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Comparing Knee Kinetics and Kinematics in Healthy Individuals and Those With Knee Osteoarthritis, With and Without Flat Feet

Maryam Sohrabi, Giti Torkaman, and Fariba Bahrami

Individuals with knee osteoarthritis (KOA) and flat feet are more likely to experience increased pain and cartilage damage. This study aimed to investigate the knee kinetics, kinematics, pain, and physical function in individuals with moderate symptomatic KOA, in comparison to asymptomatic control participants. Thirty volunteers with moderate KOA (with flat feet n = 15, with normal feet n = 15) and 30 asymptomatic people (with flat feet n = 15, with normal feet n = 15) were evaluated. The knee adduction angular impulse, knee flexion moment, knee flexion angular impulse, and knee flexion angle were measured during level walking. The pain was assessed in patients with KOA. The study found that individuals with KOA had a significant increase in the knee adduction angular impulse compared with the asymptomatic people (P < .05). The KOA with flat feet group had significantly lower knee flexion moment, knee flexion angular impulse, and knee flexion angle values than the KOA with normal feet group (P < .05). Furthermore, the KOA with flat feet group had a higher pain score than the KOA with normal feet group. Individuals with osteoarthritis and flat feet had lower knee flexion moments which may indicate reduced knee force exerted through compensatory mechanisms. Despite this reduction, they reported significantly higher levels of pain compared with those without flat feet, a finding that warrants further investigation in future studies.

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The Midfoot Joint Complex (Foot Arch) Contributes to the Upper Body Position in Bipedal Walking and Coordinates With the Lower Limb Joints

Leonardo D. Barsante, Paula M.M. Arantes, Daniela V. Vaz, Fabricio A. Magalhães, Diego S. Carvalho, Aline C. Cruz, Renan A. Resende, Juliana M. Ocarino, Sérgio T. Fonseca, and Thales R. Souza

This study estimated the contribution of the midfoot joint complex (MJC) kinematics to the pelvis anterior–posterior positions during the stance phase of walking and investigated whether the MJC is functionally coordinated with the lower limb joints to maintain similar pelvic positions across steps. Hip, knee, ankle, and MJC sagittal angles were measured in 11 nondisabled participants during walking. The joints’ contributions to pelvic positions were computed through equations derived from a link-segment model. Functional coordination across steps was identified when the MJC contribution to pelvic position varied and the summed contributions of other joints varied in the opposite direction (strong negative covariations [r ≤ −.7] in stance phase instants). We observed that the MJC plantarflexion (arch raising) during the midstance and late stance leads the pelvis backward, avoiding excessive forward displacement. The MJC was the second joint that contributed most to the pelvis positions (around 18% of all joints’ contributions), after the ankle joint. The MJC and ankle were the joints that were most frequently coordinated with the other joints (≅70% of the stance phase duration). The findings suggest that the MJC is part of the kinematic chain that determines pelvis positions during walking and is functionally coordinated with the lower limb joints.

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Dr Charles J. (Chuck) Dillman: A Remembrance

Robert Shapiro, Robert Gregor, and John Challis

In August 2023, the biomechanics community suffered a significant loss with the death of Dr Charles J. Dillman. His work in the area of sport biomechanics was groundbreaking. In this tribute, 10 former students and 9 former colleagues remember “Chuck” and his impact on their lives, careers, and the field of biomechanics.

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Early Maladaptive Schemas, Cognitive Fusion, and Anabolic-Androgenic Steroid Use Attitudes: The Mediating Role of Muscle Dysmorphia in Iran

Mehdi Ebrahimi, Zahra Zamani, and Ebrahim Bagheri

In recent decades, the interest in having an ideal body in men has caused a pathological tendency to be muscular, followed by a tendency to use anabolic-androgenic steroids (AASs). This study was designed to evaluate the mediating role of muscle dysmorphia in the relationship between early maladaptive schemas and body image-related cognitive fusion with the tendency to use AAS in male athletes. Out of the total number of men referring to fitness clubs in Isfahan, Iran, 474 men were evaluated using a multistage random cluster sampling method. The questionnaires used in this research included the Muscle Dysmorphic Disorder Inventory, Cognitive Fusion Questionnaire—Body Image, Young Schema Questionnaire—Short Form, and Prototype Willingness Model Questionnaire. The results demonstrated that the relationship of AAS use with body image-related cognitive fusion and the three maladaptive schemas with the mediation of muscle dysmorphia is significant. The present study provides significant implications in the discussion of prevention and treatment of AAS addiction.

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In Remembrance: The Life and Legacy of Michael T. Turvey (1942–2023)

Michael A. Riley and Dagmar Sternad

Michael T. Turvey passed away on August 12, 2023 at the age of 81. This obituary aims to honor his life and career by highlighting some key events in his personal and professional life, noting some of his many remarkable accomplishments, and emphasizing his exceptional mentorship, friendship, and generosity.

