In the world of posture and movement which I have worked for over forty years, most people do not understand that our brains are hardwired with reflex activity establishing a foundation for skeletal balance and equilibrium that unlocks the potential for a variety of complex and skilled postures and movements to be acquired and developed. All it takes is practice! These foundational reflexes is what is referred to as the neuromdevelopmental sequence.
It is the normal movement progression that infants follow as they grow and develop the abilities for head control as well as to roll, crawl, stand, walk, and more. It is the same sequence that provides rehab professionals guidance by giving a logical progression of postures and movement strategies. M.A.T. too follows this neurodevelopmental sequence with its patterns and exercises.
These lower developmental postures provide the necessary strength and stability and coordination required of more challenging and complex postures and movements as the human nervous system matures.
As infants, we enter this world of gravity and ground reaction force (GRF) with uncompromised stability and mobility, and follow a progression of movement patterns or developmental milestones naturally and predictable. They start with head and neck control and progressively move to rolling, creeping, crawling, kneeling, squatting, standing, stepping, walking, climbing, and running. Simply horizontal to vertical against the vertical forces of gravity and ground reaction force (GRF).
Keep in mind that each innate movement pattern serves as a stepping stone, helping to build adequate posture, balance, mobility, and stability, and alignment in order to allow one to move onto the next level. Without these basic movement patterns, higher level movement skills would be an impossibility. The great accomplishments in the sports arena would not be possible.
For the most part, a baby will begin life in the world of gravity while in the supine position or lying on their back supported by their mattress or their parent’s arms. This is an extremely low-level and flexion biased position. However at about six weeks, an infant begins to develop the ability to hold the head erect when held upright.
After this comes the prone position or on the their stomach often referred to as “tummy time.” It’s an extension biased pattern, allowing an infant to develop extension strategies against gravity to be able to lift the head and neck, and raise the face off the ground or crib mattress.
At around eight weeks, infants develop the ability to lift themselves from the prone position by their arms allowing them to develop both stability and mobility in the cervical spine, the scapulothoracic joints, and in the upper extremities. They learn to to stabilize their trunk while reaching and imparting force through their arms.
But the foundation of all posture and movement strategies is of course breathing which is the most basic movement skill an infant acquires. The diaphragm’s function is primarily known as a respiratory organ in the young infant, but at about four-and-a-half months, the diaphragm starts developing both a respiratory and postural function. This offers core and spinal stability as early as early as four-and-a-half months in the developing infant, therefore offering the potential and ability to start moving developmentally in various positions other than those being accomplished with complete support.
As the infant’s central nervous system (CNS) matures, rolling begins as early as three weeks. They usually start rolling from their sides to their back or from prone to their sides. Then around 18 weeks, they usually develop the necessary strength to start rolling from the their backs to their sides. Rolling is initially initiated at the head and is often the first change seen in postural position with infants.
Rolling, however, initiated by the lower and/or upper extremities comes later using the core of the body which lies in the middle of the lower and upper extremity kinetic chain transmitting force from one end to the other. There should be an acquired, natural flow to this movement pattern in the maturing CNS. If not, it is an indication of weak or inhibited muscles by the CNS.
Active grasping occurs somewhere between two to seven months in infants. They then move into sitting and quadruped positions once they develop the stability in the hips and pelvis. The quadruped position then transitions into crawling at around seven months. In this position, closed kinetic chain activities such as weight shifting is initiated helping to determine where the neutral spine will be.
From crawling, infants then go into the transitional postures of tall-kneeling and half kneeling as they get closer to attempting the standing position. This all occurs at and around eight months. The tall-kneeling provides an anterior-posterior challenge in the sagittal plane to the core and lower extremities without using the feet. It helps improve the stability and dynamic control of the core and pelvis before progressing to standing.
Understand that in the sequence just described, it has primarily involved vestibular sensory input to the CNS and the so called righting reflexes (RRs). These RRs develop shortly after birth of the infant in response to their new environment out of the mother’s womb involving the vertical force of gravity. They are most evident by 10-12 months old and remain active throughout life. These foundational reflexes initiate the integrated movement between the infant’s head, trunk, and body against gravity.
RRs underlie the ability to orient the infant to its new environment inclusive of gravity and to its own body. As the CNS matures, RRs will help the body as it responds to a rapid loss of balance and assist with integrated movements of the head and trunk. These RRs are responsible for taking the maturing infant through their developmental milestones of head control, rolling, sitting, and crawling.
Part of the RRs is the labyrinthine head righting reflex (LHRR) which fully emerges at about two months of age and allows the infant to start lifting the head in the sagittal plane as previously mentioned involving middle ear apparatus. It is then at about ten months in which the LHRR allows the infant to maintain their head in an upright, vertical position with their eyes facing forward and level at the ears in the frontal plane. Again, it is a reflex triggered by the vestibular system and otoliths in middle ear. These reflexes involving the middle ear apparatus in the sagittal and frontal planes for skeletal balance and equilibrium triggers postural adjustments to restore the head to a normal vertical position as the body begins to move.
Once the infant progresses to standing other reflexes come into play involving visual input such as the occular-head righting reflex (OHRR). It is the OHRR that maintains the required stability of the head and body movement while allowing the gaze of the eyes to remain focused and fixed.
The RRs are a group of reflexes responsible for the foundational movement transitions going from lying to upright and turning in relationship to gravity and space with predominately vestibular input before the infant can acquire so called equilibrium reflexes (ERs). This process begins at about six months old and lasts throughout life. The ERs appear as the infant is beginning to develop the ability to transition from a horizontal to vertical or sitting position and relies heavily on visual and proprioceptive sensory input.
ERs are can be classified as automatic and subconscious as does the RRs, but they involve varied acquired and learned patterns of movement to maintain balance in the vertical position in reaction to GRF. Maintaining the infants balance in this case is accomplished by shifting its center of gravity (COG) and/or its base of support (BOS). These reflexes are not inherent from the development of the CNS. Their movement responses are more specific and unique to each infant’s situation they experience on their journey in this environment of gravity and now GRF.
One thing I have noticed at 68 years of age, the world indeed works best when there is order and that goes too for the human nervous system when looking at the neuromuscular, fascial, and skeletal systems creating human posture and movement. In nature, there is a pre-arranged natural symmetry to these systems that are inherent, precise, and predictable.
As an infant, we are born into this world of gravity with un-compromised stability and mobility that creates chaos within the human nervous system. The neurodevelopmental sequence brings first and foremost stability to the nervous system by following this natural, inherent, and predictable path of progression in acquiring postural and movement patterns seen as developmental milestones in the infant’s quest to survive in this new environment of gravity.
These developmental milestones then allow the infant to go from horizontal to vertical in order to confront another vertical force called GRF and create new reflexes called ERs that affect their COG and/or BOS. From there, the potential and expectations of the human posture and movement system are unlimited. Just look at what athletes like Simone Biles, Sydney McClaughlin, and Noah Lyles have recently accomplished in the arena of human athletic performance. Records continue to fall and will continue to fall.
My next article will again deal with Myomemory Transformation Advantage (M.A.T.) trying further explain this system I have developed over forty years. Until then, be well.
Terry