To evaluate biokinesiological and ecokinesiological indicators of walking speed (WS) in independent older Chilean adults using an integrative approach to construct functional reserve (FR) ranges and functional classification spaces (FCS).
This observational cross-sectional study included 53 independent older adults, 40 women (mean age 69.4 ± 4.7 years; BMI 31.2 ± 4.3 kg/m²) and 13 men (mean age 70.8 ± 7.2 years; BMI 28.7 ± 3.5 kg/m²). Participants were asked to perform self-selected walking speed (SSWS) and maximum walking speed (MWS) on a 70-meter elliptical circuit for three minutes. Biokinesiological analysis was conducted at the system level to estimate walking FR, while ecokinesiological analysis was conducted at the near-environment level (basic daily activities) and the distant-environment level (instrumental and advanced daily activities) to construct the FCS.
FR was estimated through the percentage relationship between average walking speed (AWS; m/s), physiological cost index (PCI; beats/meter), and the percentage of heart rate reserve used (%HRRu) across SSWS and MWS performance. FCS for threshold, reference, and categorization values of SSWS and MWS were constructed according to documented values for: i) basic functionality thresholds, ii) referential instrumental spectrum, and iii) functional categorization as "household walker" ( 0.4 m/s), "limited community ambulator" (0.40 - 0.80 m/s), "community ambulator" (0.81 - 1.3 m/s), and "cross street safely" (> 1.3 m/s).
The %FR associated with walking speed was significantly higher in males (p = 0.017), with values exceeding +20% in most subjects. In terms of physiological %FR, it was ≈30% for PCI in both men and women (p = 0.156), while %HRRu was ≈40% in females and ≈45% in males (p = 0.131). The threshold for basic daily activities was met by 100% of participants. About 80% of older adults were below the reference limit for instrumental and advanced daily activities. 81% of women and 69% of men were categorized as "efficient in the community," while 31% of men and 14% of women met the minimum value for "effective street crossing" (advanced daily activities).
In this group of independent older Chilean adults, FR varies by analysis indicator and gender, while FCS results highlight individuals at risk of functional decline in instrumental and advanced daily activities.
Integrating SSWS and MWS as complementary physiotherapy assessments in public gerontological preventive exams could provide valuable insights for timely, specific, and proactive decision-making to support healthy and successful aging.
Physical Functional Performance
Activities of Daily Living
