A new measure for quantifying the bilateral coordination of human gait: Effects of aging and Parkinson’s disease

• Published in: Experimental brain research Vol. 181; no. 4; pp. 561 - 570
• Main Authors: Plotnik, Meir, Giladi, Nir, Hausdorff, Jeffrey M
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.08.2007; Springer Nature B.V
• Subjects: Adult; Aged; Aging; Aging - physiology; Analysis of Variance; Biological and medical sciences; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Disease; Exercise; Female; Fitness equipment; Functional Laterality - physiology; Fundamental and applied biological sciences. Psychology; Gait; Gait - physiology; Humans; Hypotheses; Legs; Male; Medical sciences; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Movement disorders; Neurology; Older people; Parkinson Disease - physiopathology; Parkinson's disease; Psychomotor Performance - physiology; Spinal cord; Vertebrates: nervous system and sense organs; Young adults; Tel Aviv Israel; Israel; Human; Nervous system diseases; Aging· Parkinson's disease,Gait; Gait; Coordination; Blateral coordination; Lower limb; Parkinson disease; Cerebral disorder; Locomotion; Asymmetry; Central nervous system disease; Degenerative disease; Timing; Extrapyramidal syndrome
• ISSN: 0014-4819; 1432-1106
• DOI: 10.1007/s00221-007-0955-7

The bilateral coordination of locomotion has been described in detail in animal studies and to some degree in man; however, the mechanisms that contribute to the bilateral coordination of gait in humans are not fully understood. The objective of the present study was to develop a measure for quantifying the bilateral coordination of gait and to evaluate the effects of aging and Parkinson's disease (PD) on this new metric. To this end, we compared the gait of healthy older adults to that of healthy young adults and patients with PD. Specifically, we defined the stride duration of one foot as a gait cycle or 360 degrees , determined the relative timing of contra-lateral heel-strikes, and defined this as the phase, varphi (ideally, varphi = 180 degrees for every step). The sum of the coefficient of variation of varphi and the mean absolute difference between varphi and 180 degrees was defined as the phase coordination index (PCI), representing variability and inaccuracy, respectively, in phase generation. PCI values were higher (poorer bilateral coordination) in patients with PD in comparison to the healthy older adults (P < 0.006). Although gait speed and stride time variability were similar in the healthy young and older adults, PCI values were significantly higher among the healthy elderly subjects compared to the young adults (P < 0.001). Regression analysis suggests that only about 40% of the variance in the values of PCI can be explained by the combination of gait asymmetry (as defined by the differences in each leg's swing times), gait speed and stride time variability, pointing to the independent nature of this new metric. This study demonstrates that bilateral coordination of gait deteriorates with aging, further deteriorates in PD, and is not strongly associated with other spatio-temporal features of gait.