Sensorimotor anatomy of gait, balance, and falls

Abstract

The review demonstrates that control of posture and locomotion is provided by systems across the caudal-to-rostral extent of the neuraxis. A common feature of the neuroanatomic organization of the postural and locomotor control systems is the presence of key nodes for convergent input of multisensory feedback in conjunction with efferent copies of the motor command. These nodes include the vestibular and reticular nuclei and interneurons in the intermediate zone of the spinal cord (Rexed's laminae VI-VIII). This organization provides both spatial and temporal coordination of the various goals of the system and ensures that the large repertoire of voluntary movements is appropriately coupled to either anticipatory or reactive postural adjustments that ensure stability and provide the framework to support the intended action. Redundancies in the system allow adaptation and compensation when sensory modalities are impaired. These alterations in behavior are learned through reward-and error-based learning processes implemented through basal ganglia and cerebellar pathways respectively. However, neurodegenerative processes or lesions of these systems can greatly compromise the capacity to sufficiently adapt and sometimes leads to maladaptive changes that impair movement control. When these impairments occur, the risk of falls can be significantly increased and interventions are required to reduce morbidity.

Quantitative Evaluation of a New Posturo-Locomotor Phenotype in a Rodent Model of Acute Unilateral Vestibulopathy

“…Locomotion is an automated behavior generated at the spinal level by the central pattern generator of locomotion (15). However, in response to external factors, the nervous system updates the spinal pattern generator based on multisensory feedback, such as visual, somatosensory or vestibular inputs.…”

“…Rexed's VII laminae are also an important site for reticulospinal and corticospinal pathway termination. Thus, the vestibulospinal pathways are well-positioned to modulate the reflex responses to anticipated or imposed body displacements (15)(16)(17).…”

Primitive Reflexes in Very Low Birth Weight Infants Later Diagnosed with Autism Spectrum Disorder

“…Why did infants with than without ASD show more abnormalities in primitive reflexes? Primitive reflexes are considered to be mediated by the brainstem, and gait and movement develop thorough bidirectional connections among the cerebrum, cerebellum and midbrain [21,22].…”

A trip to remember

“…Data Collection N Age %Fallers Country Tinetti et al (1988) 1985-1986 336 ≥75 years 32% USA O' Loughlin et al (1993Loughlin et al ( ) 1987Loughlin et al ( -1988 409 ≥65 years 29.1% Canada Campbell et al (1990) Not stated. Submitted 1989 761 ≥70 years 35.2% New Zealand Luukinen et al (1994Luukinen et al ( ) 1991 1,159 ≥70 years 30% Finland Tromp et al (2001) 1995-1997 1,285 65-89 years 1 recovery performance (Nutt et al, 1993, Sousa et al, 2012, MacKinnon, 2018. This section briefly outlines the systems involved and how they are related to ageing and falls.…”

“…Finally, the visual system will perceive the change in visual surroundings as a result of the sudden diversion in trajectory. These sensory inputs will trigger specific reflexes for supporting balance and additionally will be integrated and weighted by the central nervous system in order to produce appropriate motor responses (Nutt et al, 1993, Nielsen and Sinkjaer, 2002, Sousa et al, 2012, MacKinnon, 2018.…”