Asymmetric running is associated with pain during outdoor running in individuals with Achilles tendinopathy in the return-to-sport phase.

OBJECTIVES: To determine the relationships between (1) Achilles tendon pain and loading symmetry, and (2) number of running bouts and symptom severity, during two weeks of outdoor running in individuals with Achilles tendinopathy. DESIGN: Prospective, observational study. SETTING: Biomechanics laboratory and outdoors. PARTICIPANTS: Seventeen runners with Achilles tendinopathy in the return-to-sport phase of rehabilitation. MAIN OUTCOME MEASURES: Symptom severity was recorded with the Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire. Running bouts and Achilles tendon pain during runs were recorded with daily training logs. Ground contact time was collected during runs with wearable sensors. Linear mixed modeling determined if the relationship between Achilles tendon pain and ground contact time symmetry during running was moderated by consecutive run days. Multiple regression determined the relationship between number of running bouts and change in VISA-A scores over two weeks, adjusted for run distance. RESULTS: Greater ground contact time on the contralateral leg corresponded to increased ipsilateral tendon pain for each consecutive run day (b = -0.028, p < 0.001). Number of running bouts was not associated with 2-week changes in VISA-A scores (p = 0.672). CONCLUSIONS: Pain during running is associated with injured leg off-loading patterns, and this relationship strengthened with greater number of consecutive run days. Number of running bouts was not related to short-term symptom severity.

Gait Alterations and Association With Worsening Knee Pain and Physical Function: A Machine Learning Approach With Wearable Sensors in the Multicenter Osteoarthritis Study.

OBJECTIVE: The objective of this study was to identify gait alterations related to worsening knee pain and worsening physical function, using machine learning approaches applied to wearable sensor-derived data from a large observational cohort. METHODS: Participants in the Multicenter Osteoarthritis Study (MOST) completed a 20-m walk test wearing inertial sensors on their lower back and ankles. Parameters describing spatiotemporal features of gait were extracted from these data. We used an ensemble machine learning technique ("super learning") to optimally discriminate between those with and without worsening physical function and, separately, those with and without worsening pain over two years. We then used log-binomial regression to evaluate associations of the top 10 influential variables selected with super learning with each outcome. We also assessed whether the relation of altered gait with worsening function was mediated by changes in pain. RESULTS: Of 2,324 participants, 29% and 24% had worsening knee pain and function over two years, respectively. From the super learner, several gait parameters were found to be influential for worsening pain and for worsening function. After adjusting for confounders, greater gait asymmetry, longer average step length, and lower dominant frequency were associated with worsening pain, and lower cadence was associated with worsening function. Worsening pain partially mediated the association of cadence with function. CONCLUSION: We identified gait alterations associated with worsening knee pain and those associated with worsening physical function. These alterations could be assessed with wearable sensors in clinical settings. Further research should determine whether they might be therapeutic targets to prevent worsening pain and worsening function.

Recovery and trauma among urban African Americans with serious mental illness.

OBJECTIVE: Traumatic experiences are prevalent among people with serious mental illness and can significantly worsen outcomes. This study aimed to identify an urban cluster of trauma types, compare continuous distress ratings versus categorical experience of trauma for predicting outcomes such as depression and quality of life, and investigate the mediating role of recovery orientation in the impact of trauma exposure on outcomes. METHOD: Data came from an intervention study on African Americans with serious mental illness living in a large urban area; 212 participants completed baseline self-report measures of past trauma experiences, related distress levels, recovery, depression, and quality of life. Data were assessed using correlations and regressive path modeling. RESULTS: Overall, 56.6% of participants reported experiences with trauma. Analyses suggested an urban cluster of trauma types that was self-reported by over 25% of participants. Distress due to trauma strongly correlated with greater depression as well as reduced quality of life and recovery. Interestingly, the categorical presence of trauma history (yes/no) had no significant relationship with any outcomes. Path analyses revealed that recovery mediated the impact of trauma distress on depression and quality of life, specifically implicating the recovery subfactor of hope. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: Results suggested that cognitive reframing focused on positive appraisals of overall recovery, and the hope subfactor can have a positive influence on trauma outcomes. The study supported the role of recovery in posttraumatic growth and suggests that hope can be used to help patients process trauma healthily. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Family-centered decision making: A culturally responsive collaborative approach among Asians living in the United States.

