Stride length was defined as the distance measured parallel to the line of progression, including two consecutive steps. Stride width was defined as side-to side distance between the heel of the current foot and heel of the next opposite foot. On the other hand, step width was determined as the distance between the outermost borders of two consecutive footprints. The standard deviation of the three variables (stride length) was used to represent the variability of the stride length.
1. Introduction
Advances in medical management of patients with various conditions, particularly cardiovascular conditions, have resulted in a significant increase in longevity
[1][2]. This older population may, however, be limited by other medical problems, including arthro-skeletal stiffness and its consequences, e.g., physical disability and falls, which may lead to a decline in the functional capacity and quality of life as well as increased risk of dependence and institutionalization
[3][4]. Physical disability also reflects difficulties that individuals may experience in interaction with society
[5], which can lead to psychological disorders
[6].
Physical activity/exercise is an essential disease-preventive measure, irrespective of age
[7]. While standards and objective targets are well established, they might not necessarily apply to older people because of other various comorbidities or pre-existing chronic conditions
[8]. Gait speed has been shown to be associated with better survival among older adults and to reflect health and functional status
[9][10].
2. Stride Length Predicts Adverse Clinical Events in Older Adults
The results revealed the following: (a) baseline stride length was shorter and stride length variability was higher in the older population who developed adverse clinical events compared to those with no clinical events, while the other gait parameters were not different between groups; (b) the shorter stride length predicted MAE, physical disability and mortality in the older adults; (c) a baseline stride length ≤ 0.64 m had higher accuracy in predicting adverse clinical events compared to a stride length variability of 5.7%.
Many researchers have focused on associations between gait speed, physical disability and other adverse events in older adults
[11][12][13]. It has been reported that slowing the walking speed reflects health and functional status and predicts survival
[14][15]. However, gait is a complex neuromotor behavior, with many measurable facets in addition to velocity. It also has an intricate relationship with different aspects of the psychomotor system. In addition, other quantitative parameters of gait, such as swing phase, stride length and gait variability, demonstrated better predictive value of disability compared to speed alone
[13][16]. Body balance is a crucial factor in maintaining healthy and safe walking and for avoiding falls. Shorter stride length and higher stride length variability are two important factors directly involved in the mechanisms of poor balance, which has been shown as a marker of low survival, physical disability and other adverse clinical events
[16][17]. These parameters might indicate a certain body inability to improve or recover from future adverse events. Our results support this concept and strengthen further the importance of shorter stride length as a robust marker in predicting MAE, physical disability and mortality. In addition, our analysis proposes a summary cut-off value for stride length of 0.64 m with high accuracy compared with stride length variability in predicting clinical events; our suggestion for future direction is to establish cut-off values based on the demographic characteristics of each country.
Clinical Implications
Stride length and stride length variability, as important parameters of body balance during walking in older adults, can be a target for intervention through medical, rehabilitative and health-promoting behavioral strategies. These interventions should aim at maintaining long strides in order to sustain improved long-term physical function and survival in older adults.
3. Conclusions
The results support the significant value of stride length in predicting life-threatening clinical events in older adults. A stride length of 0.64 m accurately predicts the occurrence of future clinical events and thus should provide potential guidance towards optimum individual exercise and support.
This entry is adapted from the peer-reviewed paper 10.3390/jcm10122670