Emmanuel Souza da Rocha

The force–velocity relationship, originally described by Hill (1938), is a foundational concept in muscle physiology and biomechanics. Despite its theoretical relevance, its instructional application remains limited in educational settings without laboratory infrastructure. Here, we present a low-cost strategy for teaching the force–velocity relationship using accessible materials and commonly available software. The procedure was implemented in a regular classroom environment and involved estimating velocity from the number of repetitions performed with different loads over a fixed time interval. Classroom-derived data were used to construct force–velocity and power–velocity curves, with the objective of illustrating expected biomechanical patterns, without evaluating learning outcomes. The activity emphasized biomechanical reasoning and graphical interpretation, incorporating simplified measurement tools as part of the instructional process. The strategy is adaptable to resource-limited contexts and may be extended to other biomechanics topics that require the operationalization of theoretical relationships.

This study compares early mobilization and plaster cast rehabilitation after Achilles tendon rupture, with surgeries performed by a single surgeon. We demonstrate that long-term structural and functional deficits persist 2 yr after Achilles tendon rupture, regardless of rehabilitation type. With a computational model, we investigated the mechanisms underlying heel-rise deficits, quantifying structural contributions. Including a healthy control group revealed that the uninjured side also shows impairments, calling into question its use as a reference in clinical and research settings.

Introduction: The global rise in electronic cigarette (e-cigarette) use has raised concerns due to limited evidence regarding its impact on respiratory health. Objective: To evaluate and compare pulmonary function among e-cigarette users, tobacco smokers, and non-smokers aged 18 to 40 years. Methods: In this cross-sectional study, 45 participants were allocated into three groups: non-smokers (control), tobacco smokers, and e-cigarette users. All participants underwent spirometry testing. Inclusion criteria required a minimum of one year of consistent smoking or vaping. Individuals with less than three months of exposure, bronchodilator use, or inability to perform the test were excluded. Results: The mean age was 25.47 ± 3.93 years for the control group, 23.2 ± 3.3 years for tobacco smokers, and 21.53 ± 3.27 years for e-cigarette users. Dyspnea and wheezing were more frequently reported by tobacco smokers, while cough and wheezing predominated among e-cigarette users. Spirometric analysis revealed no significant differences in forced vital capacity (FVC) among groups. However, e-cigarette users exhibited significantly lower forced expiratory volume in one second (FEV1) and FEV1/FVC ratio compared to non-smokers, and lower FEV1/FVC compared to tobacco smokers, indicating early signs of airflow obstruction. Conclusion: Despite similar FVC values, e-cigarette users demonstrated reduced expiratory performance, as evidenced by lower FEV1 and FEV1/FVC ratio. These findings suggest that e-cigarette use may be associated with early functional impairment of pulmonary function, potentially exceeding the impact observed in conventional tobacco smokers.

Patellofemoral pain (PFP) is a common, multifactorial musculoskeletal condition that primarily affects young and physically active adults. Although previous studies have emphasized proximal and local impairments, the contribution of distal joint biomechanics remains unclear. This systematic review and meta‐analysis aimed to determine whether biomechanical and clinical parameters of the foot and ankle differ between individuals with and without PFP. A systematic search was conducted in PubMed, ScienceDirect, SciELO, and SPORTDiscus. Studies comparing adults with and without PFP in distal joint outcomes, including muscle strength, kinematics, range of motion (ROM), plantar pressure, and clinical measures (e.g., navicular drop and foot mobility), were included. Methodological quality was assessed using a modified Downs and Black scale. Random‐effects meta‐analyses were performed using Hedges’ g, and the level of evidence for each outcome was classified according to predefined criteria based on methodological quality, statistical significance, and between‐study heterogeneity. Forty‐two studies were included in the systematic review, and 38 were included in the meta‐analysis, comprising 2314 participants (PFP: n = 1211; controls: n = 1103). Individuals with PFP demonstrated greater navicular drop (SMD = −0.46; p = 0.004), supported by strong evidence, although this finding was based on only four studies (PFP: n = 84; controls: n = 84). Greater rearfoot eversion during landing and step‐down tasks, as well as greater ankle dorsiflexion during the step‐down task, were also observed; however, these findings were supported by very limited evidence. No significant between‐group differences were identified for ankle dorsiflexion ROM measured in clinical tests, foot posture index scores, or plantar pressure distribution. Overall, altered distal biomechanics, particularly greater navicular drop, appear to be associated with PFP. However, the available evidence remains limited for most outcomes, and the predominantly case–control design of the included studies precludes causal inference.

BACKGROUND: Plantar pressure provides useful information for the study of locomotion. Such measure is often conducted based on average of different number of steps. Previous studies are not clear regarding the minimum number of observations to reduce group variability in determination of peak pressures, especially when comparing people in different age groups. AIM: To determine the minimum number of steps required to determine peak pressure in different regions of the foot during the gait of people from different age groups. METHODS: Children (n=12), adults (n=13) and older adults (n=12) underwent measurements of plantar pressure using a Matscan pressure mapping system for two days, while walking barefoot at their preferred gait speed. Peak pressure was determined for 10 steps in each of the days of assessment and analyzed considering foot regions of rearfoot, midfoot and forefoot. Peak pressure variability was determined considering data from two to ten steps. RESULTS: Four steps measurements showed the lower variability in peak pressure in participants from different age groups. Although variability in rearfoot showed to be higher, the minimal number of steps we determined was useful to determine peak pressure across the different regions of the foot. INTERPRETATION: The determination of peak pressure in assessment of gait in able bodied participants from different age groups can consider data recorded from four steps.

Although the Collaborative Online International Learning (COIL) methodology is expanding, its use in physiology is still scarce. Our example COIL project of 7 weeks developed a sports-assessment service concept focused on physiology and biomechanics assessments. The program involved teams from Brazil, Germany, and Spain, comprising undergraduate and master’s students. Students perceived extracurricular activities in this format as beneficial. Coaches also expressed positive views about such initiatives, noting benefits for students and their development.