OBJECTIVE: Compared to Western cultures, self-determination needs are expressed and pursued differently in Asian cultures, where interdependence and achieving greater good for the group are prioritized. To accommodate these needs, we propose the use of family-centered decision making (FCDM) to complement the shared decision-making (SDM) practice, fostering collaborative psychiatric care for Asian individuals residing in the United States. METHOD: This article synthesizes various literature to outline the similarities and differences between SDM and FCDM, discuss implementation steps, challenges associated with implementation, potential solutions, and future research considerations. RESULTS: Our review suggests that FCDM is more responsive to and inclusive of Asian cultural experience, better reflecting these cultures' expression of self-determination. We propose a five-step framework for FCDM implementation in psychiatric rehabilitation for Asian and Asian American individuals, while identifying three further practical considerations: logistical difficulties, intrafamilial differences, and making the decision to use FCDM or not. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: Given the heterogeneity of Asian individuals in the United States, we urge providers to allow flexibility in practicing FCDM. We outline the important components for providers to help individuals with psychiatric disabilities distinguish between the characteristics of FCDM and SDM, evaluate the potential pros and cons of utilizing FCDM, and then initiate FCDM if appropriate or requested by the individuals. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Reducing Stigma Toward People with Serious Mental Illness Through a Virtual Reality Intervention: A Randomized Controlled Trial.

Background: Stigma toward people with serious mental illnesses (SMI), like schizophrenia, is a serious global public health challenge that limits the quality of life of those affected and poses a major barrier that keeps people from seeking professional help. There is an urgent need for novel, effective, and scalable interventions to decrease stigmatized perceptions of chronic psychotic disorders and to reduce the health burden imposed by them. Method: We conducted a randomized controlled trial to assess the impact of a new immersive virtual reality game (Inclúyete-VR) on the level of stigma toward people with SMI, measured by the Attribution questionnaire (AQ-27). Participants in the experimental group were exposed in an immersive way to hallucinations common in schizophrenia, then shown different psychosocial resources available for their recovery and social inclusion; those in the control group used VR software unrelated to mental health. VR sessions were delivered through Oculus headgear and lasted 25 minutes. Results: We randomly assigned 124 university students (55% female) to experimental or control conditions (n = 62 each). We used mixed ANOVA to compare outcomes before and after the intervention between the two groups. We found a significant intervention-by-time interaction (P < 0.001), with a reduction in the experimental group of overall stigma levels on the AQ-27 scale and its three subscales: dangerousness-fear, avoidance, and lack of solidarity (P < 0.001 for all). Conclusions: The Inclúyete-VR software proved effective in the short term in reducing stigma toward people with severe mental illness. The program's longer-term efficacy, scalability, and dissemination remain to be studied. ClinicalTrials.gov Identifier: NCT05393596.

Introduction to the special section on community-based participatory research (CBPR) and recovery.

Voices of people with lived experience led to a recovery-based revolution in rehabilitation practices and principles. Hence, these same voices must be included as partners in the research enterprise meant to evaluate ongoing developments in this area. Community-based participatory research (CBPR) is the one way to do this. CBPR is not really new to the rehabilitation arena; Rogers and Palmer-Erbs highlighted the paradigm shift in rehabilitation research calling for participatory action research (PAR). PAR is action-oriented and rooted in partnerships between people with lived experience, service providers, and intervention researchers. This special section briefly highlights important topics that highlight the continued need for CBPR in our research enterprise. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The power of community-based participatory research (CBPR).

OBJECTIVE: Community-based participatory research (CBPR) is based on power as fundamental to doing research. It evolved as a way of "knowing" from the broader idea of natural science. While previously viewed as objective, natural science is now understood as, at least, partially socially constructed. METHOD: History of research and epistemology is reviewed in terms of science. More specifically, we delve into science as social construction and how this conceptually opens the door to considering power in its processes. We then unpack CBPR as one way to do mental health research that artfully weaves power into method. RESULTS: Natural science has evolved from believing scientism (i.e., the scientific method) is sufficient to describe physical and social phenomena to terms of social constructivism; namely, the social processes that impact investigators are necessary to understand science and its product. This highlights the role of power; namely, investigator choices about hypotheses, methods, analyses, and interpretations influence the products of individual studies. The recovery movement is the embodiment of power that significantly changed research and rehabilitation in mental health. CBPR has emerged to include people with lived experience in the research enterprise. CBPR is partnership among people with lived experience, health scientists, and service providers in all facets of doing research. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: Integrating CBPR into rehabilitation science has led to findings and actions that better serve community objectives. Continuing to weave CBPR into research and development will further enhance recovery in practice. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Understanding Peerness in Recovery-Oriented Mental Health Care.

