In this article, we will discuss Normal Postural Reflex Mechanism. So, let’s get started.
Normal Postural Reflex Mechanism
To assess and treat the problems of the hemiplegic patient the factors underlying normal movement must be understood. The
normal postural reflex mechanism which provides a background for movement has two types of automatic reaction: righting red actions and equilibrium reactions.
Righting reactions allow the normal position of the head in space and in relation to the body, and normal alignment of trunk and limbs (Bobath, 1978). They give the rotation within the body axis which is necessary for most activities.
Equilibrium reactions maintain and regain balance. More complex than the righting reactions, they may be either visible movements or invisible changes of tone against gravity. Basic patterns of movement evolve from the righting reactions of early childhood, which later become integrated with the equilibrium reactions.
The brain is continuously receiving sensory impulses from the periphery, informing it of the body’s activities. All movement is
in response to these sensory stimuli and is monitored by proprioceptors (in muscles and joints), extroceptors (in skin and subcu-
taneous tissue) and telereceptors (the eyes and ears). Without sensation human beings do not know how to move or how to react to various situations, but in the conscious state intention may govern these reactions.
Normal function of the body depends on the efficiency of the central nervous system as an organ of integration. Every skilled
movement depends on:
Normal Postural Tone
Postural tone, which is variable, provides the background on which movement is based, and is controlled at a subcortical level. It must be high enough to resist gravity yet still permit movement. Hypertonicity is loss of dynamic tone, giving stability without mobility. Hypotonicity precludes the stable posture necessary for movement. With each movement posture changes, and cannot be separated from it.
Normal Reciprocal Innervation
Reciprocal innervation allows graded action between agonists and antagonists (Bobath, 1974). Proximally the interaction results in
a degree of co-contraction which provides fixation and stability. Distally, skilled movements are made possible by a greater degree of reciprocal inhibition.
Normal Patterns of Movement
Movement takes place in patterns that are common to all although there are slight variations in the way different people perform the same activity. Normally, the brain is not aware of individual muscles, only of patterns of movement produced by the interaction of groups of muscles.