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The Role of Imitation, Primitives, and Spatial Referent Coordinates in Motor Control: Implications for Writing and Reading

Shelia Guberman and Mark L. Latash

We review a body of literature related to the drawing and recognition of geometrical two-dimensional linear drawings including letters. Handwritten letters are viewed not as two-dimensional geometrical objects but as one-dimensional trajectories of the tip of the implement. Handwritten letters are viewed as composed of a small set of kinematic primitives. Recognition of objects is mediated by processes of their creation (actual or imagined)—the imitation principle, a particular example of action–perception coupling. The concept of spatial directional field guiding the trajectories is introduced and linked to neuronal population vectors. Further, we link the kinematic description to the theory of control with spatial referent coordinates. This framework allows interpreting a number of experimental observations and clinical cases of agnosia. It also allows formulating predictions for new experimental studies of writing.

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Consistent Individual Tendencies in Motor Speed–Accuracy Trade-Off

Matheus M. Pacheco, Charley W. Lafe, Che-Hsiu Chen, and Tsung-Yu Hsieh

The literature on speed–accuracy trade-off (SAT) in motor control has evidenced individuality in how individuals trade moments (e.g., mean and variance) of spatial and temporal errors. These individual tendencies could grasp tendencies of the system given previous experiences and constraints of the organism, a signature of the system control. Nonetheless, such tendency must be robust to small perturbations. Thirty participants performed nine conditions with different time and spatial criteria over 2 days (scanning). In between these scanning conditions, individuals performed a practice condition that required modifications of the individuals’ preferred spatial and temporal tendency in the SAT. Our results demonstrated that there were no systematic effects of practice in SAT preferences. However, individual analyses demonstrated significant changes for 25 out of 30 individuals. The latter either attests against a consistent preference or to a more complex characterization of individual SAT tendencies.

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Examining the Feasibility of a Mindfulness Flow Program for the Hong Kong Archers

Ka K. Lo, Mimi M.Y. Tse, Joanne W.Y. Chung, Queenie P.S. Law, and Fenghua Sun

Mindfulness-based interventions have gained popularity among elite athletes, but their effectiveness in enhancing archery performance has been inconsistent. This study examined the feasibility of a 12-week mindfulness flow program (MFP) specifically designed for the archers and assessed the effect of the MFP on shooting performance. Twelve members of the Hong Kong Archery Team voluntarily participated in the present study. Their shooting performance, anxiety, mindfulness, and flow state were assessed before and after the MFP intervention. The results showed that the MFP was highly feasible, with 100% attendance. The athletes highly enjoyed the MFP sessions (mean rating: 7.9/10). Improved shooting performance, increased mindfulness, and flow state levels, and reduced anxiety were also observed after the intervention. These findings suggest a positive reception from and potential benefits for athletes. However, it is suggested to conduct additional research using randomized controlled trials to explore the program’s effects and applicability in enhancing sports performance.

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Comparison of Concurrent and Asynchronous Running Kinematics and Kinetics From Marker-Based and Markerless Motion Capture Under Varying Clothing Conditions

Robert M. Kanko, Jereme B. Outerleys, Elise K. Laende, W. Scott Selbie, and Kevin J. Deluzio

As markerless motion capture is increasingly used to measure 3-dimensional human pose, it is important to understand how markerless results can be interpreted alongside historical marker-based data and how they are impacted by clothing. We compared concurrent running kinematics and kinetics between marker-based and markerless motion capture, and between 2 markerless clothing conditions. Thirty adults ran on an instrumented treadmill wearing motion capture clothing while concurrent marker-based and markerless data were recorded, and ran a second time wearing athletic clothing (shorts and t-shirt) while markerless data were recorded. Differences calculated between the concurrent signals from both systems, and also between each participant’s mean signals from both asynchronous clothing conditions were summarized across all participants using root mean square differences. Most kinematic and kinetic signals were visually consistent between systems and markerless clothing conditions. Between systems, joint center positions differed by 3 cm or less, sagittal plane joint angles differed by 5° or less, and frontal and transverse plane angles differed by 5° to 10°. Joint moments differed by 0.3 N·m/kg or less between systems. Differences were sensitive to segment coordinate system definitions, highlighting the effects of these definitions when comparing against historical data or other motion capture modalities.

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Physical Activity and Engagement Coping: A Key for Stress-Recovery in Mexican University Students

Erick-Yael Fernández-Barradas, María-Luisa Marván-Garduño, Tamara Cibrián-Llanderal, Felipe Reynoso-Sánchez, and Socorro Herrera-Meza

Physical activity and coping styles are factors that contribute to health status and to the reduction of stress. The aim of this research was to analyze the influence of physical activity and coping styles on recovery-stress state among Regular Physical Activity University Students (n = 67) and High-Performance University Athletes (n = 67) from a Mexican university. The results show statistically significant differences in the capacity of recovery from stress in High-Performance University Athletes. Additionally, two positive correlations emerged: one of engagement coping and recovery, and one of disengagement coping and stress. The interaction between engagement coping and physical activity predicted general well-being. In females, the engagement coping style predicts recovery from stress. We concluded that physical activity in combination with an engagement coping style contributes to the development of health in university students.