Background: Resistance training is commonly used to prevent the decline in muscle power associated with aging. Objective: This study aims to evaluate the effectiveness of iso-inertial (IN) training on power, physical performance, and variables associated with the risk of falls, compared to gravitational (GR) training, in physically active middle-older adults. Methods: A parallel-group, randomized controlled trial was conducted at Espai Esport Wellness Center (Granollers, Spain). In total, 44 physically active adults (age >57) were randomized 1:1 to either the IN (n=21) or GR (n=23) training groups (using R software; R Core Team). Participants completed a 6-week training program (2 sessions/week) consisting of 3 exercises (forward lunge, side lunge, and forward lunge with row). The primary outcome includes power in the eccentric phase of each exercise, evaluated using both IN and GR devices. Secondary outcomes include concentric power, physical performance, and variables associated with the risk of falls. Only outcome evaluators were blinded. We used multivariate linear regression models for the analysis. Results: In total, 27 participants completed the program (IN: n=15 IN; GR: n=12). IN training resulted in better eccentric power gains compared to GR training when assessed using the IN system, although the difference was only statistically significant for the side lunge. For forward lunge, between-group difference was 4.50 W (95% CI −2.94 to 11.94 W, P=.23); for side lunge, between-group difference was 9.24 W (95% CI 2.99-15.49 W; P<.01); and for forward lunge with row, between-group difference was 15.25 W (95% CI −0.63 to 31.13 W; P=.06). We observed no significant differences for the eccentric power using the GR system evaluation, concentric power, physical performance, and variables associated with the risk of falls. Both groups showed significant improvements from baseline across all outcomes. Conclusions: Although IN training appeared to result in greater power gains during the eccentric phase when assessed with the IN system, statistically significant differences were observed only for the side lunge exercise. Both training systems seemed equally effective in improving eccentric power as evaluated with the GR system, concentric power, physical performance, and reducing variables associated with the risk of falls.

To identify the optimal distances to accelerate and decelerate in the 4-meter (4mWT) and 6-meter (6mWT) walking tests at comfortable and fast pace in people with stroke. A cross-sectional study was conducted with 49 individuals (median age 59.45 years). Participants completed three repetitions of each walk test (4mWT and 6mWT) at comfortable and fast pace. Data were collected using an OptiTrack motion capture system (8-camera). Acceleration and deceleration distances were defined as the distances required to reach and reduce from average walking speed, respectively. For the 4mWT, the optimal acceleration and deceleration distances were 1.12-m and 1.17-m at a comfortable pace, and 1.48-m and 1.50-m at a fast pace. For the 6mWT, they were 1.37-m and 1.88-m at a comfortable pace, and 1.89-m and 2.39-m at a fast pace. It is recommended to include 1.2-m at a comfortable or 1.5-m at a fast pace for acceleration and deceleration in the 4mWT and 2-m for acceleration at both comfortable and fast pace, 2-m for deceleration at a comfortable pace and 2.5-m for deceleration at fast pace in the 6mWT. Incorporating these distances may enhance the validity and comparability of walking speed assessments in stroke populations. Clinicaltrials.gov NCT0567901.

