Influence of energy cost and physical fitness on the preferred walking speed and gait variability in elderly women

Effects of mediolateral whole-body vibration during gait with additional cognitive load

Whole-body vibration (WBV) may increase musculoskeletal disorder risk among workers standing on vibrating surfaces for prolonged periods. Limited studies were conducted to comprehend WBV impact on individuals engaged in dynamic activities. This study explored the effects of different horizontal WBV frequencies on gait parameters, lower limb kinematics, and the cognitive response of healthy subjects. Forty participants walked at constant speed on a treadmill mounted on a horizontal shaker providing harmonic vibration with an amplitude of 1 m/s2 and frequencies 2-10 Hz, with inversely proportional amplitudes. A Psychomotor Vigilance Test measured reaction time while a motion capture system recorded walking kinematics. ANOVA results revealed no significant impact of vibration frequencies on the reaction time. At 2 Hz, alterations in gait spatiotemporal parameters were significant, with reduced stride length, stride time, step length, and stance time and increased step width and cadence. Similarly, gait variability measured by standard deviation and coefficient of variation significantly increased at 2 Hz compared to the other conditions. Comparably, kinematic time series analyzed through statistical parametric mapping showed significant adjustments in different portions of the gait cycle at 2 Hz, including increased hip abduction and flexion, greater knee flexion around the heel strike, and augmented ankle dorsiflexion. Participants exhibited gait kinematic variations, mainly at 2 Hz, where the associated mediolateral displacement was higher, as a plausible strategy to maintain stability and postural control during perturbed locomotion. These findings highlight individuals' complex biomechanical adaptations in response to horizontal WBV, especially at lower frequencies, under dual-task conditions.

Kinematic Relations during Double Support Phase in Parkinsonian Gait

The gait of Parkinson’s disease (PD) patients is shuffling, slow, and hesitant. We investigated peculiar gait relations during the double support phase (DSP) in PD patients and healthy controls. We used 3D motion capture (SIMI) to collect kinematic parameters of the natural gait of 11 PD patients (Hoehn and Yahr 2–3, 5 females, 6 males) tested on medication and the same-sized control sample (5 females, 6 males). The difference between groups was evaluated by the Mann-Whitney U test; for target parameters, the Spearman correlation was computed. Compared to the controls, the Parkinsonian step length index was significantly smaller (0.27 vs. 0.35, p < 0.05), step width index higher (0.12 vs. 0.09, p < 0.05), and the DSP duration was extended (0.165 s vs. 0.13 s, p < 0.05), whereas the single support phase was shortened (0.38 s vs. 0.4 s, p < 0.05). The Parkinsonians were faster during DSP initiation and slower during DSP termination (0.908 m·s−1 vs. 0.785 m·s−1, p < 0.05); the Parkinsonian speed was more constant. The patients showed significantly decreased range of motion (ROM) in the hip, ankle, and shoulder and adopted straighter posture during the gait. Understanding gait concatenations can update physiotherapy approaches to target the roots of movement problems instead of the consequences.

The Association of Fatigue With Decreasing Regularity of Locomotion During an Incremental Test in Trained and Untrained Healthy Adults

Fatigue is a key factor that affects human motion and modulates physiology, biochemistry, and performance. Prolonged cyclic human movements (locomotion primarily) are characterized by a regular pattern, and this extended activity can induce fatigue. However, the relationship between fatigue and regularity has not yet been extensively studied. Wearable sensor methodologies can be used to monitor regularity during standardized treadmill tests (e.g., the widely used Bruce test) and to verify the effects of fatigue on locomotion regularity. Our study on 50 healthy adults [27 males and 23 females; <40 years; five dropouts; and 22 trained (T) and 23 untrained (U) subjects] showed how locomotion regularity follows a parabolic profile during the incremental test, without exception. At the beginning of the trial, increased walking speed in the absence of fatigue is associated with increased regularity (regularity index, RI, a. u., null/unity value for aperiodic/periodic patterns) up until a peak value (RI = 0.909 after 13.8 min for T and RI = 0.915 after 13.4 min for U subjects; median values, n. s.) and which is then generally followed (after 2.8 and 2.5 min, respectively, for T/U, n. s.) by the walk-to-run transition (at 12.1 min for both T and U, n. s.). Regularity then decreases with increased speed/slope/fatigue. The effect of being trained was associated with significantly higher initial regularity [0.845 (T) vs 0.810 (U), p < 0.05 corrected], longer test endurance [23.0 min (T) vs 18.6 min (U)], and prolonged decay of locomotor regularity [8.6 min (T) vs 6.5 min (U)]. In conclusion, the monitoring of locomotion regularity can be applied to the Bruce test, resulting in a consistent time profile. There is evidence of a progressive decrease in regularity following the walk-to-run transition, and these features unveil significant differences among healthy trained and untrained adult subjects.