Emotional and interpersonal support systems are fundamental to recovery-oriented support programs. Peerness represents the quality of shared lived experience that enhances such support programs. Through peerness, providers of formal peer support (FPS) strategically disclose their lived experience to help service recipients reach their goals. FPS disclosure is limited compared with the kind of free sharing in mutual support programs, with FPS focusing on information that specifically helps service recipients on their recovery journey. Peerness has additional value for shared experiences relevant for diversity, equity, and inclusion efforts. This Open Forum also considers where peerness conceptually fits into research of recovery-based services.

Association of tibial acceleration during walking to pain and impact loading in adults with knee osteoarthritis.

BACKGROUND: Higher impact loading during walking is implicated in the pathogenesis of knee osteoarthritis. Accelerometry enables the measurement of peak tibial acceleration outside the laboratory. We characterized the relations of peak tibial acceleration to knee pain and impact loading during walking in adults with knee osteoarthritis. METHODS: Adults with knee osteoarthritis reported knee pain then walked at a self-selected speed on an instrumented treadmill for 3 min with an ankle-worn inertial measurement unit. Ground reaction forces and tibial acceleration data were sampled for 1 min. Vertical impact peaks, and average and peak instantaneous load rates were determined and averaged across 10 steps. Peak tibial acceleration was extracted for all steps and averaged. Pearson's correlations and multiple linear regression analyses assessed the relation of peak tibial acceleration to pain and impact loading metrics, independently and after controlling for gait speed and pain. FINDINGS: Higher peak tibial acceleration was associated with worse knee pain (r = 0.39; p = 0.01), and higher vertical average (r = 0.40; p = 0.01) and instantaneous (r = 0.46; p = 0.004) load rates. After adjusting for gait speed and pain, peak tibial acceleration was a significant predictor of vertical average (R2 = 0.33; p = 0.003) and instantaneous (R2 = 0.28; p = 0.02) load rates, but not strongly associated with vertical impact peak. INTERPRETATIONS: Peak tibial acceleration during walking is associated with knee pain and vertical load rates in those with knee osteoarthritis. Clinicians can easily access measures of peak tibial acceleration with wearable sensors equipped with accelerometers. Future work should determine the feasibility of improving patient outcomes by using peak tibial acceleration to inform clinical management.

Computational investigation on lipid bilayer disruption induced by amphiphilic Janus nanoparticles: combined effect of Janus balance and charged lipid concentration.

Janus nanoparticles (NPs) with charged/hydrophobic compartments have garnered attention for their potential antimicrobial activity. These NPs have been shown to disrupt lipid bilayers in experimental studies, yet the underlying mechanisms of this disruption at the particle-membrane interface remain unclear. To address this knowledge gap, the present study conducts a computational investigation to systematically examine the disruption of lipid bilayers induced by amphiphilic Janus NPs. The focus of this study is on the combined effects of the hydrophobicity of the Janus NP, referred to as the Janus balance, defined as the ratio of hydrophilic to hydrophobic surface coverage, and the concentration of charged phospholipids on the interactions between Janus NPs and lipid bilayers. Computational simulations were conducted using a coarse-grained molecular dynamics (MD) approach. The results of these MD simulations reveal that while the area change of the bilayer increases monotonically with the Janus balance, the effect of charged lipid concentration in the membrane is not easy to be predicted. Specifically, it was found that the concentration of negatively charged lipids is directly proportional to the intensity of membrane disruption. Conversely, positively charged lipids have a negligible effect on membrane defects. This study provides molecular insights into the significant role of Janus balance in the disruption of lipid bilayers by Janus NPs and supports the selectivity of Janus NPs for negatively charged lipid membranes. Furthermore, the anisotropic properties of Janus NPs were found to play a crucial role in their ability to disrupt the membrane via the combination of hydrophobic and electrostatic interactions. This finding is validated by testing the current Janus NP design on a bacterial membrane-mimicking model. This computational study may serve as a foundation for further studies aimed at optimizing the properties of Janus NPs for specific antimicrobial applications.