Background/Objectives: Eccentric loading during landing is considered a key factor in the development of patellar tendinopathy and is associated with stiff landings and patellar tendinopathy. This study aims to investigate the relationship between tendon structure, presence of pain, and sex differences in landing kinematics and kinetics during countermovement jumps (CMJ) and tuck jump tests (TJT) in professional volleyball players. Methods: Professional volleyball players aged 18 to 30 years old (14 females and 25 males) participated in a cross-sectional study. Data included the Victorian Institute of Sport Assessment Patellar Tendon (VISA-P) questionnaire; patellar tendon ultrasound characterization tissue (UTC) scans, in order to identify groups with misaligned tendon fibers (MTF) or aligned tendon fibers (ATF); and biomechanical assessments for CMJ and TJT. The joint angle (JA) at the lower limb was measured at peak ground reaction force (peak_vGRF) and maximal knee flexion (max_KF). A general linear model was used to evaluate joint JA differences between tendon alignment, pain, and sex variables. Sample t-tests compared peak_vGRF, load time, load rate, and area based on tendon alignment, pain presence, sex, and jump. The statistical significance of p-value is >0.05, and the effect size (ES) was also calculated. Results: The MTF group revealed decreased knee JA during TJT at peak_vGRF (p = 0.01; ES = −0.66) and max_KF (p = 0.02; ES = −0.23). The presence of pain was associated with increased JA during the CMJ, particularly at peak_vGRF and max_KF for trunk, hip, and ankle joints. Females showed decreased peak_vGRF than males. Landing with misaligned tendon fibers showed longer load times compared to aligned tendon fibers (p = 0.021; ES = −0.80). The TJT exhibited a greater load rate than the CMJ (p = 0.00; ES = −0.62). Conclusions: Pain is a critical factor influencing greater JA during landing, particularly at the trunk, hip, and ankle joints in CMJ. Misaligned tendon fibers compromise landing dynamics by increasing trunk JA during TJT. Kinetics varied significantly by sex and jump type, while pain and tendon structure revealed limited differences.

Objective To evaluate the effectiveness of iso-inertial resistance training on eccentric power compared to gravitational training in physically active middle-older adults. Methods Parallel-group, randomised controlled trial at Espai Esport Wellness Center (Granollers, Spain). Forty-four physically active adults (>57 years of age) were randomised to iso-inertial (n=21) or gravitational (n=23) training groups (R software; 1:1 ratio). Participants had to complete a 6-week training program (2 sessions/week) consisting of three exercises (forward lunge, side lunge, forward lunge with row). Primary outcome: power in the eccentric phase of each exercise evaluated with both iso-inertial and gravitational devices. Secondary outcomes: concentric power, physical performance, risk of falls. Only outcome evaluators were blinded. We used multivariate linear regression models to analyse the effect of interventions. Results Iso-inertial training showed better eccentric power gains than gravitational training for iso-inertial system evaluation, although the difference was only statistically significant for the side lunge. Forward lunge: between-group difference 3.99 W (95% CI: -3.99 to 11.33, p: 0.28); side lunge: difference 8.50 W (95% CI: 2.13 to 14.87; p: 0.01); forward lunge with row: difference 14.07 W (95% CI: -2.07 -to 30.20, p: 0.09). We observed no differences for the gravitational system evaluation nor for concentric power, physical performance, and risk of falls. The two groups improved remarkably from baseline for all outcomes. Conclusions Iso-inertial resistance training might lead to better eccentric power gains than gravitational training. Both approaches seem equally effective in improving concentric power and physical performance, and reducing the risk of falls. Trial registration ClinicalTrials.gov (NCT06160089). WHAT IS ALREADY KNOWN ON THIS TOPIC - Physical exercise in middle-older adults is an effective strategy to promote health and improve quality of life. - Resistance training using iso-inertial devices generates an advantage in hypertrophy, electromyographic activity or balance compared to cable-resistance training in middle-older adults. - The power at which an action is performed is considered a predictor of functional capacity, as it is associated with the execution of activities of daily living such as climbing stairs, getting up from a chair or walking. WHAT THIS STUDY ADDS - The iso-inertial training system improves muscle power in the eccentric phase compared to the gravitational system, although the difference is only statistically significant for the side lunge exercise. - Iso-inertial and gravitational resistance training are equally effective in improving concentric power, and physical performance and reducing the risk of falls. - Using iso-inertial devices is recommended to evaluate power in the eccentric phase, as they may capture better the eccentric demands than gravitational devices. HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY - Using iso-inertial devices for resistance training in middle-older adults seems a promising way to improve the power in the eccentric phase of an action. - Improving eccentric power in older adults is crucial due to its transfer to daily life activities. - Regardless of the training system, clinicians should prescribe resistance training programs to middle-older adults as these programs remarkably increase power and physical performance and reduce the risk of falls.