Exploring Potential Benefits of Accumulated Multicomponent-Training in Non-Active Older Adults: From Physical Fitness to Mental Health

The present study aimed to analyze the impact of a multicomponent training (MCT) program in a group of non-active older adults, comparing two different dose distributions. Twenty-four individuals, assigned to two groups, completed 15 weeks of MCT (2 days/week). The continuous group (CMCT; n = 14, 9 females; 71.07 ± 5.09 years) trained for 60 min/session in the morning. The accumulated group (AMCT; n = 10, 5 females; 72.70 ± 3.59 years) performed the same exercises, volume, and intensity, but the training was distributed twice per day (30 min in the morning; 30 more in the afternoon). Bonferroni post hoc comparisons revealed significant (p < 0.001) and similar large improvements in both groups in lower limb strength (five times sit-to-stand test: CMCT, 12.55 ± 2.83 vs. 9.44 ± 1.72 s; AMCT, 10.37 ± 2.35 vs. 7.46 ± 1.75 s). In addition, there were large gains in preferred walking speed and instrumental daily life activities, which were higher for CMCT and AMCT, respectively (in this order: 1.00 ± 0.18 vs. 1.44 ± 0.26 m/s and 1.09 ± 0.80 vs. 1.58 ± 0.18 m/s; 33.07 ± 2.88 vs. 36.57 ± 1.65 points and 32.80 ± 1.93 vs. 36.80 ± 0.92 points); improvements in cardiorespiratory fitness, now moderate for CMCT (474.14 ± 93.60 vs. 529.64 ± 82.76 m) and large for AMCT (515.10 ± 20.24 vs. 589.60 ± 40.38 m); and medium and similar enhancements in agility in both groups (TUG test: CMCT: 7.49 ± 1.11 vs. 6.77 ± 1.16 s; AMCT: 6.84 ± 1.01 vs. 6.18 ± 0.62 s). None of the protocols had an impact on the executive function, whereas health-related quality of life showed a trend to significance in the whole sample only (EQindex overall sample, p = 0.062; d = 0.48 CMCT; d = 0.34 AMCT). Regardless of the type of dose distribution, starting multicomponent training improves physical function in non-active older adults, but does not improve cognitive function at mid-term. Because both forms of MCT showed similar compliance, slightly positive differences in accumulated strategies may indicate some benefits related to breaking afternoon sedentary behaviors, which deserves further research in longer and larger interventions. The mixed nature of MCT suggests accumulative group interventions may be a promising approach to address sedentary aging.

Domain-Specific and Total Sedentary Behavior Associated with Gait Velocity in Older Adults: The Mediating Role of Physical Fitness

Although it has been well-documented that older adults spend a significant amount of time being sedentary and have slower gait velocity, little is known of how physical fitness mediates the association between them. The main purpose of this study was to explore whether objectively measured physical fitness mediates the association between domain-specific and total sedentary behavior and gait velocity. We recruited 120 older adults aged ≥ 60 years. Sedentary behavior was assessed by the Measure of Older Adults’ Sedentary Time questionnaire. We used a Zebris pressure platform to assess gait velocity. To assess the level of overall physical fitness, we summed the z-scores of seven tests: (1) waist circumference, (2) chair stand in 30 s, (3) arm curl in 30 s, (4) 2-min step test, (5) chair sit-and-reach test, (6) back scratch test, and (7) 8-foot up-and-go test. Overall physical fitness was obtained by summing up all physical test z-scores. Gait velocity was significantly associated with all domain-specific and total sedentary behavior (β = −0.04 to −0.35, p < 0.05). Overall physical fitness was significantly associated with all domain-specific and total sedentary behavior (β = −0.21 to −1.24, p < 0.001) and gait velocity (β = 0.23 to 0.24, p < 0.001). When physical fitness was put as the mediator, significant direct effects between sedentary behavior and gait velocity disappeared. Results indicate that physical fitness fully mediates the association between sedentary behavior and gait velocity in older adults.

Components of physical fitness as prognostic factors for falls in elderly female exercise practitioners: a longitudinal study

Abstract Introduction: Physical exercise is used as a strategy for the prevention of falls because it improves the physical fitness of older adults. Objective: To determine which components of physical fitness are predictors of falls in elderly female exercise practitioners. Method: Longitudinal, descriptive, comparative study. The components of physical fitness (upper and lower limb strength and flexibility, agility, aerobic endurance, and hand grip strength) and the occurrence or not of falls in the last 12 months were analyzed in 80 older women practitioners of exercise from 2013 to 2016. Descriptive analysis, ROC curve attributing cut-off points, and binary logistic regression for the prediction of falls were used. Results: The mean age of the participants was 67.46 years (SD=7.65). Over the years, a significant difference between elderly fallers and non-fallers was observed for right hand grip strength (2013 and 2015), left hand grip strength (2014 and 2015), lower limb flexibility (2013, 2014 and 2015), agility (2015), and aerobic endurance (2015). In adjusted analysis, older women with poor lower limb flexibility in 2013 had a higher risk of falls in 2016 (OR=4.98; 95%CI 1.12 - 22.1). Older women with poor flexibility in 2015 also had a higher risk of falls (OR= 6.08; 95%CI 1.06 - 34.67). Conclusion: Poor performance in the lower limb flexibility, right and left hand grip strength, agility and aerobic endurance tests was associated with falls and these components are predictors of future falls in elderly exercise practitioners.