Weight Self-Efficacy and Recovery Among African-Americans With Serious Mental Illness and High Body Weight.

ABSTRACT: Many African-Americans with serious mental illness fail to engage in evidence-based programs that positively affect weight management. We examined how having a weight-related physical illness correlated with self-efficacy, recovery, and quality of life by contrasting illnesses with symptoms that are obviously perceived ( e.g. , sleep apnea and pain related to weight) versus those that are not ( e.g. , hypertension). African-Americans with serious mental illness who were overweight (body mass index ≥25) completed the Weight Efficacy Lifestyle Questionnaire, Recovery Assessment Scale, and Quality of Life Scale in this study assessing the impact of a program on weight and health. Silent weight-related physical disorders were not found to correlate with quality of life, recovery, or weight self-efficacy. Differences in recovery were found in people with versus without sleep apnea and weight-related pain. Findings suggest future directions for affirming approaches to promote engagement among African-Americans with serious mental illness in weight management programs.

Honest, Open, Proud (HOP) for people with mental illness in Hong Kong: a randomized controlled trial.

BACKGROUND: Self-stigma among people with mental illness is negatively associated with personal and clinical recovery. Due to the concealable nature of mental illness, people with mental illness experience constant struggles between concealment and disclosure. Disclosure of mental health challenges can potentially minimize negative impacts of self-stigma and enhance self-esteem and sense of empowerment. Honest, Open, Proud (HOP) is a peer-led intervention that promotes autonomous and dignified decisions about disclosure. PURPOSE: This study examined the effectiveness of HOP on concealment motivation, empowerment, self-stigma, stigma stress, and recovery among people with lived experience of mental illness in Hong Kong. METHODOLOGY: A total of 162 participants with a mean age of 45.38 were recruited and randomized into intervention group and waitlist control group. Participants in the intervention group were invited to attend a 6-session HOP group intervention. RESULTS: Significant improvement in optimism score from the empowerment scale was found in the intervention group compared to the waitlist control group and the effect was sustained at 1-month follow-up. However, significant changes were not found in other outcome variables. CONCLUSION: Only improvement in optimism was observed in the current study. Future study needs to examine the effects of HOP with further modification to maximize the benefit for people with lived experience of mental illness in the local context.

Self-Stigma's Effect on Psychosocial Functioning Among People With Mental Illness.

ABSTRACT: Consequences of self-stigma exhibit a four-step regressive model from being aware of public stigma, to agreeing with it, to applying it to oneself, to resulting harm on the self. We hypothesize the relationship between self-stigma and psychosocial functioning is mediated by three constructs: the why try effect, stigma stress coping resources, and personal recovery. Two hundred eight people with depressive and bipolar disorders participated the study. Data partially supported the regressive model of self-stigma. Awareness was not found to be associated with other regressive stages. The model representing the path between self-stigma-harm and psychosocial functioning was significant and robust. The path was mediated by the why try effect and personal recovery. Findings echo the growing body of research attempting to describe outcomes of self-stigma, in this case, psychosocial functioning. Programs meant to erase self-stigma, and its effect on functioning should incorporate the why try effect and personal recovery as strategic ingredients.

Inter-joint coordination variability is associated with pain severity and joint loading in persons with knee osteoarthritis.

As the lower extremity is a linked-joint system, the contribution of movements at the hip and ankle, in addition to the knee, to gait patterns should be considered for persons with knee osteoarthritis (OA). However, the relationships of joint coordination variability to OA symptoms, particularly knee pain, and joint loading is unknown. The purpose of this study was to determine the relationship of joint coordination variability to knee pain severity and joint loading in persons with knee OA. Thirty-four participants with knee OA underwent gait analysis. Vector coding was used to assess coordination variability during the early, mid, and late stance phase. Hip-knee coupling angle variability (CAV) during midstance was associated with Knee Injury and Osteoarthritis Outcome Score (KOOS) pain (r = -0.50, p = 0.002) and Visual Analog Scale pain (r = 0.36, p = 0.04). Knee-ankle CAV during midstance was associated with KOOS pain (r = -0.34, p = 0.05). Hip-knee CAV during early and midstance were associated with knee flexion moment (KFM) impulses (r = -0.46, p = 0.01). Knee-ankle CAV during early and midstance were associated with peak KFM (r = -0.51, p < 0.01; r = -0.70, p < 0.01). Moreover, knee-ankle CAV during early, mid, and late stance phase were associated with KFM impulses (r = -0.53, p < 0.01; r = -0.70, p < 0.01; r = -0.54, p < 0.01). These findings suggest that joint coordination variability may be a factor that influences pain and knee joint loading in persons with knee OA. Statement of Clinical Significance: Movement coordination of the hip, knee, and ankle should be considered in the clinical management and future research related to knee OA.

