(1) Background: The objective of this study was to determine physical and biomechanical changes in age groups upon running. (2) Method: 75 male adults (20–80s) participated in the study. Bone mineral density and lower extremity joint strength were measured according to age-increase targeting. Based on age, correlations among running characteristics, impulse, impact force, maximum vertical ground reaction force, loading rate, lower extremity joint 3D range of motion, joint moment, and power upon running motion were calculated. (3) Result: Older runners tended to show lower bone mineral density, extremity maximum strength, stride time, and stride distance, with smaller RoM and joint power of ankle and knee joints in the sagittal plane, compared with younger subjects. However, there were no significant correlations between age and impact variables (i.e., impulse, impact force, peak GRF, and loading rate) during running. (4) Conclusion: Older runners tend to show weaker physical strength characteristics, such as bone mineral density and muscle strength and lower joint functionality of ankle and knee joints during running, compared with younger runners. Therefore, strengthening the lower extremity muscle and improving dynamic joint function, especially for ankle joints, can be helpful for injury prevention during running.

This study was aimed at verifying the efficacy of EMS training by investigating the changes in upper-limb muscle functions and energy expenditure in athletes with disabilities after an 8-week intervention of EMS training. We compared variations in muscle activity, respiratory gas, and symmetry index (SI) after an 8-week intervention in eight professional male athletes with disabilities wearing an electromyostimulation (EMS) suit (age: 42.00 ± 8.67 years, height: 1.65 ± 0.16 m, weight: 64.00 ± 8.72 kg, career length: 11.75 ± 3.83 years). For EMS training, each participant wore an EMS suit. EMS was applied to the upper-limb muscles pectoralis major and triceps at 40 °C water temperature, with a 25 Hz frequency (duty cycle 10%) for 15 min, followed by a 5 Hz frequency (duty cycle 5%) for 5 min. The pre- and post-intervention measurements were taken in the same way at a pre-set time (for 1 h, twice a week) for 8 weeks. Training involved a seated chest press, and the muscle activity (pectoralis major, triceps, and antebrachial muscles), upper-limb SI, and respiratory gas variables (maximal oxygen consumption (VO₂), carbon dioxide output (VCO₂), respiratory quotient (RQ), metabolic equivalents (METs), and energy expenditure per min (Energy expended per minute; EEm)) were analyzed. Variations pre- and post-intervention across the measured variables were analyzed. Regarding the change in muscle activity, significant variations were found in the pectoralis major right (p < 0.004), pectoralis major left (p < 0.001), triceps right (p < 0.002), and antebrachial right (p < 0.001). Regarding left-to-right SI, a positive change was detected in the pectoralis major and triceps muscles. Additionally, respiratory gas analysis indicated significant variations in VO₂ (p < 0.001), VCO₂ (p < 0.001), METs (p < 0.001), and EEm (p < 0.001). EMS training improved muscle strength and respiratory gas variables and is predicted to contribute to enhanced muscle function and rehabilitation training for athletes with disabilities.

Background/Objectives: The study explored differences in gait characteristics and biomechanics according to rehabilitation aid use (normal gait (NG) vs. assisted gait (AG) groups) and obstacle height (0, 5, and 15 cm conditions) in patients with stroke-induced foot drop. Methods: A longitudinal study, within-subjects, repeated-measures study was conducted in 10 patients with mild foot drop. Participants walked at their preferred speed on a 10-m indoor track while crossing obstacles of three heights (0, 5, and 15 cm) under two gait conditions (normal walking (NG) and assisted walking (AG). The order of gait conditions and obstacle heights was randomized clinical within participants. Synchronized 3D motion capture with force plate measurements was used to calculate spatiotemporal variables, including ground reaction force (GRF), lower extremity joint angles at heel contact (HC), and toe-off (TO). A two-way repeated-measures ANOVA was used to examine the main effects and interaction effects of gait condition (NG vs. AG) and obstacle height (0, 5, and 15 cm). Results: AG showed little change in gait pattern, while there was a significant interaction between height and group. The vertical GRF (Fz) was lower in AG than NG at 5 cm, indicating reduced initial impact. There was a significant interaction for right medial–lateral (ML) GRF, with AG showing a small ML directional GRF over low obstacles (0–5 cm). At HC, AG was associated with an increase in right ankle dorsiflexion and right knee flexion. AG led to a reduction in left hip angle in the sagittal plane, and a smaller right ankle angle in the frontal plane, suppressing ML sway. At TO, AG caused an increase in right knee flexion, and bilateral ankle angles in the frontal plane at 5 cm. Conclusions: Rehabilitation aids reduced impact at initial contact, enhanced frontal plane stability, improved knee flexion and ankle alignment during the propulsion transition phase, and contributed to reduced variability and improved gait stability. The findings suggest potential utility for public health implications ambulation over curbs and thresholds, warranting larger, adequately powered clinical outcome trials.

Introduction: Early mild cognitive impairment (eMCI) is often accompanied by subtle alterations in motor function and gait control before the onset of overt dementia. Identifying these early functional changes may provide useful information for early detection and intervention. This study compared motor performance, balance, gait characteristics, and lower-limb kinematics between older women with eMCI and cognitively healthy controls. Methods: Thirty-four community-dwelling older women participated in this exploratory pilot study, including 17 women with eMCI and 17 age-matched healthy controls. Body composition was assessed using a bioelectrical impedance analyzer. Physical fitness was evaluated using the Senior Fitness Test, including grip strength, the 30-second Chair Stand Test, and the Figure-of-Eight Walk Test. Static balance was assessed using center-of-pressure variables, and gait characteristics and lower-limb kinematics were measured using a three-dimensional gait analysis system at a standardized walking speed of 1.0 m/s. Group differences were analyzed using the Mann-Whitney U -test, and effect sizes were calculated. Results: No significant between-group differences were observed in body composition or grip strength ( p > 0.05). However, the eMCI group demonstrated significantly lower performance in the 30-second Chair Stand Test ( p < 0.001). In balance assessment, total center-of-pressure path length was significantly greater, whereas sway velocity was significantly lower in the eMCI group ( p < 0.05). In gait analysis, stride length, gait cycle time, and double-limb support time were significantly greater in the eMCI group ( p < 0.001). Furthermore, women with eMCI exhibited reduced right knee joint range of motion in the frontal and transverse planes and lower right hip angular velocity in the frontal plane ( p < 0.05). Discussion: Older women with early mild cognitive impairment exhibited subtle but meaningful impairments in lower-limb strength, postural control, gait performance, and joint-level motor control despite relatively preserved body composition and basic gait ability. These findings suggest that detailed balance and gait-related kinematic variables may serve as sensitive indicators of early motor-control alterations associated with cognitive decline and may contribute to the development of early screening and intervention strategies.