporting extremities function. In addition, the orofacial system takes part in these complex movement patterns. For example, during a throwing action, the athlete automatically places the extremities in a reciprocal position, the eyes and tongue turn toward the same direction as the stepping forward (throwing) arm (eyes preceding the arm movement), enhancing further facilitation and performance of the throwing movement. The athlete depicts how all his orofacial muscles are involved in movement, to enhance maximum strength and performance. If the athlete is asked to look in the opposite direction or turn his tongue against the direction of the stepping forward arm movement, it will significantly decrease his sports performance. These principles can be powerfully used in athletic training.
Activation of the stabilizers is automatic and subconscious (the feed-forward mechanism) and precedes every purposeful movement. Any purposeful movement influences posture and this posture subsequently influences the quality of phasic (dynamic) movement.
What functional pathologies are typically associated with pain? Depending on one's individual approach any or all of the following may be pursued: joint dysfunction, trigger points, or muscle imbalances. Different functional pathologies are screened for in the hope that a "key link" will be found. Such a key link gives the clinician a foothold in the management of pain syndromes related to dysfunction. believes that there is a pivotal dysfunction which if found and treated will help alleviate pain.
Such an approach is important for treating pain because dysfunction is the primary cause of pain in the motor system. Even with structural pathology the critical difference between symptomatic and asymptomatic structural pathology is most likely due to dysfunction. A patient's recovery is contingent on restoring function in the motor system.
Assessment of structural pathology or disease is important for ruling out "red flags" for urgent or emergency referral. But the vast majority of patients do not have clinically significant structural pathology (90 percent). In these patients it is the assessment of function/dysfunction of the motor system which is paramount. Since functional pathologies are present in everyone we must identify "chains" of functional pathology which are related to a patient's symptoms or decompensation. Most importantly, our assessment should identify the key link in a patient's dysfunctional chain which either reflexly or biomechanically has the most significant effect on the the motor system. Such a key link is the starting point for efficient, efficacious treatment.
Chain reactions involving pathokinesiology and abnormal arthrokinematics occur commonly. Gait is the classic example of an activity occurring as part of a kinetic chain. Faulty gait often results from forefoot instability (i.e., hyperpronation) during mid-stance to toe off. This can travel up the chain and lead to knee, hip and low back problems. Another example of a kinetic chain involves the muscles, joints and motor program for reaching, grasping, carrying, or prehension. A dysfunction of the sternoclavicular or glenohumeral joints or muscle imbalance of the scapulothoracic muscles will result in a loss of the normal scapulohumeral rhythm. In the end the patient may develop wrist/elbow repetitive strain syndromes or myofascial syndromes of the head and neck. One should think of the craniomandibular system as being part of a kinetic chain responsible for mastication. Masticatory muscle dysfunction may affect the temperomandibular and cervicocranial joints resulting in jaw, facial, head or neck pain. Interface between muscles and joints is the rule rather than the exception in the motor system.
Chain reactions linking various dysfunctional tissues involved in a task occur as a normal consequence of soft tissue overload. Muscles being the active component of the motor system adapt and may eventually fatigue. Panjabi says, "the muscles and tendons ... are the means through which the spinal system generates forces and provides the required stability to the spine." Bogduk and Twomey say, "such processes may underlie what might otherwise be called 'fatigue' in a ligament or capsule. After prolonged strain, ligaments, capsules, and intervertebral discs of the lumbar spine may creep, and they may be liable to injury if sudden forces are unexpectedly applied during their vulnerable, recovery phase."
The goal of rehabilitation is to achieve a level of functional restoration so that the patient can safely manage the "demands" of their occupation or lifestyle.
All too often the chiropractic approach suffers because it does not adequately rehabilitate the motor system
Normalize Joint Function
Relax and/or Stretch Hypertonic Muscles
Facilitate and/or Strengthen Inhibited Muscles
Reprogram Coordinated Movement Subcortically
Successful manipulation to a key link will have a distant effect throughout the kinetic chain. It has the potential to not only reduce a local fixation, but to have a reflex effect on hypertonic and inhibited muscles related segmentally or functionally. But if there is cerebellar involvement, peripheral treatment with manipulation is unlikely to reach deep enough into the central nervous system to reprogram subcortical movement patterns. the central nervous system controls motor responses, "the neural subsystem receives information from the various transducers, determines specific requirements for spinal stability, and causes the active subsystem to achieve the stability goal. proposes propriosensory treatments such as balance training as the mainstay of subcortical training. Sensory motor stimulation from the soles of the feet (rocker/wobble boards or balance shoes) or pelvis (gymnastic balls) can increase the speed of activation of inhibited muscles and decrease the irritability threshold of hypertonic muscles on a subcortical or semi-automatic basis.
Mastering the evaluation of functional chains (gait, prehension, mastication, etc.) and finding a key link amenable to manipulation is the first step. Then, it is necessary to search for extrinsic factors which can be addressed through education and ergonomics to reduce exposure to harmful stress and strain. Finally, specific rehabilitation goals must be established such as relaxing overactive muscles, facilitating weak muscles, and improving the quality of basic movement patterns (i.e., gait, lifting, carrying, etc.). Education and exercise are the keys to preventing reinjury and recurrence.