Does the peer-led Honest, Open, Proud program reduce stigma's impact for everyone? An individual participant data meta-regression analysis.

PURPOSE: Many people with mental illness experience self-stigma and stigma-related stress and struggle with decisions whether to disclose their condition to others. The peer-led Honest, Open, Proud (HOP) group program supports them in their disclosure decisions. In randomized controlled trials, HOP has shown positive effects on self-stigma and stigma stress on average. This study examined individual predictors of HOP outcomes and tested the hypothesis that stigma stress reduction at the end of HOP mediates positive HOP effects at follow-up. METHODS: Six RCTs were included with data at baseline, post (after the HOP program) and at 3- or 4-week follow-up. Baseline variables were entered in meta-regression models to predict change in self-stigma, stigma stress, depressive symptoms and quality of life among HOP participants. Mediation models examined change in stigma stress (post) as a mediator of HOP effects on self-stigma, depressive symptoms, and quality of life at follow-up. RESULTS: More shame at baseline, and for some outcomes reduced empowerment, predicted reduced HOP effects on stigma stress, self-stigma, depressive symptoms, and quality of life. Younger age was related to greater improvements in stigma stress after the HOP program. Stigma stress reductions at the end of HOP mediated positive effects on self-stigma, depressive symptoms and quality of life at follow-up. CONCLUSION: Participants who are initially less burdened by shame may benefit more from HOP. Stigma stress reduction could be a key mechanism of change that mediates effects on more distal outcomes. Implications for the further development of HOP are discussed.

Evidence of Atypical Structural Flexibility of the Active Site Surrounding of an [FeFe] Hydrogenase from Clostridium beijerinkii.

[FeFe] hydrogenase from Clostridium beijerinkii (CbHydA1) is an unusual hydrogenase in that it can withstand prolonged exposure to O2 by reversibly converting into an O2-protected, inactive state (Hinact). It has been indicated in the past that an atypical conformation of the "SC367CP" loop near the [2Fe]H portion of the six-iron active site (H-cluster) allows the Cys367 residue to adopt an "off-H+-pathway" orientation, promoting a facile transition of the cofactor to Hinact. Here, we investigated the electronic structure of the H-cluster in the oxidized state (Hox) that directly converts to Hinact under oxidizing conditions and the related CO-inhibited state (Hox-CO). We demonstrate that both states exhibit two distinct forms in electron paramagnetic resonance (EPR) spectroscopy. The ratio between the two forms is pH-dependent but also sensitive to the buffer choice. Our IR and EPR analyses illustrate that the spectral heterogeneity is due to a perturbation of the coordination environment of the H-cluster's [4Fe4S]H subcluster without affecting the [2Fe]H subcluster. Overall, we conclude that the observation of two spectral components per state is evidence of heterogeneity of the environment of the H-cluster likely associated with conformational mobility of the SCCP loop. Such flexibility may allow Cys367 to switch rapidly between off- and on-H+-pathway rotamers. Consequently, we believe such structural mobility may be the key to maintaining high enzymatic activity while allowing a facile transition to the O2-protected state.

A multi-level intervention to reduce the stigma of substance use and criminal involvement: a pilot feasibility trial protocol.

BACKGROUND: Stigma associated with substance use and criminal involvement is pervasive and creates a barrier to evidence-based addiction care within the criminal legal system. Research has yet to examine a multi-level stigma intervention which targets the intersection of these stigmas among both criminal legal staff and legally-involved clients. METHODS: This paper presents the protocol for a non-randomized trial of a multi-level stigma intervention called Combatting Stigma to Aid Reentry and Recovery (CSTARR) that involves two interventions: (1) training for criminal legal staff to address public stigma and (2) group-based acceptance and commitment therapy to address self-stigma among legally-involved adults enrolled in substance use treatment. Staff and client participants are engaged with a program called the Tennessee Recovery Oriented Compliance Strategy in 6 East Tennessee counties. This study examines the feasibility, acceptability, and preliminary effectiveness of CSTARR using a type 1 hybrid implementation/effectiveness trial with pre to post follow-up. DISCUSSION: Stigma must be addressed in the criminal legal system to facilitate the uptake of evidence-based addiction care. This study is the first to evaluate a stigma intervention designed for the criminal legal setting and results will be used to inform a larger, randomized controlled trial. The rationale for this study, research design and measures, as well as potential implications for the field are described. TRIAL REGISTRATION: This clinical trial is registered at clinicaltrials.gov with the identifier NCT05152342. Registered 11/5/2021 at https://register. CLINICALTRIALS: gov/prs/app/action/SelectProtocol?sid=S000BIN8&selectaction=Edit&uid=U0005X4C&ts=2&cx=-u3wsbx .

Anaerobic Infrared Spectroelectrochemical Methods for Studying Oxygen-Sensitive [FeFe] Hydrogenases.

[FeFe] hydrogenases comprise an important class of H2 evolving enzymes; however, these proteins are often oxygen sensitive and require anaerobic environments for characterization. Understanding the electrochemical relationships between various active and inactive states of these enzymes is instrumental in uncovering the reaction mechanisms of the complex six-iron active center of [FeFe] hydrogenases called H-cluster. Since states of the H-cluster exhibit distinct fingerprint-like spectra in the mid-IR range, IR spectroelectrochemical experiments provide a powerful methodological framework for this goal. This chapter describes protocols for performing Fourier-transform infrared (FTIR) spectroelectrochemical experiments on [FeFe] hydrogenases under anaerobic conditions. Topics included experimental design, data acquisition, and data analysis.

Evidence for Porphyrin-Mediated Electron Transfer in the Radical SAM Enzyme HutW.

Bacteria that infect the human gut must compete for essential nutrients, including iron, under a variety of different metabolic conditions. Several enteric pathogens, including Vibrio cholerae and Escherichia coli O157:H7, have evolved mechanisms to obtain iron from heme in an anaerobic environment. Our laboratory has demonstrated that a radical S-adenosylmethionine (SAM) methyltransferase is responsible for the opening of the heme porphyrin ring and release of iron under anaerobic conditions. Furthermore, the enzyme in V. cholerae, HutW, has recently been shown to accept electrons from NADPH directly when SAM is utilized to initiate the reaction. However, how NADPH, a hydride donor, catalyzes the single electron reduction of a [4Fe-4S] cluster, and/or subsequent electron/proton transfer reactions, was not addressed. In this work, we provide evidence that the substrate, in this case, heme, facilitates electron transfer from NADPH to the [4Fe-4S] cluster. This study uncovers a new electron transfer pathway adopted by radical SAM enzymes and further expands our understanding of these enzymes in bacterial pathogens.

The Influence of Hip and Knee Joint Angles on Quadriceps Muscle-Tendon Unit Properties during Maximal Voluntary Isometric Contraction.

Determining how the quadriceps femoris musculotendinous unit functions, according to hip and knee joint angles, may help with clinical decisions when prescribing knee extension exercises. We aimed to determine the effect of hip and knee joint angles on structure and neuromuscular functioning of all constituents of the quadriceps femoris and patellar tendon properties. Twenty young males were evaluated in four positions: seated and supine in both 20° and 60° of knee flexion (SIT20, SIT60, SUP20, and SUP60). Peak knee extension torque was determined during maximal voluntary isometric contraction (MVIC). Ultrasound imaging was used at rest and during MVIC to characterize quadriceps femoris muscle and tendon aponeurosis complex stiffness. We found that peak torque and neuromuscular efficiency were higher for SUP60 and SIT60 compared to SUP20 and SIT20 position. We found higher fascicle length and lower pennation angle in positions with the knee flexed at 60°. The tendon aponeurosis complex stiffness, tendon force, stiffness, stress, and Young's modulus seemed greater in more elongated positions (60°) than in shortened positions (20°). In conclusion, clinicians should consider positioning at 60° of knee flexion rather than 20°, regardless if seated or supine, during rehabilitation to load the musculotendinous unit enough to stimulate a cellular response.